TH5508B - Liquefied natural gas production By using a two-stage mixed refrigerant with stepwise pressure boosting - Google Patents

Abstract

Equipment and liquefied natural gas production using two closed circuits of refrigerant. Where the low-level refrigerant cools the natural gas And high-level refrigerants to cool low-level refrigerants The improvement consists of separating the high-level refrigerant after pressure treatment. And the vapor stream is completely transformed into a liquid with an external cooling fluid. After adding pressure

Claims (6)

1. In the liquefied natural gas production process using double-circuit mixed refrigerant Which the high level refrigerant acts as the cooling object to the low level refrigerant And low level refrigerant to keep cool And cause a liquid-to-natural gas conversion With - cooling It is then transformed into a liquid-to-natural gas stream by transferring heat to the low-level mixed refrigerant within the first closed refrigerant cycle. Where the refrigerant is re-heated during that heat transfer - the pressure is applied to the newly heated low-level refrigerant to a higher pressure; And then cooled with external cooling liquid - cooling against low refrigerant added with multi-stage heat transfer from high-level mixed refrigerant within closed refrigeration cycle. Second Where the high-level refrigerant is re-heated during that heat transfer - Giving higher pressure to the newly heated high-level refrigerant. And after that it is cooled by external cooling liquid In order to make part of the refrigerant liquid Modification of refrigerant ingredients High levels in the manner in which low molecular weight ingredients are present to perform low cooling functions by; - separation of such high refrigerants into vapor and liquid flows; - Extra cooling. And the expansion of the liquid to have a temperature And the pressure drop in a number of steps to act as cooling on low refrigeration And to keep cool And transforms into a liquid to the stream of material Refrigeration in vapor condition and - to pressurize the refrigerant stream in vapor condition It is then condensed with an external cooling liquid before further cooling with a liquid stream. And enlarged in order to make the temperature And pressure drop for lowest cooling to low refrigerant 2. The process according to claim 1 in which the high-level refrigerant in the newly heated vapor condition from the final stage of heat transfer with the low-level refrigerant is combined with the refrigerant stream. In liquid state In order to transfer Heat within the intermediate steps of heat transfer to such a low level of refrigerant 3. The process according to claim 1, in which the high-level refrigerant from the low-temperature stage of heat transfer to the low-level refrigerant is also transported to the higher stage of the heat transfer object. Low level cooling 4. The process according to claim 1, in which the high-level refrigerant that is vapor, after being pressured, will turn into a liquid only part It is then separated by nature, where the liquid part is combined with the liquid part of the high refrigerant. And the vapor part is given extra pressure and condensed into water droplets from outside cooling liquid. 5. Liquefied natural gas production facility using two closed circuit mixed refrigerant Where the high level of the refrigerant cools the low level refrigerant And low level refrigerant to cool and liquefy natural gas Which includes - the first heat exchanger To provide cooling and liquid-to-natural gas from low-level refrigeration materials - at least one other pressurized unit. To make the pressure on the refrigerant low to have a higher pressure - Support heat exchanger. For multi-stage cooling of the low-level refrigerant with a high-level refrigerant - the low-level refrigerant into a vapor stream. And liquid flows - vapor delivery devices And an independent flow of liquid to the first heat exchanger And delivered back to the aforementioned compressor - One or more compressors To press the pressure on the refrigerant to a higher pressure. - Heat exchanger to add cooling. For the cooling of a high-pressure refrigerant that has been added pressure using an external cooling fluid. Modifications for high-end refrigerant mixtures in a manner that Low molecular weight mixtures are available to perform low cooling functions, including: - A high-level refrigerant into a vapor stream. And fluid flows - pressure compressors and heat exchanger to cool. To make the vapor stream of such high refrigerant Converts to liquid - a high-level refrigerant that supplies vapor through the support heat exchanger. And let that current expand For cooling against low refrigerant flows - a high-level refrigerant flow device passes through a booster heat exchanger. This includes devices that will act to separate the part of the current. And then each current is amplified to have a temperature And lower pressure for cooling the aforementioned low refrigerant flows; 6. The equipment according to claim 5 also consists of a second set of separators. To act as a second liquid stream of refrigerant high Equipped with a device that combines the second liquid stream with the first liquid stream of the high refrigerant. With a pressure compressor And a heat transfer machine to provide additional cooling For the vapor flow from the second separator to a liquid state