CN210509312U - Cold formula LNG cold energy power generation system returns based on joint cycle method - Google Patents
Cold formula LNG cold energy power generation system returns based on joint cycle method Download PDFInfo
- Publication number
- CN210509312U CN210509312U CN201921188559.6U CN201921188559U CN210509312U CN 210509312 U CN210509312 U CN 210509312U CN 201921188559 U CN201921188559 U CN 201921188559U CN 210509312 U CN210509312 U CN 210509312U
- Authority
- CN
- China
- Prior art keywords
- power generation
- working medium
- cold energy
- lng
- expansion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The utility model relates to a recooling formula LNG cold energy power generation system based on combined cycle method, including LNG air supply, rankine cycle unit, expansion power generation unit, the rankine cycle unit has first turbo expander, the expansion power generation unit has second turbo expander, the rankine cycle unit shares the working medium condenser with the expansion power generation unit; and the outlet of the second turbo expander is connected with the air-temperature gasifier through the working medium condenser. The utility model introduces the outlet material flow of the second stage expander in the combined power generation cycle by using LNG cold energy into the working medium condenser of the Rankine cycle part, fully utilizes the cold energy at the outlet of the second stage expander, and improves the power generation capacity of the whole system on the premise of not increasing any main equipment; compared with other schemes of utilizing NG cold energy behind the turboexpander, the scheme has the advantages of simple structure, small occupied area, no need of a large number of downstream supporting facilities and the like.
Description
Technical Field
The utility model relates to a power generation system based on LNG cold energy is a return cold type LNG cold energy power generation system based on combined cycle method particularly.
Background
LNG (liquefied natural gas) is a low-temperature mixture at-162 ℃ under normal pressure, and releases a large amount of cold energy during regasification, typically 830 and 860 KJ/kg. In various countries around the world, efforts are made to search for methods for utilizing LNG cold energy, one of the major approaches to power generation, and currently, methods for generating power by using LNG cold energy mainly include a rankine cycle method, a direct expansion method, or a combined cycle method combining the rankine cycle method and the direct expansion method.
In a traditional combined method power generation system (namely superposition of a Rankine cycle method and a direct expansion method), NG directly enters an air temperature type gasifier to be heated after passing through a secondary expansion machine, and cold energy generated by expansion acting of the NG is not utilized.
Chinese patent publication No. CN102943698A, published as 2013, 2.27, proposes a four-stage LNG cold energy recycling system, in which although an ice storage device is used to collect NG cold energy passing through an expander, the cold storage part is complicated, a plurality of main devices are added, and the generated ice blocks are not easy to be processed and need to be used in cooperation with a downstream cold end or an ice block transport vehicle.
Chinese patent publication No. CN106194302A, published 2016, 12, month, and 7, proposes a comprehensive LNG cold energy utilization system, in which a scheme of recovering LNG cold energy in three stages is provided before a direct expansion part, thereby realizing cascade utilization of LNG cold energy. However, the system is too large and complex, and the cold energy contained in the NG after the direct expansion part is not utilized, but the part of low-temperature NG is directly subjected to heat exchange with the seawater and then is input into a pipe network system.
Chinese patent documents with publication number CN108087050A and publication number 2018, 5 and 29 provide a system for generating power and supplying cold by comprehensively utilizing LNG cold energy, a refrigeration house and an ice storage system are arranged behind a direct expansion part to recover the LNG cold energy, the scheme has various devices, needs devices such as a refrigeration house, a working medium pump, an ice storage pond and the like, and has high investment and large occupied area.
In summary, in the existing combined power generation system, the cold energy of NG after the secondary expansion machine is usually directly wasted or provided to the cold and ice storage part for use, but the cold and ice storage scheme has the problems of more newly added equipment, large floor area, need to be used with downstream and the like. Therefore, the technical problem to be solved at present is to explore how to utilize the cold energy of NG after the secondary expansion machine on the premise of not increasing too many devices as much as possible and ensuring the simplicity of the system.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: in a traditional combined method power generation system, only the cold energy of LNG is often utilized, but the cold energy caused by temperature reduction after the secondary expansion machine does work is ignored. This portion of the cold energy is related to the pressure differential across the secondary expander and the inlet temperature, with the greater the pressure differential across the expander, the lower the inlet temperature, and the lower the temperature of the outlet stream, the greater the cold energy it has. However, if the pressure difference of the expansion machine is increased, the power consumption of the front LNG pump is increased, and the equipment investment is increased; if the inlet temperature of the secondary expansion machine is reduced, the work done by the secondary expansion machine is reduced, and the net output work of the whole system is reduced. Finding the appropriate LNG pressure and secondary expander inlet temperature is therefore one of the key points in constructing this cycle.
