CN-121993291-A - Power circulation system utilizing exhaust waste heat and LNG cold energy of gas turbine

CN121993291ACN 121993291 ACN121993291 ACN 121993291ACN-121993291-A

Abstract

The invention provides a power circulation system utilizing exhaust waste heat of a gas turbine and LNG cold energy, which comprises the gas turbine, a supercritical carbon dioxide circulation system, a kalina circulation system, a transcritical carbon dioxide circulation system and liquefied natural gas, wherein the supercritical carbon dioxide circulation system comprises a first heater, the kalina circulation system comprises a second heater and a first condenser, the transcritical carbon dioxide circulation system comprises a third heater and a second condenser, the gas turbine, the first heater, the second heater and the third heater are sequentially connected, so that the exhaust of the gas turbine provides heat sources for the three circulation systems respectively, the second condenser is connected with the first condenser, and the liquefied natural gas sequentially enters the second condenser and the first condenser to condense corresponding working media. The invention reasonably utilizes the requirements of different power cycles on the temperature of the heat source, and realizes the efficient cascade utilization of the exhaust heat energy of the gas turbine. Meanwhile, the cold energy of LNG gasification is effectively and reasonably utilized.

Inventors

TIAN XINPING
WEI XINGGUANG
Lu Bohui
XIAO JUNFENG
GAO SONG
HU MENGQI
XIA LIN
LIAN XIAOLONG
HE XINXIN
WANG YIFENG
JIANG SHIJIE

Assignees

西安热工研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20260114

Claims (10)

1. The power circulation system utilizing the exhaust waste heat of the gas turbine and the LNG cold energy is characterized by comprising the gas turbine, a supercritical carbon dioxide circulation system, a kalina circulation system, a transcritical carbon dioxide circulation system and liquefied natural gas, wherein the supercritical carbon dioxide circulation system comprises a first heater, the kalina circulation system comprises a second heater and a first condenser, and the transcritical carbon dioxide circulation system comprises a third heater and a second condenser; The gas turbine, the first heater, the second heater and the third heater are sequentially connected, so that the exhaust gas of the gas turbine provides heat sources for the supercritical carbon dioxide circulation system, the kalina circulation system and the transcritical carbon dioxide circulation system respectively; the second condenser is connected with the first condenser, and the liquefied natural gas sequentially enters the second condenser and the first condenser to condense corresponding working media.
2. The system of claim 1, wherein the first condenser is coupled to the gas turbine, wherein the lng condenses on working fluid within the second condenser and the first condenser while absorbing heat to gasify and warm to ambient temperature as fuel to the gas turbine.
3. The system of claim 1, wherein the supercritical carbon dioxide circulation system further comprises a supercritical carbon dioxide circulation turbine, a high temperature regenerator, a low temperature regenerator, and a first heat exchanger; The inlet of the supercritical carbon dioxide circulating turbine is connected with the outlet of the first heater, and the outlet of the supercritical carbon dioxide circulating turbine is connected with the first inlet of the high-temperature heat regenerator; the first inlet of the low-temperature heat regenerator is connected with the first outlet of the high-temperature heat regenerator, and the first outlet of the low-temperature heat regenerator is connected with the first inlet of the first heat exchanger.
4. The system of claim 3, wherein the supercritical carbon dioxide circulation system further comprises a main compressor; the inlet of the main compressor is connected with the first outlet of the first heat exchanger, and the outlet of the main compressor is connected with the second inlet of the low-temperature heat regenerator.
5. The system of claim 4, wherein the supercritical carbon dioxide circulation system further comprises a recompressor; The inlet of the recompression is connected with the first outlet of the low-temperature heat regenerator, the outlet of the recompression is connected with the second outlet of the low-temperature heat regenerator, and the recompression is connected with the second inlet of the high-temperature heat regenerator after merging.
6. The system of claim 5, wherein the second outlet of the high temperature regenerator is connected to the inlet of the first heater.
7. The system of claim 3, wherein the kalina cycle system further comprises a first working fluid pump; and the inlet and the outlet of the first working medium pump are respectively connected with the outlet of the first condenser and the inlet of the first heat exchanger.
8. The system of claim 7, wherein the kalina cycle system further comprises a gas-liquid separator, a kalina cycle turbine, and a mixer; the inlet of the gas-liquid separator is connected with the second outlet of the first heat exchanger, and the gas outlet of the gas-liquid separator is connected with the inlet of the second heater; The inlet of the kalina circulating turbine is connected with the outlet of the second heater, and the outlet of the kalina circulating turbine is connected with the first inlet of the mixer; the outlet of the mixer is connected to the inlet of the first condenser.
9. The system of claim 8, wherein the transcritical carbon dioxide circulation system further comprises a second working fluid pump and a second heat exchanger; The inlet of the second working medium pump is connected with the outlet of the second condenser, and the outlet of the second working medium pump is connected with the first inlet of the second heat exchanger; The second inlet of the second heat exchanger is connected with the liquid outlet of the gas-liquid separator, the first outlet of the second heat exchanger is connected with the second inlet of the mixer, and the second outlet of the second heat exchanger is connected with the inlet of the third heater.
10. The system of any one of claims 1 to 9, wherein the transcritical carbon dioxide circulation system further comprises a transcritical carbon dioxide turbine; The inlet of the transcritical carbon dioxide turbine is connected with the outlet of the third heater, and the outlet of the transcritical carbon dioxide turbine is connected with the inlet of the second condenser.

