Exergoeconomic optimization of solar heat pump systems of heat supply (original) (raw)
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Performance characteristics and energy–exergy analysis of solar-assisted heat pump system
Building and Environment, 2008
In this study solar-assisted heat pump (SAHP) system with flat plate collectors was investigated experimentally and tested for domestic space heating. SAHP system was located in a test room with 60 m 2 floor area in Firat University, Elazig (38,411N, 39,141E) Turkey. The experiments were performed in heating season of January 2003. The coefficient of performance of the SAHP system was calculated. The system COP of the SAHP was obtained as 3.08 while the exergy loss of the solar collector was found to be 1.92 kW. The second law efficiency of the compressor, condenser, evaporator and solar heat exchanger in SAHP system were evaluated 42.1%, 83.7%, 43.2% and 9.4%, respectively. The first law efficiency and exergetic efficiency of the whole system are found to be 65.6%, 30.8%, respectively. Consequently the energy and exergy loss analysis results show that the COP increase when the exergy loss of evaporator decrease.
IOP Conference Series: Materials Science and Engineering, 2019
In recent years, there are various utilization methods of solar thermal energy and it is hard to find which system is the best to utilize energy as work from the view point of energy concept alone. Therefore, we conducted exergy analysis of two different solar energy utilization methods: one is a multiple source & multiple use heat pump we have developed; and the other is a conventional solar water heater. In order to clarify the performance gap depending on the solar radiation between the multiple source & multiple use heat pump and the solar water heater, exergy analysis was carried out on a clear-sky day and a daily average under the condition of equal exergy output. The results show that the performance of the solar water heater highly depends on the weather conditions, on the other hand, the multiple source & multiple use heat pump shows high performance regardless of the weather conditions.
Exergetic Optimization of Solar Air Heaters and Comparison with Energy Analysis
International Journal of Thermodynamics, 2005
In this paper, an exergetic optimization of the solar air heater is developed. For this means, an integrated mathematical model of thermal and optical performance of the solar heater is derived. The most geometric parameters and operation conditions are considered as variables in this analysis. Some correlations for exergy efficiency of heater components are obtained. Then, exergy efficiency of the heater is derived by using these correlations. In the process of deriving an equation for the exergy efficiency, while the overall thermal loss coefficient and other heat transfer coefficients of the heater are assumed to be variable, the common error of using the Petela efficiency is corrected to reach the improved equation of solar radiation exergy. Finally, through the MATLAB toolbox the exergy efficiency equation is maximized. Then exergy efficiency is compared with the thermal efficiency of the heater, resulting in an extraordinary increase of the exergy efficiency according to the optimized parameters and benefit of this approach for such systems.
Experiments on a solar-assisted heat pump and an exergy analysis of the system
Applied Thermal Engineering, 2002
In this work a experimental study of a solar assisted heat pump with direct expansion of the refrigerant within the solar collector, is presented. The maximum exergy efficiency, defined as the ratio of the outlet to the inlet exergy flow in every component of the heat pump cycle, is determined taking into account the typical parameters and performance coefficients. The results of this exergy analysis point out that the main source of irreversibility can be found in the evaporator of the heat pump (that is, the solar collector) emphasizing that incoming solar radiation is not used to full advantage in this piece of equipment. Ó
Techno-economic review of solar heat pump systems for residential heating applications
Renewable and Sustainable Energy Reviews, 2018
Solar heat pump systems (SHPs) have been investigated for several decades and have been proven to increase the share of renewable energy and reduce electric energy demand in residential heating applications. Many review articles have been published on the subject, however literature discussing the techno-economics of different solar technologies (thermal, photovoltaic and hybrid thermal/photovoltaic) in combination with heat pumps is lacking, and thus to directly compare the merits of different SHPs is not an easy task. The objectives of this study are: a) review the different system boundaries and the main performance indicators used for assessing energetic and economic performances; b) review techno-economic studies in the literature and identify which studies give enough information and are compatible enough for making an economic inter-comparison; c) present an economic inter-comparison based on the identified systems. The results show that there is a lack of studies including an economic assessment of solar photovoltaic and heat pump systems. Additionally, there are no consistent boundaries or approaches to the study structures, making comparisons between systems difficult. In conclusion, a standardized or broadly accepted definition of technical and economic performance for SHPs is needed. Despite this, the study has shown that there are clear trends for decreasing payback times for SHPs, both solar thermal (ST) and photovoltaic (PV), with decreasing heating degree-days and with increasing solar resource. 1.1. Summary of review studies on SHPs for residential heating applications A general classification of the review studies on SHPs for residential heating applications is shown in Table 1. The studies are classified into three main categories: reviews on solar thermal heat pump systems, reviews on heat pumps with a marginal scope on solar and reviews on integrated systems for zero energy buildings.
