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Journal articles on the topic 'Circulating water temperature'
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1
Song, Xun Cheng, Xiao Long Xu, Sha Sha Hu, and Zhi Chuan Guan. "Full Transient Features of Heat Transfer and Sensitivities on Deep Water Wells." Advanced Materials Research 524-527 (May 2012): 1423–28. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.1423.
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Wellbore temperature is significant to well program and safety drilling for deep water drilling operations. On the basis of transient heat transfer mechanisms involved in deep water drilling among wellbore and formation and sea water, wellbore temperature profile, especially near sea bed and sensitivities to drilling fluid circulating duration, inlet temperature, water depth, water temperature, riser insulation and drilling fluid specific heat capacity have been analyzed via this model. Analysis show that deep-water wellbore temperature is much lower than a land well, the temperatures above sea bed normally ranges 10-30°C, and decreases with increased circulating duration; temperature at both outlet and bottom hole decreases drastically with increased water depth, and heat generation must be considered into estimating wellbore temperature profile especially one at bottom hole.
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Jeong, Yong-Dae, and Yujin Nam. "Performance test of PVT-water system considering ambient air and circulating water temperature." KIEAE Journal 15, no. 5 (October 31, 2015): 83–88. http://dx.doi.org/10.12813/kieae.2015.15.5.083.
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Lv, Ziqiang, Jiuju Cai, Wenqiang Sun, and Lianyong Wang. "Analysis and Optimization of Open Circulating Cooling Water System." Water 10, no. 11 (November 7, 2018): 1592. http://dx.doi.org/10.3390/w10111592.
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Open circulating cooling water system is widely used in process industry. For a system with a fixed structure, the water consumption and blowdown usually change with the varying parameters such as quality and temperature. With the purpose of water saving, it is very important to optimize the operation strategy of water systems. Considering the factors including evaporation, leakage, blowdown and heat transfer, the mass and energy conservation equations of water system are established. On this basis, the quality and temperature models of makeup and blowdown water are, respectively, developed. The water consumption and discharge profiles and the optimal operating strategy of the open recirculating cooling water system under different conditions are obtained. The concept of cycles of temperature is proposed to evaluate the temperature relationship of various parts of the open circulating cooling water system. A mathematical relationship is established to analyze the influence of the water temperature on the makeup water rate of the system under the condition of insufficient cooling capacity of the cooling tower. In addition, the co-influences of quality and temperature parameters on the system are analyzed.
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Taguchi, Akiko, Jebadurai Ratnaraj, Barbara Kabon, Neeru Sharma, Rainer Lenhardt, Daniel I. Sessler, and Andrea Kurz. "Effects of a Circulating-water Garment and Forced-air Warming on Body Heat Content and Core Temperature." Anesthesiology 100, no. 5 (May 1, 2004): 1058–64. http://dx.doi.org/10.1097/00000542-200405000-00005.
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Background Forced-air warming is sometimes unable to maintain perioperative normothermia. Therefore, the authors compared heat transfer, regional heat distribution, and core rewarming of forced-air warming with a novel circulating-water garment. Methods Nine volunteers were each evaluated on two randomly ordered study days. They were anesthetized and cooled to a core temperature near 34 degrees C. The volunteers were subsequently warmed for 2.5 h with either a circulating-water garment or a forced-air cover. Overall, heat balance was determined from the difference between cutaneous heat loss (thermal flux transducers) and metabolic heat production (oxygen consumption). Average arm and leg (peripheral) tissue temperatures were determined from 18 intramuscular needle thermocouples, 15 skin thermal flux transducers, and "deep" hand and foot thermometers. Results Heat production (approximately 60 kcal/h) and loss (approximately 45 kcal/h) were similar with each treatment before warming. The increases in heat transfer across anterior portions of the skin surface were similar with each warming system (approximately 65 kcal/h). Forced-air warming had no effect on posterior heat transfer, whereas circulating-water transferred 21+/-9 kcal/h through the posterior skin surface after a half hour of warming. Over 2.5 h, circulating water thus increased body heat content 56% more than forced air. Core temperatures thus increased faster than with circulating water than forced air, especially during the first hour, with the result that core temperature was 1.1 degrees +/- 0.7 degrees C greater after 2.5 h (P < 0.001). Peripheral tissue heat content increased twice as much as core heat content with each device, but the core-to-peripheral tissue temperature gradient remained positive throughout the study. Conclusions The circulating-water system transferred more heat than forced air, with the difference resulting largely from posterior heating. Circulating water rewarmed patients 0.4 degrees C/h faster than forced air. A substantial peripheral-to-core tissue temperature gradient with each device indicated that peripheral tissues insulated the core, thus slowing heat transfer.
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Nicolis, Imani N., Corinna N. Beale, Willie A. Bidot, Michael Esmail, and Scott E. Perkins. "Performance and Consistency of Circulating Warm Water Blankets for Rodents." Journal of the American Association for Laboratory Animal Science 61, no. 1 (January 1, 2022): 96–100. http://dx.doi.org/10.30802/aalas-jaalas-21-000073.
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General anesthesia as used for rodent research can have adverse effects on physiologic mechanisms. Thermoregulation is often greatly inhibited, with resultant deleterious effects on cardiac and respiratory function. These potential effects can be mitigated by providing external heat support. The circulating warm water blanket and associated heat pump are often used in rodent procedures. The current study demonstrated that the heating pump and water blanket require quality control assessment to ensure adequate function. Our data showed that of the 6 pumps tested, 5 were able to achieve a temperature that met or exceeded the documented thermoneutral zone for mice. Pumps required 20 min of warming to reach their maximal attainable temperatures for the designated user setting. Although the pumps reached a temperature that was sufficient to provide external thermal support, only 1 of the 6 pumps reached the temperature that was set by the user during the trial. Surface temperatures across the water blanket were recorded to analyze whether a difference in heat support was influenced by animal placement along the water blanket; however, the location points did not yield statistically different results. Two pumps were eliminated from the study due to failure to pass the preparation phase of the trial. The results of this study support the need for facilities to establish quality control measures to ensure that heat support systems are functioning at a level required to maintain normothermia during anesthetic procedures.
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Lv, Jing, and Jie Yang. "Designing and Researching of Gas Cooler in Trans-Critical Carbon Dioxide Water Heater." Advanced Materials Research 171-172 (December 2010): 368–73. http://dx.doi.org/10.4028/www.scientific.net/amr.171-172.368.
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In this paper a gas cooler for trans-critical carbon dioxide water heater was designed and calculated according to the theory basis for the optimal design. The characteristic parameters of gas cooler in heat pump hot water system were compared and analyzed, applying the data from trans-critical carbon dioxide water heater test bed, under one-time heating condition, by different flow of chilled water and hot water, different inlet temperatures of chilled water and hot water. To sum up, coefficient of performance can be increased by increasing the chilled water inlet temperature or hot water circulating flow, while it can be decreased by increasing the inlet temperature of hot water circulating system，the parameters (flow of water, inlet temperature, the refrigerant mass flow, gas cooler pressure and inlet temperature of refrigerant) need to be adjusted to different requirements, for ensuring the high efficiency of system.
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Sanford, MM. "Rewarming cardiac surgical patients: warm water vs warm air." American Journal of Critical Care 6, no. 1 (January 1, 1997): 39–45. http://dx.doi.org/10.4037/ajcc1997.6.1.39.
