Dual Source Heat Pump Research Articles

Modeling of a residential house coupled with a dual source heat pump using TRNSYS software

With the information technology revolution and the improving requirement for indoor air environment, energy consumption for air conditioning is increasing in Tunisia. In this research, a heating a residential house using the abundant and universal sources is proposed for a residential house in Tunisia. The effect of the incidence solar radiation in the coupling of a residential house and a heat pump system in all directions during the winter has been studied. The effect of ON–OFF technology in the level of the evaporator of the heat pump has been demonstrated. We present a mathematical description of the house on TRNSYS, as well as the numerical results of the simulation of coupling of the several components. The incidence solar radiation, the temperature distribution and the energy consumed and delivered, and its impact on air-conditioning load in rooms have been measured using the Tunisian climate. Numerical results have been obtained for 24h in January and 4500h operation in winter. Results show that the system may be satisfactorily used for residential building or greenhouse heating in the Mediterranean and region of Tunisia.

The Combined Solar with a Dual Heat Source Heat Pump Applied in a Greenhouse Heating System - An Operation Optimization of Water Source Heat Pump

Based on the finite-time thermodynamic theory, an operation optimization, of water source heat pump in the combined solar with a dual heat source heat pump which is applied in a greenhouse heating system, is made. According to the ε-NTU method and entropy theory, heat exchange and balance equations are obtained. The function relationship between COP and the indoor temperature Tn, the ambient temperature Ta, low temperature heat source inlet temperature Tie and high temperature heat source inlet temperature Tic is also obtained. By means of programming, the impact of parameters on the COP and the way of regulating this water source heat pump system are presented in this article. The results show that: when a separate water source heat pump is running, by adjusting the hot water temperature and the match status of each indoor heating system, the energy-saving operation can be realized.

Heating performance characteristics of a dual source heat pump using air and waste heat in electric vehicles

A heat pump has been considered as an alternative to an electric heater to increase the efficiency of the heating unit in electric vehicles. However, the heating performance of a single source heat pump has yet to be improved at low outdoor temperatures. This study investigates the feasibility of a dual source heat pump using both air and waste heat in electric vehicles. The performance of the dual source heat pump was measured at various operation modes: air source-only, waste heat-only and dual heat source. The heating performance of the dual source heat pump was higher than those of the single source heat pumps. In addition, an alternating single mode operation of air source-only and waste heat-only modes was proposed to improve performance at low outdoor air temperatures.

공기, 지열 및 복합 열원 열펌프의 중간기 에너지 소비량에 관한 연구

This study is to compare energy consumption of air-source, ground-source and dual-source heat pump systems during intermediate season using dynamic simulation. Ground-source heat pump has higher COP than that of air-source but requires additional power consumption of auxiliary equipment such as circulation pump. During intermediate season when the outdoor air temperature is favorable, total COP of air-source heat pump may be greater than that of ground-source when circulation pump power consumption is included. Dual-source heat pump which selects the more favorable heat source is compared with air-source only and ground-source only heat pumps for total power consumption. Results show that power consumption of dual-source heat pump is lower than that of ground-source only by 0.73%.

이중열원을 이용한 전기자동차용 히트펌프 시스템의 난방 성능 특성에 관한 연구

An electric vehicle is an environment-friendly automobile which does not emit any tailpipe pollutant. In a conventional vehicle with an internal combustion engine, the internal cabin of the vehicle is usually heated using waste heat from the engine. However, for an electric vehicle, an alternative solution for heating is required because it does not have a combustion engine. Recently, a heat pump system which is widely used for residential heating due to its higher efficiency has been studied for its use as a heating system in electric vehicles. In this study, a heat pump system utilizing air source and waste heat source from electric devices was investigated experimentally. The performance of the heat pump system was measured by varying the mass flow rate ratio. The experimental results show that the heating capacity and COP in the dual heat source heat pump were increased by 20.9% and 8.6%, respectively, from those of the air-source heat pump.

