The greenhouse design heat load is the main parameter of greenhouse heating and the basis of greenhouse heating design. This value is also the main basis for selecting heat dissipation equipment and air source heat pumps during design. Obviously, if this value is too large, the initial investment will increase and cause waste; if it is too small, it will not meet the use requirements and may cause serious losses in production.
In actual projects, since the outdoor temperature, wind speed, wind direction, light, etc. are constantly changing, the heat loss also changes with time. For the design of planting and breeding air source heat pump projects, a very unfavorable condition should be selected to calculate the heat required to be supplemented, that is, the greenhouse should maintain the required temperature and the heat obtained and lost in a certain period of time should be balanced.
In actual greenhouse projects, since the lowest outdoor environment temperature generally occurs in the second half of the night to the early morning, the heat supply requirement at this time is the largest, so the greenhouse design generally uses the air source heat pump heat supply at this moment as the heating design heat load.
There is no solar radiation at night, and there are generally no staff on site. Even if there are, the heat generation is very limited; the lighting or other electrical equipment in the greenhouse (such as window opening, curtain motor, circulation fan, etc.) are generally small and work for a short time, so their heat generation can be ignored. Generally, no materials enter or leave the greenhouse at night.
The heat transferred from the greenhouse is generally not ventilated at night, and the ventilation system does not work; the transpiration of plants at night is very weak, and the physiological and biochemical energy conversion of crops is relatively insignificant; generally, no materials enter or leave the greenhouse at night.
The greenhouse uses air source heat pumps for planting and breeding heat pumps, which are different from common civil air source heat pumps. The thermal inertia of common building materials (bricks, reinforced concrete, etc.) is relatively large. When the ambient temperature changes, it generally takes several hours to affect the room according to its different thermal inertia, and the fluctuation range is also small. Therefore, the heating design temperature of civil buildings uses the daily average temperature as the statistical calculation value.
The greenhouse design heat load is the main parameter of greenhouse heating and the basis of greenhouse heating design. This value is also the main basis for selecting heat dissipation equipment and air source heat pumps during design. Obviously, if this value is too large, the initial investment will increase and cause waste; if it is too small, it will not meet the use requirements and may cause serious losses in production.
In actual projects, since the outdoor temperature, wind speed, wind direction, light, etc. are constantly changing, the heat loss also changes with time. For the design of planting and breeding air source heat pump projects, a very unfavorable condition should be selected to calculate the heat required to be supplemented, that is, the greenhouse should maintain the required temperature and the heat obtained and lost in a certain period of time should be balanced.
In actual greenhouse projects, since the lowest outdoor environment temperature generally occurs in the second half of the night to the early morning, the heat supply requirement at this time is the largest, so the greenhouse design generally uses the air source heat pump heat supply at this moment as the heating design heat load.
There is no solar radiation at night, and there are generally no staff on site. Even if there are, the heat generation is very limited; the lighting or other electrical equipment in the greenhouse (such as window opening, curtain motor, circulation fan, etc.) are generally small and work for a short time, so their heat generation can be ignored. Generally, no materials enter or leave the greenhouse at night.
The heat transferred from the greenhouse is generally not ventilated at night, and the ventilation system does not work; the transpiration of plants at night is very weak, and the physiological and biochemical energy conversion of crops is relatively insignificant; generally, no materials enter or leave the greenhouse at night.
The greenhouse uses air source heat pumps for planting and breeding heat pumps, which are different from common civil air source heat pumps. The thermal inertia of common building materials (bricks, reinforced concrete, etc.) is relatively large. When the ambient temperature changes, it generally takes several hours to affect the room according to its different thermal inertia, and the fluctuation range is also small. Therefore, the heating design temperature of civil buildings uses the daily average temperature as the statistical calculation value.
