The effect of condenser heat transfer on the energy performance of a plate heat pipe solar collector

2005 ◽  
Vol 29 (10) ◽  
pp. 903-912 ◽  
Author(s):  
Jorge Facão ◽  
Armando C. Oliveira
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Solar Collector ◽  
Energy Performance ◽  
Plate Heat

scholarly journals Analysis of a plate heat pipe solar collector

2006 ◽  
Vol 1 (1) ◽  
pp. 1-9 ◽  
Author(s):  
J. Facao ◽  
A. C. Oliveira
Keyword(s):  
Heat Pipe ◽  
Solar Collector ◽  
Plate Heat

scholarly journals Numerical and Experimental Study on Energy Performance of Photovoltaic-Heat Pipe Solar Collector in Northern China

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hongbing Chen ◽  
Xilin Chen ◽  
Sai Chu ◽  
Lei Zhang ◽  
Yaxuan Xiong
Keyword(s):  
Heat Pipe ◽  
Water Flow ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Water Flow Rate ◽  
Northern China ◽  
Energy Performance ◽  
Good Choice ◽  
Water Type ◽  
Pv Panel

Several studies have found that the decrease of photovoltaic (PV) cell temperature would increase the solar-to-electricity conversion efficiency. Water type PV/thermal (PV/T) system was a good choice but it could become freezing in cold areas of Northern China. This paper proposed a simple combination of common-used PV panel and heat pipe, called PV-heat pipe (PV-HP) solar collector, for both electrical and thermal energy generation. A simplified one-dimensional steady state model was developed to study the electrical and thermal performance of the PV-HP solar collector under different solar radiations, water flow rates, and water temperatures at the inlet of manifold. A testing rig was conducted to verify the model and the testing data matched very well with the simulation values. The results indicated that the thermal efficiency could be minus in the afternoon. The thermal and electrical efficiencies decreased linearly as the inlet water temperature and water flow rate increased. The thermal efficiency increased while the electrical efficiency decreased linearly as the solar radiation increased.

A211 Visualization experiment about effect of wettability on heat transfer of flat-plate heat pipe

2014 ◽  
Vol 2014 (0) ◽  
pp. _A211-1_-_A211-2_
Author(s):  
Masaru Ogasawara ◽  
Shota Yanagisawa ◽  
Takahiro Ito ◽  
Yoshiyuki Tsuji ◽  
Seiji Yamashita ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Heat Pipe ◽  
Plate Heat ◽  
Visualization Experiment ◽  
Flat Plate Heat Pipe

Study on Heat Transfer Characteristics of Loop Heat Pipe for Solar Collector

2012 ◽  
Author(s):  
Shota Sato ◽  
Shigeki Hirasawa ◽  
Tsuyoshi Kawanami ◽  
Katsuaki Shirai
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Rate ◽  
Solar Collector ◽  
Transfer Rate ◽  
Thermal Conductance ◽  
Filling Ratio ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Single Tube

We experimentally study the thermal conductance of single-tube and loop heat pipes for a solar collector. The evaporator of the heat pipe is 1 m long, 6 mm in diameter and has 30° inclination. The thermal conductance is defined as the heat transfer rate divided by the temperature difference between the evaporator-wall and the condenser-wall. Effects of heat transfer rate, saturation temperature of the working fluid, liquid filling ratio, inclination angle, and position of the evaporator on the thermal conductance are examined. We found that the thermal conductance of the 30°-inclined loop heat pipe with an upper-evaporator is 40–50 (W/K), which is 1.8 times higher than that of the vertical loop type and 3 times higher than that of the single-tube type. Thus, the inclined loop heat pipe is preferable for a solar collector. There is an optimum liquid filling ratio. When the liquid filling ratio is too small, a dry-out portion appears in the evaporator. When the liquid filling ratio is too large, the liquid flows in the condenser to decrease heat transfer area. Also we numerically analyze the thermal conductance of a vertical loop heat pipe.

