Low-temperature refrigeration method for recycling oil gas

Abstract

The invention discloses a cryogenic refrigeration method for oil gas recovery, comprising at least two stages of refrigeration system, which is characterized in that every stage of refrigeration system comprises a compressor, a condenser, an expansion valve and an evaporator, a refrigerant exchanges heat with the oil gas in the evaporator to condense and recovery the oil gas, the refrigerant of the first stage of refrigeration system passes the condenser of the next stage of refrigeration system and exchanges heat with the refrigerant of the next stage of refrigeration system after throttling. The cryogenic refrigeration method has the advantages that the condensation of the first stage of refrigeration system is heat exchange between the refrigerant and air, and the condensations of other stages are the heat exchange between refrigerants, so the heat exchange efficiency is greatly improved, compared to the air condensation, the temperature of the refrigerant in the condenser is greatly reduced, the temperature of the refrigerant can become more lower after throttling, thus recovering the oil gas with a more lower condensation temperature, the system needed in the cryogenic refrigeration method has simple structure, high operation efficiency, convenient operation and maintenance, high reliability, less initial investment and low running cost.

Description

technical field [0001] The invention relates to a low-temperature condensing device, which is used for recovering vapors of volatile substances, such as gasoline and alcohol. Background technique [0002] Volatile fuel such as gasoline produces a large amount of evaporation loss during storage, transportation, loading and unloading, forming fuel vapor. At present, the total evaporation loss of the oil product storage and transportation system of domestic refineries accounts for about 0.3% of the crude oil processing volume of the refinery, mainly due to storage and transportation losses. Fuel vapor is directly discharged into the atmosphere. On the one hand, it causes a lot of energy waste. On the other hand, the flammable and explosive oil gas poses a serious safety hazard. In addition, the volatilized oil gas contains various hydrocarbon gases. These hydrocarbon gases themselves are toxic to the human body, and the fuel vapor is prone to photochemical reactions with nitro...

AI Technical Summary

Problems solved by technology

Therefore, if each stage of the cooling and condensation process is equipped with independent refrigeration systems, and each refrigeration system produces a low temperature relative to the ambient temperature, the system of the condensation recovery device will be more complicated, with many components, large volume, and low operating efficiency. Difficulty in operation and maintenance, reduced reliability, and resulting in large initial investment and high operating costs for recovery devices

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