In order to explore the influence of water velocity on the heat collection performance of the active heat storage and release system for solar greenhouses,six different flow rates were selected for treatment in this e...In order to explore the influence of water velocity on the heat collection performance of the active heat storage and release system for solar greenhouses,six different flow rates were selected for treatment in this experiment.The comprehensive heat transfer coefficient of the active heat storage and release system at the heat collection stage was calculated by measuring the indoor solar radiation intensity,indoor air temperature and measured water tank temperature.The prediction model of water temperature in the heat collection stage was established,and the initial value of water temperature and the comprehensive heat transfer coefficient were input through MATLAB software.The simulated value of water temperature was compared with the measured value and the results showed that the best heat transfer effect could be achieved when the water flow speed was 1.0 m3h-1.The average relative error between the simulated water tank temperature and the measured value is 2.70-6.91%.The results indicate that the model is established correctly,and the variation trend of water temperature can be predicted according to the model in the heat collection stage.展开更多
Greenhouse Building Energy Simulation(BES)models were developed to estimate the energy load using TRNSYS(ver.16,University of Wisconsin,USA),a commercial BES program.Validation was conducted based on data recorded dur...Greenhouse Building Energy Simulation(BES)models were developed to estimate the energy load using TRNSYS(ver.16,University of Wisconsin,USA),a commercial BES program.Validation was conducted based on data recorded during field experiments.The BES greenhouse modeling is reliable,as validation showed 5.2%and 5.5%compared with two field experiments,respectively.As the next step,the heating characteristics of the greenhouses were analyzed to predict the maximum and annual total heating loads based on the greenhouse types and target locations in the Republic of Korea using the validated greenhouse model.The BES-computed results indicated that the annual heating load was greatly affected by the local climate conditions of the target region.The annual heating load of greenhouses located in Chuncheon,the northernmost region,was 44.6%higher than greenhouses in Jeju,the southernmost area among the studied regions.The regression models for prediction of maximum heating load of Venlo type greenhouse and widespan type greenhouse were developed based on the BES computed results to easily predict maximum heating load at field and they explained nearly 95%and 80%of the variance in the data set used,respectively,with the predictor variables.Then a BES model of geothermal energy system was additionally designed and incorporated into the BES greenhouse model.The feasibility of the geothermal energy system for greenhouse was estimated through economic analysis.展开更多
基金National Natural Science Foundation of Sichuan Province(Project No.:2022NSFSC1645)Key R&D Program Project of Xinjiang Province(Project No.:2023B02020)National Agricultural Science and Technology Innovation System Sichuan Characteristic Vegetable Innovation Team Project,Sichuan Innovation Team Program of CARS(Project No.:SCCXTD-2024-22)。
文摘In order to explore the influence of water velocity on the heat collection performance of the active heat storage and release system for solar greenhouses,six different flow rates were selected for treatment in this experiment.The comprehensive heat transfer coefficient of the active heat storage and release system at the heat collection stage was calculated by measuring the indoor solar radiation intensity,indoor air temperature and measured water tank temperature.The prediction model of water temperature in the heat collection stage was established,and the initial value of water temperature and the comprehensive heat transfer coefficient were input through MATLAB software.The simulated value of water temperature was compared with the measured value and the results showed that the best heat transfer effect could be achieved when the water flow speed was 1.0 m3h-1.The average relative error between the simulated water tank temperature and the measured value is 2.70-6.91%.The results indicate that the model is established correctly,and the variation trend of water temperature can be predicted according to the model in the heat collection stage.
基金This work was carried out with the support of the“Cooperative Research Program for Agriculture Science&Technology Development(Project No.PJ009412)”Rural Development Administration,Republic of Korea.
文摘Greenhouse Building Energy Simulation(BES)models were developed to estimate the energy load using TRNSYS(ver.16,University of Wisconsin,USA),a commercial BES program.Validation was conducted based on data recorded during field experiments.The BES greenhouse modeling is reliable,as validation showed 5.2%and 5.5%compared with two field experiments,respectively.As the next step,the heating characteristics of the greenhouses were analyzed to predict the maximum and annual total heating loads based on the greenhouse types and target locations in the Republic of Korea using the validated greenhouse model.The BES-computed results indicated that the annual heating load was greatly affected by the local climate conditions of the target region.The annual heating load of greenhouses located in Chuncheon,the northernmost region,was 44.6%higher than greenhouses in Jeju,the southernmost area among the studied regions.The regression models for prediction of maximum heating load of Venlo type greenhouse and widespan type greenhouse were developed based on the BES computed results to easily predict maximum heating load at field and they explained nearly 95%and 80%of the variance in the data set used,respectively,with the predictor variables.Then a BES model of geothermal energy system was additionally designed and incorporated into the BES greenhouse model.The feasibility of the geothermal energy system for greenhouse was estimated through economic analysis.
