| Ventilation plays a very important role in the production of solar greenhouse.Solar greenhouse needs ventilation system to regulate and control indoor temperature and humidity,and provide a suitable growth environment for plant growth.Using wet curtain ventilation system to cool solar greenhouse in summer,using natural ventilation to cool down in transition season,using heat recovery ventilation in winter,can better realize energy saving and environmental control.Green agriculture plays an important role in the journey to carbon peak and carbon neutrality.In this study,Energy Plus software was used to realize the continuous operation of solar greenhouse model all year round,and to carry out the numerical simulation of energy consumption optimization of solar greenhouse ventilation.In this paper,Sketchup was first used to build a solar greenhouse model.Taking cucumber cultivation environment control as an example,the influences of different ventilation conditions and shading conditions on solar greenhouse environment were analyzed by using Energy Plus module.The effects of covering thermal insulation and adding ventilation and heat recovery measures on solar greenhouse environment were analyzed.The most energy saving ventilation opening temperature and vent area,as well as the length and height of shading,and the covering period of insulation are selected.On this basis,the effects of various measures on solar greenhouse load,temperature and energy consumption are studied,and the heating cost of solar greenhouse in winter is analyzed.The main research results are as follows:（1）The natural ventilation model,wet curtain model,shading model,insulation blanket model,air source heat pump model,ventilation and heat recovery model of solar greenhouse were established.In terms of load reduction,Energy Plus was used to obtain the load values of each season.In summer and transition seasons,natural ventilation can reduce the load.The ventilation opening range of the minimum cooling load in summer is when the indoor temperature is 26-32℃ and the outdoor temperature is less than 30℃,and the natural ventilation opening area of the minimum cooling load is 180 m~2.The natural ventilation opening temperature range with the lowest transitional seasonal load is when the indoor temperature is 26-32℃ and the outdoor temperature is less than 30℃.The ventilation area with the lowest load is 100 m~2.The longer the shading time,the lower the cooling load of solar greenhouse.The lower the height of sunshade,the lower the cooling load of solar greenhouse;In winter and transition season,the thermal load is obviously reduced by covering the thermal insulation at night.（2）In terms of temperature reduction,natural ventilation was opened in summer and transition season,and the cooling effect was obvious.The temperature was greatly reduced when the sun visor was added,and the growth trend became slow in the warming stage.The maximum outdoor temperature in summer is 37℃,and the indoor temperature is between 18℃and 31℃ after treatment,which proves the cooling effect of the combined operation system of sun shading,natural ventilation and wet curtain.In terms of increasing the room temperature,the temperature is greatly improved by covering the insulation quilt.The night temperature in winter is as low as-12℃.Under the operation of air source heat pump combined with ventilation heat recovery and insulation quilt system,the temperature in the whole winter is increased from 16℃ to 26℃,and the heating effect is remarkable.（3）In terms of energy consumption,the power consumption of ventilation opening in summer is reduced by 51% on average;In transition season,the power consumption of opening ventilation is reduced by 86.7% on average in the period without insulation cover.In the transition season,the power consumption of thermal insulation was reduced by 47.6%.When ventilation heat recovery is added in winter,power consumption is reduced by 15% on average.Various ventilation and heating measures reduce energy consumption significantly.The COP of the total average heating coefficient in winter is 3.3.The COP of heating coefficient has the same variation trend with outdoor temperature,and the COP is larger when the ambient temperature is higher.In summer,the solar greenhouse with shading,natural ventilation and wet curtain had the best energy saving effect.Under this mode,the power consumption in summer was 3633 k W·h.In winter,air source heat pump combined with ventilation heat recovery and insulation quilt has the best energy saving effect,and the total power consumption in winter is 12785 k W·h.Combined operation of shading and natural ventilation in transition season,heat preservation and heat pump assisted temperature control scheme has the best energy saving effect,with a total power consumption of 7490 k W·h.（4）In terms of heating costs,the system unit daily heating demand of 1041.42 k J/（m~2·d）,relative heating costs of 0.044 yuan/（m~2·d）,the heating system has obvious advantages in energy conservation and environmental protection,compared with coal-fired boilers,natural gas boilers,electric boilers respectively energy saving 78.8%,74%,71%.Through simulation,the best energy-saving operation strategy under annual operation conditions is obtained. |
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