Refrigerant recovery process and system of refrigerating system

Abstract

The invention relates to a refrigerant recovery process and system of a refrigerating system. The refrigerant recovery process and system are applicable to low-temperature systems of petrochemical plants. The refrigerant recovery process of the refrigerating system includes steps of: (1) setting a pressure value, and designing that pressure is reduced and refrigerants are discharged when pressure of a buffer tank exceeds the preset pressure value; (2) increasing pressure of the refrigerants discharged in step (1) after pressure relief to exceed that of a storage tank; (3) storing the pressure-increased refrigerants in the storage tank. The refrigerant recovery system of the refrigerating system comprises the buffer tank, wherein the buffer tank is connected with a compressor through an inlet pipe, the compressor is connected with the storage tank through an outlet pipe, and control valves are arranged on the inlet pipe and the outlet pipe respectively. The refrigerant recovery process and system can recover the refrigerants timely during the pilot run in the early period after start-up or when a device abnormally shuts down, so that massive waste of the refrigerants is avoided. Meanwhile, system energy consumption and production cost are reduced.

Description

technical field [0001] The invention relates to a refrigeration system refrigerant recovery process and system, which is suitable for low-temperature systems of petrochemical plants. Background technique [0002] In the production process of chemical products, it is often necessary to use low-temperature systems for low-temperature treatment. Commonly used refrigerants include propylene, ethylene, methane, ethane, propane, etc. For example, in the production process of propylene, commonly used refrigerants include propylene, ethylene, etc. [0003] Propylene can be produced through propane dehydrogenation. At present, propane dehydrogenation units that have been operated and are under construction in China mainly use the CATOFIN patented technology of LUMMUS Company and the Oleflex technology of UOP Company to produce polymer-grade propylene through catalytic dehydrogenation of propane. The propane raw material undergoes dehydrogenation reaction in a fixed bed reactor. The ...

AI Technical Summary

Problems solved by technology

However, during the initial trial operation of the start-up or when the device is abnormally shut down, the ethylene refrigeration system is in the shutdown state, and the operating temperature of the buffer tank rises slowly due to the loss of cooling capacity. When the temperature rises to -45°C, the safety valve takes off and the pressure regulating valve Also in the open state, a large amount of ethylene is discharged to the flare system, causing great waste

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