寒潮天气表冷器-风机集放热系统对连栋大棚热湿环境的影响  

Influences of air thermal energy utilization system with fan-coil units on the thermal and humid environment of multi-span tunnel in cold wave

作　　者：宗成骥 王平智[1,2] 陈先知 李明[1,2] 何雪颖[1] 王建玉 徐丹 宋卫堂 Zong Chengji;Wang Pingzhi;Chen Xianzhi;Li Ming;He Xueying;Wang Jianyu;Xu Dan;Song Weitang(College of Water Resources and Civil Engineering,China Agricultural University,Beijing 100083,China;Key Laboratory of Agricultural Engineering in Structure and Environment,Ministry of Agriculture and Rural Affairs,Beijing 100083,China;Wenzhou Vocational College of Science and Technology,Wenzhou Controlled-Environment Vegetable Engineering Center,Wenzhou 325000,China)

机构地区：[1]中国农业大学水利与土木工程学院,北京100083 [2]农业部设施农业工程重点实验室,北京100083 [3]温州科技职业学院,温州市设施蔬菜工程技术中心,温州325000

出　　处：《农业工程学报》2021年第15期214-221,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2020YFD1000300);浙江省科技计划项目(2019C02009);现代农业产业技术体系建设专项资金项目(CARS-23-C02)。

摘　　要：连栋塑料大棚棚内环境易受寒潮侵扰,为调节棚内热湿环境,将表冷器-风机集放系统应用于连栋塑料大棚中,在白天适宜条件下运行系统,将棚内空气盈余的热量收集并储存在蓄热水箱中,夜间气温较低时,再将储存的热量释放出来用以加温。对表冷器-风机集放热系统的运行效果进行试验,通过集热量、放热量和性能系数等评价集放热性能,并且将水气温差作为主要影响因素对系统运行阶段分别进行热流量分析和分析。结果表明,在寒潮下系统可以保证棚内气温比棚外高5.2~7.8℃。集热量达到了390.6~693 MJ,放热量为361.2~609 MJ,系统性能系数达到了4.4~7.2,节能效果较为显著。系统在运行过程中水气温差每增长1℃,集热流量增加0.82 kW,放热流量增加0.58 kW,单位时间内换热量较大;此外系统在集热阶段析湿系数约为1.70,表冷器-风机进出口空气含湿量差最高可达1.3×10^(-3) kg/kg,说明在集热阶段系统具有冷凝除湿的效果;同时在冷凝除湿过程中系统效率随着水气温差的增加而增加,最高可达到82.8%,能量利用率较高。该研究对保证连栋塑料大棚安全越冬生产具有重要意义。Multi-span plastic tunnel greenhouse has widely been used in the cultivation of vegetables,fruits,and flowers.However,it is easily suffered from freezing damage to crops,particularly from cold waves in winter.In this study,an air thermal energy utilization system was developed with the fan-coil units to effectively control the thermal and humid environment in the shed.A field experimented was also performed on a two-span plastic tunnel in Wenzhou city of China during the cold wave from January 8 to January 13,2021.The system was composed of fan-coil units,water reservoir,circulating water pump,supply and return water pipes,as well as control devices.The circulation of water in the system was utilized to collect and then store the surplus heat in the shed during the day,while finally released at night to heating the two-span plastic tunnel.In the collected phase,once the air temperature in the shed reached 15℃on the day,or it was 5℃higher than the water temperature in the water reservoir,the system was started until the air temperature dropped to 10℃,or it was 2℃lower than the water temperature.In the released phase,once the outside air temperature was below 2℃at night,or it was 4℃lower than the water temperature,the system was started to operate until the air temperature reached 5℃,or it was only 2℃higher than the water temperature.The collected and released performance of the system was evaluated using the collection and discharge heat,as well as heat flow,according to the change of water temperature in the experiment.The difference between water and air temperature was taken as the main influencing factor to analyze the heat flow in the collected and released phases.An exergy analysis of condensation dehumidification was also made during this time.The results showed that the system ensured the temperature inside the shed was 5.2-7.8℃to protect crops from freezing damage,higher than that outside the shed in cold waves.The heat collection was 390.6-693 MJ,while the heat release was 361.2-609 MJ.

关 键 词：设施 温度 连栋大棚 表冷器-风机 热湿环境 加温 除湿 

分 类 号：S625.2[农业科学—园艺学] S625.4