Description

Power circulation system utilizing exhaust waste heat and LNG cold energy of gas turbine Technical Field The invention belongs to the technical field of power circulation systems, and particularly relates to a power circulation system utilizing exhaust waste heat of a gas turbine and LNG cold energy. Background Gas turbines have been developed in recent years due to their flexible starting, clean and efficient performance. The exhaust temperature of the gas turbine is higher, and the efficiency of a gas turbine circulation system can be effectively improved by effectively and reasonably utilizing the heat energy of the exhaust waste heat of the gas turbine. The supercritical carbon dioxide circulation has the advantages of compact structure, high efficiency and the like because the carbon dioxide working medium is always above the critical point, and the supercritical carbon dioxide circulation can realize the high-efficiency utilization of medium-high temperature waste heat. Due to the variable-temperature evaporation characteristic of the kalina cycle, the irreversible loss in the evaporation process is effectively reduced, so that the kalina cycle has high efficiency in the field of medium-low temperature waste heat utilization. Because the boiling point of the carbon dioxide is lower, the transcritical carbon dioxide circulation can effectively realize reasonable utilization of a low-temperature heat source. But the temperature requirement for the cold source is higher. The LNG temperature rises from-162 ℃ to 25 ℃ and releases about 830kJ/kg of cold energy. However, most LNG regasification terminals now release cold energy into the sea water or air, causing great waste of cold energy and environmental pollution problems. Therefore, the LNG regasification cold energy is effectively and reasonably utilized, and has strong economic value and environmental value. In view of the above, it is necessary to provide a power cycle system which is reasonable in design and effectively solves the above problems, and which utilizes the exhaust waste heat of the gas turbine and the LNG cold energy. Disclosure of Invention The invention aims to at least solve one of the technical problems in the prior art and provides a power circulation system utilizing exhaust waste heat and LNG cold energy of a gas turbine. The invention provides a power circulation system utilizing exhaust waste heat of a gas turbine and LNG cold energy, which comprises the gas turbine, a supercritical carbon dioxide circulation system, a kalina circulation system, a transcritical carbon dioxide circulation system and liquefied natural gas, wherein the supercritical carbon dioxide circulation system comprises a first heater, the kalina circulation system comprises a second heater and a first condenser, and the transcritical carbon dioxide circulation system comprises a third heater and a second condenser; The gas turbine, the first heater, the second heater and the third heater are sequentially connected, so that the exhaust gas of the gas turbine provides heat sources for the supercritical carbon dioxide circulation system, the kalina circulation system and the transcritical carbon dioxide circulation system respectively; the second condenser is connected with the first condenser, and the liquefied natural gas sequentially enters the second condenser and the first condenser to condense corresponding working media. Optionally, the first condenser is connected with the gas turbine, wherein the liquefied natural gas is gasified by absorbing heat and is heated to normal temperature while condensing the working media in the second condenser and the first condenser, and the liquefied natural gas is taken as fuel to enter the gas turbine. Optionally, the supercritical carbon dioxide circulating system further comprises a supercritical carbon dioxide circulating turbine, a high-temperature heat regenerator, a low-temperature heat regenerator and a first heat exchanger; The inlet of the supercritical carbon dioxide circulating turbine is connected with the outlet of the first heater, and the outlet of the supercritical carbon dioxide circulating turbine is connected with the first inlet of the high-temperature heat regenerator; the first inlet of the low-temperature heat regenerator is connected with the first outlet of the high-temperature heat regenerator, and the first outlet of the low-temperature heat regenerator is connected with the first inlet of the first heat exchanger. Optionally, the supercritical carbon dioxide circulation system further comprises a main compressor; the inlet of the main compressor is connected with the first outlet of the first heat exchanger, and the outlet of the main compressor is connected with the second inlet of the low-temperature heat regenerator. Optionally, the supercritical carbon dioxide circulation system further comprises a recompressor; The inlet of the recompression is connected with the first outlet of the lo