The weather is getting colder and colder. Do you know how to raise the temperature in a glass greenhouse?

The temperature control in the glass greenhouse is required to maintain the set temperature suitable for crop growth, with uniform spatial distribution and gentle time change. Its control measures mainly include heat preservation and heating.

1. Heat Preservation

First, heat transfer through the covering material of the envelope structure (wall, transparent roof, etc.); The second is the air exchange heat transfer through the gap air leakage; Three is the ground heat transfer with soil heat exchange. These three kinds of heat transfer account for 70% ~ 80%, 10% ~ 20% and less than 10% of the total heat dissipation respectively. As a result of various heat dissipation effects, the thermal insulation capacity of single-layer unheated greenhouse and plastic greenhouse is relatively small. Even if they are well sealed, the temperature at night is only 2 ~ 3℃ higher than the outside temperature. On windy sunny nights, there are sometimes temperature inversions in which the indoor temperature is lower than the outside temperature. Specific insulation measures are as follows:

(1) Reduce ventilation volume;

(2) Multi-layer covering insulation; Can be used in greenhouse or greenhouse set small arch shed, small arch shed coat in the arch shed, big arch shed on both sides of the grass curtain, greenhouse, big arch shed plus activity type insulation curtain and other multi-layer coverage method, have obvious insulation effect.

(3) The solar greenhouse built into semi-underground or appropriate will reduce the height of the room, reduce the heat dissipation area of the night protection facilities, but also to improve the indoor day and night temperature and ground temperature.

(4) The greenhouse adopts high ridge mulching cultivation, with more organic fertilizer and less chemical fertilizer, because the redecomposition process of organic fertilizer releases a lot of heat and raises the temperature in the greenhouse, while the fertilizer is on the contrary.

(5) Reduce transverse heat conduction loss; Try to use water that has been preheated in the greenhouse. Do not water on cloudy days or at night.

Two, heating

Heating measures mainly include: (1) heating stove coal fire; (2) boiler heating;

Generally, most of them use stove coal fire heating, and in recent years, they also use boiler heating or geothermal heating. Hot water or steam can also be used to convert into hot air heating. Most plastic greenhouses have no heating equipment, and a few try short-term heating of hot blast furnaces, which has obvious effect on improving production and output value in advance. The radiation heating method of LPG through combustion furnace also has significant effect on protecting greenhouses from freezing damage.