Comparison of mechanical vapor recompression technology for solution regeneration in heat-source tower heat pumps

2018 ◽  
Vol 40 (3) ◽  
pp. 360-378
Author(s):  
Songhui Ai ◽  
Baolong Wang ◽  
Xianting Li ◽  
Wenxing Shi
Keyword(s):  
Heat Source ◽  
Heat Pump ◽  
Coefficient Of Performance ◽  
Normal Operation ◽  
Regeneration System ◽  
Pump System ◽  
Heat Pump System ◽  
Single Effect ◽  
Vapor Recompression ◽  
Regeneration Systems

Solution regeneration of the heat-source tower is significant to guarantee the normal operation of the heat-source tower. Mechanical vapor recompression system is an efficient system for evaporation of solution. In this paper, mechanical vapor recompression system is applied to regenerate solution of heat-source tower. To clarify the merits of mechanical vapor recompression solution regeneration system, several typical solution regeneration systems are modelled. As a result, mechanical vapor recompression shows 35.7%, 73.5% and 91.2% energy saving compared to air-driven heat pump, three-effect evaporating system, and single effect evaporating system, respectively. Furthermore, a heat-source tower heat pump with solution generation system is installed in a typical building in Yangtze river region. The whole heating season performance is simulated to find the effects of different solution regeneration system on the whole heat pump system. As a conclusion, the seasonal coefficient of performance of heat pump is decreased 1.6% by mechanical vapor recompression regeneration system. Comparatively, the seasonal coefficient of performance of heat pump is decreased 2.6%, 4.2% and 10.0% by air-driven heat pump, three-effect evaporating system, and single effect evaporating system, respectively. Practical application: Solution regeneration systems for heat-source tower heat pump systems have been applied in building projects especially in hot summer and cold winter zone in China based on previous investigation. A heat-source tower heat pump system combined with heat pump solution regeneration system has been applied in an office building in Changsha, Hunan Province in China. And its practical operation energy consumption has been reduced obviously compared with traditional single effect evaporation system. Therefore, it is of vital importance to demonstrate the operating performance of different solution regeneration systems applied in heat-source tower heat pump systems in building.

Air-water heat pump applied as water boiler in single-family house, coefficient of performance analysis under the real conditions

2018 ◽  
Vol 3 (2) ◽  
pp. 58-61
Author(s):  
Agnieszka Lisowska-Lis ◽  
Robert Leszczyński
Keyword(s):  
Heat Source ◽  
Heat Pump ◽  
Air Temperature ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Single Family ◽  
Pump System ◽  
Heat Pump System ◽  
System Temperature ◽  
Family House

The subject of the research was an air-water heat pump, model PCUW 2.5kW from HEWALEX, installed in a single-family house. The pump is only used for heating water. The research was carried out from 25-08-2017 to 18-09-2017 in the village of Zborowice, in Malopolska region, Poland. The data were recorded from the heat pump system: temperature of the lower heat source (external air), temperature of the upper heat source (water temperature in the tank), time of heat pump was calculated during the analysed cycle of work and electrical energy consumption. The Coefficient Of Performance (COP) of the analysed air-water heat pump was determined. The analysis of the results was carried out using the MATLAB and EXCEL statistical tools. The correlation between COP coefficient and external air temperature is strong: 0.67.

Effective Utilization System of Unused Energy in Aquarium

2003 ◽  
Author(s):  
Satoru Okamoto
Keyword(s):  
Heat Source ◽  
Electric Power ◽  
Latent Heat ◽  
Heat Pump ◽  
Heat Storage ◽  
Coefficient Of Performance ◽  
Latent Heat Storage ◽  
Pump System ◽  
Heat Pump System ◽  
Power Load

This paper introduces a heat pump system with a latent heat storage utilization seawater installed in an aquarium. For heating purpose such as air conditioning in order to maintain the indoor conditions at constant temperature and constant relative humidity, and cooling water supply to the fish tank in the aquarium, heat from seawater is collected as the heat source for the heat pump system. With regard to the heat pump system using low-temperature unutilized heat source, development is introduced on a heat source load responsive heat pump system, with combines a load variation responsive heat pump utilizing seawater with a latent heat (ice plus water slurry) storage system using nighttime electric power serving for electric power load leveling. The experimental COP (Coefficient of performance) of the proposed heat exchanger from seawater and latent heat storage cooling assisted heat pump system will be shown in detail.

