Performance Research of Air-Cooled Heat Pump for Small Residential

2012 ◽  
Vol 516-517 ◽  
pp. 1180-1183
Author(s):  
Hui Fan Zheng ◽  
Chun Li Yang ◽  
Yan Hua Li ◽  
Yao Hua Liang

An experimental setup is designed and built to study the operation characteristics of the air-cooled heat pump system for small residential in this paper. Based on the experimental setup, the characteristics of the energy efficiency ratio(EER) and cooling capacity have been researched when the outlet temperature of cooling water and outdoor environment temperature change. The experimental data demonstrate that the cooling capacity and EER of the system increases with increasing outlet cooling water temperatures and decreases with increasing outdoor environment temperatures. In addition, the correlation of the system EER is calculated by using the least square method based on the experimental data.

2012 ◽  
Vol 614-615 ◽  
pp. 682-687
Author(s):  
Wen Hui Zhang ◽  
Zhe Wang ◽  
Yi Gong ◽  
Xue Hong Wu ◽  
Yan Li Lu

The performance of the CO2 trans-critical system is affected significantly not only by optimal system pressure but also by instantaneous ambient temperatures. This paper presents the results of a study carried out to elucidate the influence of the source and sink temperatures on the experimental research of a CO2 trans-critical refrigeration and heat pump system which used a new dual expansion valve and a balance CO2 liquid receiver adjustment device. The unit had been fully tested along a multistate experimental study, at various evaporating temperatures and different gas cooler outlet pressures. The results showed that: the source and sink temperatures rose from 15°C to 25°C, trans-critical CO2 systems COPH average increase of 4.4% each 5°C, but COP decrease of 6.8%. The influence of the source temperature on the chilled water outlet temperature which is less than the sink temperature. The effect of the source or sink temperature on the cooling water outlet temperature to average every 5°C to change the range of from 0.7°C to 1.9°C.


2021 ◽  
Vol 245 ◽  
pp. 01025
Author(s):  
Han Wang ◽  
Dali Yu ◽  
Chi Xu ◽  
Muhammad Salman Khan ◽  
Yunqing Bai

Small Modular Lead-based Reactor (SMLR) has generated great interest in academic research all around the world due to its good safety characteristics and relatively high core outlet temperature. In this paper, a Combined Cooling Heating and Power (CCHP) system with usage of absorption heat pump, which couples with a SMLR, was proposed to fulfill the energy demands in remote areas. Thermodynamic analysis was implemented to improve the performance of the CCHP system based on SMLR. To meet the remote areas’ energy needs, the main parameters and mass flow rate of a 35 MWth SMLR design were analyzed. The SMLR CCHP with absorption heat pump system can provide electric power 12.5MWe, heating 9.5MWh, and cooling 2.54MWc. The total energy utilization efficiency of the system can be 69.12 %. This work can provide a reference in the design and optimization of the CCHP system to meet the energy demands in the remote areas.


2020 ◽  
Vol 17 (2) ◽  
pp. 78-86
Author(s):  
M.K. Bezrodny ◽  

The paper studies application feasibility and energy efficiency of the ventilation and air conditioning heat pump system for maintaining comfort conditions inside the production area with an excessive internal moisture generation during the warm season. In this regard, a thermodynamic analysis of a heat pump system with a partial exhaust air recirculation and a variable ratio of fresh outside air was carried out. Numerical analysis was then done to estimate the influence of changes in the environment temperature and relative humidity and the characteristics of the ventilation and air conditioning object on the system parameters. This allowed to determine potential capabilities of this system to maintain comfortable conditions in the production area. It was also shown that the required additional cooling of the supply air at the entrance to the premise for air conditioning demands can be determined by a simple coefficient and its calculation method is provided in the article. The heat pump system of temperature and humidity maintenance has the highest energy efficiency in the zone of relatively low environment temperatures and largely depends on the relative humidity of the outside air. This suggests that the studied system is suitable for application in countries with temperate continental climate.


