Gas-driven refrigeration

Compressed refrigeration and air conditioning systems driven by internal combustion engines or gas turbines have gone to the market to replace some electric-driven compressed refrigeration and air conditioning systems. The widespread use of the system saves a lot of energy, reduces investment in electricity, and extends the service life of the compressor, and improves energy efficiency.

According to the driving force of pumping heat energy can be divided into the following three categories:

1. Compressed refrigeration driven by natural gas engine

The refrigerant used in refrigeration is mostly fluorocarbon, refrigerant only phase change, the power engine mainly uses electric motor. In recent years, the principle of natural gas engine is promoted as shown in the following figure. Instead of motor drive, it can adjust the refrigeration capacity flexibly, with higher efficiency in some load, and the total operation cost is low.

2.heat-driven absorption refrigeration

The working medium is used as substances with significantly different evaporation temperature, the components with lower evaporation temperature are refrigerant, and the components with higher evaporation temperature are absorbent. In the process of refrigeration cycle, the working medium pair only concentration change, no chemical change. Its driving force is natural gas combustion heat or a variety of heat sources, or even waste heat.

The principle of the absorption refrigeration system is shown in the following figure. The main differences between the refrigeration system and the compression refrigeration system are: the generator, absorber and solution pump replace the compressor; the heat energy replaces electric energy or mechanical energy; the cooling production is the working medium is heated in the generator to produce water vapor, condensed into liquid water in the condenser, and the evaporator through the throttle valve.

3.desiccant dehumidification system

Refrigeration and air conditioning system is generally to let the air cooling, remove the moisture in the air, that is, latent heat cooling, and cooling, that is, significant thermal cooling. Substant thermal cooling often consumes half of the cooling energy. The adsorption (absorption) system using desiccant is to directly remove air moisture without cooling air. The combination of drying system and cooling system can flexibly control the humidity and temperature of the air.

The combined system can avoid the condensate in the catheter during single cooling, which can reduce the humidity of indoor items, reduce mold growth and improve air quality; low humidity can make the human body feel comfortable at higher temperature. For example, when the relative humidity is low to 30%, the feeling is as comfortable as the temperature drops by 2℃; low humidity allows the cooler temperature setting value in the air conditioner to increase and save energy; using the drying system can reduce the load of the refrigeration system, and save the investment and operation cost. The drying system is suitable for low dew points or where latent thermal cooling and sensible thermal cooling load are high.