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BACKGROUND: Hypothermia is experienced by 60% to 90% of adult patients after surgery. The detrimental physiological consequences of prolonged hypothermia are a significant risk for cardiac surgical patients. OBJECTIVE: To compare the effect of a warmed convective-air blanket with that of a warmed circulating-water blanket on the rates of increase in skin and core temperatures and on total rewarming time in patients with hypothermia after cardiac surgery. METHODS: A quasi-experimental, repeated-measures design was used to study rewarming in 76 adult patients who were hypothermic after cardiac surgery. Subjects were randomized to two groups: 40 were warmed with a convective-air blanket; 36, with a circulating-water blanket. Skin and core temperatures were recorded every 15 minutes until the subject's pulmonary artery temperature reached 37 degrees C. Total time required for rewarming was the period between time of placement of the blanket and time of removal. The effects of 13 other variables on the time required for rewarming were also determined. RESULTS: Both skin and core temperatures increased more rapidly in patients treated with the warm circulating-water blanket than in those treated with the convective-air blanket. The mean time required for rewarming was 45 minutes shorter in the group treated with the circulating-water blanket. The patient's age, volume of i.v. fluids received, length of anesthesia, starting core temperature, and treatment method had significant effects on the time required for rewarming. CONCLUSIONS: The data suggest that rewarming with a circulating-water blanket produces normothermia more rapidly than rewarming with a warm convective-air blanket in adult patients who are hypothermic after cardiac surgery.
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Li, Zhi Wei, Hong Zhou He, and Huang Huang Zhuang. "Experimental Study on Compact External Heat Exchanger for a 4 MWth Circulating Fluidized Bed Combustor." Applied Mechanics and Materials 448-453 (October 2013): 3259–69. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.3259.
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The characteristics of the external heat exchanger (EHE) for a 4 MWth circulation fluidized bed combustor were studied in the present paper. The length, width and height of EHE were 1.5 m, 0.8 m and 9 m, respectively. The circulating ash flow passing the heating surface bed could be controlled by adjusting the fluidizing air flow and the heating transferred from the circulating ash to the cooling water. The ash flow rate passing through the heat transfer bed was from 0.4 to 2.2 kg/s. The ash average temperature was from 500 to 750 °C. And the heat transfer rate between the ash and the cooling water was between 150 and 300 W/(m2·°C). The relationships among the circulating ash temperature, the heat transfer, heat transfer rate, the heat transfer coefficient and the circulating ash flow passing through the heating exchange cell were also presented and could be used for further commercial EHE design.
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Ma, Jiaze, Chen Li, Fuyu Liu, Yufei Wang, Tiecheng Liu, and Xiao Feng. "Optimization of circulating cooling water networks considering the constraint of return water temperature." Journal of Cleaner Production 199 (October 2018): 916–22. http://dx.doi.org/10.1016/j.jclepro.2018.07.239.
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Vidal, Jeanne, Régis Hehn, Carole Glaas, and Albert Genter. "How Can Temperature Logs Help Identify Permeable Fractures and Define a Conceptual Model of Fluid Circulation? An Example from Deep Geothermal Wells in the Upper Rhine Graben." Geofluids 2019 (July 10, 2019): 1–14. http://dx.doi.org/10.1155/2019/3978364.
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Identifying fluid circulation in fracture zones (FZs) is a key challenge in the extraction of deep geothermal heat from natural reservoirs in the Upper Rhine Graben. This study focuses on permeable FZs present within the granitic basement penetrated by deep geothermal well GPK-1 at Soultz and GRT-1 and GRT-2 at Rittershoffen (France). The various temperature (T) log datasets acquired from these wells during production and at equilibrium, with the associated flow logs, allow for the unique opportunity to interpret fluid circulation at the borehole scale. All permeable FZs identified by permeability indicators measured during drilling operations and from image logs spatially coincide with positive or negative T anomalies observed in the T logs during production and/or at equilibrium. However, within the FZs, partially open fractures act as narrower paths for circulation at different temperatures. These temperatures can even be estimated with confidence if the associated flow log is available. The polarity of the T anomalies correlates with the state of equilibrium of the well and thus can change over the well history. During production, the temperature of the water inflow through the fractures can be estimated relative to the mixture of water circulating below the fractures. At thermal equilibrium, the water temperature is estimated with respect to the temperature of the surrounding rock formation. Because temperature fluxes and geothermal fluids are intimately linked, T logs are a useful, reliable, and very sensitive tool to localize the inflow of geothermal water through FZs.
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Lu, Yesheng, Junning Cui, Jiubin Tan, Xingyuan Bian, and Yamin Zhao. "Temperature Fluctuation Attenuation of Circulating Cooling Water Using Dynamic Thermal Filtering." Applied Sciences 10, no. 15 (August 2, 2020): 5338. http://dx.doi.org/10.3390/app10155338.
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The Demand for circulating cooling water (CCW) with high temperature stability and a quick response to temperature control is essential for precision engineering, so a dynamic thermal filtering method is proposed in this paper. Some CCW is bypassed, blocked, and used as a thermal capacity medium, and the temperature fluctuation of CCW is significantly reduced by heat exchanging with the medium. The temperature of the medium dynamically follows the set value of the CCW temperature by real time updating, and so realizes a quick CCW temperature control response. The attenuation ratio of temperature fluctuation was derived, theoretically validating the effectiveness of the method. The experimental results indicate that a CCW temperature fluctuation attenuation ratio of tens of dB (−3.47 dB, −6.91 dB, −10.97 dB and −15.28 dB corresponding to temperature fluctuation frequencies of 0.01 Hz, 0.025 Hz, 0.053 Hz and 0.105 Hz, respectively) is achieved by the proposed method. The updating time of thermal capacity medium is 82 s, which means that the temperature fluctuation attenuation remains functionally valid when the set value of CCW changes. The proposed method is low cost in operation and provides an effective approach to satisfy the challenging demand for CCW with high stability and a good dynamic temperature control performance.
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Jiang, Xiao Ling, Zong Ming Lei, and Qing Bao Meng. "Evaluation of Equivalent Circulating Density in Deep Water Dynamic Kill Drilling." Applied Mechanics and Materials 121-126 (October 2011): 3048–52. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.3048.
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Dynamic kill drilling is a technology which is applied in order to control the deep water drilling shallow gas or shallow wells flowing by establish a normal cycle automatically in the deepwater shallow wells section. Equivalent circulating density (ECD) is an important parameters to control the bottom hole pressure, in the ECD estimate, if we don’t consider the effects of low temperature on rheological parameters of drilling fluid, it will result in errors in ECD estimates. Considering the impact of low temperature on the rheological parameters, this paper determines the temperature, rheological parameters and the annulus circulating pressure loss of each well section. Then Superposing each well section annular circulating pressure loss together, and finally calculate the equivalent circulating density. The deeper the water the greater of difference between ECD prediction model and the results calculated by rheological parameters on ground, and the more shallow wells the larger of difference. Therefore, in the process of deep water surface layer dynamic killing, We need to predict the equivalent circulating density of drilling fluids (ECD) accurately.
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Wang, Qing Yang, Tian Yu Sun, Jian Zhang, and Jian Xing Ren. "Experimental Research on the Effect of Cross-Wind to Wet-Cooling Tower Performance." Advanced Materials Research 860-863 (December 2013): 1412–15. http://dx.doi.org/10.4028/www.scientific.net/amr.860-863.1412.
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Environmental cross-wind has a influence on cooling capacity of wet cooling tower to a great extent in power plant.The variation of circulating-water temperature difference (Δt) and cooling coefficient of efficiency(η) with cross-wind velocity, circulating water inlet temperature and flow rate, are shown under cross-wind conditions, compared with cases without wind. By using experimental platform of cooling water system based on 300MW thermal power unit,it is found that with cross-wind velocity increasing,cooling temperature difference and cooling efficiency decrease first then increase at the knee point when the velocity value is 0.8m/s. In addition, the correlation betweenΔt ,η and parameters,such as circulating-water inlet temperature and flow rate, is derived for cases with windless conditions.
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Liu, Jian Tao, Xiao Cheng Ma, Kun Kun You, Jian Xing Ren, and Yong Wen Yang. "Analysis on Circulating Water Heat Utilization Technology in Thermal Power Plants." Advanced Materials Research 753-755 (August 2013): 2727–30. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.2727.