Comparison of Heat Transfer in Solar Collectors With Heat-Pipe Versus Flow-Through Absorbers

1987 ◽  
Vol 109 (4) ◽  
pp. 253-258 ◽  
Author(s):  
J. R. Hull
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Solar Collector ◽  
Hot Water ◽  
Solar Collectors ◽  
Heat Transfer Characteristics ◽  
Absorption Chiller ◽  
Transfer Characteristics ◽  
Proper Design ◽  
Flow Through

Analysis of heat transfer in solar collectors with heat-pipe absorbers is compared to that for collectors with flow-through absorbers for systems that produce hot water or other heated fluids. In these applications the heat-pipe absorber suffers a heat transfer penalty compared with the flow-through absorber, but in many cases the penalty can be minimized by proper design at the heat-pipe condenser and system manifold. When the solar collector is used to drive an absorption chiller, the heat-pipe absorber has better heat transfer characteristics than the flow-through absorber.

scholarly journals EXPERIMENTAL INVESTIGATION OF ENERGY CHARACTERISTICS OF EVACUATED TUBE HEAT-PIPE SOLAR COLLECTOR SYSTEM

2015 ◽  
Author(s):  
Antanas KAVOLYNAS ◽  
Rolandas DREJERIS
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Flow Rate ◽  
Solar Collector ◽  
Storage Tank ◽  
Hot Water ◽  
Heat Transfer Agent ◽  
Energy Characteristics ◽  
Collector System ◽  
Evacuated Tube

Evacuated tube heat-pipe solar collector system with closed heat pipe has been experimentally investigated. Experiments have been fulfilled using the solar imitator whose energy irradiance on the surface of the solar collector at the constant ambient conditions is 800 W/m². Energy characteristics of the solar collector system with different flow-rates of the heat-transfer agent have been investigated using various flow-rate speeds of the heat-transfer agent. It has been stated that the increase of the flow-rate of the heat-transfer agent in the system from 0.01 to 0.12 kg/s would minimize the average collector efficiency from 0.81 to 0.55. When the reduced flow-rate of the heat-transfer agent has been used in the system, the higher temperature of the hot water is reached in the storage tank and at the same time the temperature of the heat-transfer agent in the system is increased. Thus, more energy has been lost in the pipeline and hot water storage tank, but less energy is used for the circulation of the heat-transfer agent energy. Increasing the agent flow-rate speed in the system has reduced the heat losses in the pipeline, but more energy is used for the energy circulation of the heat-transfer agent. Therefore, the medium efficiency of the solar collector system has changed insignificantly (0.47 ± 0.01).

Thermal Performance Analysis of a Novel U-Tube Evacuated Tube Solar Collector

2020 ◽  
Author(s):  
Celine S. L. Lim ◽  
Vivek R. Pawar ◽  
Sarvenaz Sobhansarbandi
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Solar Collector ◽  
Performance Comparison ◽  
Heat Transfer Fluid ◽  
Cfd Modeling ◽  
Ansys Fluent ◽  
Evacuated Tube Solar Collector ◽  
Evacuated Tube

Abstract Solar water heating (SWH) systems are the most common application of renewable energy technology that converts solar radiation into useful energy for domestic/industrial activities. The novelty of this study is the design of a new SWH that combines the heat transfer and storage both in a single unit. The selected type of collector for this purpose is an evacuated tube solar collector (ETC). The new design of the ETC has been developed by applying a U-tube inside the collector which contains the heat transfer fluid (HTF). The HTF flows into an external heat exchanger that transfers heat to the water. The implementation of sugar alcohol namely Erythritol (C4H10O4) as the HTF for moderate operating temperature applications was investigated. Moreover, the utilization of solid-liquid phase change material, Tritriacontane paraffin (C33H68), inside the ETC, allows direct heat storage on the system and delayed release of heat. A computational fluid dynamics (CFD) modeling of a single U-tube ETC is performed using ANSYS Fluent in stagnation (on-demand) operation. A 3D model of the ETC is developed and the appropriate boundary conditions are applied. Moreover, the thermal performance comparison of U-tube vs heat pipe ETC has been done. The results from this study shows the maximum fin temperature difference of 46°C of U-tube ETC compared with heat pipe ETC.

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