摘要:
A closed loop single component, e.g. propane or Freon refrigerant, refrigeration cycle is added to a single or dual mixed refrigerant natural gas liquefaction process to precool the natural gas prior to adsorptive drying. By means of pressure control, the single component refrigerant temperature can be accurately controlled to ensure against hydrate formation in the natural gas feed and to maximize the precooling of the natural gas feed prior to drying. The addition of the single component refrigeration cycle overcomes the difficulty of controlling the precooling temperature which occurs when cooling by a multicomponent refrigerant, and thus improves plant reliability and minimizes the equipment sizes associated with the drying operation.
摘要:
A process of and apparatus for liquefying a dry gas with low boiling point in a first circuit through heat exchange with a main refrigerating fluid in a second circuit itself pre-cooled to its at least partial liquefaction through heat exchange with an auxiliary refrigerating fluid in a third circuit, wherein, for a same amount of treated products, the required total compression input power for the refrigerating fluids is reduced by performing in said third circuit an intermediate condensation between the two last compression stages followed by a phase separation, the gaseous phase being compressed to a high pressure in the last compression stage whereas the liquid phase is compressed to a high pressure by a pump and recycled to a cryogenic heat exchanger for cooling the gas initially in the moist state thereby at least partially drying same.
摘要:
Described herein is a method and system for liquefying a natural gas feed stream to produce an LNG product. The natural gas feed stream is liquefied, by indirect heat exchange with a gaseous methane or natural gas refrigerant circulating in a gaseous expander cycle, to produce a first LNG stream. The first LNG stream is expanded, and the resulting vapor and liquid phases are separated to produce a first flash gas stream and a second LNG stream. The second LNG stream is then expanded, with the resulting vapor and liquid phases being separated to produce the second flash gas stream and a third LNG stream, all or a portion of which forms the LNG product. Refrigeration is recovered from the second flash gas by using said stream to sub-cool the second LNG stream or a supplementary LNG stream.
摘要:
Provided are an LNG storage container with an inner shell, which is capable of efficiently storing LNG or pressurized LNG (PLNG) pressurized at a predetermined pressure and supplying the LNG or PLNG to a consumption place, and capable of reducing manufacturing costs by minimizing the use of a metal having excellent low temperature characteristic, and a method for manufacturing the same. The LNG storage container includes: an inner shell configured to store LNG inside; an outer shell configured to enclose the outside of the inner shell such that a space is formed between the inner shell and the outer shell; a support installed in the space between the inner shell and the outer shell to support the inner shell and the outer shell; and a heat insulation layer part installed in the space between the inner shell and the outer shell and configured to reduce a heat transfer.
摘要:
A method for liquefying a hydrocarbon-rich stream, in particular a natural gas stream, is disclosed. A liquefaction of the hydrocarbon-rich stream takes place countercurrent to a refrigerant mixture cycle cascade consisting of two or three refrigerant mixture cycles. No additional process steps are involved in the heat exchange between the hydrocarbon-rich stream which is to be precooled and the refrigerant mixture of the first refrigerant mixture cycle.
摘要:
Apparatus for liquefying natural gas, comprising a series of heat exchangers for cooling the natural gas in countercurrent heat exchange relationship with a refrigerant, compression means for compressing the refrigerant, expansion means for isentropically expanding at least two separate streams of the compressed refrigerant, said expanded streams of refrigerant communicating with a cool end of a respective one of the heat exchangers, and a precooling refrigeration system for precooling the natural gas to a temperature below 0° C. before it is fed to the series of heat exchangers, and for precooling the compressed refrigerant discharged from a warm end of the series of heat exchangers to a temperature below 0° C. before it is fed back into the series of heat exchangers or to the expansion means.
摘要:
A method and system for liquefying a methane-rich high-pressure feed gas stream using a first heat exchanger zone and a second heat exchanger zone. The feed gas stream is mixed with a refrigerant stream to form a second gas stream, which is compressed, cooled, and directed to a second heat exchanger zone to be additionally cooled below ambient temperature. It is then expanded to a pressure less than 2,000 psia and no greater than the pressure to which the second gas stream was compressed, and then separated into a first expanded refrigerant stream and a chilled gas stream. The first expanded refrigerant stream is expanded and then passed through the first heat exchanger zone such that it has a temperature that is cooler, by at least 5° F., than the highest fluid temperature within the first heat exchanger zone.
摘要:
A process for cooling a hydrocarbon-rich fraction, in particular natural gas, against a refrigerant circuit. In this process, the compressed refrigerant is divided into three refrigerant substreams. Whereas the first substream is work-producingly expanded in a warm expander and the second substream is work-producingly expanded in a cold expander, the third substream is work-producingly expanded at the lowest temperature level. The result therefrom is that the operating point of the cold expander is shifted in such a manner that the refrigeration output of the two expanders is situated in a ratio between 40/60 and 60/40.
摘要:
A method for producing pressurized liquefied natural gas and a production system therefor are provided. The method for producing pressurized liquefied natural gas includes: performing a dehydration process to remove water from natural gas supplied from a natural gas field, without a process of removing acid gas from the natural gas; and performing a liquefaction process to produce pressurized liquefied natural gas by liquefying the natural gas, which has undergone the dehydration process, at a pressure of 13 to 25 bar and a temperature of −120 to −95° C., without a process of fractionating natural gas liquid (NGL). Accordingly, it is possible to reduce plant construction costs and maintenance expenses and reduce LNG production costs. In addition, it is possible to guarantee high economic profit and reduce payback period in small and medium-sized gas fields, from which economic feasibility could not be ensured by the use of a conventional method.
摘要:
A method for liquefaction using a closed loop refrigeration system, the method comprising the steps of (a) compressing a gaseous refrigerant stream in at least one compressor; (b) cooling the compressed gaseous refrigerant stream in a first heat exchanger; (c) expanding at least a first portion of the cooled, compressed gaseous refrigerant stream from the first heat exchanger in a first expander to provide a first expanded gaseous refrigerant stream; and (d) cooling and substantially liquefying a feed gas stream to form a substantially liquefied feed gas stream in a second heat exchanger through indirect heat exchange against at least a first portion of the first expanded gaseous refrigerant stream from the first expander, wherein the first expanded gaseous refrigerant stream exiting the first expander is substantially vapor.