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 The Effect of Coupling Solar Thermal System and Geothermal Heat Pump Systems in Areas with Unbalanced Heating and Cooling Demand

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 31
Author(s):  
Jihyun Hwang ◽  
Doosam Song ◽  
Taewon Lee
Keyword(s):  
Heat Source ◽  
Water Supply ◽  
Heat Pump ◽  
Coefficient Of Performance ◽  
Maximum Temperature ◽  
Geothermal Heat ◽  
Pump System ◽  
Heat Pump System ◽  
Solar Heat ◽  
Heating And Cooling

Geothermal source heat pump (GSHP) systems as renewable energy systems are being more frequently installed as part of the zero-energy building drive. However, in South Korea, where a large amount of heating load can be required, maintaining high system performance by using only a GSHP is difficult owing to the gradual degradation of its thermal performance. The performance of a solar-assisted GSHP system was therefore experimentally analyzed and compared with a GSHP-only system. The results showed that the heating coefficient of performance of the GSHP-only operation was 5.4, while that of the solar-assisted GSHP operation was 7.0. In the case of the GSHP-only system, the maximum temperature of the heat pump water supply on the heat source side was initially 13.1 °C, but this rapidly decreased to 11.4 °C during operation. For the solar-assisted GSHP system, the temperature of the water supply to the heat source side of the heat pump was controlled at 15–20.9 °C, and the power consumption for system operation was reduced by about 20% compared with that for the GSHP-only system. Much higher temperatures could be supplied when solar heat is used instead of ground heat, as solar heat contributes to the performance improvement of the heat pump system.

scholarly journals Absorption and adsorption chillers applied to air conditioning systems

2010 ◽  
Vol 31 (2) ◽  
pp. 77-94 ◽  
Author(s):  
Agnieszka Kuczyńska ◽  
Władysław Szaflik
Keyword(s):  
Heat Source ◽  
Air Conditioning ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Geothermal Heat ◽  
Pump System ◽  
Desorption Process ◽  
Heat Pump System ◽  
Adsorption Chiller ◽  
Air Conditioning Systems

Absorption and adsorption chillers applied to air conditioning systemsThis work presents an application possibility of sorption refrigerators driven by low temperature fluid for air conditioning of buildings. Thermodynamic models were formulated and absorption LiBr-water chiller with 10 kW cooling power as well as adsorption chiller with silica gel bed were investigated. Both of them are using water for desorption process with temperatureTdes= 80 °C. Coefficient of performance (COP) for both cooling cycles was analyzed in the same conditions of the driving heat source, cooling waterTc= 25 °C and temperature in evaporatorTevap= 5 °C. In this study, the computer software EES was used to investigate the performance of absorption heat pump system and its behaviour in configuration with geothermal heat source.

Performance Characteristics of a Combined Ejector-Absorption Heat Pump Using NH3-H2O

1999 ◽  
Author(s):  
D. A. Kouremenos ◽  
E. D. Rogdakis ◽  
G. K. Alexis
Keyword(s):  
Heat Pump ◽  
Gain Factor ◽  
Coefficient Of Performance ◽  
Detailed Calculation ◽  
Absorption System ◽  
Evaporator Temperature ◽  
Pump System ◽  
Heat Gain ◽  
Absorption Heat Pump ◽  
Heat Pump System

Abstract Absorption system have been investigated for many years. However, coefficient of performance COP or heat gain factor HGF for absorption systems are significantly lower than those for conventional compression systems. This has restricted their wide application. This paper discusses the behavior of mixture NH3-H2O through of an ejector, operating in an absorption heat pump system. This combination improves the performance of conventional absorption system and with the phasing out of ozone-damaging refrigerants, absorption refrigerators, heat pumps and air-conditioning now provide a potential alternative. For the detailed calculation of the proposed system a method has been developed, which employs analytical functions describing the thermodynamic properties of die mixture. The influence of three major parameters: generator, condenser and evaporator temperature, on ejector efficiency and heat gain factor of the system is discussed. Also the maximum value of HGF was estimated by correlation of above three temperatures.