2010 ◽  
Vol 121-122 ◽  
pp. 986-991
Author(s):  
Jing Gang Wang ◽  
Xiao Xia Gao ◽  
Bo Liang ◽  
Hua Hui Zhou

A large number of cooling water exists in chemical plant, use water source heat pump and lithium bromide absorption heat pump system to achieve water cooling instead of cooling tower, at the same time, extract heat for building cooling and heating. Respectively introduced the summer cooling system and winter heating system, and a feasibility analysis was carried out. The conclusion is get: water source heat pump system and lithium bromide absorption heat pump system for cooling water waste heat recovery is certain feasibility; the environment optimization can be achieved in chemical plant, at the same time, energy conservation and emission reduction is realized.


2009 ◽  
Vol 20 (4) ◽  
pp. 517-532 ◽  
Author(s):  
Guozhong Zheng ◽  
Youyin Jing

Water source heat pumps have outstanding advantages: significant energy conservation, working stability and notable pollution reduction. In this paper, the benefits and features of the water source heat pump are described. Then the methodology for studying the thermodynamics performance in variant conditions is described and the thermodynamics analysis of a specific water source heat pump is presented based on the first law of thermodynamics and exergy analysis theory to study the thermodynamics performance in variant condition. Coefficient of Performance (COP) and exergy efficiency in variant operating condition are calculated. The relation of COP and exergy efficiency with the outlet temperature of the chilled water and the inlet temperature of the cooling water are respectively studied. The operating strategies of both summer and winter condition are then concluded. Finally, the thermodynamics performance of the water source heat pump is compared with the other common refrigerating and heating equipments. It is concluded that the water source heat pump has great advantage over others in terms of energy saving. It is expected that the study would be beneficial to the researchers and engineers.


Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3883
Author(s):  
Jorge E. De León-Ruiz ◽  
Ignacio Carvajal-Mariscal ◽  
Antonin Ponsich

The present work conducts an evaluation of the feasibility and the overall performance and consequent optimization of a direct expansion solar assisted heat pump (DXSAHP) employed for domestic water heating. For the study conducted R134a, R404A, R407C and R410A working fluids were evaluated as well as the use of four, six and eight flat-plate solar collectors and a worktime ranging from 1 to 6 h. The case study is based in Mexico City with a 300 L container and a hot water outlet temperature of 51 °C. The paper introduces a new evaluation criterion based on the thermal capacity and all the evaluations conducted throughout this research revolve around this performance metric. The results show that, the system would require at least 4 h of operation to achieve the outlet temperature. Additionally, it was found that the R410A refrigerant has the best heat transfer properties; with an average condensation heat rate of 6.31 kW, followed by the R407C with 5.72 kW, the R404A with 5.42 kW and the R134a with 5.18 kW. Diversely, the R134a refrigerant requires 0.402 kW of compression work, 62% less than the R410A, which requires 1.06 kW. Consequently, R134a delivers the highest COP, which ranges from 7 to 14, followed by the R407C and R404A refrigerants, which present a similar behaviour between them, with COP ranging from 5 to 9 and 4 to 8, respectively, and finally the R410A, achieving the lowest COP, ranging from 3.5 to 6.5. Moreover, it was found that the R134a presents a higher dispersion regarding the energy exchange rate, which reveals that it is the fluid most susceptible to external factors, such as the weather. Contrarily, the remaining refrigerants present a more consistent performance. Finally, the optimization revealed that the R407C refrigerant is the most suitable given that it requires 20% less compression work than the R404A. This provides the heat pump system with a steadier behaviour, a COP ranging from 7 to 8, 30% higher than R410A, a worktime decrease of 1.5 h and heat transfer area of 5.5 flat-plate solar collectors, equivalent to a 31% reduction, both compared to R134a.


2010 ◽  
Vol 171-172 ◽  
pp. 67-72
Author(s):  
Yong Lan Yin ◽  
Qing Gao ◽  
Bai Fa Zhu ◽  
Ming Li

To extend the area in applications of solar heat pump and drainwater heat recovery, the gravity film exchanger was employed to establish the solar assisted drainwater heat pump system. In this paper, two gravity film exchangers were assembled in the hybrid heat pump system to discuss the effect of water distribution ratio in two exchangers on the electric power complement and outlet water temperature of the condenser. The technology of Matlab/Simulink was used in modeling and simulations of the system by the performance curves and performance parameters of the corresponding system components. In the designing processes, the dynamic characteristics can be predicted, and the optimal operating conditions can also be concluded that appropriate water distribution ratio should be selected respectively for higher outlet temperature of the condenser or lower electric power complement.


