SIMULATION ON OPERATION CHARACTERISTICS OF HYBRID GROUND-AIR SOURCE HEAT PUMP SYSTEM WITH NATURAL COLD STORAGE

2014 ◽  
Vol 22 (02) ◽  
pp. 1440004 ◽  
Author(s):  
Z. W. HAN ◽  
X. MENG ◽  
M. LIN ◽  
Y. H. ZHANG ◽  
J. YANG ◽  
...  
Keyword(s):  
Heat Pump ◽  
Cold Storage ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Air Source Heat Pump ◽  
Operational Life ◽  
Vapor Compression Refrigeration Cycle ◽  
Set Up ◽  
Operation Characteristics

To solve the problem of the coefficient of performance (COP) decrease and power crunch in cooling dominated South China associated with the long-term usage of ground-source heat pump system (GSHPS), a hybrid ground-air source heat pump system (HGASHPS) with natural cold storage is presented in this paper. The system consists of a GSHP system and compound air-cooled chillers (CACC), which can be operated according to the vapor compression refrigeration cycle or separate type heat pipe natural cycle. The mathematical models of each part of the system were set up and the conversion conditions between operation modes for the system were determined. The transient simulation for HGASHPS with natural cold storage in Nanjing was carried out. The operation characteristics of the systems in operational life were comparatively analyzed. The simulation results indicated that the HGASHPS with natural cold storage could retain the thermal balance of soil temperature field in one year cycle and increase the COP and reliability of the system.

scholarly journals Frosting Phenomenon and Frost-Free Technology of Outdoor Air Heat Exchanger for an Air-Source Heat Pump System in China: An Analysis and Review

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2642 ◽  
Author(s):  
Yi Zhang ◽  
Guanmin Zhang ◽  
Aiqun Zhang ◽  
Yinhan Jin ◽  
Ruirui Ru ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Operating Cost ◽  
Heating System ◽  
Coefficient Of Performance ◽  
Outdoor Air ◽  
Pump System ◽  
Heat Pump System ◽  
Reduce Operating Cost ◽  
Air Source Heat Pump

Frost layer on the outdoor air heat exchanger surface in an air-source heat pump (ASHP) can decrease the system coefficient of performance (COP). Although the common defrosting and anti-frosting methods can improve the COP, the periodic defrosting not only reduces the system energy efficiency but also deteriorates the indoor environment. To solve these problems, it is necessary to clearly understand the frosting phenomenon and to achieve the system frost-free operation. This paper focused firstly on the analyses of frosting pathways and frosting maps. Followed by summarizing the characteristics of frost-free technologies. And then the performances of two types of frost-free ASHP (FFASHP) systems were reviewed, and the exergy and economic analysis of a FFASHP heating system were carried out. Finally, the existing problems related to the FFASHP technologies were proposed. Results show that the existing frosting maps need to be further improved. The FFASHP systems can not only achieve continuous frost-free operation but reduce operating cost. And the total COP of the FFASHP heating system is approximately 30–64% higher than that of the conventional ASHP system under the same frosting conditions. However, the investment cost of the FFASHP system increases, and its reliability also needs further field test in a wider frosting environment. In the future, combined with a new frosting map, the control strategy for the FFASHP system should be optimized.

Heating Performance Investigations on Two Applications of a Solar Assisted Air Source Heat Pump System

2011 ◽  
Vol 374-377 ◽  
pp. 284-287 ◽  
Author(s):  
Yu Wang ◽  
Yu Wen You ◽  
Zhi Gang Zhang
Keyword(s):  
Heat Pump ◽  
Solar Collector ◽  
Coefficient Of Performance ◽  
Experimental Investigations ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Performance ◽  
Air Source Heat Pump

A solar assisted air source heat pump (SAASHP) system is proposed to improve heating performance of air source heat pump (ASHP).The proposed system has been applied in two buildings, a series of experimental investigations were conducted in the both applications, it indicated that the SAASHP system gets better heating performance than ASHP system, the coefficient of performance (COP) gets 10% and 65% increase respectively in two applications. It is also concluded that the ratio of solar collector area to construction area significantly affects the improvement of heating performance in SAASHP system. This work may promote further research and more applications of SAASHP system.