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The thermal power unit is the major unit in Chinas power supply. Circulating water has large low-temperature waste-heat which can be recycled. The principles of water source heat pump technology is analyzed, characteristic of circulating water system in thermal power unit is studied. Then two kinds of connection methods between circulating water system and water source heat pump (WSHP) are presented.
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Oh, Sunhee, Yong Cho, and Rin Yun. "Optimization of a Raw Water Source Heat Pump for a Vertical Water Treatment Building." International Journal of Air-Conditioning and Refrigeration 23, no. 01 (March 2015): 1550002. http://dx.doi.org/10.1142/s2010132515500029.
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The optimum operation conditions of a raw water source heat pump for a vertical water treatment building were derived by changing operation parameters, such as temperature of thermal storage tank, temperature and inlet air flow rate of the conditioned spaces, and circulating water flow rate between thermal storage tank and air handling unit (AHU) through dynamic simulator of a transient system simulation program (TRNSYS). Minimum electric power consumption was found at temperature of thermal storage tank, which was ranged 18–23°C for cooling season. In heating season, temperature 40–45°C brings the highest coefficient of performance (COP) and temperature range of 30–35°C brings the lowest power consumption. When the temperature of the conditioned spaces was controlled between 27–28°C for cooling season, and 18–20°C for heating season the minimum electric power consumption was obtained. Inlet air flow rate of 1.1 m3/h for the conditioned spaces shows the highest performance of the present system, and effects of circulating water flow rate between thermal storage tank and AHU on minimum electric power consumption of the system were negligible.
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Li, Zhao, Huimin Wei, Tao Wu, and Xiaoze Du. "Optimization for Circulating Cooling Water Distribution of Indirect Dry Cooling System in a Thermal Power Plant under Crosswind Condition with Evolution Strategies Algorithm." Energies 14, no. 4 (February 22, 2021): 1167. http://dx.doi.org/10.3390/en14041167.
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Crosswind has an adverse impact on the performance of an indirect dry cooling system. In order to mitigate the adverse influence, this study redistributed the circulating cooling water among air-cooled heat exchanger sectors so that the performance of the indirect dry cooling system could be improved. An evolution strategies algorithm combined with numerical effectiveness-based heat exchanger model was established to minimize the operation costs of the whole system. Based on a 660 MW practical power plant, optimal circulating cooling water operation strategies under varied crosswind speeds and ambient temperatures were calculated to show its application. According to the calculated results, the performance of the indirect dry cooling system could be enhanced by optimizing circulating cooling water distribution under any crosswind speed, especially under high ambient wind speeds. There is a slight promotion of the coal savings with a rise in ambient temperature: improvements of about 5%. The standard coal consumption rate could save as much as 2.50 g/kWh under crosswind speed of 10 m s−1 and ambient temperature of 32 °C, compared to the 0.1 g/kWh under crosswind speed of 2 m s−1 and ambient temperature of 32 °C.
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Liu, He, Cui, and Zhou. "Effects of Different Temperatures on the Softening of Red-Bed Sandstone in Turbulent Flow." Journal of Marine Science and Engineering 7, no. 10 (October 6, 2019): 355. http://dx.doi.org/10.3390/jmse7100355.
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The rates of chemical reactions are highly dependent on temperature, meaning that the actual geological rock mass is affected by different temperatures. Only when the temperature effect is considered can the mechanism of the influence of temperature on the interaction between water and rock be further understood. It was found that the condition of turbulent flow is more likely to promote the softening of red-bed sandstone than the conditions of laminar flow and static water in an experimental study on the softening effects of different flow patterns on red-bed sandstone. Therefore, based on a multi-functional self-circulating open channel hydraulic test system, this paper designs and completes equal volume saturated tests of red-bed sandstone at low temperature (1 °C), medium temperature (23 °C), and high temperature (45 °C) under the turbulent conditions of three equal temperature gradients. The chemical action of the circulating solution in water flow at different temperatures, the propagation of micro-cracks in rock and the changes in mechanical indexes are discussed. The influence laws and mechanisms of the different temperatures on the softening of red-bed sandstone in turbulent flow are revealed. The results show that low-temperature flow can inhibit the softening of red-bed sandstone in the range of 1–45 °C. With the increase in water flow temperature, the development degrees of micro-structures and the mechanical damage of the corresponding rock become more notable. That is, temperature affects the physical and chemical water–rock interactions and then changes the internal structure of rock, thus affecting the softening and failure processes of red-bed sandstone. The study provides a theoretical basis for the further investigation of the softening laws and mechanisms of other red layered soft rocks by temperature under turbulent conditions.
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Lu, Yesheng, Junning Cui, Jiubin Tan, and Xingyuan Bian. "Quick Response Circulating Water Cooling of ±3 mK Using Dynamic Thermal Filtering." Applied Sciences 10, no. 16 (August 7, 2020): 5483. http://dx.doi.org/10.3390/app10165483.
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An enhanced circulating cooling water (CCW) machine is developed to simultaneously achieve high temperature stability and dynamic performance of CCW temperature control. Dynamic thermal filtering based on an auto-updatable thermal capacity medium is proposed to reduce the temperature fluctuation of the CCW. Agile thermal control is presented to realize a quick response and high resolution of temperature control, through thermal inertia minimization and bidirectional regulation of heating/cooling power. Experimental results indicate that a temperature stability of ±3 mK (peak to peak value) and a settling time of 128 s, corresponding to a 1 K step set value, are achieved. It can therefore be concluded that the developed machine can satisfy the challenging requirements of precision manufacturing.
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Yang, Jinyan, Yong Xu, Jie Zhou, and Shiqiang Wu. "Reservoir water intake pump house location optimization on water age." MATEC Web of Conferences 246 (2018): 02051. http://dx.doi.org/10.1051/matecconf/201824602051.
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Reservoir circulating currents and water age is considered to optimize the intake pump house locations. Since the air temperature, water depth and nitrogen and phosphor input is hard to control, to optimize the water age and cycling currents of reservoir by water intake pump house location optimization is one of the most usefully way to control the risk of eutrophication of reservoir by growth inhibition of age.
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Usmonov, N., Sh Sanayev, and Z. Yusupov. "CALCULATION OF TEMPERATURE OF ROUTINE WATER COOLED IN IRRIGATED LAYERS." Technical science and innovation 2019, no. 3 (September 18, 2019): 249–55. http://dx.doi.org/10.51346/tstu-01.19.3.-77-0036.
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The article describes the developed mathematical model, algorithm and program for calculating the process of cooling the water leaving the evaporative cooler and the final temperature of humid air. The compilation of a mathematical model is based on the analysis of literature data. Practically at all industrial enterprises, technological equipment is cooled by means of circulating water supply systems equipped with evaporative coolers. The article made a choice of a cooling system for air conditioning systems of residential premises. The developed basic design scheme of the evaporative water and air cooler with the irrigated layer is presented, as well as the estimated thermal and material balance. One of the main elements of these devices is a heat-mass transfer nozzle - sprinkler. This article presents the results of mathematical modeling of processes occurring in the volume of the sprinkler evaporator chamber, Raschig rings composed of vertical polymeric materials. Expressions are obtained for determining the values of air temperature based on the calculation of thermal modeling of the process of cooling circulating water in evaporative coolers of the type in question.
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Yang, Li, Yunfeng Ren, Zhihua Wang, Zhouming Hang, and Yunxia Luo. "Simulation and Economic Research of Circulating Cooling Water Waste Heat and Water Resource Recovery System." Energies 14, no. 9 (April 27, 2021): 2496. http://dx.doi.org/10.3390/en14092496.
