| With the in-depth promotion of the national rural revitalization strategy,the solar greenhouse industry has been developing rapidly,and it has become an important pillar industry of China’s agricultural economy.In the process of continuous development of solar greenhouse industry,the production of solar greenhouse is also faced with urgent problems,especially the problem of low temperature and high humidity in winter greenhouse.When the humidity in the greenhouse is too high,it will cause greenhouse crops to induce a variety of diseases,crop yield loss is greater,serious may fail to yield.In order to solve the greenhouse humidity problems in the production process,combined with the growth of greenhouse crop demand,this article is based on the principle of refrigeration dehumidification and heat recovery technology,as the research object,with refrigeration dehumidifier for solar greenhouse in winter low temperature and humidity environment requirements as the background,using the methods of experiment,the emphasis was on the performance of refrigeration dehumidifier,the main research contents are as follows.First of all,by means of literature materials and visiting experts and so on,according to the present our country winter sunlight greenhouse crops commonly performed research hot wet environment demand,the results show that indoor air temperature in winter of the majority of greenhouse in China any deviation from the suitable temperature and humidity of greenhouse crops(25 and 30℃temperature humidity 60%to 80%during the day and night temperature humidity 60%80%10-15℃)requirements,based on the sunlight greenhouse dehumidification requirements,to meet the dehumidification air temperature in the greenhouse crop growth needs,combined with heat recovery technology,developed a type of compact type low temperature refrigeration dehumidification system prototype.Secondly,in view of the proposed compact low-temperature refrigerating dehumidification device prototype,the wind tunnel test method was adopted to build the refrigerating dehumidification device performance test bench,and the selection of various equipment needed in the test bench to be built was determined.In addition,the experimental scheme,experimental steps and the processing of experimental data are described in detail,and the evaluation parameters of the performance of the dehumidifier are determined.Thirdly,the wind tunnel test platform of indoor refrigerating dehumidification device is built.For the performance of the refrigeration dehumidification devices,trial design for 60 group experiment condition,by changing the circulating air volume,temperature and relative humidity to study the impact of the three variables of the various indicators,each index respectively,the water condensation rate(D),the input power(P),unit capacity input power(DCPP),heating capacity(Q),the heating coefficient of performance(COP),through the study found that three variables affect the performance of dehumidification devices are as follows:(1)the dehumidification capacity of the refrigerating dehumidification device and the dehumidification amount per unit input power are related to the external parameters of temperature and relative humidity,and also related to the circulating air volume.With the increase of the inlet temperature and relative humidity of the dehumidification device,both increase together,and there is an optimal air volume to maximize the two parameters.The optimal air volume is related to relative humidity in the experimental range,but has no obvious relationship with temperature.The optimal recommended air volume is675m~3/h when the relative humidity is greater than 80%,and 540m~3/h when the relative humidity is less than 80%.Under the low temperature condition of 8℃,relative humidity of 90%and different air volume,COP is 1.68,1.77,1.58,1.28.Other performance parameters of refrigerant dehumidification device,such as input power,heat supply and heat supply performance coefficient,are related to the temperature and relative humidity of the external environmental parameters,which increase with the increase of the inlet temperature and relative humidity of the dehumidification device.Except COP,there is no obvious optimal air volume to maximize it.Therefore,the maximum optimal air volume of COP is 540m~3/h.The heating capacity of the refrigerated dehumidifier has a certain positive effect on the greenhouse environment no matter in what kind of working conditions.The theoretical heating capacity of the refrigerated dehumidifier is 3278 k J/h,3715k J/h,3404 k J/h and 3079 k J/h under the low temperature working conditions of 8℃and different air flows with relative humidity of 90%.(3)the direct condition affecting the frosting of the refrigerating dehumidifier is the inlet temperature of the dehumidifier.When the inlet temperature of the dehumidifier is less than or equal to 14℃in the experimental range,the dehumidifier will certainly face the risk of frosting.The frosting and defrosting process of refrigerating dehumidifier directly affect the performance of the dehumidifier.Especially when the inlet temperature is less than or equal to 8℃,the pressure difference of the dehumidifier increases significantly.Finally,again on the basis of the use of refrigerated dehumidification device in solar greenhouse recommendations are recommended that the temperature range of refrigerated dehumidification device is greater than or equal to 8℃,the air volume used changes with the relative humidity,in the face of high humidity environment when the relative humidity is less than 80%,the rated air volume of 540m~3/h is better;When the relative humidity is greater than 80%,the recommended air volume is 675 m~3/h. |
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