Journal articles on the topic 'Annual refrigeration capacity'
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1
Радченко, Микола Іванович, Євген Іванович Трушляков, Сергій Анатолійович Кантор, Богдан Сергійович Портной, and Анатолій Анатолійович Зубарєв. "МЕТОД ВИЗНАЧЕННЯ ТЕПЛОВОГО НАВАНТАЖЕННЯ СИСТЕМИ КОНДИЦІЮВАННЯ ПОВІТРЯ ЗА МАКСИМАЛЬНИМ ТЕМПОМ ПРИРОЩЕННЯ ХОЛОДОПРОДУКТИВНОСТІ (на прикладі кондиціювання повітря енергетичного призначення)." Aerospace technic and technology, no. 4 (October 14, 2018): 44–48. http://dx.doi.org/10.32620/aktt.2018.4.05.
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It is justified the necessity of taking into consideration changes in thermal loads on the air conditioning system (heat and moisture treatment of air by cooling it with decreasing temperature and moisture content) in accordance with the current climatic conditions of operation. Since the effect of air cooling depends on the duration of its use and the amount of cold consumption, it is suggested that it be determined by the amount of cold spent per year for air conditioning at the GTU inlet, that is, for annual refrigerating capacity. The example of heat-using air conditioning at the inlet of a gas turbine unite (energy–efficient air conditioning systems) analyzes the annual costs of cooling for cooling ambient air to the temperature of 15 °C by an absorption lithium-bromide chiller and two-stage air cooling: to a temperature of 15 °C in an absorption lithium-bromide chiller and down to temperature 10 °С – in a refrigerant ejector chiller as the stages of a two-stage absorption-ejector chiller, depending on the installed (project) refrigerating capacity of waste heat recovery chiller.It is shown that, based on the varying rate of increment in the annual production of cold (annual refrigeration capacity) due to the change in the thermal load in accordance with current climatic conditions, it is necessary to select such a design thermal load for the air conditioning system (installed refrigeration capacity of chillers), which ensures the achievement of maximum or close to it annual production of cold at a relatively high rate of its increment. It is analyzed the dependence of the increment on the annual refrigerated capacity, relative to the installed refrigeration capacity, on the installed refrigeration capacity, in order to determine the installed refrigeration capacity, which provides the maximum rate of increase in the annual refrigerating capacity (annual production of cold). Based on the results of the research, it is proposed the method for determining the rational thermal load of the air conditioning system (installed – the design refrigeration capacity of the chiller) in accordance with the changing climatic conditions of operation during the year, which provides nearby the maximum annual production of cold at relatively high rates of its growth
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Радченко, Андрій Миколайович, Богдан Сергійович Портной, Сергій Анатолійович Кантор, Олександр Ігорович Прядко, and Іван Володимирович Калініченко. "ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТД ХОЛОДИЛЬНИМИ МАШИНАМИ ШЛЯХОМ АКУМУЛЯЦІЇ ХОЛОДУ." Aerospace technic and technology, no. 4 (August 28, 2020): 22–27. http://dx.doi.org/10.32620/aktt.2020.4.03.
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The efficiency of air cooling at the inlet of gas turbine engines by exhaust heat conversion chiller, which transforms the GTE exhaust gases heat into cold, under variable climatic operating conditions, has been investigated. Considered is the use of a combined absorption-ejector exhaust heat conversion chiller with a step-by-step principle of air cooling at the gas turbine engines inlet: preliminary down to 15°C – by an absorption lithium-bromide chiller (ACh), which is used as a high-temperature air cooling stage, and further cooling down to 10°C – by a refrigerant ejector chiller (ECh) as a low-temperature cooling stage. Reserves have been identified for reducing the design (installed) refrigeration capacity of chillers by accumulating excess cold at reduced current heat loads with its use at increased heat loads. In this case, the design (installed) refrigeration capacity of chillers was determined by two methods: the first – based on the close to the maximum reduction in annual fuel consumption, the second – according to the maximum rate of increase in the reduction in annual fuel consumption. A scheme of the air cooling system at the gas turbine engines inlet using the refrigeration capacity reserve of the ACh, which provides preliminary cooling of the ambient air at the gas turbine engines inlet, in the booster stage, using the ACh accumulated excess refrigeration capacity has been proposed. The ACh excess refrigerating capacity, which is formed at decreased heat loads on the air coolers at the gas turbine engines inlet, is accumulated in the cold accumulator and is used at increased heat loads. The simulation results show the advisability of using the air cooling system at the gas turbine engine inlet with using the ACh accumulated excess refrigeration capacity, which allows reducing the ACh design (installed) refrigeration capacity by approximately 40%.
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Портной, Богдан Сергійович. "ВИБІР ТЕПЛОВОГО НАВАНТАЖЕННЯ АПАРАТІВ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТУ В РІЗНИХ КЛІМАТИЧНИХ УМОВАХ." Aerospace technic and technology, no. 4 (October 14, 2018): 49–52. http://dx.doi.org/10.32620/aktt.2018.4.06.