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Industrial circulating cooling water contains a large amount of low-quality energy, which is lost to the environment through cooling towers. It is of great significance and potential to recover the waste heat to improve energy-saving effects and economic efficiency. However, the effect of common water harvesting and energy saving devices is not significant. Heat pumps have been shown to be effective in improving low-quality heat energy in energy conversion systems, although there are not many applications of heat pump scenarios in engineering practice. Based on this, a recovery solution of circulating cooling water waste heat and water resource using lithium bromide absorption heat pump has been put forward. The energy-saving performance of the recovery system was simulated and analyzed using Aspen Plus V10.0 (Bedford, MA, USA) to explore the effects of the parameters of the working medium in evaporators, condensers, absorbers, generators, heat exchangers, etc., and the modelling results indicated that the evaporation pressure and temperature have a great influence on the system COP (coefficient of performance) and can raise the thermal economy of the system. The heat from driving steam and heating capacity both increased with the increase in generating temperature, while the increase in temperature difference between evaporation and condensation inhibits the COP of heat pump systems. Furthermore, economic analyses and comparisons of the recovery solutions were conducted and the recovery solution of circulating cooling water waste heat with heat pump had the best economic performance due to the annual income from the recovery of waste heat and water resource. The static payback period results indicate that the recovery solution from circulating cooling water waste heat with a heat pump has better economic performance than the scenario with a cooling tower. The waste heat recovery solution with a heat pump can improve the thermal economy of the system and has a great guiding significance for engineering practice.
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Li, Xiaxia, Liming Shen, and Ying Huang. "An experiment to assess the heat transfer performance of thermoelectric-driven conditioned mattress." Thermal Science, no. 00 (2021): 146. http://dx.doi.org/10.2298/tsci201111146l.
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This study sets out to describe the design, construction and testing of thermoelectric-driven conditioned mattress intended to reduce the human-mattress interface temperature, in order to satisfy the personal sleep thermal comfort requirements in hot conditions. A prototype of thermoelectric-driven conditioned mattress is constructed and tested. A series of experimental studies related to the temperature of different cushion layers and time from start-up to stable state have been carried out, specifically to analyze the difference in heat transfer performance of two types of temperature control layers (i.e., integral water cushion and circulating water pipes) in cooling operations. The steady-state results showed that, the type of temperature control layer and pre-set temperature exhibited a remarkable influence on the cooling performance of mattress. The mattress with integral water cushion had a superior cooling performance as compared to mattress with circulating water pipes under similar consitons. Specifically, the upper surface temperature of mattress with integral water cushion at the the pre-set temperature of 20?C, 18?C and 16?C were 1.97?C, 2.46?C and 3.08?C lower than indoor air temperature, respectively. Besides, the temperature contour maps of temperature control layer and upper cushion layer for two types of mattresses were constructed using the bilinear interpolation, respectively, thus expected to provide reference for the untested temperatures in this study. This study aims to effectively evaluate the heat transfer performance of the thermoelectric-driven conditioned mattress, and shows highly practical value in further applications of this system in improving human thermal comfort during sleep.
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Schroeder, Daniel C., Alexandra C. Maul, Maria Guschlbauer, Simon-Richard Finke, David de la Puente Bethencourt, Tobias Neumann, Stephan A. Padosch, et al. "Esophageal Heat Exchanger Versus Water-Circulating Cooling Blanket for Targeted Temperature Management." Therapeutic Hypothermia and Temperature Management 9, no. 4 (December 1, 2019): 251–57. http://dx.doi.org/10.1089/ther.2018.0054.
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Li, Yang, and Xiu Juan Liang. "Research for Water Quality Problems of Power Plant Circulating Cooling Water Source Heat Pump System in the Cold and Severe Cold Regions." Applied Mechanics and Materials 535 (February 2014): 399–402. http://dx.doi.org/10.4028/www.scientific.net/amm.535.399.
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In the northern cold areas, the circulating cooling water contains a large number of low temperature waste heat.Cold and heat sources can be used as a heat pump heating to the building. The experiment shows that the system has significant economic, energy conservation and environmental value. This article describes the plant circulating cooling water source heat pump system, water quality, corrosion and fouling problems, and solve these problems need to pay attention.
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Alghamdi, Mohammed, Faissal Abdel-Hady, A. Mazher, and Abdulrahim Alzahrani. "Integration of Process Modeling, Design, and Optimization with an Experimental Study of a Solar-Driven Humidification and Dehumidification Desalination System." Processes 6, no. 9 (September 7, 2018): 163. http://dx.doi.org/10.3390/pr6090163.
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Solar energy is becoming a promising source of heat and power for electrical generation and desalination plants. In this work, an integrated study of modeling, optimization, and experimental work is undertaken for a parabolic trough concentrator combined with a humidification and dehumidification desalination unit. The objective is to study the design performance and economic feasibility of a solar-driven desalination system. The design involves the circulation of a closed loop of synthetic blend motor oil in the concentrators and the desalination unit heat input section. The air circulation in the humidification and dehumidification unit operates in a closed loop, where the circulating water runs during the daytime and requires only makeup feed water to maintain the humidifier water level. Energy losses are reduced by minimizing the waste of treated streams. The process is environmentally friendly, since no significant chemical treatment is required. Design, construction, and operation are performed, and the system is analyzed at different circulating oil and air flow rates to obtain the optimum operating conditions. A case study in Saudi Arabia is carried out. The study reveals unit capability of producing 24.31 kg/day at a circulating air rate of 0.0631 kg/s and oil circulation rate of 0.0983 kg/s. The tradeoff between productivity, gain output ratio, and production cost revealed a unit cost of 12.54 US$/m3. The impact of the circulating water temperature has been tracked and shown to positively influence the process productivity. At a high productivity rate, the humidifier efficiency was found to be 69.1%, and the thermal efficiency was determined to be 82.94%. The efficiency of the parabolic trough collectors improved with the closed loop oil circulation, and the highest performance was achieved from noon until 14:00 p.m.
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Bosak, Mykola, Oleksandr Hvozdetskyi, Bohdan Pitsyshyn, and Serhii Vdovychuk. "THE RESEARCH OF CIRCULATION WATER SUPPLY SYSTEM OF POWER UNIT OF THERMAL POWER PLANT WITH HELLER COOLING TOWER." Theory and Building Practice 2020, no. 2 (November 20, 2020): 1–9. http://dx.doi.org/10.23939/jtbp2020.02.001.
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Analytical hydraulic researches of the circulating water cooling system of the power unit of a thermal power plant with Heller cooling tower have been performed. Analytical studies were performed on the basis of experimental data obtained during the start-up tests of the circulating water cooling system of the “Hrazdan-5” power unit with a capacity of 300 MW. Studies of the circulating water cooling system were carried out at an electric power of the power unit of 200 - 299 MW, with a thermal load of 320 - 396 Gcal/hr. By circulating pumps (CP), water mixed with condensate is fed to the cooling tower, from where it is returned through the turbine for spraying by nozzles in the turbine steam condenser. An attempt to increase the water supply to the condenser by increasing the size of the nozzles did not give the expected results. The amount of the water supply to the circulating pumping station depends on the pressure loss in the circulating water cooling system. The highest pressure losses are in hydro turbines (HT), which are part of the circulating pumping station. Therefore, by adjusting the load of the hydro turbine, with a decrease in water pressure losses, you can increase the water supply by circulating pumps to the condenser. Experimental data and theoretical dependences were used to calculate the changed hydraulic characteristics of the circulating water cooling system. As a result of reducing the pressure losses in the section of the hydro turbine from 1.04 to 0.15 kgf/cm2, the dictating point for the pressure of circulating pumping station will be the turbine steam condenser. The thermal power plant cooling tower is designed to service two power units. Activation of the peak cooler sectors of the cooling tower gives a reduction of the cooled water temperature by 2-4 °С only with the spraying system.
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Aryani, Titin. "ANALISIS KUALITAS AIR MINUM DALAM KEMASAN (AMDK) DI YOGYAKARTA DITINJAU DARI PARAMETER FISIKA DAN KIMIA AIR." MEDIA ILMU KESEHATAN 6, no. 1 (November 11, 2019): 46–56. http://dx.doi.org/10.30989/mik.v6i1.178.
