| With the continuous development and expansion of the field of livestock and poultry breeding,the problems of breed,feed and epidemic prevention in livestock and poultry breeding industry have been basically solved,but the quality of breeding environment is still one of the important factors restricting the level of production and breeding.In view of the large amount of ammonia in the livestock and poultry house,it is not suitable to use the end of the air conditioning system in wet condition,so the capillary radiation grid is used as the end equipment of the air conditioning system in this paper.The most outstanding advantage of capillary grid radiant air conditioning system is that it can effectively use low-grade energy to meet the needs of building heating and cooling,so it is widely used.In the design of radiant air conditioning system,it is necessary to determine the temperature of water supply and cooling capacity at the radiation end.The temperature of water supply and return not only directly affects the surface temperature of capillary roof,but also condensation will occur when the surface temperature of capillary roof is lower than the dew point temperature of indoor air.In addition,the temperature of water supply and return directly affects the cooling and heating capacity of the capillary roof,so the temperature of water supply and return at the radiation end is the key factor affecting the capillary radiation air conditioning system.In this paper,the ground source heat pump and capillary grid radiation air conditioning system are used in Xingan County of Jiangxi Province.In view of establishing CFD model alone,it can only simulate the distribution of indoor temperature field and wind speed field,which is difficult to realize online control.TRNSYS can realize the simulation of dynamic on-line control,but in each time step of the simulation operation,assuming that the indoor air is evenly mixed,the temperature,wind speed,relative humidity and other parameters are equal at any place,it is impossible to predict the air distribution in the air-conditioned room.Based on this,this paper first simulated the distribution of temperature field in the delivery pigsty under different water supply temperature by FLUENT software and analyzed it.Based on the simulation results of fluent,the TRNSYS ground source heat pump + capillary grid radiant air conditioning system simulation model is established to simulate the influence of water supply temperature on indoor temperature and cooling capacity of capillary grid radiant air conditioning system,and the optimal water supply temperature of capillary network is analyzed.At the same time,compared with the changes of indoor temperature,unitperformance coefficient and system energy consumption in summer under different depth of ground source heat pump system buried pipe,the optimal buried pipe depth of ground source heat pump system is analyzed,which verifies that the operation of ground source heat pump +capillary grid radiation air conditioning system under this condition is in line with the indoor design parameters of delivery pig house in summer,and the indoor thermal environment effect is good.First of all,this paper selects 20?,18?,16? and 14? water supply temperature conditions in fluent simulation scheme to analyze the influence of different water supply temperature on indoor temperature.The results show that the high temperature cold water supply at the end of capillary in summer basically meets the temperature requirements of delivery pig house,and the water supply temperature of capillary network has a great impact on indoor thermal environment.Reducing the water supply temperature will improve the cooling capacity of capillary network.The indoor temperature will increase about 0.6 ~ 1.2?when the water supply temperature increases by 2?.However,the decrease of water supply temperature is accompanied by the possibility of condensation.Considering the design temperature requirements of pigsty,the water supply temperature should not be lower than16?.Based on this,the simulation model of ground source heat pump + capillary grid radiant air conditioning system is established by TRNSYS,and the influence of different water supply temperature on the cooling capacity per unit area of capillary grid is analyzed.The results show that the cooling capacity of capillary network decreases with the increase of water supply temperature,which is approximately linear.The cooling capacity per unit area decreases about 9.7w/m2 for every 2 ? increase of water supply temperature,while the improvement of cooling capacity of capillary network is not obvious by water supply flow.Considering comprehensively,the water supply temperature is set at 16 ?.Then,the parameters such as outlet temperature,unit performance and system energy consumption are simulated and analyzed when the horizontal buried pipe of GSHP system is in different depth.It is concluded that with the increase of buried pipe depth,the outlet temperature of horizontal buried pipe decreases gradually,and the energy efficiency ratio EER increases gradually.After determining the best buried pipe depth of GSHP system and the best water supply temperature of capillary network,the parameters of simulation model components of GSHP +capillary grid radiation air conditioning system are set.The simulation results show that the indoor temperature is between 24.72 ? and 27.61 ?,the indoor average temperature is25.62?,the indoor action temperature is between 23.7? and 26.1?,and the indoor average action temperature is 24.68?,It can meet the requirements of relevant parameters of summer delivery pig house,and the indoor thermal environment effect is better.This study proves that CFD technology not only provides an economic and practical method for the study of thermal environment in livestock and poultry houses,but also provides a solution for the optimization of energy saving of radiation cooling and heating inlivestock and poultry houses,which has certain theoretical significance and engineering practical value. |
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