LNG newcomer – Regarding the issue of MRC mixed refrigeration, is my understanding correct?
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Our refrigerant uses nitrogen, methane, ethylene, propane, and isopentane for cyclic compression cooling. My own understanding is that after the mixed refrigerant is compressed by the centrifuge, the light components enter the cold box through the gas phase channel; they are then depressurized via throttling to become a liquid phase, and return to the cold box to absorb heat, after which they vaporize and flow back to the centrifuge ； Propane and isopentane enter the cold box through the liquid-phase channel, absorb heat in the pre-cooling section, vaporize, and flow back to the centrifuge; this cycle repeats, is that correct?
The light components enter the cold box through the gas channel, and become a liquid phase after throttling to reduce pressure? Liquefaction can be achieved in this way; can pressure reduction lead to liquefaction?
The gas phase expands and its pressure is reduced through a Joule-Thomson valve, which causes a temperature drop; this can lead to liquefaction, right?
The light components undergo condensation heat exchange, cooling to a certain temperature before the pressure is reduced through a throttle valve
It shouldn’t be understood in that way. After being compressed, the gaseous refrigerant first goes through pre-cooling; thereafter, it passes through a throttle valve where it absorbs heat, which causes its phase transition temperature to drop, and part of it turns into a liquid phase, thereby cooling the subsequent processes； After being cooled inside the cold box, the liquid refrigerant heats the materials located there; it then proceeds to subsequent heat exchange stages for further pre-cooling (after throttling), and subsequently undergoes more heat exchange processes before merging with the gas refrigerant, until it returns to the compressor inlet ；
Dude, you’d better take a look at engineering thermodynamics; it’s best to find a pressure-enthalpy diagram so that you can understand a refrigeration cycle by just looking at it