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Backgroud: Nowadays, bottled water has become the most substitute water for cooking drinking water. Although bottled water seemed attractive, it is crucial to assess its quality.
Objective: This quantitative study aimed to determine the quality of the 5 brands of bottled water circulating in Yogyakarta, in terms of physical parameters (temperature, smell, taste, color, turbidity, and TDS electroconductivity) and chemical parameters of water (pH, the presence of Cl-ions, and the presence of metals such as Cr, Fe, Zn, Cd).
Methods: The sampling technique used was purposive sampling. The instrument used to determine the quality of bottled water is the standard of drinking water quality standards.
Result: The results showed that five samples of bottled water circulating in Yogyakarta, are all qualified bottled water both in terms of physical parameters (temperature, smell, taste, color, turbidity, electroconductivity, and TDS) and chemical parameters of water (pH , the presence of Cl-ions, and the presence of metals such as Cr, Fe, Zn, Cd).
Conclusion: Five samples of bottled water circulating in Yogyakarta were suitable for consumption.
Keywords: Bottled water, water analysis, water quality, water chemistry parameters
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Vinceslio, Eric M., Zane Fayos, Aaron Bernadette, and Jan-Michael Van Gent. "Expeditionary Immersion Circulating Heating Device: A Promising Technique for Treating Frostbite Injuries and Warming Intravenous Fluids in a Forward Deployed Cold Weather Environment." Military Medicine 185, no. 11-12 (November 1, 2020): e2039-e2043. http://dx.doi.org/10.1093/milmed/usaa213.
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Abstract Introduction Cold weather injuries require prompt warm water immersion therapy, which proves to be a difficult task in the cold austere environment. Current guidelines recommend 104 °F water immersion, but producing and maintaining large volumes of warm water is challenging in sub-freezing temperatures. We describe a novel process of utilizing a sous vide immersion circulator to maintain warm fluids for immersion therapy and efficient fluid rewarming in a cold forward-deployed setting for the treatment of cold weather injuries in an effort to bridge the gap between current medical guidelines and practices. Materials and Methods Large water cans were warmed to 104 °F with the immersion circulator. A thermometer was inserted into a 1-inch steak, frozen to 30 °F, and placed in a basin with only the warmed water while the internal temperature was monitored until physiologic temperature was achieved. The time to this endpoint was recorded. A 1-L bag of normal saline and a 450-mL bag of whole blood were also separately warmed by the same technique. The temperature of the normal saline was monitored at 0-, 5-, 7-, 8-, 9-, and 10 -minute intervals. The process was similarly repeated, measuring the whole blood temperature at 0-, 5-, 7-, and 10-minute intervals. Results Ambient internal tent temperatures averaged 54 °F; outdoor temperatures were consistently sub-freezing. The 5-gallon cans of water at ambient temperature heated to 104 °F in 15 minutes. The water temperature remained constant for 3 weeks with the circulator running. The frozen steak started at 30 °F and reached 98 °F in 52 minutes and 45 seconds. The bag of normal saline and whole blood, refrigerated to 39 °F, achieved temperatures of 102 °F and 94 °F respectively after 10 minutes. Conclusion A heating immersion circulator device is a lightweight, flameless, and inexpensive way to consistently heat large volumes of water for treatment of cold weather injuries, hypothermia, and whole blood rewarming in a cold austere environment.
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Chen, Jin Mao, Xiao Ying Sun, Guan Jun Leng, Ru Juan Yi, and Bo Gao. "Improvement of Engine Coolant Ultrasonic Cavitation Apparatus." Applied Mechanics and Materials 733 (February 2015): 574–77. http://dx.doi.org/10.4028/www.scientific.net/amm.733.574.
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The structure of cast iron specimen and the temperature control unit of the engine coolant ultrasonic cavitation apparatus were improved in this paper. The broken problem of cast iron specimen was solved by split-structure design, which also solved the loose binding problem between specimen and sonotrode. The temperature control unit included a beaker with water circulating jacket, water bath, circulating pump and connection hose. The temperature control unit overcame the difficulty of the temperature control of test coolant solution. More important, the temperature control inside the soundproof box was realized, which avoided the effect of ultrasonic vibration noise on the health of operator. The unit has the characteristics of simple, practical and easy to use.
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Zhou, Zhen, Weimin Qiao, Yangbo Lin, Xuelian Shen, Dalong Hu, Jianqiao Zhang, Lu-Man Jiang, and Luochun Wang. "Phosphonate removal from discharged circulating cooling water using iron–carbon micro-electrolysis." Water Science and Technology 70, no. 3 (June 3, 2014): 524–32. http://dx.doi.org/10.2166/wst.2014.248.
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Phosphonate is a commonly used corrosion and scale inhibitor for a circulating cooling water (CCW) system. Its discharge could cause eutrophication of receiving waters. The iron–carbon (Fe/C) micro-electrolysis technology was used to degrade and remove phosphonate from discharged CCW. The influences of initial pH, Fe/C ratio (FCR) and temperature on phosphonate removal were investigated in a series of batch tests and optimized by response surface methodology. The quadratic model of phosphonate removal was obtained with satisfactory degrees of fitness. The optimum conditions with total phosphorus removal efficiency of 95% were obtained at pH 7.0, FCR of 1.25, and temperature of 45 °C. The phosphonate removal mechanisms were also studied. Phosphonate removal occurred predominantly via two consecutive reactive phases: the degradation of phosphonate complexes (Ca–phosphonate) and the precipitation of Fe/C micro-electrolysis products (PO43−, Ca2+ and Fe3+).
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Jiang, Li-li, Hai-Tao Yu, Lie-fei Pei, and Xin-gang Hou. "The Effect of Temperatures on the Synergistic Effect between a Magnetic Field and Functionalized Graphene Oxide-Carbon Nanotube Composite for Pb2+ and Phenol Adsorption." Journal of Nanomaterials 2018 (July 30, 2018): 1–13. http://dx.doi.org/10.1155/2018/9167938.
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The effect of temperature on scale inhibition and adsorption properties for Pb2+ and phenol was studied under the synergistic effect of the magnetic field and the adsorbent. The sulfhydryl and amino-modified graphene oxide/oxidized multiwalled carbon nanotubes (NH2-SH-GO/o-MWCNTs) were synthesized and applied as the adsorbent. Additionally, changes in pH, conductivity, molecular activation energy, the relative variation of intramolecular energy and the relative variation in the proportion of free water, and adsorption capacity of the adsorbent were studied under different temperatures of circulating water. The relative variation of the proportion of free water increased with the increasing temperatures. The above results indicated that higher temperature would be detrimental to scale inhibition. The higher the temperatures, the lower the intramolecular energies. And the more stable molecules are formed in the circulating water. Thus, the results reduced the tendency to scale formation. The increased temperatures promoted the adsorption capacity of the adsorbent for Pb2+ and phenol. The adsorption process for Pb2+ and phenol conformed to the pseudo-second-order kinetic model and Freundlich isotherm model under the synergistic effect of magnetic field and NH2-SH-GO/MWCNTs. After five cycles, the adsorption capacities of the adsorbent for Pb2+ and phenol separately decreased by 59.86% and 76.36%. The aforementioned results reveal that temperatures can promote the adsorption process for Pb2+ and phenol, and the synergistic effect between magnetic field and the adsorbent has a potential application for water treatment.
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Kim, Chanhee, and Minwoo Chean. "Development of a Constant Temperature Control Light Emitting Diode Light Cold Mask Reflecting Real-Time Skin Temperature Change." Journal of Nanoscience and Nanotechnology 21, no. 3 (March 1, 2021): 1789–94. http://dx.doi.org/10.1166/jnn.2021.18920.
