Performance Evaluation of Photovoltaic Power-Generation System Equipped With a Cooling Device Utilizing Siphonage: 2nd Report — Improvement of a PV System Placed on a Residential Rooftop

Solar Energy ◽  
2005 ◽  
Author(s):  
Kaoru Furushima ◽  
Yutaka Nawata ◽  
Michio Sadatomi
Keyword(s):  
Cooling System ◽  
Cooling Water ◽  
Hot Water ◽  
Present System ◽  
Cooling Device ◽  
Pv System ◽  
Pv Module ◽  
Power Generation System ◽  
Pv Cooling

PV modules have a problem that the power generated decreases with the rise of the PV module temperature. In order to solve the problem, we recently developed a new PV cooling device utilizing siphonage. In the first report [1] of this series, we presented the experimental results on the PV mounted on an open rack and that the cooling system is effective in both the improvement of the PV efficiency and the reduction of fuel consumption by reusing hot water from the system. In this study, we conducted long-term monitoring tests on the open rack-mount PV system with a cooling panel behind the PV module and with an insulation board (made of foam polystyrene) behind the cooling panel, simulating the residential rooftop PV system. The data obtained in the experiment have been compared with those obtained for the previous system with the cooling panel but without the insulation board. The comparison shows that the increment in energy production after equipping the cooling panel is much more for the present system with the insulation board irrespective of the cooling start temperature, being the PV temperature when cooling water was started to flow. This result suggests that the installation of the cooling system is more useful for the residential rooftop PV system than the open rack-mount system.

Performance Evaluation of Photovoltaic Power-Generation System Equipped With a Cooling Device Utilizing Siphonage

2005 ◽  
Vol 128 (2) ◽  
pp. 146-151 ◽  
Author(s):  
Kaoru Furushima ◽  
Yutaka Nawata
Keyword(s):  
Power Generation ◽  
Cooling Water ◽  
Ground Level ◽  
Hot Water ◽  
Generation System ◽  
Cooling Device ◽  
Pv System ◽  
Pv Modules ◽  
Power Generation System ◽  
Hot Water Supply System

In order to construct an efficient photovoltaic (PV) power-generation system, we have developed a new system equipped with a cooling device utilizing siphonage. The major components of the system are an array of PV modules and cooling panels attached to the backside of the PV modules. The PV modules are cooled with cooling water flowing through a narrow gap in each cooling panel, and hot water discharged from the cooling panel can be reused. In order to save energy for introducing cooling water into the panel, siphonage from an upper level of a building to the ground level is utilized. From long-term monitoring tests in summer for the PV system, we confirmed that the cooling of the PV modules increases the electric power and that the reuse of hot water from the cooling panel contributes very much for saving energy consumed in a hot-water-supply system.

Performance Evaluation of Photovoltaic Power-Generation System Equipped With a Cooling Device Utilizing Siphonage

Solar Energy ◽  
2004 ◽  
Author(s):  
Kaoru Furushima ◽  
Yutaka Nawata
Keyword(s):  
Power Generation ◽  
Cooling Water ◽  
Hot Water ◽  
Test Facility ◽  
Generation System ◽  
Cooling Device ◽  
Pv Module ◽  
Pv Modules ◽  
Power Generation System ◽  
Pv Power Generation

Recently, the photovoltaic (PV) power generation system has attracted attention as one of clean energies. Especially, residential roofing PV system connected with power grids has been popularized as a result of increasing concerns over global warming and continuing decline in PV manufacturing costs. The power generated by the PV module increases with irradiance, but it decreases as PV module temperature becomes high. The PV temperature depends on ambient temperature, and becomes more than 60°C in summer. Therefore, the power generated does not necessarily increase even if the irradiance increases in summer. However, if the PV modules were cooled under such a high PV temperature condition, more electrical power would be obtained from PV modules. In this study, a PV power generating system equipped with a cooling device has been developed. The major components of the system are an array of PV modules and cooling panels attached to the backside of the PV modules. The respective PV module is cooled with cooling water flowing through a narrow gap in each cooling panel. Hot water discharged from the cooling panel is delivered to a storage tank and can be reused in anywhere. In order to save energy for introducing cooling water into the panel, a siphonage from an upper level of a building to the ground level is utilized. A siphon tube is connected to a discharge port of the cooling panel, thus the pressure at the discharge port becomes negative. Cooling water enters into the bottom end of the cooling panel at atmospheric pressure and goes up to the top, discharge side. By adopting this cooling water system, we could spread the cooling water evenly over the entire backside of the PV module and thus realized an effective cooling device. In addition, we could make the cooling device light and smaller because no auxiliary pumping system is needed for introducing cooling water. To provide field performance data for the present PV power generation system equipped with the special cooling device mentioned above, long-term monitoring tests in a natural environment were conducted in summer for a test facility constructed at the Yatsushiro National College of Technology (YNCT), Japan. As a result, it was confirmed that the cooling of the PV modules increases the electric power and that the reuse of hot water from the cooling panel contributes very much for saving energy consumed for heating water.

