1) Process description
The mixed refrigerant for this unit will consist of purified methane, nitrogen and hydrocarbon refrigerants.
From the top of the cold box enters the buffer tank at the inlet of the mixed refrigerant compressor, and then goes to the refrigerant compressor. After being compressed in the first stage, it enters the interstage cooler for cooling and partial condensation, and is gasified in the interstage separator. liquid separation. The gas enters the compressor for secondary compression, the high pressure refrigerant at the outlet of the secondary compressor enters the final stage cooler for cooling and is partially condensed, and the gas-liquid mixture enters the final stage separator for separation.
The medium pressure refrigerant liquid separated by the interstage separator is pressurized by the pump and then enters the separator after the final cooler .This process is very improtant in mini LNG plant.
The high-pressure refrigerant gas and refrigerant liquid separated by the final separator are transported into the cold box by pipeline. The high-pressure refrigerant liquid is subcooled to -65 ℃ in the heat exchanger, throttled and depressurized and returned to the return passage of the heat exchanger. The high-pressure refrigerant gas continues to be cooled and condensed to -162°C in the heat exchanger, throttled and depressurized and returned to the reflux channel of the cold end of the heat exchanger, evaporated upward, and merged with the throttled and depressurized liquid phase in the middle. It flows upward and absorbs heat from the purified gas and high-pressure refrigerant. The reflux refrigerant is all evaporated into gas and comes out from the hot end of the heat exchanger. The temperature is about ~ 36 ℃ , and the pressure is about 0.31MPa.A .
From the cold box enters the balance tank at the inlet of the refrigerant compressor, and circulates and compresses for refrigeration. The temperature of the low-pressure refrigerant coming out of the cold box is generally higher than the dew point, and no liquid will be produced. The purpose of setting the inlet balance tank is to ensure that liquid does not enter the compressor during abnormal operation, during start-up and during refrigerant replenishment. The liquid collected in the inlet balance tank is not discharged, but is naturally vaporized and returned to the refrigeration cycle, which can avoid the loss of refrigerant when the system is abnormal.
2) Design parameters
Compressor type Centrifugal , air-cooled (process gas)
Suction pressure: 0. 31 MPa.A
Suction temperature: ~36 ℃
Exhaust pressure: 3.4 MPa.A (referring to the outlet flange of the final cooler)
Exhaust temperature: ~ 40℃ (referring to the outlet flange of the final cooler)
3) Scope of application
The compressor inlet guide vane and the compressor inlet and outlet return adjustment are adopted to adjust the load adjustment range of 30~110%.
Sichuan Rongteng Automation Equipment Co., Ltd.
www. rtgastreat.com
E-mail: sales01@rtgastreat.com
Phone/whatsapp: +86 138 8076 0589
Address: No. 8, Section 2 of Tengfei Road, Shigao Subdistrict,
Tianfu New Area, Meishan city, Sichuan China 620564
Tianfu New Area, Meishan city, Sichuan China 620564
Post time: Dec-20-2022