The Comparison of Experiment Results and CFD Simulation in the Heat Pump System Using Thermobank and Two-Phase Ejector for Heating Room and Cold Storage

2016 ◽  
Vol 24 (01) ◽  
pp. 1650004 ◽  
Author(s):  
Le Ngoc Cuong ◽  
Jong-Taek Oh
Keyword(s):  
Heat Pump ◽  
Cold Storage ◽  
Cfd Simulation ◽  
Waste Heat ◽  
Coefficient Of Performance ◽  
Two Phase ◽  
Pump System ◽  
Heat Pump System ◽  
Dimension Formula ◽  
Floor Panel

In this paper, the heat pump system has been developed by CFD simulation and experimental investigation. It studies the thermal behavior of a thermobank and COP on heat pump system and cold storage. The thermobank stores the waste heat of during refrigeration cycles and this energy is used for defrosting process and heating room. It also reduces defrosting time and condensation load so that the temperature regulation in the cold storage is constant. The system is investigated experimentally and CFD simulated under thermobank. The dimension [Formula: see text] of cold storage is [Formula: see text][Formula: see text]m, thermobank is [Formula: see text][Formula: see text]mm. The temperature of ambient on CFD simulation process is 20[Formula: see text]C. This heat pump system can be used to keep preservation of agricultural products in cold storage warehouse together with floor panel heating for room in winter. The ejector is used in system with the aim of increasing coefficient of performance (COP) and decrease in compressor displacement. As the experimental results, its COP is increased about 38.57% when using thermobank and ejector in heat pump system.

Development of Heat Pump System Using Thermobank and Ejector for Heating Room and Cold Storage

2015 ◽  
pp. 784-802
Author(s):  
Jong-Taek Oh ◽  
Cuong Ne Ngoc
Keyword(s):  
Experimental Investigation ◽  
Heat Pump ◽  
Cold Storage ◽  
Temperature Regulation ◽  
Cfd Simulation ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Simulation Process ◽  
Wasted Heat

In this study, heat pump system has been developed by CFD simulation and experimental investigation. It studies the thermal behavior of a thermobank and COP on heat pump system and cold storage. The thermobank stores the wasted heat of during refrigeration cycles and its energy is used for defrosting process and heating room. It also reduces defrosting time and condensation load so that the temperature regulation in the cold storage is constant. The system is investigated experimentally and CFD simulated under thermobank. The dimension L×W×H of cold storage is 3×1,6×1,4 m, thermobank is 600×300×400mm. The temperature of ambient on CFD simulation process is 150C.This heat pump system can be used to keep preservation of agricultural products in cold storage warehouse together with floor panel heating for room in winter. The ejector is used in system which the purpose increases in coefficient of performance (COP) and decrease in compressor displacement. As the calculated results, its COP is increased about 38% when using thermobank and ejector in heat pump system.

Ejector Influence on Performance of Ammonia Absorption Heat Pump System

2012 ◽  
Vol 163 ◽  
pp. 107-110
Author(s):  
Wei Sheng ◽  
Xiu Fang Liu ◽  
Xiao Zhuan Chen ◽  
Hua Wang
Keyword(s):  
Performance Analysis ◽  
Heat Pump ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Absorption Heat Pump ◽  
Heat Pump System ◽  
Ammonia Absorption ◽  
Single Effect ◽  
Set Up

A single-effect ammonia absorption-ejection heat pump system is set up. Combined with T-S diagram, performance analysis is presented on the heat pump system with ejector or without ejector. The results show that, with the ejector coefficient equal to 0.5, and the cooling coefficient of performance of the single-effect ammonia absorption heat pump equal to 0.3, 0.45 and 1.45 can at least be gained for the heating coefficient of performance and the cooling coefficient of performance respectively. In this paper, relation curve diagram is also presented for the heating coefficient of performance of absorption-ejection heat pump system, the cooling coefficient of performance of single-effect absorption heat pump system and the ejector coefficient.

scholarly journals Experimental Study on the Performance of a Household Dual-Source Heat Pump Water Heater

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2811 ◽  
Author(s):  
Xiang Gou ◽  
Shian Liu ◽  
Yang Fu ◽  
Qiyan Zhang ◽  
Saima Iram ◽  
...  
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Coefficient Of Performance ◽  
Water Heater ◽  
Pump System ◽  
Heat Pump System ◽  
Air Source Heat Pump ◽  
Heat Pump Water Heater ◽  
Dual Source ◽  
Bath Water

A household dual source heat pump water heater is proposed to utilize the energy of wastewater and air heat in a bathroom. The heat pump system integrates a wastewater source heat pump (WSHP), air source heat pump (ASHP), and a preheater. This aims at energy saving through recovering the heat of wastewater and ventilation air during the bathing process. The experiment was conducted to verify the feasibility of a dual heat source heat pump water heater system in a bath unit. It is found that the system can achieve an average coefficient of performance (COP) of 4.80 and 4.38 with and without preheater, respectively. At a bath water temperature of 40 °C, a flow rate of 6 L/min, and a room temperature of 26.5 °C, the COP of system can reach 6.08, which shows a significantly promising method for energy saving in-house.