Modeling of a Smart Heat Pump Made of Laminated Thermoelectric and Electrocaloric Materials

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Dudong Feng ◽  
Shi-Chune Yao ◽  
Tian Zhang ◽  
Qiming Zhang
Keyword(s):  
Heat Pump ◽  
Temperature Difference ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Laminated Structure ◽  
Heat Pump System ◽  
Simple Arrangement ◽  
Parametric Effects ◽  
Hybrid Heat Pump ◽  
Physical Features

In this study, a smart heat pump, which could be used for the cooling of electronics, made of laminated structure of thermoelectric (TE) and electrocaloric (EC) materials, is studied. A simple arrangement of two TE layers sandwiched with one EC layer is modeled. This smart heat pump utilized the newly developed EC materials of giant adiabatic temperature change and the TE materials of high figure of merit. The system has the advantages of no moving parts, made of solid state, operable over large working temperature difference, and can be formed into very small size. The operation of the device is numerically modeled considering the three major parametric effects: EC operation as a function of time, electric current applied on TE, and temperature difference between the hot and cold sinks. The results on coefficient of performance (COP) and heat flow per unit area are discussed. This study is performed as an early attempt of analyzing the basic physical features of TE–EC–TE laminated structure heat pump and extends the understanding by further discussing the tradeoff between lower COP and larger overall temperature difference coverage in the TE/EC hybrid heat pump system with multilaminated structure.

scholarly journals Theoretical Analysis of a Single-Stage Gas-fired Ejector Heat Pump Water Heater

2021 ◽  
pp. 1-28
Author(s):  
Jeremy Spitzenberger ◽  
Pengtao Wang ◽  
Laith Ismael ◽  
Hongbin Ma ◽  
Ahmad Abuheiba ◽  
...  
Keyword(s):  
Heat Pump ◽  
Thermal Energy ◽  
Ambient Air ◽  
Single Stage ◽  
Coefficient Of Performance ◽  
Water Heater ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Capacity ◽  
Condenser Temperature

Abstract Ejector driven systems have the ability to operate at high efficiencies, utilizing recycled thermal energy as a power source. For a typical ejector heat pump system, the increase of the condenser temperature reduces the coefficient of performance (COP). In addition, if the condenser temperature is higher than the critical temperature, the ejector may not function. In this situation, the condenser temperature must be reduced, and an additional heater will be utilized to heat the production water from the condenser temperature to the desired temperature. In this investigation, a single-stage gas-fired ejector heat pump (EHP) is investigated and thermodynamically modeled in order to optimize the system COP for the purpose of heating water by utilizing the thermal energy from the ambient air. The effects of the high-temperature evaporator (HTE) and low-temperature evaporator (LTE) temperatures on the ejector critical back pressure and the EHP system performance are examined for a HTE temperature range of 120-180 °C and LTE temperatures of 15.5, 17.5, and 19.5 °C. Results show that an optimized COP of the EHP system exists which depends on HTE and LTE temperatures, primary nozzle throat diameters. In addition, it is found that the EHP COP is independent of the ejector COP. From this investigation a maximum EHP COP of 1.31 is able to be achieved for a HTE temperature of 160 °C and a LTE temperature of 19.5 °C with a total heating capacity of 15.98 kW.

scholarly journals Study of Heat-source-Tower Heat Pump System Efficiency

2015 ◽  
Vol 121 ◽  
pp. 915-921 ◽  
Author(s):  
Jianlin Cheng ◽  
Nianpin Li ◽  
Kuan Wang
Keyword(s):  
Heat Source ◽  
Heat Pump ◽  
System Efficiency ◽  
Pump System ◽  
Heat Pump System
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