Simulation and Experimental Analysis of a Solar Driven Absorption Chiller With Partially Wetted Evaporator

2008 ◽  
Author(s):  
Jan Albers ◽  
Giovanni Nurzia ◽  
Felix Ziegler
Keyword(s):  
Cooling System ◽  
Cooling Water ◽  
Hot Water ◽  
Absorption Chiller ◽  
Efficient Operation ◽  
Part Load ◽  
Solar Cooling ◽  
Wetted Area ◽  
Solar Cooling System ◽  
Load Conditions

The efficient operation of a solar cooling system strongly depends on the chiller behaviour under part-load conditions since driving energy and cooling load are never constant. For this reason the performance of a single stage, hot water driven 30 kW H2O/LiBr-absorption chiller employed in a solar cooling system with a field of 350 m2 evacuated tube collectors has been analysed under part-load conditions with both simulations and experiments. A simulation model has been developed for the whole absorption chiller (Type Yazaki WFC-10), where all internal mass and energy balances are solved. The connection to the external heat reservoirs of hot, chilled and cooling water is done by lumped and distributed UA-values for the main heat exchangers. In addition to an analytical evaporator model — which is described in detail — experimental correlations for UA-values have been used for condenser, generator and solution heat exchanger. For the absorber a basic model based on Nusselt theory has been employed. The evaporator model was developed taking into account the distribution of refrigerant on the tube bundle as well as the change in operation from a partially dry to an overflowing evaporator. A linear model is derived to calculate the wetted area. The influence of these effects on cooling capacity and COP is calculated for three different combinations of hot and cooling water temperature. The comparison to experimental data shows a good agreement in the various operational modes of the evaporator. The model is able to predict the transition from partially dry to an overflowing evaporator quite well. The present deviations in the domain with high refrigerant overflow can be attributed to the simple absorber model and the linear wetted area model. Nevertheless the results of this investigation can be used to improve control strategies for new and existing solar cooling systems.

Simulation and performance study of a two-bed adsorption cooling system operated with activated carbon-ethanol

2021 ◽  
pp. 095440622110420
Author(s):  
V Baiju ◽  
A Asif Sha ◽  
NK Mohammed Sajid ◽  
K Muhammedali Shafeeque
Keyword(s):  
Water Temperature ◽  
Performance Optimization ◽  
Cooling System ◽  
Cooling Water ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Performance Study ◽  
Evaporator Temperature ◽  
Adsorption Cooling System

This paper presents the transient model of a two-bed adsorption cooling system performed in the SIMULINK platform. The inlet chilled water temperature in the evaporator, temperature of cooling water and hot water temperature of the adsorbent bed and its effect on systems coefficient of performance, refrigeration effect and specific cooling power have been studied and presented. It is observed that the systems coefficient of performance is 0.57 when the inlet hot water temperature about 80 °C. In this study, the optimum cooling power and systems coefficient of performance are also determined in terms of the phase time, shifting duration and hot water inflow temperature. The results indicates that the cooling water and hot water inlet temperatures significantly affects the coefficient of performance, specific cooling power and cooling power of the system. The effect of mass flow rate on the cooler efficiency is also presented. A two bed adsorption system of capacity 13.5 kW having an evaporator and condenser temperatures of 6°C and 28°C, respectively, are considered for the present investigation. The adsorbent mass considered is 45 kg with a shifting duration of 20 sec. The result of this study gives the basis for performance optimization of a practical continuous operating vapour adsorption cooler.

scholarly journals CFD Simulation of Silica Gel as an Adsorbent on Finned Tube Adsorbent Bed

2018 ◽  
Vol 67 ◽  
pp. 01014 ◽  
Author(s):  
Andre Kurniawan ◽  
Nasruddin ◽  
Asep Rachmat
Keyword(s):  
Silica Gel ◽  
Outer Surface ◽  
Cooling System ◽  
Cooling Water ◽  
Momentum Conservation ◽  
Hot Water ◽  
Adsorption Rate ◽  
Conservation Equations ◽  
Absolute Adsorption ◽  
Adsorption Technology

The adsorption technology is becoming the more expected solution by today’s researchers for fix the energy and environmental issues. The main part of the cooling system adsorption is adsorbent and adsorbate. One of the most widely used adsorbents in research of adsorption technology is silica gel. A new silica gel-water adsorption chiller design was developed that composed of two sorption chambers with compact fin tube heat exchangers as adsorber, condenser, and evaporator. Energy, mass, and momentum conservation equations of the adsorption systems have been used for the CFD two and three dimensional models. The geometry of simulation is simply made within silica gel layer between two fins. The simulation is also implemented using a finite volume method through the CFD software Fluent. User defined functions are given to modify the energy, mass, and momentum conservation equations. The simulation of adsorption process is adjusted at unsteady condition. Adsorption and desorption processes are simulated with room temperature for cooling water inlet at temperature 305.15 °K, hot water inlet at temperature 353.15 °K, mass flow rate cooling water inlet at 0.3 kg/s and pressure 32 KPa. For the whole adsorbent bed area, the result shows that the highest absolute adsorption rate at the outer surface, while the lowest rate is at the center. After adsorption was finished, the condition is reversed. The highest absolute adsorption rate is achieved at center, while the lowest rate is achieved at the outer surface.