Simulative Study on Solar-Assisted Air Source Heat Pump System

2013 ◽  
Vol 671-674 ◽  
pp. 2141-2144 ◽  
Author(s):  
Qiang Wang ◽  
Feng Zhen Liu ◽  
Li Jun Hou ◽  
Jian Hua Gao
Keyword(s):  
Heat Pump ◽  
Operating Conditions ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Pump Unit ◽  
Pump System ◽  
Heat Pump System ◽  
Air Source Heat Pump ◽  
Heat Pump Unit ◽  
The Stability

A solar assisted air source heat pump unit is designed. The mathematical model of the unit is established and two hybrid operating conditions of the system are simulated. The simulative studying results shows that in winter the solar assisted air source heat pump unit can make full use of solar energy and the coefficient of performance (COP) of air source heat pump can be improved. In summer the cooling heat of air source heat pump could be recovered to improve the stability of solar hot water collector and the COP of the air source heat pump unit is greatly improved. The performance of solar assisted air source heat pump unit is better than that of with no solar assisted air source heat pump.

scholarly journals Design and Performance Evaluation of a Heat Pump System Utilizing a Permanent Dewatering System

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2273
Author(s):  
Seung-Hoon Park ◽  
Yong-Sung Jang ◽  
Eui-Jong Kim
Keyword(s):  
Energy Source ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Large Scale ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Air Source Heat Pump ◽  
And Performance

The earth provides a vast resource of groundwater from aquifers a few meters beneath the surface. Thus, buildings that use underground space must be equipped with dewatering wells to drain the permeated groundwater to the sewage pipelines to ensure the structural stability of the building. Although the inflowing groundwater temperatures and flow rates are stable enough for groundwater to be used as an energy source, 79% of the permeated groundwater is discarded through the sewers, generating significant sewerage expenses. This study introduced a novel heat exchanger module to utilize the permeated groundwater as an unused energy source using heat pumps, and the performance of the system was evaluated by TRNSYS simulations. First, the sizing of the unit heat exchanger module was proposed according to the mean inflow rate of the permeated groundwater. Second, the heat pump system was configured using multiple modules in the source-side loop. Finally, the performance of the proposed heat pump system was compared with that of a conventional air source heat pump using realistic load and temperature profiles. This preliminary study demonstrated interesting performance results, with a coefficient of performance for heating that was higher than that of a conventional heat pump system by 0.79. The results show the potential utilization of the systems for a construction project requiring large-scale underground spaces, where abundant groundwater is available.

scholarly journals An Experimental Study on External Ventilation to the Heating Performance of Household Air Source Heat Pump

2021 ◽  
Vol 9 ◽  
Author(s):  
Hang Zou ◽  
Zhanqiang Liu ◽  
Enshen Long
Keyword(s):  
Heat Pump ◽  
Great Influence ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Performance ◽  
Air Source Heat Pump ◽  
Ventilation Condition ◽  
Ventilation Conditions

The external ventilation conditions have a great influence on the heating performance of the air source heat pump (ASHP) systems. The outdoor units of residential household air source heat pumps are often installed in narrow spaces such as balconies. The ventilation conditions of the outdoor unit will influent the heating performance of the air source heat pump. It is necessary to study the effect of the outdoor unit ventilation conditions on the heating performance of residential household heat pumps. This paper experimentally studied the heating performances of an air source heat pump system with the outdoor unit mounted in a balcony in different external ventilation conditions. The results indicate that the ventilation conditions for the outdoor units have a significant effect on the heating performance of the system. When the inlet of the outdoor unit was close to the sliding door and completely blocked, the ventilation environment was the worst and the coefficient of performance (COP) was the lowest. In addition, the unfavorable ventilation environment could result in a reduction of the COP by 26.2%. When the inlet of the outdoor unit was partially blocked, the heating performance could be improved and the COP was also slightly improved. The great heating performance was obtained under the cross-ventilation condition. This paper can guide the design of the installation position of the household air source heat pump outdoor units in actual engineering.

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