The utility model adopts the following technical proposal:
a combined cycle method based return cooling type LNG cold energy power generation system comprises an LNG source, a Rankine cycle unit and an expansion power generation unit, wherein the Rankine cycle unit is provided with a first turbine expander 5, the expansion power generation unit is provided with a second turbine expander 7, and the Rankine cycle unit and the expansion power generation unit share a working medium condenser 2; the outlet of the second turboexpander 7 is connected with an air-temperature gasifier 10 through the working medium condenser 2.
Preferably, the Rankine cycle unit comprises a working medium booster pump 3, a working medium evaporator 4, a first turboexpander 5 and a working medium condenser 2 which are connected in sequence; the working medium condenser 2 is arranged at the front end of the working medium booster pump 3; the first turboexpander 5 is also connected to a first generator 6.
Preferably, the front end of the expansion power generation unit is communicated with an LNG (liquefied natural gas) source through a booster pump 1, and the rear end of the expansion power generation unit is connected with the air-temperature gasifier 10 after passing through the working medium condenser 2 and the second turbo expander 7 in sequence and passing through the working medium condenser 2 again.
Further, the working medium evaporator 4 exchanges heat with a water supply pipeline, and a water pump 9 is arranged on the water supply pipeline.
Further, the expansion power generation unit further comprises a second generator 8, and the second generator 8 is connected with the second turbo expander 7.
Preferably, the first turboexpander 5 is connected to the first generator 6 by a mechanical shaft.
Preferably, in the expansion power generation unit, the second turbo expander 7 is connected to the second power generator 8 through a mechanical shaft.
Preferably, the rankine cycle unit is a first-stage rankine cycle unit, and the expansion power generation unit is a second-stage expansion power generation unit.
The beneficial effects of the utility model reside in that:
1) the outlet material flow of the second-stage expander in the combined power generation cycle utilizing LNG cold energy is introduced into a working medium condenser of the Rankine cycle part, the cold energy at the outlet of the second-stage expander is fully utilized, and the power generation capacity of the whole system is improved on the premise of not increasing any main equipment.
2) Compared with other schemes of utilizing NG cold energy behind the turboexpander, the scheme has the advantages of simple structure, small occupied area, no need of a large number of downstream supporting facilities and the like.
Drawings
Fig. 1 is the utility model discloses the structural schematic of formula LNG cold energy power generation system returns cold based on combined cycle method.
In the figure, 1 is a booster pump, 2 is a working medium condenser, 3 is a working medium booster pump, 4 is a working medium evaporator, 5 is a first turbo expander, 6 is a first generator, 7 is a second turbo expander, 8 is a second generator, 9 is a working medium condenser, and 10 is an air temperature type gasifier.
Detailed Description
The present invention will be further described with reference to the accompanying drawings and specific embodiments.
As shown in fig. 1, a recooling type LNG cold energy power generation system based on a combined cycle method is composed of an LNG booster pump 1, a working medium condenser 2, a working medium booster pump 3, a working medium evaporator 4, a first turbo expander 5, a first power generator 6, a second turbo expander 7, a second power generator 8, a water pump 9, and an air-temperature type gasifier 10.
The working medium condenser 2, the working medium booster pump 3, the working medium evaporator 4, the first turbine generator expander 5 and the first generator 6 form a first-stage Rankine cycle unit.
The second turbo-generator 7 and the second generator 8 constitute a second stage expansion power generation unit.
In the first-stage Rankine cycle power generation unit, a working medium condenser 2 is sequentially connected with a working medium booster pump 3, a working medium evaporator 4 and a first turbine expander 5 through pipelines and returns to the working medium condenser 2 to form a closed circulation loop, and a refrigerant working medium I is filled in the loop. The first turboexpander 5 is connected to a first generator 6 via a mechanical shaft.
In the second stage expansion power generation unit, the second turbo expander 7 is connected to the second power generator 8 through a mechanical shaft.
The use method of the back cooling type LNG cold energy power generation system based on the combined cycle method comprises the following steps:
LNG output from the LNG storage tank is pressurized by the LNG booster pump 1 and then delivered to the working medium condenser 2, the LNG in the working medium condenser 2 absorbs heat of the refrigerant working medium I and is gasified into gaseous natural gas, then the gaseous natural gas enters the second stage turboexpander 7 to do work, the temperature of the expanded natural gas is reduced, the gaseous natural gas is sent back to the working medium condenser 2 to absorb heat of the refrigerant working medium I, the temperature is raised, the natural gas which is heated again is heated by the air-temperature gasifier 10, and the natural gas is delivered into a pipe network after reaching the requirement of the pipe network.