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It is proposed the definition of the installed (rational) refrigeration capacity of a waste heat-recovery absorption-ejector chiller that utilizes the heat of the exhaust gases of a gas turbine unite to cool the air at the inlet. Since the effect of air cooling, in particular in the form of a reduction in the specific fuel consumption, depends on its depth (the magnitude of the decrease in air temperature) and duration, it is proposed to determine it by the annual fuel economy. As an example of air cooling at the inlet of a gas turbine unit, the value of reducing specific fuel consumption due to cooling the air at the inlet to the temperature of 15 °C by an absorption lithium-bromide chiller and two-stage air cooling: to a temperature of 15 °C in an absorption lithium-bromide chiller and down to 10 °C – in a refrigerant ejector chiller as the stages of a two-stage absorption-ejector chiller, depending on the installed (design) refrigeration capacity is analyzed.It is shown that proceeding from the different rate of increment of the annual reduction in the specific fuel consumption due to the change in the thermal load in accordance with the current climatic conditions, it is necessary to choose such design heat load for the air cooling system (installed refrigeration capacity of the chillers), which ensures the achievement of the maximum or close to annual reduction in the specific fuel consumption at relatively high rates of its increment. In order to determine the installed refrigeration capacity, which ensures the maximum annual refrigeration capacity (annual production of cold), the dependence of the increment of annual fuel economy from the installed refrigeration capacity is analyzed. Based on the results of the investigation, it was proposed to determine the rational thermal load of the air cooling system (installed - the design refrigeration capacity of the chiller) in accordance with the changing climatic conditions of operation during the year, which provides a maximum annual reduction in the specific fuel consumption at relatively high rates of its increment
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Радченко, Андрій Миколайович. "МЕТОД ВИЗНАЧЕННЯ ХОЛОДОПРОДУКТИВНОСТІ ТЕРМОТРАНСФОРМАТОРА ЗА МАКСИМАЛЬНИМ ТЕМПОМ ПРИРОЩЕННЯ ТЕРМОЧАСОВОГО ПОТЕНЦІАЛУ ОХОЛОДЖЕННЯ ПОВІТРЯ." Aerospace technic and technology, no. 4 (October 14, 2018): 53–57. http://dx.doi.org/10.32620/aktt.2018.4.07.
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It is proved a possibility of using the thermohour cooling potential method, developed by the author, for defining the installed (design) refrigeration capacity of term transformer (refrigeration machine), providing a maximum rate of thermo-hour cooling potential increasing according to the current climatic conditions for a definite period of operation.It is proposed to define the effect, gained due to cooling air, in particular at the inlet of GTU, depends on duration and depth of cooling, by thermohour potential ÕS,°С·h, as air temperature decrease Δta multiplied by duration τ of GTU operation at decreased temperature: ÕS = ∑(Δta ∙°τ), which to some extent characterizes heat load on the cooling system.It is shown that taking into consideration a different rate of annual thermohour cooling potential arising with increasing the installed refrigeration capacity of term transformer, caused by changing the heat load according to current climatic conditions during a year, it is necessary to choose such design heat load on the air cooling system (refrigeration capacity of term transformer) that provides a maximum value of annual thermohour cooling potential or close it with relatively high rates of its increasing. To define the installed refrigeration capacity, providing a maximum rate of annual thermohour cooling potential increasing, it is analyzed the dependence of annual thermohour cooling potential related to the installed refrigeration capacity of term transformer, from the installed refrigeration capacity of term transformer. As a result of the investigation, it is proposed the method of defining the design heat load (installed refrigeration capacity) of term transformer with maximum rates of increasing thermohour cooling potential, as a further development of methodology of rational designing of them transformers for combustion engine inlet air cooling on the base of thermohour potential, developed by author
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Yang, Shutong, Youlei Wang, and Yufei Wang. "Optimization of Cascade Cooling System Based on Lithium Bromide Refrigeration in the Polysilicon Industry." Processes 9, no. 9 (September 18, 2021): 1681. http://dx.doi.org/10.3390/pr9091681.
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Cascade cooling systems containing different cooling methods (e.g., air cooling, water cooling, refrigerating) are used to satisfy the cooling process of hot streams with large temperature spans. An effective cooling system can significantly save energy and costs. In a cascade cooling system, the heat load distribution between different cooling methods has great impacts on the capital cost and operation cost of the system, but the relative optimization method is not well established. In this work, a cascade cooling system containing waste heat recovery, air cooling, water cooling, absorption refrigeration, and compression refrigeration is proposed. The objective is to find the optimal heat load distribution between different cooling methods with the minimum total annual cost. Aspen Plus and MATLAB were combined to solve the established mathematical optimization model, and the genetic algorithm (GA) in MATLAB was adopted to solve the model. A case study in a polysilicon enterprise was used to illustrate the feasibility and economy of the cascade cooling system. Compared to the base case, which only includes air cooling, water cooling, and compression refrigeration, the cascade cooling system can reduce the total annual cost by USD 931,025·y−1 and save 7,800,820 kWh of electricity per year. It also can recover 3139 kW of low-grade waste heat, and generate and replace a cooling capacity of 2404 kW.
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Dubey, Swapnil, and Alison Subiantoro. "Numerical Study of Integrated Solar Photovoltaic–Thermal Module with a Refrigeration System for Air-Conditioning and Hot Water Production under the Tropical Climate Conditions of Singapore." International Journal of Air-Conditioning and Refrigeration 26, no. 03 (September 2018): 1850021. http://dx.doi.org/10.1142/s2010132518500219.
