To make refrigeration greener, the ancients got a trick thousands of years ago

The proposal of the "dual carbon" goal will push the refrigeration and air-conditioning industry to develop in the direction of energy conservation, greenness and low carbon in the future. Making full use of natural cold sources will become one of the important ways to reduce air conditioning energy consumption.

Natural cooling source refers to the use of natural cooling sources in nature to provide cooling for air-conditioning systems, including evaporative cooling technology, heat pipe cooling technology, direct fresh air cooling technology and fluorine pump cooling technology.

Among them, evaporative cooling technology is a process of cooling the air by evaporating water. Water absorbs the heat of the air and evaporates to cool the air. The drier the air, the stronger its ability to hold water. When water is sprayed on the air, the greater the degree of reduction in air temperature. If tap water or well water with lower temperature is used, the cooling effect of the air will be better.

Compared with traditional air conditioners, evaporative cooling technology air conditioners reduce the use of Freon and can effectively protect the atmospheric environment. Therefore, they are also called "green air conditioners". They are a truly energy-saving, environmentally friendly and sustainable refrigeration and air-conditioning technology.

This environmentally friendly and low-carbon evaporative cooling technology was actually known and used by the ancients thousands of years ago. The Han Dynasty inventor Ding Huan invented the seven-wheel fan, "a seven-wheel fan with seven wheels, each with a diameter of one meter (Volume 1 of "Xijing Miscellaneous Records")", and later generations used hydraulic power to drive it and introduce water flow to the location of air flow, using evaporative cooling to lower the air temperature, making people feel "cool and rustling, not silk or bamboo, but the sound of nature heard from afar (Qianlong's "Forty Scenes of Yuanmingyuan")".

Nowadays, with the development of society, air conditioners and multi-split units that use electricity to drive refrigeration have entered thousands of households. Evaporative cooling has also evolved from an extremely simple ventilation and cooling method to an energy-saving and green technology that utilizes renewable energy such as dry air. Currently, this refrigeration technology has been widely used in my country's industrial buildings, power plants (nuclear power plants), public buildings, rail transit, data centers and outdoor places, and has achieved good results.

Subway Operations

Taking rail transit as an example, the operating capacity of the subway is constantly improving and the station load is continuously increasing. While ensuring that the public areas have sufficient cooling capacity, the subway stations use variable frequency fans and direct evaporative cooling units to adjust the temperature and humidity of the supply air. At the same time, intelligent environmental control methods are used to regulate the direct evaporative cooling ventilation and air-conditioning system to bring coolness to the public areas of the station hall and platform.

In the future, green refrigeration based on evaporative cooling technology will inject strong momentum into green development and contribute more wisdom and strength to global energy conservation, emission reduction and low-carbon transformation.

Audit expert: Zheng Chaochao, Senior Engineer, China Electronics Engineering Design Institute

China Association for Science and Technology Department of Science Popularization

Xinhuanet

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