In the first-stage Rankine cycle power generation unit, a refrigerant working medium I is condensed into a low-pressure liquid state in a working medium condenser 2, then is pressurized into a high-pressure liquid state by a working medium booster pump 3 and then enters a working medium evaporator 4, the refrigerant working medium I absorbs heat of heat source water (seawater, lake water, river water and the like) pressurized by a water pump 9 in the working medium evaporator 4 and is evaporated into a high-pressure gas state, the high-pressure gas refrigerant working medium I enters a first turbine expander 5, expands in the first turbine expander 5 to do work and is reduced in pressure into a low-pressure gas refrigerant working medium I, and the low-pressure gas refrigerant working medium I enters the working medium condenser 2 to be condensed into a low-pressure liquid state again to continue to circulate next time. The work of the refrigerant working medium I in the first turbo expander 5 is converted into mechanical energy, and the mechanical energy drives the first generator 6 to generate electricity through a mechanical shaft.
In the second stage expansion power generation unit, the work of the natural gas in the second turbo expander 7 is converted into mechanical energy and drives the second generator 8 to generate electricity through a mechanical shaft.
The above mention of "finding the appropriate LNG pressure and secondary expander inlet temperature is one of the key points in constructing this cycle. "in the rankine cycle portion of power generation using LNG cooling energy, the following is generally assumed: 1. the condensing pressure of the working medium is micro positive pressure: 0.11 MPa; 2. the end difference of the heat exchanger was 5 ℃. The inlet temperature of the secondary expansion machine 7 is the LNG outlet temperature of the working medium condenser 2, the Rankine cycle refrigerant is selected to be closely related to the temperature, simulation software is utilized, after various common Rankine cycle working media are compared, R290 is selected to serve as the cycle working medium (refrigerant working medium I) of the system, and the inlet temperature of the secondary expansion machine is determined to be minus 45.55 ℃. In addition, the net output work of the system is the maximum when the LNG pump boosts the LNG to 4.3MPa according to the simulation of the system.
The core of the embodiment is as follows: the outlet material flow of the second-stage expander in the combined power generation cycle utilizing LNG cold energy is introduced into a working medium condenser of the Rankine cycle part, the cold energy at the outlet of the second-stage expander is fully utilized, and the power generation capacity of the whole system is improved on the premise of not increasing any main equipment.
Taking the LNG mass flow of 2000kg/h, the NG outlet pressure of 0.6MPa and the heat source water temperature of 20 ℃ as an example, the net output work of the back cooling type LNG cold energy power generation system based on the combined circulation method is about: 108.3 KW. Under the same other conditions, the net output work of the conventional combined power generation system using LNG cold energy is about: 96.4 KW. Under the same condition, the net output power of the back cooling type LNG cold energy power generation system based on the combined cycle method is about 12% higher than that of the traditional combined method power generation system utilizing LNG cold energy.
Compared with other schemes of utilizing the NG cold energy behind the turboexpander, the scheme has the advantages of simple structure, small occupied area, no need of a large number of downstream supporting facilities and the like.
The foregoing are preferred embodiments of the present invention, and those skilled in the art can make various changes or modifications without departing from the general concept of the present invention, and such changes or modifications are intended to be included within the scope of the present invention.
Claims (8)
1. A combined cycle method-based back-cooling type LNG cold energy power generation system comprises an LNG source, a Rankine cycle unit and an expansion power generation unit, wherein the Rankine cycle unit is provided with a first turbine expansion machine (5), the expansion power generation unit is provided with a second turbine expansion machine (7), and the system is characterized in that:
the Rankine cycle unit and the expansion power generation unit share a working medium condenser (2); the outlet of the second turbine expansion machine (7) is connected with the air-temperature type gasifier (10) through the working medium condenser (2).
2. The combined cycle method based recooling LNG cold energy power generation system of claim 1, wherein: the Rankine cycle unit comprises a working medium booster pump (3), a working medium evaporator (4), a first turboexpander (5) and a working medium condenser (2) which are sequentially connected; the working medium condenser (2) is arranged at the front end of the working medium booster pump (3); the first turboexpander (5) is also connected to a first generator (6).
3. The combined cycle method based recooling LNG cold energy power generation system of claim 1, wherein: the front end of the expansion power generation unit is communicated with an LNG (liquefied natural gas) source through a booster pump (1), and the rear end of the expansion power generation unit is connected with the air-temperature gasifier (10) after passing through the working medium condenser (2) and the second turbo expander (7) in sequence and passing through the working medium condenser (2) again.