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Thermal systems of buildings in the tropics are highly energy intensive. In this study, a novel integrated solar photovoltaic–thermal–refrigeration (PVTR) system used to produce hot water and air-conditioning in the tropical climate conditions of Singapore was analyzed. A dynamic simulation model was formulated for the analysis. Mathematical models were developed for the PV sandwich attached with a solar flat plate collector and for the main components of the refrigeration system. Thorough investigation of the electrical and thermal performances of the system were conducted through the analysis of coefficient of performance (COP), cooling capacity, water temperature and heat capacity in water heater, photovoltaic (PV) module temperature and PV efficiency. The results show that attractive electrical and thermal performance can be achieved with a maximum annual cooling COP of 9.8 and a heating COP of 11.3. The PV efficiency and power saving were 14% and 53%, respectively. The annual cooling, heating and PV energy produced were 9.7, 15.6 and 1.6[Formula: see text]MWh, respectively. The financial payback period of the system was 3.2 years and greenhouse gas (GHG) emission reduction annually was 12.6 tons of CO2 equivalents (tCO2e).
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Saengsikhiao, Piyanut, and Juntakan Taweekun. "The Data Mining Technique Using RapidMiner Software for New Zeotropic Refrigerant." Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 83, no. 1 (June 3, 2021): 70–90. http://dx.doi.org/10.37934/arfmts.83.1.7090.
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This research presents the development of environmentally-friendly and energy efficient refrigerant for medium temperature refrigeration systems that new azeotropic refrigerant mixture of hydrofluorocarbons and hydrocarbon that can retrofit in the refrigeration system using R404A. The medium back pressure refrigeration testing standard that follow CAN/ANSI/AHRI540 standard air-conditioning, heating, and refrigeration institute (AHRI) and The properties of refrigerants and refrigeration simulation system that used national institute of standards and technology (NIST) reference fluid thermodynamic and transport properties database (REFPROP) software and NIST vapor compression cycle model accounting for refrigerant thermodynamic and transport properties (CYCLE_D-HX) software. The methodology uses decision tree function in datamining by rapid minor software that first of KDnuggets annual software poll that showed new azeotropic refrigerant mixture had cooling capacity, refrigerant effect, GWP and boiling point were lower than R404A but work and pressure for medium temperature refrigeration system of azeotropic refrigerant mixture were higher than R404A. The artificial intelligence (AI) by data mining technic can predictive environmentally-friendly and energy efficient refrigerant for medium temperature refrigeration. The result of refrigerant mixed by R134A, R32, R125 and R1270 and is consistent with the evolution of fourth-generation refrigerants that contain a mixture of HFCs and HCs which are required to produce a low-GWP, zero-ozone-depletion-potential (ODP), high-capacity, low-operating-pressure, and nontoxic refrigerant.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Микола Іванович Радченко, Сергій Анатолійович Кантор, and Веніамін Сергійович Ткаченко. "ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ КОНДИЦІЮВАННЯ ЗОВНІШНЬОГО ПОВІТРЯ СИСТЕМИ КОМБІНОВАНОГО ТИПУ." Aerospace technic and technology, no. 4 (August 31, 2019): 9–14. http://dx.doi.org/10.32620/aktt.2019.4.02.
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One of the most attractive reserves of enhancing the energetic efficiency of air conditioning systems is to provide the operation of refrigeration compressors in nominal or close to nominal modes by choosing rational design cooling loads (cooling capacities) and their distribution according to a cooling load behaviour within the overall design (installed) cooling load band to match current changeable climatic conditions and provide close to maximum annual cooling capacity generation according to cooling duties. The direction of increasing the efficiency of outdoor air conditioning in combined central-local type systems by rationally distributing the heat load - cooling capacity of the central air conditioner into zones of variable heat load in accordance with current climatic conditions and its relatively stable value, i.e. cooling capacity required for further air cooling at the entrance to the indoor recirculation air conditioning system is justified. By comparing the values of the excessive production of cold and its deficit within every 3 days for a rational design heat load of the air conditioning system (cooling capacity of the installed refrigeration machine), which provides close to maximum annual production of cold, and the corresponding values of the excess and deficit of cooling capacity in accordance with current climatic conditions during July substantiated the feasibility of accumulating the excess of cooling capacity of a central air conditioner at low current loads and its use for covering cooling deficit at elevated heat loads through pre-cooling the outdoor air. It is developed a scheme of a combined central-local air conditioning system, which includes the subsystems for the outdoor air conditioning in a central air conditioner and the local indoor recirculated air conditioning.
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Yang, Zongming, Mykola Radchenko, Andrii Radchenko, Dariusz Mikielewicz, and Roman Radchenko. "Gas Turbine Intake Air Hybrid Cooling Systems and a New Approach to Their Rational Designing." Energies 15, no. 4 (February 17, 2022): 1474. http://dx.doi.org/10.3390/en15041474.