Economic analysis and design optimization of a direct expansion solar assisted heat pump
Solar Energy, 2019
One option to reduce the energy consumption to produce domestic hot water is to replace the electrical heaters by direct expansion solar assisted heat pumps. Although, there are many studies on the performance of this system, there are few studies on economic analysis of the equipment. In this paper, an economic analysis comparing the payback of heat pump over an electrical heater is carried out. The heat pump is modeled using lumped models for heat exchangers and a black box model for the compressor. The results show that the augment of collector size increases the COP, but it decreases the collector efficiency. The economic analysis showed that there is a collector size that minimizes the payback time. Additionally, the influence of the environmental conditions, the refrigerant, the costs and the heating capacity on the payback period and optimum collector size were investigated. The results showed that there is an economically optimum size of collector area for the DX-SAHP, which it is the same for different environmental conditions. A case study was made for three different cities and the payback time found is the range of 1.77-3.24 years.
Renewable energy, Exergoeconomic, Cogeneration system, Solar power Increasing environmental pollutions and the expense of fossil fuels necessitates employment of efficient instruments and easily producible clean sources as abasic solution to this problem. Cogeneration systems are used for their high performance with a performance of approximately eighty-five percent Cogeneration production system with renewable energy source is the best solution to fuel suitable and high cost Amon all renewable energy sources, use of solar power is of interest. Solar power is the best choice because it's free and clean. This project illustrates the analyzed exergy and eregyeconomic simulations of solar hybrid cycle. Thermo economic and exergoeconomic analysis where used in this research, with exergoeconomic we can analyze cycle cost, payback period and exergy performance. Case study for this project was a building with 480 m² or square meters area in Zahedan, Iran. In this study, a small scale hybrid solar heating, cooling and power generation set-up including solar collector, screw expender auxiliary heater, adsorption chiller, etc., was proposed and extensively investigated.
Practical study on heat pump enhancement by the solar energy
E3S Web of Conferences, 2021
The heat pumps system is one of the most remarkable system that is widely used around the world, their capacity is different according to necessity. The energy consumption in those systems will limit their effectiveness. This study will try to prove the positive reactance of the new changes (the additional heat exchanger) on the heat pump work, where the power consumption will reduce about (13-17%). The study includes the experimental results of the laboratory model, which has been manufactured in the laboratories of the technical college of Mosul/Northern technical university-Iraq. The model consists of the heat pump that was improved by using the additional heat exchanger, its duty is to heat the refrigerant before entering the compressor, by using solar energy. The results of this work prove the positive effect of the additional heat exchanger, on the coefficient of performance of the heat pump, in both modes of heating and cooling. The conclusions are useful to the industries th...
Investigation of Performance of Solar-Assisted Heat Pump Systems: Muğla Example
Mugla Journal of Science and Technology, 2018
In this study, the combination of solar thermal systems with heat pump has been investigated numerically. The potential utility of the collectors is found by comparing heat pump systems with combined systems. All simulations for the Muğla province were made using the POLYSUN program. The simulated systems are designed to meet the demand for hot water and residential heating of single-dwelling houses. The results of this study show that the seasonal performance factor of the system increases as the collector field added to the air source heat pump system increases. However, in the systems where the heat demand is met, the heating effect coefficient of the heat pump (COPHP) decreases. In this system, solar energy is used to meet the need for hot water, while also supporting housing heating. However, it has been determined that the heat pump should be selected at a sufficient capacity because the increase in the number of collectors by selecting the heat pump at the insufficient capacity cannot meet the demand. However, it has been determined that the heat pump should be selected at a sufficient capacity because the increase in the number of collectors by selecting the heat pump at the insufficient capacity cannot meet the demand. In the systems where the heat demand cannot be met, the heating effect coefficient after 2 collectors is found to be constant. Collectors used in excess of 2 collectors are closed when there is no need for them. However, it supports heating in winter.