How to design the ground anti-freezing ventilation and overhead layer of cold storage？

‌ According to the cold storage design standard GB50072-2021, there are four antifreeze methods for the cold storage floor, including natural ventilation, mechanical ventilation, overhead layer design and antifreeze heating pipe (this scheme is not included, Sheron freezing note).。

First, the ground natural ventilation: the use of natural ventilation of the ground anti-freezing design should meet the following requirements:

1. Both ends of the natural ventilation pipe should be straight through and slope to the outside。The total length of the straight pipe should not be greater than 30 meters, and the length under the ground of the cold room should not be greater than 24 meters。

2. The diameter of the ventilation pipe should be cement pipe with an inner diameter of 250mm or 300mm, and the center distance of the pipe should not be greater than 1.2 meters, the bottom end of the pipe mouth should be 150mm higher than the ground, the pipe mouth should be added to the grid。

3, the layout of the ventilation pipe should be parallel to the local maximum frequency wind direction in summer。

Second, mechanical ventilation: The use of mechanical ventilation of the ground anti-freezing design should meet the following requirements:

1. The diameter of the branch ventilation pipe should be cement pipe with an inner diameter of 250mm or 300mm, and the center distance of the pipe should be 1.5-2.0 m equidistant arrangement, the wind speed in the pipe is uniform, should not be less than 1m/s。

2. The section area of the main air duct should not be less than 0.8*1.2m(W * H)。

3. The supply air temperature in the heating area should be 10°C, and the exhaust air should be 5°C。

3. Aerial building antifreeze: The ground antifreeze design using aerial antifreeze should meet the following requirements:

1. The overhead ground inlet and outlet is 150mm higher than the ground, and the inlet should be added with a grid。

2, the overhead layer should not be less than 1 meter。

3, the overhead layer air intake should face the local maximum frequency wind direction in summer。