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Gas turbine intake air cooling (TIAC) by exhaust gas heat recovery chillers is a general trend to improve turbine fuel efficiency at increased ambient temperatures. The high efficiency absorption lithium–bromide chillers of a simple cycle are the most widely used, but they are unable to cool inlet air lower than 15 °C. A two-stage hybrid absorption–ejector chillers were developed with absorption chiller as a high temperature stage and ejector chiller as a low temperature stage to subcool air from 15 °C to 10 °C and lower. A novel trend in TIAC by two-stage air cooling in hybrid chillers has been substantiated to provide about 50% higher annual fuel saving in temperate climate as compared with absorption cooling. A new approach to reduce practically twice design cooling capacity of absorption chiller due to its rational distribution with accumulating excessive refrigeration energy at decreased thermal loads to cover the picked demands and advanced design methodology based on it was proposed. The method behind this is issued from comparing a behavior of the characteristic curves of refrigeration energy required for TIAC with its available values according to various design cooling capacities to cover daily fluctuation of thermal loads at reduced by 15 to 20% design cooling capacity and practically maximum annual fuel reduction.
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Radchenko, Andrii M. "Gas turbine intake air cooling systems of combined type and their optimum designing." Joupnal of New Technologies in Environmental Science 5, no. 2 (June 30, 2020): 3–24. http://dx.doi.org/10.30540/jntes-2020-2.1.
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Turbine intake air cooling (TIAC) by absorption lithium-bromide chillers (ACh) utilizing the exhaust heat is considered as the most effective fuel saving technology for temperate climatic conditions. But the cooling potential of TIAC systems based on ACh of a simple cycle is limited by a comparatively increased chilled water temperature of about 7°C excluding cooling intake air lower than 15°C. The application of a refrigerant as a coolant enables deeper cooling intake air to 10°C and lower. The application of two-stage hybrid absorption-ejector chillers (AECh) with a refrigerant ejector chiller (ECh) as a low temperature stage makes it possible to increase the annual fuel saving approximately twice in temperate climate due to deeper cooling air as compared with ACh. Furthermore, this effect can be achieved with the sizes of TIAC system reduced by about 20 % due to determining the rational refrigeration capacity of AECh providing practically maximum annual fuel saving increment and the use of the current excessive refrigeration capacities to cover peaked loads.
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Khir, Tahar, Rahim K. Jassim, and Galal M. Zaki. "Application of Exergoeconomic Techniques to the Optimization of a Refrigeration Evaporator Coil With Continuous Fins." Journal of Energy Resources Technology 129, no. 3 (July 16, 2006): 266–77. http://dx.doi.org/10.1115/1.2751507.
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An optimization for the geometrical parameters of continuous fins on an array of tubes of a refrigeration evaporator is developed in this paper using the exergy method. The method is based on exergy, economic analysis, and optimization theory. As there are humid air and refrigerant single- and two-phase streams involved in the heat transfer process, then there are irreversibilities or exergy destruction, due to pressure losses İΔP, due to temperature difference İΔT and due to specific humidity gradient İΔω. These principal components of total irreversibility are not independent, and their relative contribution to total irreversibility of a cross-flow refrigeration evaporator is investigated. A change in geometry was obtained by varying the evaporator tube diameter for a selected evaporator capacity, and hence the evaporator tube length and total heat transfer area are calculated for a fixed evaporator face length. In this way, the effect of changes in the geometry on the total number of exergy destruction units of the heat exchange process is investigated. The optimum balance between the three components of irreversibility (İΔP,İΔT, and İΔω) is also determined, thereby giving the optimum solution for the heat exchanger area. The total cost function, which provides a measure of the contribution of the evaporator to the total cost of the refrigeration system, is expressed on the basis of annual capital and electrical energy costs. The total cost function is minimized with respect to the total heat transfer area and the total number of exergy destruction units (NI). The relationship between the operational variables, heat transfer area, refrigerant and air irreversibilities, and the total annual cost for this type of evaporator are developed, presented, and discussed. The pressure, temperature, and specific humidity irreversibilities are found to be 30.34%, 33.78%, and 35.88%, respectively, of the total irreversibility, which is 8.5% of the evaporator capacity.
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Трушляков, Євген Іванович, Микола Іванович Радченко, Андрій Миколайович Радченко, Сергій Георгійович Фордуй, Сергій Анатолійович Кантор, Веніамін Сергійович Ткаченко, and Богдан Сергійович Портной. "ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ ШЛЯХОМ РОЗПОДІЛУ ТЕПЛОВОГО НАВАНТАЖЕННЯ ЗА СТУПЕНЕВИМ ПРИНЦИПОМ." Aerospace technic and technology, no. 8 (August 31, 2019): 49–53. http://dx.doi.org/10.32620/aktt.2019.8.07.
