Research On Indoor Characteristics By Hot Air Heating Of Greenhouse In Cold Area

Due to its geographical location,Northeast China's winter is very cold and less solar radiation,but agricultural greenhouses is a major industry of northeast economic development.Due to the geographical location,the winter in northeast China is cold,and the solar radiation energy is relatively low.Compared with other places,the thermal insulation and heating over the winter of greenhouses in cold areas are more important How to maximize the solar energy,how to better achieve thermal insulation,and how to use heating to ensure the greenhouse temperature uniformity requirements are the focus of this paper.This paper takes greenhouse greenhouses in Harbin,Heilongjiang Province as the research object and carries out the following researches:(1)Greenhouse was established based on software Energy Plus,3 d model,load characteristics was made on the basis of optimizing the structure in the greenhouse,calculated in the total load,heating load and the load of the hour of the season,then simulated to study the effect of heat insulation foundation load inside the greenhouse,and the effect of heat insulation membrane layer inside the shed load,conclude that shed light is greater than the influence of the thermal ground heat dissipation,it is cold and greenhouses energy saving measures must be taken.(2)The characteristics of the greenhouse were analyzed specifically.Due to the large span of the greenhouse and the low height of the rectangular frame,it was easy to have uneven airflow in the space,which led to the problem of temperature partitioning.Four different air supply modes were designed for the greenhouse,and Airpak preliminary modeling preparation and grid division were carried out.(3)The software Airpak was used to build a 3d model of the greenhouse.Based on the completion of load calculation,an all-air air supply system was designed to simulate the temperature field,humidity field and airflow field of the greenhouse during the day and at night under four different air supply modes,and the optimal air supply mode was selected for both sides.The research results of this subject can guide the scientific design of greenhouses and provide theoretical guidance for the design of enclosure structure and heating system of greenhouses in northeast China.