The research goal is to develop a new solar water heater system(SWHS) that uses a solar bubble pump instead of an electric pump.The pump is powered by the steam produced from an evacuated tube collector.Therefore,heat...The research goal is to develop a new solar water heater system(SWHS) that uses a solar bubble pump instead of an electric pump.The pump is powered by the steam produced from an evacuated tube collector.Therefore,heat could be transferred downward from the collector to a hot water storage tank.The designed system consists of two sets of heat-pipe evacuated tube collectors,a solar bubble pump installed at an upper level and a water storage tank with a heat exchanger at a lower level.Discharge heads of 1 and 5 m were tested.The bubble pump could operate at the collector temperature of about 90-100 ℃ and vapor gage pressure of 80-90 kPa.It is found that water circulation within the SWHS depends on the incident solar intensity and system discharge head.Experimental investigations are conducted to obtain the system thermal efficiencies from the hourly,daily and long-term performance tests.The thermal performance of the proposed system is compared with conventional solar water heaters.The results show that the proposed system achieves system characteristic efficiency of 10% higher than that of the conventional systems using electric pump if taking the consumption of electric power into account.And the former is a zero carbon system.展开更多
A two-meter parabolic solar concentration dish has been modulated to produce boiled water over 100℃ for various purposes of central heating services. For an effective performance, the system required both continuous ...A two-meter parabolic solar concentration dish has been modulated to produce boiled water over 100℃ for various purposes of central heating services. For an effective performance, the system required both continuous exposure of the dish to sunlight during the day time as well as to an electric control circuit （tracking system）. The amount of the potable water was dependent particularly on the accurate centering of the system which could increase upon preheating. This system has therefore been possible to heat up water at home via increasing the temperature in hot tank by both covering the hot water tank and isolating it from the surroundings using insulators. Applications of a successful parabolic solar concentration has also been designed to provide desalinated water for domestic usage which operates with temperatures higher than other types of the solar radiation for the future.展开更多
This experimental analysis shows the measured reduction in energy consumption as well as the effects of voltage on cycle temperatures, pressures, flow rates and also compressor speed （revolutions per minute）. The do...This experimental analysis shows the measured reduction in energy consumption as well as the effects of voltage on cycle temperatures, pressures, flow rates and also compressor speed （revolutions per minute）. The domestic refrigerator used R134a as refrigerant. Two energy consumption procedures were adapted from the JIS and ISO standards. The biggest difference between two standards is that the fridge is not opened in the ISO test while it is opened a number of times in the JIS test. The tests were carried out between 190 V and 250 V in steps of 10 V. The reduction in energy consumption was of 49.78 W-h per day or 6.27% of the total consumption. The experiments also showed that the voltage drop resulted in only a small rpm drop which in turn did not result in a noticeable refrigerant flow-rate change. Consequently the temperatures and pressures were not affected.展开更多
The seasonal heat storage tank is the most important component of the SDH （solar district heating） system, which allows significant increase in the share of solar energy in heat supply in comparison with conventiona...The seasonal heat storage tank is the most important component of the SDH （solar district heating） system, which allows significant increase in the share of solar energy in heat supply in comparison with conventional solar systems with short-term accumulation of heat. The adverse impact of their investment sophistication on competitiveness may be compensated by the increased use. For example： Cooperation with heat pump allows to increase the accumulation capacity of the seasonal heat storage tank and causes the direct use of heating energy and accumulation of cooling energy produced by heat pump. In the final stage of the heating period, it can be used to remote cooling supplied buildings. Experimentation on mathematical model is possible to obtain valuable insights about the dynamics of the processes of charging and discharging in the seasonal storage tank and subsequently used in the design, implementation and operation.展开更多
基金Project(2011-0021376) supported by Basic Science Program through the National Research Foundation (NRF) Funded by the Ministry of Education,Science and Technology of Korea
文摘The research goal is to develop a new solar water heater system(SWHS) that uses a solar bubble pump instead of an electric pump.The pump is powered by the steam produced from an evacuated tube collector.Therefore,heat could be transferred downward from the collector to a hot water storage tank.The designed system consists of two sets of heat-pipe evacuated tube collectors,a solar bubble pump installed at an upper level and a water storage tank with a heat exchanger at a lower level.Discharge heads of 1 and 5 m were tested.The bubble pump could operate at the collector temperature of about 90-100 ℃ and vapor gage pressure of 80-90 kPa.It is found that water circulation within the SWHS depends on the incident solar intensity and system discharge head.Experimental investigations are conducted to obtain the system thermal efficiencies from the hourly,daily and long-term performance tests.The thermal performance of the proposed system is compared with conventional solar water heaters.The results show that the proposed system achieves system characteristic efficiency of 10% higher than that of the conventional systems using electric pump if taking the consumption of electric power into account.And the former is a zero carbon system.
文摘A two-meter parabolic solar concentration dish has been modulated to produce boiled water over 100℃ for various purposes of central heating services. For an effective performance, the system required both continuous exposure of the dish to sunlight during the day time as well as to an electric control circuit （tracking system）. The amount of the potable water was dependent particularly on the accurate centering of the system which could increase upon preheating. This system has therefore been possible to heat up water at home via increasing the temperature in hot tank by both covering the hot water tank and isolating it from the surroundings using insulators. Applications of a successful parabolic solar concentration has also been designed to provide desalinated water for domestic usage which operates with temperatures higher than other types of the solar radiation for the future.
文摘This experimental analysis shows the measured reduction in energy consumption as well as the effects of voltage on cycle temperatures, pressures, flow rates and also compressor speed （revolutions per minute）. The domestic refrigerator used R134a as refrigerant. Two energy consumption procedures were adapted from the JIS and ISO standards. The biggest difference between two standards is that the fridge is not opened in the ISO test while it is opened a number of times in the JIS test. The tests were carried out between 190 V and 250 V in steps of 10 V. The reduction in energy consumption was of 49.78 W-h per day or 6.27% of the total consumption. The experiments also showed that the voltage drop resulted in only a small rpm drop which in turn did not result in a noticeable refrigerant flow-rate change. Consequently the temperatures and pressures were not affected.
文摘The seasonal heat storage tank is the most important component of the SDH （solar district heating） system, which allows significant increase in the share of solar energy in heat supply in comparison with conventional solar systems with short-term accumulation of heat. The adverse impact of their investment sophistication on competitiveness may be compensated by the increased use. For example： Cooperation with heat pump allows to increase the accumulation capacity of the seasonal heat storage tank and causes the direct use of heating energy and accumulation of cooling energy produced by heat pump. In the final stage of the heating period, it can be used to remote cooling supplied buildings. Experimentation on mathematical model is possible to obtain valuable insights about the dynamics of the processes of charging and discharging in the seasonal storage tank and subsequently used in the design, implementation and operation.
