Research trend of compression type heat pump and natural refrigerant

摘要

Compression type heat pumps are widely used because of their versatility. Conventionally, a natural refrigerantsuch as ammonia or ether has been used as a refrigerant of a compression type heat pump. However, it is no longer useddue to the risk of flammability and toxicity. Instead, fluorocarbon refrigerants have been used as a refrigerant forcompression type heat pumps. Fluorocarbon refrigerants are widely used because they are nonflammable and nontoxic.However, fluorocarbon refrigerants destroy the ozone layer and have a great impact on global warming. In the future,we will take a long time to fade out fluorocarbon refrigerants. Therefore, natural refrigerant is needed again.Technologies and evaluations for toxicity and danger also developed. As a result, refrigeration air conditioners usingnatural refrigerants have been developed. In this presentation, we will introduce the history of refrigerant and theresearch trend of compression type heat pump using natural refrigerant.