KR800001457B1 - Regassification installation for liquified natural gases with concurrent production of electric power - Google Patents

Abstract

Energy consumption in the regasification of liquefied natural gas is reduced by using appts. contg. 2 sections, the one contg. a closed cycle turbine and the other having a conventional open cycle turbine. The heat released by the latter section is used to drive the closed circuit turbine. The closed circuit contains 2 heat exchangers, a compressor, and the expansion turbine.

Description

Regasification method of liquefied natural gas for power generation

Explanatory drawing of the apparatus of this invention

The present invention relates to a method for regasifying liquefied natural gas (hereinafter referred to as LNG) to generate power or power.

Regasification of LNG in current methods requires the heat energy supplied by open-loop circulation of seawater, either by combustion of gas or in general at locations where tanks and similar vessels are anchored. .

The combustion method has a disadvantage in that the operation cost is high because it requires 2% of heat to convert to gas.

The seawater circulation method has disadvantages to consider, especially due to the high cost of installing the water circulation system and the change of ambient heat parallelism or insufficient heat available in winter. This insufficiency of heat requires the use of an auxiliary heat source resulting in fuel consumption.

Two known methods have the disadvantage of attenuating large amounts of energy contained in the form of refrigeration in the LNG itself.

The method for the regasification of LNG with the generation of energy according to the invention aims at eliminating the above mentioned drawbacks.

The basic feature of the apparatus for regasifying LNG according to the invention lies in the combination of two thermodynamic circuits.

The use of two thermodynamic circuits can take full advantage of the refrigeration power of LNG and the heat of the fuel used. In addition, the use of two thermodynamic circuits is very economical as there is no need to use complicated and expensive geothermal ovens for installation.

The heat required to operate the device is supplied by the waste heat of a conventional gas turbine with an open regenerative cycle. The gas turbine in open-cycle form is the first of the two thermodynamic circuits of the method.

The second thermodynamic circuit was formed by a closed-loop gas turbine using nitrogen as the working fluid. Two thermodynamic circuits for making the regasification apparatus of LNG according to the invention are shown in the figures and will be described in connection with the detailed operating conditions. The values stated are for illustration only and nitrogen may be replaced by other gases, inter alia with rare gases, hydrogen and other inert gases or mixtures thereof.

For example, the LNG in the storage tank reaches the heat-exchanger 1 through the conduit 10. LNG at a pressure of about 70 atmospheres and a temperature of -155 ° C is converted from the liquid state to the gaseous state in the heat exchanger 1 and then passed through the conduit 11.

The nitrogen cycle closed loop includes a section 12, a compressor 2, a section 13, a heat exchanger 3, a section 14, a turbine 4, a section 15, and a heat exchanger 1.

The apparatus described above operates as follows. That is, the heat exchanger 1 can regasify LNG and liquefy nitrogen. Liquefied nitrogen (eg 2.7 atm and -134 ° C.) reaches the compressor 2 and raises the pressure there (for example 32 atm and 38 °) under this condition the nitrogen reaches the heat exchanger 3 and is heated there (Eg 325 ° C). Nitrogen is then reached to the expansion turbine 4 where it is used for mechanical forces with final cooling to about 50 ° C. Nitrogen is again driven into the heat exchanger 1 and frozen as described above to begin recycling.

The heat exchanger 3 usually uses waste gas from a gas turbine. Exhaust gas passes through section 16 heat exchanger 3 and section 17 open into the atmosphere. The gas turbine of the open-cycle type is indicated by the reference number 6, and a recycle cycle type is suitable to simplify the realization of the nitrogen closed loop.

The open cycle gas turbine is a simple cycle form without a regenerative heat exchanger (7) and the arrangement is more complicated, including more complex designs for nitrogen and closed loops, with the number (18) indicating the air inlet of the open cycle gas turbine and Fuel inlets connected to (8), for example natural gas or other suitable dyes.

Numerals 9 and 5 in the figures denote power generators connected to open cycle gas turbines and closed loop turbines, respectively.

As described above, the combination of the two thermodynamic circuits can regasify LNG as waste heat of the nitrogen-closed loop corresponding to the heat consumption of the conventional gas turbine, so that the efficiency of the current thermodynamic cycle cannot exceed 40%. Conversion to mechanical force can be achieved with an efficiency of about 55%.

Conventional gas turbines can be replaced by other machines (such as diesel or internal combustion engines) or by heat engines that can utilize waste heat.

Claims (1)

The working gas medium is circulated in a closed loop gas turbine plant with a turbine so that the medium drives the turbine to generate energy: only the liquid can effectively gasify the liquefied natural gas, thus working gas medium from the turbine. Pass through indirect heat exchange with liquefied natural gas: open loop for energy generation of working gas medium from gasification of liquefied natural gas to transfer heat from waste heat to working gas medium before passing through turbine A method of gasification of liquefied natural gas for energy generation comprising passing through waste heat from a gas turbine and indirect heat exchange.

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