scholarly journals Flat plate solar water heater with closed-loop oscillating heat pipes

2021 ◽  
pp. 192-192
Author(s):  
Piyanun Charoensawan ◽  
Patomsok Wilaipon ◽  
Nopparat Seehawong

The flat plate solar water heater, using the closed-loop oscillating heat pipes (CLOHP), was constructed and investigated. The flat plate collector consisted of 10 pipes of CLOHP and the collector area was 1.5?1 m2. Each CLOHP was made of a copper capillary tube with a 1.5 mm inner diameter, a 2.8 mm outer diameter and had 20 turns. The distilled water was used as the working fluid with a filling ratio of 50% the tube?s total internal volume. The evaporator section of the CLOHP was placed on the absorber plate of the collector, and its condenser section was wrapped around the copper tube, in which hot water flowed through. The solar water heater was tested under the solar simulator with halogen lamps generating the uniform artificial solar energy. The irradiation intensity and the water flow rate of the solar water heater were adjusted. It was found that the thermal performance of the solar water heater clearly improved with an increase in the irradiation intensity from 480 to 1086 W/m2. However, the water flow rate in the range of 1.5-3.0 L/min, had a thermal performance that was slightly different. The thermal efficiency of 0.67 was archived at the high irradiation intensity of 947-1086 W/m2. Moreover, the mathematical model to predict the thermal efficiency of the flat plate solar water heater with the CLOHPs was obtained.

Author(s):  
Amit K. Bhakta ◽  
Nitesh K. Panday ◽  
Shailenrda N. Singh

This paper reports the overall thermal performance of a cylindrical parabolic concentrating solar water heater (CPCSWH) with inserting nail type twisted tape (NTT) in the copper absorber tube for the nail twist pitch ratios 4.787, 6.914 and 9.042 respectively. The experiments are conducted for a constant volumetric water flow rate and during the time period 9:00 h to 15:00 h. The useful heat gain, hourly solar energy collected and hourly solar energy stored of this solar water heater are found higher for nail twist pitch ratio 4.787. The above said parameters are found to be a peak at noon and observed to follow the path of variation of solar intensity. At the starting of the experiment, the value of charging efficiency is observed to be maximum. Whereas the maximum value of instantaneous efficiency and overall thermal efficiency are observed at noon. The key finding is that the nail twist pitch ratio enhances the overall thermal performance of the CPCSWH.


2017 ◽  
Vol 5 (10) ◽  
pp. 112-116
Author(s):  
Anupras Shukla ◽  
Pushpraj Singh

In this paper, we are studying about solar water heater. The solar water heater are consisting of several components such as circular pipe, flexible pipe, and metallic container for water and circulating pump. We are analyzed the outlet temperatures of hot water using of various flow rate (in liters/ Minutes).


2014 ◽  
Vol 624 ◽  
pp. 332-338 ◽  
Author(s):  
Shouquat Hossain ◽  
Ali Wadi Abbas ◽  
Jeyraj Selvaraj ◽  
Ferdous Ahmed ◽  
Nasrudin Bin Abd Rahim

An investigation is reported of the thermal performance of a flat plate solar water heater with a circulating absorber pipe surface. The thermal performance of the 2-side parallel serpentine flow solar water heater depends significantly on the heat transfer rate between the absorber surface and the water, and on the amount of solar radiation incident on the absorber surface. The modified pipe arrangement has a higher characteristic length for convective heat transfer from the absorber to the water, in addition to having more surface area exposed to solar radiation. It means during the operation of water heater, more solar energy is converted into useful heat. However, this modification has reduced the efficiency of the system marginally.


2014 ◽  
Vol 592-594 ◽  
pp. 1706-1713
Author(s):  
R. Venkatesh ◽  
W. Christraj

Of all the renewable sources of energy available, solar thermal energy is the most abundant one and is available in both direct as well as indirect forms. In order to increase the thermal performance of solar collectors, the multipurpose solar collectors were investigated experimentally by the storage tank of the conventional solar water collector is modified as riser tubes and header. It is fitted in the bottom of the solar air heater as an absorber in the normal air heater. The thermal performance of thermosyphon flat plate solar water heater was investigated on both summer and winter seasons. The maximum daily average of 72.05%, 0.0316 kg/sm2and 0.873 m/s were recorded for the relative humidity, mass flow rate and wind speed at summer season respectively. Corresponding figure at for winter was 19.5 % 0.0295 kg/sm2and 0.722 m/s respectively. A minimum daily average of 11.23% and 0.384 m/s for the relative humidity and wind speed respectively. These results show that the mass flow rate obtained was a function of solar radiation and relative humidity. The less humid the ambient air becomes, the higher the heat gained by the system hence higher water flow rate. The maximum value of relative humidity obtained is due to low solar radiation on winter season. The heat removal factor (FR) and collector efficiency factor (Fo) were found to be higher for Multipurpose solar water heater as compared to conventional solar water heaters for summer as well as winter season. These factors for Multipurpose solar water heater were more during summer and winter.


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