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To treat and improve skin condition, photo masks using LEDs have been developed and widely marketed to consumers. However, since the skin condition of the user varies, it is difficult to simulate suitable conditions, because various variables such as light output intensity and irradiation time must be applied to the mask development. Currently, photo masks on the market were developed considering only the parameters related to light irradiation. Existing products do not consider the burning sensation after skin treatment and skin temperature increase from the use of masks, which has been causing user inconvenience. In this paper, the LED light cold mask was designed, fabricated, and analyzed for light output characteristics to control wavelength selection and output to maximize the therapeutic effect of various LED lights. Additionally, circulating water was used to eliminate the burning sensation caused by the use of LED masks. The temperature of the circulating water was lowered below 10 °C using a thermoelectric element and PT100 Ω temperature sensor. An infrared temperature sensor was used to measure the skin temperature in real time. When the skin temperature increased by 0.5 °C, the water was cooled and circulated. As a result, it was confirmed that the temperature of the skin could be maintained uniformly within the set temperature range.
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Ahn, Chang Hyuk, Saeromi Lee, Ho Myeon Song, Jae Roh Park, and Jin Chul Joo. "Assessment of Water Quality and Thermal Stress for an Artificial Fish Shelter in an Urban Small Pond during Early Summer." Water 11, no. 1 (January 14, 2019): 139. http://dx.doi.org/10.3390/w11010139.
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: This study evaluated water quality variations in an artificial deep pool (ADP), which is an underground artificial structure built in a shallow pond as a fish shelter. The water temperature, pH, dissolved oxygen (DO), and electrical conductivity (EC) were measured on an hourly basis in the open space and inside the ADP, and a phenomenological study was performed, dividing seasons into normal and rainy seasons and environments into stagnant and circulating conditions. The results showed that the water quality parameters inside the ADP exhibit lower fluctuations and diurnal variations compared with the open space. On average, the water temperature inside the ADP is lower than outside it by 1.7–3.7 °C in stagnant conditions, and by 0.6–0.7 °C in circulating conditions during early summer. Thermal stratification occurs inside the ADP but is temporarily disturbed due to the mixing from the forced circulation and the rainwater input through rainfall events. The ADP provided a constant and optimal water temperature for living and spawning for bitterling (i.e., 15.0–21.0 °C), which dominated in experimental pond during spring to summer. Most importantly, the ADP was able to significantly reduce the thermal stress of the fish in the study site, and as a result, the bitterling, a cool water fish species, could successfully become dominant. Finally, the deployment of the ADP appears to provide a practical alternative for effective fishery resources management to improve species diversity and fish communities in an artificial freshwater ecosystem (garden pond, park pond, other artificial wetlands, etc.).
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Qin, Pan Pan, Hui Chen, Li Li Chen, Zhen Qu, Lu Ning Yu, and Shi Kui Liu. "Utilization of Waste Heat of Circulating Cooling Water in Hot-Stamping Power System." Advanced Materials Research 588-589 (November 2012): 1829–32. http://dx.doi.org/10.4028/www.scientific.net/amr.588-589.1829.
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This paper studies the possibility of using heat pump instead of cooling tower to decrease temperature and recover waste heat of circulating cooling water of power system. Making use of heat transfer theory the paper carried on analysis and calculation about recoverable waste heat of circulating cooling water in hot-stamping power system which includes hot-stamping, closing in and extrusion intermediate frequency induction furnace. The results show that the whole process can recover calories which is 2.642×106kJ per hour.Using the recycled calories can make 15.82 tons hot water per hour which is 60°C. This research shows that using heat pump to recover the waste heat of circulating cooling water is effectual.
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Perez-Protto, S., D. I. Sessler, L. F. Reynolds, M. H. Bakri, E. Mascha, J. Cywinski, B. Parker, and M. Argalious. "Circulating-water garment or the combination of a circulating-water mattress and forced-air cover to maintain core temperature during major upper-abdominal surgery." British Journal of Anaesthesia 105, no. 4 (October 2010): 466–70. http://dx.doi.org/10.1093/bja/aeq170.
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Sailani, Sunaina. "TO STUDY AND ANALYSIS OF FLAT PLATE SOLAR WATER HEATER PV CELLS." International Journal of Engineering Technologies and Management Research 5, no. 3 (February 14, 2020): 159–65. http://dx.doi.org/10.29121/ijetmr.v5.i3.2018.188.
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In this study we are obtaining the maximum temperature of solar water heater using of PV cells. The flat plate solar water heater are consisting using several parts such as collector , flat plate glass , circulating pump, PV cells , frame . The centrifugal pump is operated by PV Cells. Water temperature is measured by digital temperature meter. Hot water is storage in container. The most elements of these are a clear front cover, collector housing associated an absorbent material.
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Zhu, Dong, Hongwen Jing, Qian Yin, and Guansheng Han. "Experimental Study on the Damage of Granite by Acoustic Emission after Cyclic Heating and Cooling with Circulating Water." Processes 6, no. 8 (July 25, 2018): 101. http://dx.doi.org/10.3390/pr6080101.
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Hot dry rock is developed by injecting cold water into high-temperature rock mass. At the same time, cold water is heated in contact with the rock mass. With the continuous influx of cold water, the surrounding rock will undergo a rapid cooling process, which results in several cycles of heating and cooling. However, there is little research on the influence of cycles of heating and cooling with circulating water on the mechanical properties of rock, which is of great importance to the stability of rock mass engineering in the process of energy development. In this paper, the effects of cyclic heating and cooling with circulating water on the damage of granite are studied using uniaxial compressive, Brazilian and acoustic emission (AE) tests. The results show that heat treatment temperature and number of cycles have important effects on the mechanical properties of granite as follows: (1) at the same treatment temperature, an increase in the number of cycles means that the distribution of physical and mechanical parameters of the granite show an almost exponential downward trend. The uniaxial compression of granite results in its transformation from brittle to plastic, and the failure mode changes from slipping of the shear surface to plastic failure. With increased cycles of heating and cooling with circulating water, the tensile strength of granite also decreases; temperature has an obvious influence on physical and mechanical parameters, cracking of samples, and plays a controlling role in the failure mode of samples. In addition, (2) at the same temperature, the heating and cooling numbers N have a significant influence on the AE distribution characteristics of the sample under uniaxial compression and the number of AE collisions, and the cumulative number of AE decreases with the increase of N. (3) The concepts of mechanical damage and high-temperature and cold-water shock damage during uniaxial compression of samples were proposed based on AE, and the damage equations were established respectively. The curve equations of damage value (D) and cycle numbers N after thermal shock damage of high temperature and cold water were overlaid. The cracking mechanism of high-temperature and cold water impact on granite was analyzed, and the thermal shock stress equation of high temperature and water cooling was established.
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Plattner, Olga, Andrea Kurz, Daniel I. Sessler, Takehiko Ikeda, Richard Christensen, Danielle Marder, and David Clough. "Efficacy of Intraoperative Cooling Methods." Anesthesiology 87, no. 5 (November 1, 1997): 1089–95. http://dx.doi.org/10.1097/00000542-199711000-00013.
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Background Patients may require perioperative cooling for a variety of reasons including treatment of a malignant hyperthermia crisis and induction of therapeutic hypothermia for neurosurgery. The authors compared heat transfer and core cooling rates with five cooling methods. Methods Six healthy volunteers were anesthetized with desflurane and nitrous oxide. The cooling methods were 1) circulating water (5 degrees C, full-length mattress and cover), 2) forced air (10 degrees C, full-length cover), 3) gastric lavage (500 ml iced water every 10 min), 4) bladder lavage (300 ml iced Ringer's solution every 10 min), and 5) ice-water immersion. Each method was applied for 40 min or until the volunteers' core temperatures approached 34 degrees C. The volunteers were rewarmed to normothermia between treatments. Core cooling rates were evaluated using linear regression. Results The first volunteer developed abdominal cramping and diarrhea after gastric lavage. Consequently, the technique was not again attempted. Bladder lavage increased heat loss approximately 10 W and decreased core temperature 0.8 +/- 0.3 degrees C/h (r2 = 0.99 +/- 0.002; means +/- SD). Forced-air and circulating-water cooling comparably increased heat flux, approximately 170 W. Consequently, core cooling rates were similar during the two treatments at 1.7 +/- 0.5 degrees C/h (r2 = 0.99 +/- 0.001) and 1.6 +/- 1.1 degrees C/h (r2 = 0.98 +/- 0.02), respectively. Immersion in an ice water slurry increased heat loss approximately 600-800 W and decreased core temperature 9.7 +/- 4.4 degrees C/h (r2 = 0.98 +/- 0.01). Immersion cooling was associated with an afterdrop of approximately 2 degrees C. Conclusions Bladder lavage provided only trivial cooling and gastric lavage provoked complications. Forced-air and circulating-water cooling transferred relatively little heat but are noninvasive and easy to implement. Forced-air or circulating-water cooling, perhaps combined with intravenous administration of refrigerated fluids, may be sufficient in some patients. When noninvasive methods prove insufficient for rapid cooling, ice-water immersion or peritoneal lavage probably should be the next lines of defense.