Dual source heat pump systems: Operation and performance

Dual source heat pump systems comprise of a main cold source heat pump that is supported by an additional heat source. Two arrangements have been studied in detail: air source heat pumps combined with solar collectors; and ground source heat pumps coupled with solar collectors.In addition to a situation where solar collectors are devoted solely to direct heating, the solar system can be used with the heat pump in either a series or a dual source scheme. When set up in series, a higher COP can be achieved, but there is often a lower free energy fraction. This is due to the lack of direct solar heating, meaning that auxiliary energy is required more frequently.A careful analysis of all the plant elements, including location, heating and cooling demand, solar collector area, thermal ground probe length, etc. is fundamental for achieving the best outcome in terms of both good primary energy savings and profitable economical performance.

Performance analysis of air-water dual source heat pump water heater with heat recovery

A new air-water dual source heat pump water heater with heat recovery is proposed. The heat pump system can heat water by using a single air source, a single water source, or air-water dual sources. The water is first pre-heated by waste hot water, then heated by the heat pump. Waste heat is recovered by first preheating the cold water and as water source of the heat pump. According to the correlated formulas of the coefficient of performance of air-source heat pump and water-source heat pump, and the gain coefficient of heat recovery-preheater, the formulas for the coefficient of performance of heat pump in six operating modes are obtained by using the dimensionless correspondence analysis method. The system characteristics of heat absorption and release associated with the heat recovery-preheater are analyzed at different working conditions. The developed approaches can provide reference for the optimization of the operating modes and parameters. The results of analysis and experiments show that the coefficient of performance of the device can reach 4–5.5 in winter, twice as much as air source heat pump water heater. The utilization of waste heat in the proposed system is higher than that in the system which only uses waste water to preheating or as heat source. Thus, the effect of energy saving of the new system is obvious. On the other hand, the dimensionless correspondence analysis method is introduced to performance analysis of the heat pump, which also has theoretical significance and practical value.

The Numerical Simulation of the Solar-Air Dual-Source Heat Pump System

The heat pump technology which is as an effective energy-saving technology has attracted more and more attentions. A novel solar-air dual-source heat pump system which could synchronously use two heat sources has been provided. In this paper, the mathematical model of the new heat pump system has been built and the calculation accuracy of the mathematical model has been proved. Based on a novel solar-air dual-source heat pump system, the mathematical models of the thermophysical parameters of working fluids, compressor, capillary, condenser, evaporator, and heat pump system have been established. The distribution parameter method has been adopted in the mathematical models of condenser and evaporator. Three operation modes of the novel solar-air dual-source heat pump system have been simulated. The simulated results and the experimental results have been compared. The experiments of the novel solar-air dual-source heat pump system have been accomplished in the constant temperature and humidity laboratory. The compared results show that the error is less than 10%.

A New Three Medium Composite Heat Exchanger

The solar-air compound heat pump system which core component is a three medium composite heat exchanger is a new heat pump system. Compared with the conventional air source heat pump system, the COP of the new dual heat source heat pump system is at least increased by 40%, and the energy-saving effect is obvious. At present, the only dual heat source composite heat exchanger used in heat system is a finned-tube three medium composite heat exchanger. With the heat exchanger, the synchronous heat exchange between a liquid heat source, a gaseous heat source and a refrigerant could be realized, and the performance of the heat pump system could be effectively improved. But the structural defects of the finned-tube three medium composite heat exchanger result in processing difficulty, and it is difficult to form a batch production with the present processing technology. The hidden sealing danger of the heat exchanger also exists. In the paper, a new three medium composite heat exchanger has been designed. The structural flaw of the finned-tube three medium composite heat exchanger has been better avoided. And it makes the process easier and the batch production more convenient.

Experimental and theoretical investigation of combined solar heat pump system for residential heating

In order to investigate the performance of the combined solar-heat pump system with energy storage in encapsulated phase change material (PCM) packings for residential heating in Trabzon, Turkey, an experimental set-up was constructed. Also, a comparative study of the performance of this system has been undertaken theoretically. Simulations have been made with basic computer program of three basic combined configurations, as well as conventional solar and conventional heat pump systems in Trabzon by using meteorological data. The experimental results were obtained from December to May during the heating season for four heating systems. These systems are a conventional solar system, a series heat pump system, a parallel heat pump system and a dual source heat pump system. The experimentally obtained results are used to calculate the collector efficiency, heat pump coefficient of performance (COP), seasonal heating performance, the fraction of annual load met by free energy, storage and collector efficiencies and total energy consumption of the systems during the heating season.