Development of Solar Cell Module Cooling Device Using Coolant Circulation and Control System

2014 ◽  
Vol 672-674 ◽  
pp. 30-37
Author(s):  
Yong Ki Cho ◽  
Jong Jo Lee ◽  
Weon Jin Song
Keyword(s):  
Power Generation ◽  
Control System ◽  
Solar Cell ◽  
Cooling System ◽  
Cooling Device ◽  
Average Temperature ◽  
Pv Module ◽  
Coolant Circulation ◽  
And Control ◽  
Cell Module

This research has recognized the problems of temperature rise in most solar cell (PV: photovoltaic) modules currently utilized. First, if the temperature rises to 70~80°C, it damages the white-pipe tempered glasses used on the module surface and reduces the module lifespan to a significant extent. Also, if the temperature is risen by 1°C, the modules excluding a thin film module would show efficiency degradation by approx. 0.45~0.55%. To address such problems, if a cooling system is used to lower the average temperature of the PV module, its lifespan and power generation amount increase. In order to maximize the power generation efficiency and cooling device usage by establishing a control system, this research seeks to explore the following goals.

Simulation and Experimental Analysis of a Solar Driven Absorption Chiller With Partially Wetted Evaporator

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Jan Albers ◽  
Giovanni Nurzia ◽  
Felix Ziegler
Keyword(s):  
Cooling System ◽  
Cooling Water ◽  
Hot Water ◽  
Absorption Chiller ◽  
Efficient Operation ◽  
Part Load ◽  
Solar Cooling ◽  
Wetted Area ◽  
Solar Cooling System ◽  
Load Conditions

The efficient operation of a solar cooling system strongly depends on the chiller behavior under part load conditions, since driving energy and cooling load are never constant. For this reason, the performance of a single stage, hot water driven 30 kW H2O/LiBr-absorption chiller employed in a solar cooling system with a field of 350 m2 evacuated tube collector has been analyzed under part load conditions with both simulations and experiments. A simulation model has been developed for the whole absorption chiller (Type Yazaki WFC-10), where all internal mass and energy balances are solved. The connection to the external heat reservoirs of hot, chilled, and cooling water is done by lumped and distributed UA values for the main heat exchangers. In addition to an analytical evaporator model—which is described in detail—experimental correlations for UA values have been used for the condenser, generator, and solution heat exchanger. For the absorber, a basic model based on the Nusselt theory has been employed. The evaporator model was developed, taking into account the distribution of refrigerant on the tube bundle, as well as the change in operation from a partially dry to an overflowing evaporator. A linear model is derived to calculate the wetted area. The influence of these effects on cooling capacity and coefficient of performance (COP) is calculated for three different combinations of hot and cooling water temperature. The comparison to experimental data shows a good agreement in the various operational modes of the evaporator. The model is able to predict the transition from partially dry to an overflowing evaporator quite well. The present deviations in the domain with high refrigerant overflow can be attributed to the simple absorber model and the linear wetted area model. Nevertheless, the results of this investigation can be used to improve control strategies for new and existing solar cooling systems.

Fluid Mechanical Design of a Dry-Cooling System Thermal Storage Reservoir, or Stratification Minimization in Horizontal Channel Flow

1983 ◽  
Vol 105 (2) ◽  
pp. 174-180 ◽  
Author(s):  
E. C. Guyer ◽  
M. W. Golay
Keyword(s):  
Cold Water ◽  
Cooling System ◽  
Plug Flow ◽  
Cooling Water ◽  
Thermal Storage ◽  
The United States ◽  
Hot Water ◽  
Flow Mode ◽  
Storage Reservoir ◽  
Dry Cooling