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Maintaining the operation of refrigeration compressors in nominal or close modes by selecting a rational design thermal load and distributing it in response to the behavior of the current thermal load according to the current climatic conditions is one of the promising reserves for improving the energy efficiency of air conditioning systems, which implementation ensures maximum or close to it in the annual cooling production according to air conditioning duties. In general case, the total range of current thermal loads of any air-conditioning system includes a range of unstable loads caused by precooling of ambient air with significant fluctuations in the cooling capacity according to current climatic conditions, and a range of relatively stable cooling capacity expended for further lowering the air temperature from a certain threshold temperature to the final outlet temperature. If a range of stable thermal load can be provided within operating a conventional compressor in a mode close to nominal, then precooling the ambient air with significant fluctuations in thermal load requires adjusting the cooling capacity by using a variable speed compressor or using the excess of heat accumulated at reduced load. Such a stage principle of cooling ensures the operation of refrigerating machines matching the behavior of current thermal loads of any air-conditioning system, whether the central air conditioning system with ambient air procession in the central air conditioner or its combination with the local indoors recirculation air conditioning systems in the air-conditioning system. in essence, as combinations of subsystems – precooling of ambient air with the regulation of cooling capacity and subsequent cooling air to the mouth of the set point temperature under relatively stable thermal load.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Микола Іванович Радченко, Сергій Георгійович Фордуй, Сергій Анатолійович Кантор, and Богдан Сергійович Портной. "МЕТОДОЛОГІЧНІ ПІДХОДИ ДО ВИЗНАЧЕННЯ ХОЛОДОПРОДУКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ ЗА ЗМІННИХ КЛІМАТИЧНИХ УМОВ." Aerospace technic and technology, no. 7 (August 31, 2019): 71–75. http://dx.doi.org/10.32620/aktt.2019.7.09.
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One of the most attractive reserves for improving the energy efficiency of air conditioning systems is to ensure the operation of refrigeration compressors in nominal or close to nominal modes by selecting a rational design heat load and distributing it within its design value according to the behavior of the current heat load under variable current climatic conditions to provide the maximum or close to maximum annual cooling capacity generation according to cooling duties of air conditioning. In the general case, the overall range of current thermal loads of any air conditioning system includes a range of unstable loads associated with the precooling of ambient air with significant fluctuations in cooling capacity according with current climatic conditions, and a relatively stable range of cooling capacity consumed to further reduce air temperature from a certain threshold temperature to the final outlet temperature. It is quite obvious that a stable range of heat load can be ensured within operating a conventional compressor in a mode close to the nominal mode while precooling the ambient air with significant fluctuations in heat load requires regulation of the cooling capacity through the use of a variable speed compressor. Thus, in response of the behavior of the change in current heat loads, any air conditioning system, whether the central air-conditioning system with its heat procession in a central air conditioner, or a combination thereof with a local recirculation system of indoor air, essentially consists of two subsystems: pre-cooling the ambient air and then cooling it to the set point temperature. The proposed method of distribution of design heat load depending on the behavior of the current heat load is useful for the rational design of central air conditioning systems and their combined versions with the local air conditioning system.
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Sivtseva, A. I., A. S. Kurilko, A. N. Petrov, and L. V. Petrova. "The thermal condition and stability of underground tourist complex workings." IOP Conference Series: Earth and Environmental Science 839, no. 2 (September 1, 2021): 022094. http://dx.doi.org/10.1088/1755-1315/839/2/022094.
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Abstract The article presents the development of measures to ensure the required thermal condition and recommendations for support setting of underground mine workings in the conditions of the cryolithozone, ensuring the stability of the workings and safe living conditions in the galleries of the tourist complex “The Kingdom of permafrost” (TKoP), located on the 5th km of the Vilyuysky tract in Yakutsk. The following research methods were used: field observation of the temperature condition, visual inspection of the slope and underground mining of the tourist complex, the choice of a rational type of support setting, calculation of the parameters of the support, mathematical modeling and numerical calculations of the temperature condition. The main research results are obtained: the results of field observation of the thermal condition of underground mine workings of the tourist complex “The Kingdom of permafrost” in the winter and spring period of operation, the results of visual inspection of the slope, galleries and chambers, and recommendations for ensuring stability and support setting the existing fallout zones are given. The calculation of the temperature condition of the TKoP and the required capacity of refrigeration machines was performed using the Museum CVM software package developed in the Laboratory of Mining Thermophysics of the IGDS SB RAS. To reduce the energy consumption for the production of artificial cold in the summer, it is recommended to carry out annual autumn and spring cooling charges with artificial ventilation. The recommendations for support setting mine workings have been developed.
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Virtue, J. G., P. D. Gee, N. M. Secomb, P. R. O'Leary, and B. P. Grear. "Facilitating feral camel removal in Australia through commercial use." Rangeland Journal 38, no. 2 (2016): 143. http://dx.doi.org/10.1071/rj15066.
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Approximately 16.5% of feral camel removal under the Australian Feral Camel Management Project (AFCMP) was by commercial means, via mustering for transport to abattoir (9.3%) and pet-meating in the field (7.2%). The challenges of commercial use of feral camels as a removal method include: variable density, mobility and distribution of the feral camel population; achieving landholder collaboration; accessibility to remote areas by road; availability of yard infrastructure and trucking capacity; and distance to slaughter facilities and end-markets. However, the AFCMP recognised commercial use as important to some Aboriginal communities, bringing a range of economic and social benefits as well as environmental outcomes in terms of reduced feral camel density. To facilitate mustering offtake, a removal assistance scheme was developed, whereby a formal landholder agreement was entered into with various legal requirements, including animal welfare. The agreement incentivised removal of both sexes: payments were for cow camels received at abattoir, but with a concurrent requirement for approximately equal sexes to be delivered to abattoir in an annual contract period. Additional project costs included contract development and oversight, landholder engagement, training and animal welfare auditing. Pet-meating, by way of ground culling and in-field butchering for meat storage in mobile refrigeration units, was also supported by the AFCMP via measures to increase harvest efficiency such as satellite tracking, aerial spotting and improved road access. However, pet-meating ceased mid-project due to changed industry demands. Post-AFCMP, mustering operations continue to service market demand for camel meat. The camel industry is also looking to camel farming to ensure greater continuity and quality of supply than can be achieved through wild harvest.
