The invention discloses a refrigerating 
system which comprises a refrigerating compressor, a four-way 
reversing valve, three heat exchangers, a 
throttle mechanism, a gas-liquid separator, a refrigerating medium pump and four three-way reversing valves. The refrigerating compressor, the four-way 
reversing valve, the three heat exchangers, the 
throttle mechanism, the gas-liquid separator, the refrigerating medium pump and the four three-way reversing valves form a refrigerating 
fluid circulation sub 
system and a refrigerating medium circulation sub 
system together, and therefore dual purposes of 
refrigeration and heating through a 
heat pump are achieved. The four-way 
reversing valve and a refrigerating medium reversing mechanism composed of the three-way reversing valves can be omitted, so that only a single function of 
refrigeration or heating through the 
heat pump is achieved. Refrigerating fluid which is combustible, prone to explosion and poisonous is adopted, components in contact with the combustible and poisonous refrigerating fluid and the refrigerating medium pump generating 
noise are placed in a special 
machine room or placed outdoors, a refrigerating medium is made of safe matter which is good in environment-friendly performance, incombustible and free of poison such as water, 
carbon dioxide and the like, and 
phase change of the refrigerating medium, namely, 
latent heat of the refrigerating medium is used for conducting 
heat transfer. According to the refrigerating system, the refrigerating fluid which is combustible, prone to explosion and poisonous can be adopted and the refrigerating system has the advantages of being safe, 
environmentally friendly and capable of saving energy.