The use of a capacitive Thermal Storage Reservoir (TSR) initially filled with cold water as part of a dry cooling system for a central power station is attractive economically if the reservoir can be designed to operate in an approximate “plug-flow” mode—discharging cold water to the condenser and filling with hot water from the cooling tower. Such a system would avoid the loss of station capacity associated with dry cooling at high dry-bulb temperatures, and the economic penalties due to such losses when they are coincident with electrical demand peaks (as is common in the United States). The initial employment of this concept is most likely to occur in solar-powered thermal electric power stations in arid climates in view of the likely low thermal efficiency and limited cooling water access of such plants. Buoyant flow stratification hinders attaining this goal since it can cause “short circuiting” of the TSR. For adequate flow control, a long narrow reservoir configuration is desirable. In investigating the behavior of such a TSR experimentally, it was found over the range of cases examined that injection of water into a long narrow reservoir which is initially at a different temperature always results in a stratified flow superimposed upon the gross plug flow of the TSR, and it was found that acceptable performance could be obtained inexpensively by placing flow-constricting barriers at regular intervals along the reservoir length. Experimental investigation of barrier design and spacing has permitted definition of a practical prototype TSR design which provides approximately 87 percent of the thermal capacity of a plug flow TSR.

scholarly journals Enhancement of Poly-Crystal PV Panels Performance by Air-to-Air Heat Exchanger Cooling System

2021 ◽  
Vol 16 ◽  
pp. 157-163
Author(s):  
Khaleel Abushgair
Keyword(s):  
Heat Exchanger ◽  
Cooling System ◽  
Ambient Air ◽  
Bottom Surface ◽  
Solar Panels ◽  
Pv System ◽  
System A ◽  
Pv Module ◽  
Back Panel ◽  
The Impact

The temperature of silicon Poly-Crystal photovoltaic (PV) solar panels has a significant impact on their efficiency emphasizing the necessity of cooling approach to be used. The current study looked at the impact of adopting a unique forced convictive air-to-air heat exchanger as a cooling approach to boost the efficiency of PV solar panels, as efficiency of silicon Poly-Crystal PV solar panels would decrease as its temperature increased. The research was carried out experimentally with both an uncooled and cooled PV system. A unique cooling system for PV panels was designed and experimentally investigated in Amman, Jordan included a heat exchanger connected to a blower that drove ambient air over the back-panel surface and a chimney to draw the cooled air outside. This cooling system would improve the PV panel's efficiency. It was found that by directing cooled air over the bottom surface of the PV module at an ideal rate of 0.01020 m3/s, the temperature of the PV module could be reduced from an average of 40 °C (without cooling) to 34 °C. As a result, the efficiency and output power of PV modules increased by roughly 2 % and 12.8 %, respectively.

scholarly journals РЕЗЕРВИ ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ТРАНСФОРМАЦІЇ ТЕПЛОТИ УСТАНОВКИ АВТОНОМНОГО ЕНЕРГОЗАБЕЗПЕЧЕННЯ

2019 ◽  
pp. 25-30
Author(s):  
Сергій Георгійович Фордуй ◽  
Андрій Миколайович Радченко ◽  
Анатолій Анатолійович Зубарєв ◽  
Володимир Володимирович Бойчук ◽  
Олексій Валерійович Остапенко
Keyword(s):  
Thermal State ◽  
Cooling System ◽  
Lithium Bromide ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Hot Water ◽  
Lubricating Oil ◽  
Air Conditioner ◽  
Piston Engine ◽  
Exhaust Heat

It is analyzed the efficiency of heat conversion in the integrated electricity, heat and cooling supply of the enterprise. The installation for energy supply includes two JMS 420 GS-N.LC GE Jenbacher cogeneration gas engines manufactured as cogeneration modules with heat exchangers for removing the heat of exhaust gases, scavenge gas-air mixture, cooling water of engine and lubricating oil. The heat of hot water is transformed by the absorption lithium-bromide chiller AR-D500L2 Century into the cold, which is spent on technological needs and for the operation of the central air conditioner for cooling the incoming air of the engine room, where from it is sucked by the turbocharger of the engine. The presence of significant heat losses, which account for about 30% of the total heat removed from the cogeneration gas piston module and is due to the inconsistency of the joint operation modes of the absorption lithium-bromide chiller and the gas piston engine, was revealed. This inconsistency is caused by the contradictory conditions of their effective operation according to the temperature of the return coolant at the outlet of the absorption lithium-bromide chiller and the entrance to the engine cooling system. The thermal state of the gas piston engine is ensured by maintaining the temperature of the return coolant at the entrance to it is not higher than 70 °C. At the same time, during the transformation of the heat of the coolant into the cold in an absorption lithium-bromide chiller, the temperature decreasing in the machine is no more than 10 ... 15 °С, that is, up to 75 ... 80 °С, if the temperature of the heat coolant outlet from the cogeneration gas piston module, i.e. at the inlet of the absorption lithium-bromide chiller, 90 °С. Therefore, the return coolant is additionally cooled in the "emergency heat release" radiator by removing its heat into surroundings. It is shown the possibility of increasing the cooling capacity of the system by conversion of the return coolant exhaust heat into cold in absorption lithium-bromide and ejector chillers through the data procession of monitoring the heat conversion system in the integrated energy plant.

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