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Yang, Chao, Ying Jun Ruan, Wei Guo Zhou, Jian Wang, and Zhi Li Zhang. "Feasibility of CCHP System in Certain Large-Scale Public Building." Advanced Materials Research 608-609 (December 2012): 1156–65. http://dx.doi.org/10.4028/www.scientific.net/amr.608-609.1156.
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According to the information of a large-scale public building in Shanghai, annual hourly loads of cooling, heating and power are calculated separately on the basis of Hourly Load Apportionment Ratio Method. Based on load characteristics and local practical condition, three cases are proposed for further comparison and selection by PRUE, ESR, CRR and PBP, and then the optimal case is to be determined. Moreover, the impact of installed capacity and gas price on the effect of applying CCHP system would be discussed. The result shows that both hotel and office area are appropriate for utilizing CCHP system; the combination of electro-refrigerator and absorption refrigerator is more economically preferable; PBP increases at first and then decreases while the capacity of electric generator rises, and when the capacity of generator and refrigerator are 4000kW and 4500RT, the PBP is lowest; The PBP will be 3 to 5 years if the price of natural gas could be fixed between 2.5 Yuan/m3 and 3Yuan/m3, which is a remarkable indicator of economical efficiency.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Сергій Анатолійович Кантор, Веніамін Сергійович Ткаченко, Сергій Георгійович Фордуй, and Ян Зонмін. "ВИЗНАЧЕННЯ ПРОЕКТНОЇ ХОЛОДОПРОДУКТИВНОСТІ СИСТЕМИ КОНДИЦІЮВАННЯ ПОВІТРЯ В КОНКРЕТНИХ КЛІМАТИЧНИХ УМОВАХ І РІЗНИМИ МЕТОДАМИ." Aerospace technic and technology, no. 6 (December 24, 2019): 15–19. http://dx.doi.org/10.32620/aktt.2019.6.03.
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The cold output for the heat-moisture treatment of ambient air in air conditioning systems depends on its parameters (temperature and relative humidity), which vary significantly during operation. To determine the installed (design) cooling capacity of air conditioning system chillers, it is proposed to use a reduction in fuel consumption of a power plant or cooling capacity generation following its current conditioning spending over a certain period, since both of these indicators characterize the efficiency of using the installed cooling capacities of the air conditioning system. To extend the results of the investigation to a wide range of air conditioning units, two methods were used to determine the design cooling capacity (refrigerating capacity): by the maximum annual value and by the maximum growth rate of the efficiency indicator. The first method allows choosing the design cooling capacity, which provides a maximum annual reduction in the specific fuel consumption due to air cooling or maximum cooling capacity generation, which is necessary for air cooling following current climatic conditions. The second method allows determining the minimum design (installed) cooling capacity of chillers, which provides the maximum rate of reduction in fuel consumption by the power plant and the increment in the annual cooling capacity generation following the installed cooling capacity of chillers. The efficiency of air conditioning systems was analyzed for different climatic conditions: a temperate climate using the example of Voznesensk city (Ukraine) and the subtropical climate of Nanjing city (China). It is shown that the design cooling capacity values calculated by both indicators of its use efficiency are the same for the same climatic conditions. Wherein, if to determine the design cooling capacity by both methods - by the maximum annual value and the maximum rate of growth of the indicator, its values turned out to be quite close for tropical climatic conditions and somewhat different for a temperate climate.
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Cavallaro, Kathleen F., Jeannot Francois, Roody Jacques, Derline Mentor, Idrissa Yalcouye, Karen Wilkins, Nathan Mueller, Rebecca Turner, Aaron Wallace, and Rania A. Tohme. "Demonstration of the Use of Remote Temperature Monitoring Devices in Vaccine Refrigerators in Haiti." Public Health Reports 133, no. 1 (December 20, 2017): 39–44. http://dx.doi.org/10.1177/0033354917742119.
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After the 2010 earthquake, Haiti committed to introducing 4 new antigens into its routine immunization schedule, which required improving its cold chain (ie, temperature-controlled supply chain) and increasing vaccine storage capacity by installing new refrigerators. We tested the feasibility of using remote temperature monitoring devices (RTMDs) in Haiti in a sample of vaccine refrigerators fueled by solar panels, propane gas, or electricity. We analyzed data from 16 RTMDs monitoring 24 refrigerators in 15 sites from March through August 2014. Although 5 of the 16 RTMDs exhibited intermittent data gaps, we identified typical temperature patterns consistent with refrigerator door opening and closing, propane depletion, thermostat insufficiency, and overstocking. Actual start-up, annual maintenance, and annual electricity costs for using RTMDs were $686, $179, and $9 per refrigerator, respectively. In Haiti, RTMD use was feasible. RTMDs could be prioritized for use with existing refrigerators with high volumes of vaccines and new refrigerators to certify their functionality before use. Vaccine vial monitors could provide additional useful information about cumulative heat exposure and possible vaccine denaturation.