4. The combined cycle method based recooling LNG cold energy power generation system of claim 2, wherein: the working medium evaporator (4) exchanges heat with a water supply pipeline, and a water pump (9) is arranged on the water supply pipeline.
5. The combined cycle method based recooling LNG cold energy power generation system of claim 3, wherein: the expansion power generation unit further comprises a second generator (8), and the second generator (8) is connected with a second turbine expansion machine (7).
6. The combined cycle method based recooling LNG cold energy power generation system of claim 1, wherein: the first turboexpander (5) is connected to a first generator (6) via a mechanical shaft.
7. The combined cycle method based recooling LNG cold energy power generation system of claim 1, wherein: in the expansion power generation unit, a second turbine expander (7) is connected with a second generator (8) through a mechanical shaft.
8. The combined cycle method based recooling LNG cold energy power generation system of claim 1, wherein: the Rankine cycle unit is a first-stage Rankine cycle unit, and the expansion power generation unit is a second-stage expansion power generation unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921188559.6U CN210509312U (en) | 2019-07-25 | 2019-07-25 | Cold formula LNG cold energy power generation system returns based on joint cycle method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921188559.6U CN210509312U (en) | 2019-07-25 | 2019-07-25 | Cold formula LNG cold energy power generation system returns based on joint cycle method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210509312U true CN210509312U (en) | 2020-05-12 |
Family
ID=70585433
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921188559.6U Active CN210509312U (en) | 2019-07-25 | 2019-07-25 | Cold formula LNG cold energy power generation system returns based on joint cycle method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210509312U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112364465A (en) * | 2020-12-07 | 2021-02-12 | 中国市政工程华北设计研究总院有限公司 | Method for calculating height of supporting leg of air-temperature gasifier |
-
2019
- 2019-07-25 CN CN201921188559.6U patent/CN210509312U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112364465A (en) * | 2020-12-07 | 2021-02-12 | 中国市政工程华北设计研究总院有限公司 | Method for calculating height of supporting leg of air-temperature gasifier |
| CN112364465B (en) * | 2020-12-07 | 2022-04-15 | 中国市政工程华北设计研究总院有限公司 | Method for calculating height of supporting leg of air-temperature gasifier |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110374838B (en) | Transcritical carbon dioxide energy storage system and method based on LNG (liquefied Natural gas) cold energy utilization | |
| CN108533344B (en) | Nested LNG two-stage parallel cold energy power generation and ice making method and system thereof | |
| CN103438612B (en) | Compressed gas distributed energy source system using rare gases as working medium | |
| CN111121390A (en) | Liquefied air energy storage power generation system coupled with steam-water system of coal-fired power generating unit | |
| CN111121389A (en) | Liquefied air energy storage and power generation system of deep coupling coal-fired unit | |
| CN217737678U (en) | Liquefied air energy storage system of coupling LNG cold energy and ORC | |
| US4227374A (en) | Methods and means for storing energy | |
| JPH03215139A (en) | Power generating method | |
| CN116006292A (en) | Liquefied air energy storage system coupling LNG cold energy, ORC technology and natural heat source and working method of liquefied air energy storage system | |
| CN210509312U (en) | Cold formula LNG cold energy power generation system returns based on joint cycle method | |
| JPH04127850A (en) | Liquid air storage power generating system | |
| CN104373165A (en) | System for generating power through liquefied natural gas cold energy | |
| CN211903494U (en) | Liquefied air energy storage power generation system coupled with steam-water system of coal-fired power generating unit | |
| CN209990560U (en) | Cold energy cascade utilization system based on thermoacoustic technology | |
| CN109595461B (en) | LNG regasification and liquid air preparation system and working method | |
| CN108331627B (en) | Single-cycle two-stage LNG cold energy power generation and ice making method and system | |
| CN216282169U (en) | LNG power station combined cycle unit inlet gas cooling system with cold accumulation | |
| CN108487951B (en) | Combined power generation method by utilizing steel slag heat energy and fuel gas-supercritical carbon dioxide | |
| CN108317011B (en) | Natural gas pressure energy recovery system of integrated gas turbine | |
| JPH11343865A (en) | Cryogenic turbine power generation system | |
| JP3697476B2 (en) | Combined power generation system using gas pressure energy | |
| CN210239766U (en) | Utilize natural working medium to retrieve LNG cold energy power generation's device | |
| CN209976590U (en) | Steam condensing system and power generation system | |
| CN113309591A (en) | LNG cold energy utilization device | |
| CN212339737U (en) | Liquefied air energy storage and power generation system of deep coupling coal-fired unit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |