TH94945A - Closed cycle mixed refrigerant system - Google Patents

Abstract

DC60 This invention provides a procedure for arranging cooling. And control cooling In the cooling loop used to produce liquefied natural gas The band made a cool touch with an exchanger. Hot containing refrigerant And by controlling the amount of components in the refrigerant mix, the required level of cooling that is supplied to the heat exchanger can be maintained. This invention provides a procedure for arranging cooling. And control cooling In the cooling loop used to produce liquid natural gas. The band made a cool touch with an exchanger. Hot containing refrigerant And by controlling the amount of ingredients of the refrigerant mixture, the required level of cooling that is supplied to the heat exchanger can be maintained.

Claims (32)

1. A method for providing cooling for the liquefaction process of natural gas in which a cooling ring containing a refrigerant mixture is passed through a heat exchanger, which involves continuous control of the refrigerant mixture by changing the liquid level in a phase separator at the warm end. 2. The method as claimed in claim 1, in which the refrigerant mixture contains isopentane. 3. The method claimed in claim 1 in which the fluid level in the phase separator at the heated end is reduced as the required heat transfer of the heat exchanger increases. 4. The method claimed under claim 1, whereby the liquid level is controlled online. 5. A method in accordance with claim 1 in which the fluid level in the phase separator at the heated end is increased when the required heat transfer of the heat exchanger is reduced. 6. The method claimed under claim 1 where the said heat exchanger and the said phase separator at the warm end are connected by fluid. 7. The method claimed under claim 1 in which the said cooling ring and the said heat exchanger are connected by fluid. 8. The method claimed under claim 2 in which such control is achieved is by altering the amount of isopentane present in the refrigerant mixture. 9. The method for providing cooling for the liquefied natural gas production process consists of the following steps: a) contacting the liquefied natural gas stream with a heat exchanger; b) contacting the heat exchanger with a cooling ring containing a refrigerant mixture; c) adjusting the refrigerant mixture by controlling the amount of heavier condensable components in the refrigerant mixture in response to variations in the heat exchanger's performance; and d) recovering the liquefied natural gas. 10. The method pursuant to claim Article 9, whereby the heavier condensable component is isopentane. 11. The method pursuant to claim 9, in which the variation of performance in the said heat exchanger is selected from a group consisting of an increase in temperature in the said heat exchanger and a decrease in temperature in the said heat exchanger. 12. The method claimed under claim 9 in which the amount of the heavier condensable component in the refrigerant mixture is increased in response to an increase in temperature in the heat exchanger. 13. A method pursuant to claim 9 in which the amount of the heavier condensable component in the refrigerant mixture is reduced in response to a decrease in temperature in the heat exchanger. 14. A method for providing cooling for the liquefaction process of natural gas, in which a cooling ring consisting of two heated-end separators and a cold-end separator is interconnected by a fluid flow control, which includes fluid level control in the heated-end separators. 15. The method as claimed in claim 14 in which the said cooling ring comes into contact with the heat exchanger. 16. The method claimed under claim 14 where the refrigerant mixture contains isopentane. 17. The method claimed under claim 14 in which the fluid level in the heated end of the separator is reduced as the required heat transfer of the heat exchanger increases. 18. The method claimed under claim 14 in which the liquid level is controlled online. 19. The method claimed under claim 14 in which the fluid level in the heated end of the separator is increased when the required heat transfer of the heat exchanger is decreased. 20. The method claimed under claim 16 in which such control is achieved by altering the amount of isopentane present in the refrigerant mixture. 21. The method claimed under claim 14 where the separator at the first heated end is connected by a fluid to the separator at the second heated end. 22. A method for providing cooling for the liquefaction process of natural gas, in which a cooling ring consisting of a heated end separator and a cold end separator are connected by a fluid exchange, comprising the following steps: a) controlling the liquid level in the heated end separator; b) removing vapor from the cold end separator; c) allowing the vapor to exchange heat with a separate liquid nitrogen storage system; and d) returning the liquid from the heat exchange in step c) to the heat exchanger. 23. The method stipulated in claim 22 in which such control of the liquid level is performed online. 24. The method claimed under claim 22 in which the liquid level in the heated end separator is controlled by changing the amount of isopentane present in the liquid. 25. The method as claimed in claim 22 in which the said cooling ring comes into contact with the heat exchanger. 26. The method claimed under claim 22 in which the fluid level in the heated end of the separator is reduced as the required heat transfer of the heat exchanger increases. 27. Method for providing cooling for the liquefaction process of natural gas in which the cooling ring, consisting of a heated end separator and a cold end separator, is fluid-interconnected and includes fluid level control in the heated end separator and control of the flow of natural gas from the separator to the heat exchanger. 28. The method claimed under claim 27 in which the liquid level in the heated end separator is controlled by changing the amount of isopentane present in the liquid. 29. The method claimed under claim 27 in which such control of the liquid level is performed online. 30. The method claimed under claim 27 whereby the flow of natural gas from the separator to the heat exchanger is controlled by the temperature of such separator, whereby the gas stream enters such heat exchanger and the bottom liquid stream is forced from such separator for re-entry into such separator. 31. The method claimed under claim 30, in which the liquid stream at the bottom consists of butane, propane, and pentane. 32. The method under the claim of Article 30 in which the gas flow from the said separator, after the said heat exchanger, is forced into the said separator.