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Ayou, Dereje S., and Valerie Eveloy. "Integration of Municipal Air-Conditioning, Power, and Gas Supplies Using an LNG Cold Exergy-Assisted Kalina Cycle System." Energies 13, no. 18 (September 4, 2020): 4599. http://dx.doi.org/10.3390/en13184599.
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A Kalina cycle-based integration concept of municipal air-conditioning, electricity and gas is investigated thermodynamically, economically, and environmentally to reduce the carbon intensity of these supplies, with attention to hot climatic conditions. The proposed poly-generation system is driven by low-grade renewable or surplus heat, and utilizes waste exergy from liquefied natural gas vaporization for refrigeration and power augmentation. At nominal conditions (130 °C driving heat), approximately 561 and 151 kJ of refrigeration and useful power per kg of liquefied natural gas regasified are generated by the proposed system, respectively, at effective first-law and exergetic efficiencies of 33% and 35%, respectively. The Kalina sub-system condenser cryogenic heat rejection condition is found to triple the system useful electrical output compared with high ambient temperature condenser heat sinking conditions. Per million ton per annum of liquefied natural gas vaporization capacity, yearly net power savings of approximately 74 GWhe could be achieved compared to standard air-conditioning, electricity, and gas supply systems, resulting in 11.1 kton of natural gas saved and 30.4 kton of carbon dioxide-equivalent emissions avoided annually. The yearly net monetary savings would range from 0.9 to 4.7 million USD per million ton per annum of liquefied natural gas regasified at local subsidized and international electricity market prices, respectively, with corresponding payback periods of 1.7 and 2.5 years, respectively.
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Im, Piljae, Xiaobing Liu, and Hugh Henderson. "Operational Performance Characterization of a Heat Pump System Utilizing Recycled Water as Heat Sink and Heat Source in a Cool and Dry Climate." Energies 11, no. 1 (January 16, 2018): 211. http://dx.doi.org/10.3390/en11010211.
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The wastewater leaving from homes and businesses contains abundant low-grade energy, which can be utilized through heat pump technology to heat and cool buildings. Although the energy in the wastewater has been successfully utilized to condition buildings in other countries, it is barely utilized in the United States, until recently. In 2013, the Denver Museum of Nature & Science at Denver, the United States implemented a unique heat pump system that utilizes recycled wastewater from a municipal water system to cool and heat its 13,000 m2 new addition. This recycled water heat pump (RWHP) system uses seven 105 kW (cooling capacity) modular water-to-water heat pumps (WWHPs). Each WWHP uses R-410A refrigerant, has two compressors, and can independently provide either 52 °C hot water (HW) or 7 °C chilled water (CHW) to the building. This paper presents performance characterization results of this RWHP system based on the measured data from December 2014 through August 2015. The annual energy consumption of the RWHP system was also calculated and compared with that of a baseline Heating, Ventilation, and Air Conditioning (HVAC) system which meets the minimum energy efficiencies that are allowed by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1-2013. The performance analysis results indicate that recycled water temperatures were favorable for effective operation of heat pumps. As a result, on an annual basis, the RWHP system avoided 50% of source energy consumption (resulting from reduction in natural gas consumption although electricity consumption was increased slightly), reduced CO2 emissions by 41%, and saved 34% in energy costs as compared with the baseline system.
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Radchenko, Mykola, Andrii Radchenko, Roman Radchenko, Serhiy Kantor, Dmytro Konovalov, and Victoria Kornienko. "Rational loads of turbine inlet air absorption-ejector cooling systems." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, September 9, 2021, 095765092110454. http://dx.doi.org/10.1177/09576509211045455.
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An increase in gas turbine efficiency is possible by inlet air cooling in chillers converting a heat of exhaust gas into refrigeration. In traditional absorption lithium-bromide chillers of a simple cycle an inlet air can be cooled to 15°С. More decrease of turbine inlet air temperature and greater fuel saving accordingly is possible in refrigerant ejector chiller as a simple in design and cheap. The innovative turbine inlet air cooling (TIC) system with absorption chiller as a high-temperature and ejector chiller as a low-temperature stages for cooling air to 7 or 10 °C is proposed. Its application in temperate climate provides annual fuel saving by 1.5 to 2 times higher compared with traditional air cooling in absorption chiller to 15 °C. A novel universal method of analysing the efficiency of TIC system operation and rational designing has been developed. The method involves the simple numerical simulation based on real input data of site actual climatic conditions. The annual fuel saving is chosen as a primary criterion. The novelty of the methodological approach consists in replacing the current yearly changeable fuel reduction due to TIC by its hour-by-hour summation as an annual fuel saving. The increment of annual fuel saving referred to needed refrigeration capacity of TIC system is used as an indicator to select a design refrigeration capacity. A rational design refrigeration capacity determined by applying the novel methodology allows to decrease the TIC system sizes by 10 to 20% compared with traditional designing issuing from the peaked thermal load during a year. So far as it was developed analytically by introducing quite reasonable criterion indicator and based on the simple summation procedure the method is quite applicable for designing in power and energy.