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Li, Aqian, and Zhaolei Zheng. "Effect of Spark Ignition Timing and Water Injection Temperature on the Knock Combustion of a GDI Engine." Energies 13, no. 18 (September 20, 2020): 4931. http://dx.doi.org/10.3390/en13184931.
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A turbocharged downsizing spark ignition (SI) engine cooperating with an in-cylinder direct injection technology is one of the most effective ways to improve the power and economy of gasoline engines. However, engine knock has limited the application and development of the downsizing of gasoline engines. Water injection technology can effectively suppress the knock. In this study, a method of numerical simulation was used to explore the effect of the water injection temperature on the combustion and suppression of the knock. First of all, the knock of the gasoline engine was induced by advancing the spark timing. Then, when the other conditions were the same, different water injection temperatures were set. The results show that lowering the water injection temperature reduced the knock intensity in the cylinder, but increasing the water injection temperature made the water distribution more uniform, and the peak values of each monitoring point were more consistent. The circulating work power increased with the increase of the water injection temperature. For emissions, as the temperature of the water injection increased, the emissions of soot and unburned hydrocarbons (UHCs) decreased, and NOx slightly increased.
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Ditommaso, Savina, Cinzia Biasin, Monica Giacomuzzi, Carla Maria Zotti, Alberto Cavanna, and Angela Ruggenini Moiraghi. "Peracetic Acid in the Disinfection of a Hospital Water System Contaminated With Legionella Species." Infection Control & Hospital Epidemiology 26, no. 5 (May 2005): 490–93. http://dx.doi.org/10.1086/502573.
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AbstractObjective:To assess the efficacy of an alternative disinfection method for hospital water distribution systems contaminated with Legionella.Methods:Disinfection with peracetic acid was performed in a small hospital contaminated with L. pneumophila serotype 1. The disinfectant was used at concentrations of 50 ppm (first three surveillance phases) and 1,000 ppm (fourth surveillance phase) for 30 minutes.Results:Environmental monitoring revealed that disinfection was maintained 1 week after treatment; however, levels of recontamination surpassing baseline values were detected after approximately 1 month. Comparison of water temperatures measured at the distal outlets showed a statistically significant association between temperature and bacterial load. The circulating water temperature was found to be lower in the two wards farthest away from the hot water production plant than in other wards. It was thought that the lower water temperature in the two wards promoted the bacterial growth even after disinfection.Conclusion:Peracetic acid may be useful in emergency situations, but does not provide definitive protection even if used monthly.
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Franklin, Michelle A., Mark C. Rochat, Mark E. Payton, Kristyn D. Broaddus, and Kenneth E. Bartels. "Comparison of Three Intraoperative Patient Warming Systems." Journal of the American Animal Hospital Association 48, no. 1 (January 1, 2012): 18–24. http://dx.doi.org/10.5326/jaaha-ms-5650.
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The purpose of this randomized clinical trial was to compare the efficacy of three patient warming devices (i.e., circulating water blanket, forced-air, and warming panels) used either alone or in combination on patients undergoing surgeries lasting >60 min. In total, 238 dogs were included and divided into either the celiotomy or nonceliotomy group. Dogs in each group were further divided into one of three subgroups. Dogs in subgroup 1 (n=39) were placed on a circulating water blanket with a forced-air warming blanket placed over the trunk. Subgroup 2 dogs (n=40) were placed on a forced-air warming blanket only. Subgroup 3 dogs (n=40) were placed on warming panels. Significant temperature drops occurred from time of induction (38.1°C±0.64°C) to the start of surgical procedures (36.7°C±0.95°C). Although body temperature was maintained once the warming units were started in all groups, there were significant differences in temperatures for the type of surgical procedures (i.e., celiotomies versus nonceliotomies) performed over time except for subgroup 3. The warming panels and forced-air devices were equally effective in preserving body temperature in anesthetized patients.
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Jiang, Lili, Xiayan Yao, Haitao Yu, Xingang Hou, Zongshu Zou, Fengman Shen, and Chuantong Li. "Effect of permanent magnetic field on scale inhibition property of circulating water." Water Science and Technology 76, no. 8 (June 16, 2017): 1981–91. http://dx.doi.org/10.2166/wst.2017.357.
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Effect of a permanent magnet field on the scale inhibition property of circulating water was investigated. Orthogonal experiments of L16(45) were performed and analyzed using the range analysis method. The operating parameters included magnetic field intensity, initial concentration of Ca2+ and Mg2+, magnetic treatment time, temperature, and flow velocity. Scale inhibition rate, hardness, relative variation in the proportion of free water molecules, electrical conductivity, and relative variation of molecular energy were chosen as the objectives. In addition, the morphology and the composition of CaCO3 and MgCO3 scale were studied by X-ray diffraction analysis. The optimal conditions were initial concentration of 900 mg/L, magnetic field intensity of 0.5 T, temperature of 303 K, time of 54 h and flow velocity of 0.17 m/s. The nuclear magnetic resonance results demonstrated that the number of hydrogen bonds increased between water molecules and hydrated ions. The magnetic field can promote the increase in the number of hydrogen bonds, which can inhibit the formation of calcium and magnesium carbonate precipitation. Moreover, the ratio of calcite, aragonite and vaterite will be changed at different magnetic field intensities, and the aragonite ratio will reach the peak at the optimum conditions.
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Yusuf, A., and M. H. Ali. "Comparative Study of Conventional and Water Circulating-Heat Sink Cooling Base Thermoelectric Generator System for Optimum Solar Thermal Waste Heat Recovery." Journal of Applied Sciences and Environmental Management 25, no. 4 (October 8, 2021): 503–9. http://dx.doi.org/10.4314/jasem.v25i4.3.
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A novel technique for waste heat recovery in solar thermal power generation is investigated through experimentation and systematically presented. Power generation using Thermoelectric Generator (TEG) is a promising technique in waste heat recovery application. In this topology, TEG array is directly attached to the back of the solar Photovoltaic panel (model AP-AM15) to receive the transmitted heat at the back of the PV panel as waste heat. More so, a circulating water-heat sink is attached to the TEG cold side to improve the temperature gradient. Base on Seebeck effect, the TEG directly converts the temperature difference into electricity. The experimental result shows that efficiency between the range of 2.1% and 4.7% for the conventional cooling system while the output power approximately ranges between 0.05W and 0.47W, the circulating water-heat sink technique has efficiency ranging between 2.9% and 10.3% with output power between the range of 0.10W and 2.2W. The daily average increase in efficiency was found to be 263.76%. This shows that the daily average power is improved by a factor of 2.6376 with the water circulating water-heat sink technique. This is an indication of waste heat recovery from the solar thermal power generation.
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Ihn, CH, JD Joo, HS Chung, JW Choi, DW Kim, YS Jeon, YS Kim, and WY Choi. "Comparison of Three Warming Devices for the Prevention of Core Hypothermia and Post-Anaesthesia Shivering." Journal of International Medical Research 36, no. 5 (October 2008): 923–31. http://dx.doi.org/10.1177/147323000803600508.
