scholarly journals THERMAL PERFORMANCE OF A SOLAR-ASSISTED HEAT PUMP WITH A DOUBLE PASS SOLAR AIR COLLECTOR UNDER CLIMATE CONDITIONS OF IRAQ

Author(s):  
Firas Ahmed Khalil
Author(s):  
Akhilesh Gupta ◽  
Ravi Kumar ◽  
Bharat Ramani

Solar collector is a type of heat exchanger which transfers solar radiation energy into the heat energy. Conventional solar air collectors have poor thermal efficiency primarily due to high heat losses and low convective heat transfer coefficient between the absorber plate and flowing air stream, leading to higher absorber plate temperature and greater thermal losses. Attempts have been made to improve the thermal performance of conventional solar air collectors by employing various design and flow arrangements. Double pass counter flow solar air collector with porous material in the second air passage is one of the important and effective design improvement that has been proposed to improve the thermal performance. This paper presents the performance and economic analysis of double pass solar air collector with and without porous material. Effects of various parameters on the thermal performance and pressure drop characteristics have been studied experimentally. The study concludes that double pass arrangement with porous material is economical and having short payback period. Also, the thermal performance of double pass solar air collector with porous material is significantly higher compared to double pass solar air collector without porous material and single pass arrangement.


2020 ◽  
pp. 98-117
Author(s):  
Mohammed Fahmi ◽  
Wissam Khalil ◽  
Amer Shareef

In this research, an experimental study has been performed in order to enhance the thermal performance of a double-pass solar air collector by employing extended surfaces. In order to increase the heat transfer area, triangular-shaped fins were mounted on the longitudinal direction of the absorber plate. Four models of the solar air collectors were made of aluminum with different fin configurations. The experiments were carried out at the winter season in the climate of Iraq - Ramadi city with longitude 43.268 and latitude (33.43). The used range of mass flow rate in the experiments was from 0.027 kg/s to 0.037 kg/s. The comparison with previous studies in terms of thermal efficiency showed good agreement where the percentage of error does not exceed 1% between them. The results also provided that the existing of fins was a good technique for enhancing the thermal performance of double-pass solar air collector with a marginal increase in pressure drop. Consequently, it is possible to adopt this kind of solar air collectors for many agricultural applications such as solar dryer.


2014 ◽  
Vol 13 (8) ◽  
pp. 1965-1970 ◽  
Author(s):  
Spiru Paraschiv ◽  
Lizica Simona Paraschiv ◽  
Ion V. Ion

2021 ◽  
Author(s):  
Jamie Fine

Society’s use of fossil fuels has led to increasingly high levels of CO2 in the atmosphere. These levels have been linked to global average temperature rises, and increases in the severity and frequency of major weather events. To combat these effects, nations around the world have committed to reducing their CO2 emissions, and transition to renewable energy. This thesis focuses on the development of a novel solar heating system, which combines a hybrid solar panel and cascade heat pump. The thesis begins by presenting a high-level literature review of solar and heat pump technologies, followed by the initial design development of the system. Two design iterations are presented, illustrating that the final design was selected because it exhibits improved peak heat output, and reduced sensitivity to panel temperature. Next, a manuscript-based chapter is presented that focuses on utilizing the proposed solar heating system for water distillation. Case studies are presented that compare the performance of the proposed system with a solar still at four different locations. The final conclusion from these studies is that using the proposed system offers area-based performance improvements of 780% compared to a basic solar still. A second manuscript-based study is then presented, which focuses on utilizing the proposed solar heating system for domestic hot water production. Additional case studies are detailed that compare the proposed system to an evacuated tube design, and a single heat pump. The conclusions from these studies are that the proposed system exceeds the performance of the evacuated tube system by up to 64%, and that the proposed system is most beneficial during seasons with higher average dry-bulb temperatures, and increased solar irradiation. A final manuscript-based study is then presented, which focuses on a methodology for improving alternate mode thermal performance estimates for hybrid solar panels. The conclusion from this study is that the proposed methodology can successfully estimate thermal performance within 5% of actual values. Each of these studies contributes to the project goal of developing a novel solar energy heating system, which can be further developed to reduce global CO2 emissions, and reduce the effects of climate change.


Sign in / Sign up

Export Citation Format

Share Document