2021 ◽  
pp. 353-353
Author(s):  
Xiaoya Ji ◽  
Guoyuan Ma ◽  
Feng Zhou ◽  
Lei Wang ◽  
Guoqiang Wu ◽  
...  

Based on the simulation results of the typical rural ultra-low energy building (ULEB) in 5 different climatic regions of China, three indicative technical parameters for paralleled-loop exhaust air heat pump (PEAHP) R&D- which are nominal heating/cooling capacity, maximum required fresh air to return air ratio (MFRR) and system energy efficiency grades- were calculated and summarized according to the demand of indoor thermal comforts by using statistic method. The nominal heating/cooling capacities were determined according to the peak loads, which are 6.84/2.01kW, 5/2.96 kW, 3.9/4.6 kW, 3.08/5.02 kW and 3.4/0.46 kW in the ULEB of Harbin, Beijing, Shanghai, Guangzhou and Kunming respectively. To ensure both thermal comforts and energy conservation, during the heating season, full fresh air supply is suggested in Beijing and the 1:0.5 MFRR is suggested in Harbin, Shanghai, Guangzhou and Kunming. During the cooling season, the 1:5 MFRR is suggested in Shanghai and Guangzhou, the 1:3, 1:1.5 and 1:0.5 MFRR are suggested in Harbin, Beijing and Kunming respectively. The PEAHP energy efficiency grades 1~5 are 7.92~11.7, 7.58~11.5, 7.5~11.35, 6.12~9.27 and 4.64~7.03 during the heating season of Harbin, Beijing, Shanghai, Guangzhou and Kunming respectively, and are 2.33~3.54, 3.93~5.96, 4.61~6.98, 4.62~6.99 and 2.04~3.1 for the cooling season respectively.


2021 ◽  
Vol 13 (6) ◽  
pp. 3464
Author(s):  
Hélio A. G. Diniz ◽  
Tiago F. Paulino ◽  
Juan J. G. Pabon ◽  
Antônio A. T. Maia ◽  
Raphael N. Oliveira

This paper presents a distributed mathematical model for a carbon dioxide direct expansion solar-assisted heat pump used to heat bath water. The main components are a gas cooler, a needle valve, an evaporator/collector, and a compressor. To develop the heat exchange models, mass, energy, and momentum balances were used. The model was validated for transient as well as steady state conditions using experimental data. A reasonably good agreement was observed between the predicted temperatures and experimental data. The simulations showed that the time step required to demonstrate the behavior of the heat pump in the transient regime is greater than the time step required for the steady state. The results obtained with the mathematical model revealed that a reduction in the water mass flow rate results in an increase in the water outlet temperature. In addition, when the carbon dioxide mass flow rate is reduced, the compressor inlet and outlet temperatures increase as well as the water outlet temperature.


Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 553 ◽  
Author(s):  
Muhammad Kashif Shahzad ◽  
Mirza Abdullah Rehan ◽  
Muzaffar Ali ◽  
Azeem Mustafa ◽  
Zafar Abbas ◽  
...  

This paper presents an experimental evaluation of a closed loop lake water heat pump (LWHPs) system based on the slinky coiled configuration. Initially, a mathematical model is developed in the Engineering Equation Solver (EES) for the heat pump system and the submerged coils in a lake. System performance is determined for the submerged slinky copper coils under the various operating conditions. Afterwards, parametric analysis is performed considering different influencing parameters, such as the lake water temperature, ambient temperature, and mass flow rate of the circulating fluid at constant lake depth of 4 ft. The experimental setup is developed for 3.51 kW cooling capacity after cooling load calculation for a small room. In the current study, slinky copper coils are used to exchange heat with lake water. The experimental setup is installed in Taxila, Pakistan, and the system’s performance is analyzed during selected days. After experimentation based on hourly and daily operation characteristics, it is observed that the lake water temperature has significant influence on the heat transfer rate between slinky coil and lake water. While the lake water temperature in summer decreases and increases in winter with the depth. The resulted daily average coefficient of performance (COP) of the system is within the range of 3.24–3.46 during the selected days of cooling season. Based on these results, it can be concluded that the LWHP systems can be considered a viable solution for Pakistan having a well-established canal system.


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