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The efficacy of forced air warming with a surgical access blanket in preventing a decrease in core temperature during anaesthesia and post-anaesthesia shivering (PAS) was compared with two widely used interventions comprising forced air warming combined with an upper body blanket, and a circulating water mattress, in a prospective, randomized double-blind study. A total of 90 patients undergoing total abdominal hysterectomy were studied, 30 in each group. Core temperature was measured 15, 30, 45, 60, 90 and 120 min after induction of anaesthesia. PAS was evaluated every 5 min after emergence from anaesthesia over a period of 1 h. Core temperature fell in all three groups compared with the baseline, but forced air warming using a surgical access blanket was more effective than the other warming methods in ameliorating the temperature decrease. The surgical access blanket was also superior to the circulating water mattress in reducing PAS.
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Petrushchenkov, Valery, and Michail Shcheglov. "On possibility of replacement of saturated steam with hot water at circulating heating of fuel oil." E3S Web of Conferences 140 (2019): 05005. http://dx.doi.org/10.1051/e3sconf/201914005005.
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Circulating heating of fuel oil in railway tanks is performed, as a rule, with the help of saturated steam by preparing a heating flow of fuel oil with a temperature of about 80...90°C. For the operation services of fuel oil storages, it is interesting to consider replacing steam with hot water. The behavior of the existing system of circulating heating of fuel oil of M100 brand when changing the heating medium for the heater of fuel oil flow in the form of a plate heat exchanger is considered. The initial temperature of hot water is assumed to be equal to the design temperature of 115°C in the steam-fuel heat exchanger. The values of the thermal capacity of the heater flow of fuel oil, fuel oil consumption, flow rate and the temperature of the heating water flow at the outlet of the heat exchanger are defined depending on the temperature of the heated fuel oil in the range of 80...90°C. Reducing the temperature of fuel oil at the outlet of the heat exchanger from 90 to 80°C allows to increase its capacity by 30.1%, that is, to accelerate the heating of fuel oil in the tank and reduce the time of its discharge.
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Chi, Xin Li, Sheng Lin, Xi Chang Han, and Da Ren Wang. "Application Studies of Fuzzy Control on Adding Medicament in Circulating Water Treatment." Advanced Materials Research 466-467 (February 2012): 328–31. http://dx.doi.org/10.4028/www.scientific.net/amr.466-467.328.
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Considering the control problem of circulating water system in the power plants with pure delay, inertia, and sensitivity to the environmental temperature, this paper applies the fuzzy algorithm to adding medicament control in circulating water system. The main procedure of fuzzy control algorithm consists of fuzzification, fuzzy inference and defuzzification. The fuzzy input and output variables are chosen as seven classes. Then, according to the actual operation situations and the expert experiences, the fuzzy rules are determined in the form of table. The effectiveness of the proposed fuzzy control method is proved by some practical examples.
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Wang, Qing, Hai Bo Long, Hong Peng Liu, and Zhi Feng Wang. "Process Simulation of Oil Shale Circulating Fluidized Bed Boiler Based on Aspen Plus." Advanced Materials Research 614-615 (December 2012): 49–52. http://dx.doi.org/10.4028/www.scientific.net/amr.614-615.49.
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A model for the combustion of oil shale in the 65t/h circulating fluidized bed (CFB) boiler was developed, consisting of oil shale combustion, steam-water and ash circulation system, calculating the O2 and RO2 content of flue gas emission under three kinds of oil shale combustion in 65t/h CFB boiler. The calculated results indicate that the simulation values are consistent with the experimental values. Effect of boiler load on the temperature of furnace, flue gas emission, inlet and outlet flue gas of economizer was discussed based on the model. Boiler load on the increase results in a increase in temperature of furnace, flue gas emission, inlet and outlet flue gas of economizer. The main performance parameters of 65t/h oil shale CFB boiler system were discussed and preliminarily predicted by the model.
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Liu, Jiayou, and Fengzhong Sun. "Experimental Study on Operation Regulation of a Coupled High–Low Energy Flue Gas Waste Heat Recovery System Based on Exhaust Gas Temperature Control." Energies 12, no. 4 (February 21, 2019): 706. http://dx.doi.org/10.3390/en12040706.
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Controlling the exhaust gas temperature (EGT) of coal–fired boilers at a reasonable value is beneficial to ensuring unit efficiency and preventing acid corrosion and fouling of tail heating surfaces in power plants. To obtain the operation regulation of coupled high–low energy flue gas waste heat recovery system (CWHRS) under a given EGT, experimental equipment was designed and built. Experiments were carried out to maintain the exhaust gas temperature under different flue gas flow, flue gas temperature and air temperature conditions. As the flue gas flows, the flue gas temperatures and air temperatures increased, and the bypass flue gas flow proportions or the water flows of the additional economizer were increased to maintain the EGT at about 85 °C. An improved low temperature economizer (LTE) and front located air heater (FAH) system were put forward. As the flow of the crossover pipe increased, the EGT and the inlet water temperature of the LTE increased. As the flow of the circulating loop increased, the EGT and the inlet water temperature of the LTE decreased. Operation regulations of LTE–FAH system under four cases were given. The operation regulations of CWHRS and LTE–FAH system can provide references for power plant operation.
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Shin, Ji-Hyun, Yoon-Bok Seong, Yong-In Kim, and Young-Hum Cho. "Development of Changeover Operating Method Based on Performance Prediction of Hybrid Geothermal Heat Pump Systems through Field Test and Numerical Analysis." Energies 13, no. 20 (October 13, 2020): 5333. http://dx.doi.org/10.3390/en13205333.
Full textAbstract:
The installation and operation of geothermal systems increased due to the expectation of good cooling and heating performance due to stable heat source temperatures. In actual geothermal system operations, heat source temperature rises or falls due to an imbalance of heating and cooling energy usage. Problems of source side temperature result in reduced geothermal system performance. The purpose of this study is to develop hybrid geothermal system operation technology to stabilize temperature and improve system performance by utilizing auxiliary heat source system. The auxiliary heat source system is operated by comparing the performance when operating the geothermal heat pump system alone and the performance when operating the hybrid geothermal heat pump system. The performance of a hybrid geothermal system is determined by the circulating water temperature of the geothermal system and the circulating water temperature of the auxiliary heat source system. Hybrid geothermal heat pump system performance is predicted through numerical analysis and collection of hybrid geothermal system performance data at various temperature ranges through field test. An operating method was developed using the predicted performance as the changeover operating point of the hybrid geothermal heat pump system. When applying the development and operation technology, it handled about 11% more load than the existing geothermal system operation. The addition of an auxiliary heat source increases the initial investment cost compared to the existing geothermal system, but decreases energy consumption, confirming that the initial investment cost of 15.3 years is recovered.
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Usmonov, Nzomjon, Yusufbek Abdullabekov, and Saodat Axmatova. "Development of an experimental facility for cooling circulated water of industrial plants." E3S Web of Conferences 304 (2021): 01011. http://dx.doi.org/10.1051/e3sconf/202130401011.
Full textAbstract:
The article discusses the installation and the hydrodynamic results analysis of three-phase fluidized bed experimental studies. An energy coefficient linear dependence of the circulating water evaporative cooler of the considered type on the irrigation coefficient has been experimentally established. The dependence of the fraction of circulating water evaporated moisture in an evaporative cooler of the type under consideration on the cooled water temperature at the inlet to the cooler and the irrigation coefficient has been established. The analysis of hydrodynamic and thermal processes occurring in a three-phase fluidized bed is carried out, and the main technological parameters for the optimal operation of installations with the specified bed are obtained in relation to solving the problem of cooling the circulating water. The dependence of the expansion of a three-phase fluidized bed on air velocity and irrigation density has been investigated. On the basis of the performed experimental studies, empirical formulas for calculations are derived.