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Syngounas, Evangelos, Dimitrios Tsimpoukis, Maria K. Koukou, and Michail Gr Vrachopoulos. "Integration of a solar-powered absorption chiller for performance enhancement of a supermarket CO2 refrigeration plant." Green Energy and Sustainability, February 20, 2022, 1–24. http://dx.doi.org/10.47248/ges2202010003.
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CO2 refrigeration configurations are the most viable solution for commercial refrigeration plants, which are however accompanied with energy challenges due to their low energy efficiency when operating under high ambient temperatures. This study examines the coupling of a CO2 booster system with a solar absorption chiller, used to sub-cool the CO2 of the main cycle. The refrigeration system under study is projected to cover the cooling requirements of a supermarket refrigeration plant with an installed capacity of 80 kWR for the medium and 20 kWR for the low-temperature circuit, in the region of Athens, Greece. The investigated process involves utilization of an absorption chiller module with 60 kWR of cooling capacity working with a LiBr-H20 pair powered by heat produced in fifty evacuated-tube solar collectors with a total collecting area of 115 m2. The energy performance analysis was based on validated numerical models developed in MATLAB using the CoolProp library. Through parametric analysis the coefficient of performance (COP) of the proposed topology was compared to the COP of a conventional booster system under constant low (450 W/m2) and high (800 W/m2) incident solar radiation for the temperature range 1–40 °C, resulting in maximum COP increments of 26.44% and 47.34% respectively. Performance simulation on an annualized basis was also conducted, by using the average hourly values of ambient temperature and solar radiation for every month of the year. The results showed that in comparison to the conventional booster system, the sub-cooling rates achieved a maximum increment of COP of 47.48% hourly and 16.36% monthly for August which is the warmest month of the year. Annual electricity consumption decreased by 8.93%, resulting in an energy savings of 30.19 MWh/year.
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Syngounas, Evangelos, Dimitrios Tsimpoukis, Maria K. Koukou, and Michail G. Vrachopoulos. "Energetic, exergetic and financial evaluation of a solar-powered absorption chiller integration into a CO2 commercial refrigeration system." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, March 29, 2022, 095765092210775. http://dx.doi.org/10.1177/09576509221077540.
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This study investigates the integration of a solar absorption chiller by means of subcooling to a CO2 booster system that serves the refrigeration needs of a supermarket refrigeration plant with an installed capacity of 80 kW and 20 kW for medium and low-temperature regimes, respectively. The proposed energy saving configuration is analyzed in an energetic, exergetic, and financial manner, using the climatic data for the city of Athens, Greece. The current approach constitutes the theoretical reference for the actual implementation of this novelty either in new plants or as a retrofit in existing ones. The proposed solution includes the employment of a single-stage absorption chiller operating with LiBr–H20 working pair, which is driven by heat produced in evacuated tube collectors installed in the store’s rooftop. The energy analysis is conducted with validated numerical models that are developed in MATLAB using the CoolProp library. The collecting area and the corresponding chiller capacity of the proposed configuration are selected through financial evaluation. More specifically, the collecting area is analyzed parametrically from 25 m2 to 200 m2. Finally, 100 m2 of collecting area with 60 kW of chiller capacity are proved to be the optimum solution financially with 8.4 years payback period and 44.57 k€ net present value. This optimum solution results in an annual power consumption decrease of 8.12% which leads to energy savings of 27.45 MWh/year.
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Mokheimer, Esmail M. A., and Yousef N. Dabwan. "Performance Analysis of Integrated Solar Tower With a Conventional Heat and Power Co-Generation Plant." Journal of Energy Resources Technology 141, no. 2 (September 26, 2018). http://dx.doi.org/10.1115/1.4041409.
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This paper presents the results of a thermo-economic analysis of integrating solar tower (ST) with heat and power cogeneration plants that is progressively being installed to produce heat and electricity to operate absorption refrigeration systems or steam for industrial processes. The annual performance of an integrated solar-tower gas-turbine-cogeneration power plant (ISTGCPP) with different sizes of gas turbine and solar collector's area have been examined and presented. Thermoflex + PEACE software's were used to thermodynamically and economically assess different integration configurations of the ISTGCPP. The optimal integrated solar field size has been identified and the pertinent reduction in CO2 emissions due to integrating the ST system is estimated. For the considered cogeneration plant (that is required to produce 81.44 kg/s of steam at 394 °C and 45.88 bars), the study revealed that (ISTGCPP) with gas turbine of electric power generation capacity less than 50 MWe capacities have more economic feasibility for integrating solar energy. The levelized electricity cost (LEC) for the (ISTGCPP) varied between $0.067 and $0.069/kWh for gas turbine of electric power generation capacity less than 50 MWe. Moreover, the study demonstrated that (ISTGCPP) has more economic feasibility than a stand-alone ST power plant; the LEC for ISTGCPP is reduced by 50–60% relative to the stand-alone ST power plant. Moreover, a conceptual procedure to identify the optimal configuration of the ISTGCPP has been developed and presented in this paper.