WO2017067118A1

WO2017067118A1 - Combined expansion power system applicable to electricity production from high-pressure gas

Info

Publication number: WO2017067118A1
Application number: PCT/CN2016/074090
Authority: WO
Inventors: 彭学军
Original assignee: 彭学军
Priority date: 2015-10-20
Filing date: 2016-02-19
Publication date: 2017-04-27
Also published as: CN105201555A

Abstract

A combined expansion power system applicable to electricity production from high-pressure gas combines piston expanders with radial-inflow turbo-expanders, controls the number of stages of expansion of piston expanders by configuring a gas intake control system of the piston expanders, and improves the efficiency of the piston expanders. The piston expanders and the radial-inflow turbo-expanders are jointly configured; the piston expanders are used for implementing expansion of a high-pressure section, and the radial-inflow turbo-expanders are used for expansion of a low-pressure section. The system makes full use of the overall enthalpy of a high-pressure gas, and meanwhile, the adoption of a reheating process can increase the efficiency of the system. Compared with a common high-pressure gas expansion system where a throttle is used for controlling the intake pressure to be constant, the present system has advantages of large expansion ratio and high overall system efficiency.

Description

Combined expansion power system applied to high pressure gas power generation

This application claims the priority of the invention patent application filed on October 20, 2015, the Chinese Patent Office, the application No. 201510683496.1, entitled "A Combined Expansion Power System for High Pressure Gas Power Generation", the entire contents of which are incorporated by reference. In this application.

Technical field

The invention relates to the field of gas expansion power generation technology, in particular to a joint expansion power system applied to high-pressure gas power generation.

Background technique

With the continuous growth of China's power grid capacity, the peak-to-valley difference is increasing, the renewable energy and distributed energy supply are booming, and the demand for large-scale development of the energy storage power generation industry is also growing. For the construction of the “smart grid” currently implemented in the country, the large-scale energy storage system is an indispensable part. In order to solve the problem of large-scale storage of electric energy, it has consumed enormous human and financial resources, and developed various energy storage methods, battery packs, mechanical flywheels, supercapacitor stacks, superconducting magnetic storage, etc., which are ultimately inefficient. , short life, inconvenient access, small storage capacity, large investment costs, etc., difficult to operate. Large-scale energy storage power generation systems that have been widely used at present are pumped storage methods and compressed air storage.

Compressed air energy storage system is a new type of energy storage technology. Due to its high efficiency, low cost and long life, it will not bring pollution and ecological problems, and it has gradually become the focus of current research in various countries. The working principle of the compressed air energy storage power generation system is similar to that of pumped water storage. When the power consumption of the power system is at a low point, the system stores energy, and uses the surplus power in the system to drive the air compressor to compress the air and compress the air. The form is stored in the gas storage device; when the power load of the power system reaches a peak power generation, the system releases energy, and the gas storage device releases the compressed air in the gas storage space, drives the expander to work, and drives the generator to generate electricity. The electric energy-air potential energy-electric energy conversion.

As the core work component of the compressed air energy storage power generation system, the expander has a great influence on the efficiency of the compressed air energy storage power generation system. In large compressed air energy storage systems, due to the large air flow, the expander can use a conventional axial flow turbine system with high efficiency, but when the air flow is small, design and manufacture small and efficient axial flow. Turbines are very difficult.

In addition, during the operation of the compressed air energy storage power system, due to the air pressure of the air storage chamber Gradually, in order to maintain the constant pressure at the inlet of the expander, a throttle valve is usually used to stabilize the air throttling to a lower pressure, and then enter the expander to expand work. Due to the use of the throttle valve, the function of the high-pressure air is reduced, thereby reducing the efficiency of the system.

Summary of the invention

It is an object of the present invention to provide a combined expansion power system for use in high pressure gas power generation. The system organically couples the piston expander and the centripetal turboexpander to rationally utilize the energy of the high pressure gas to increase the efficiency of the expansion power generation system.

To achieve the above object, the present invention provides a combined expansion power system for high-pressure gas power generation, including a piston expansion unit, a turbo expansion unit, and a reheater; an intake port of the piston expansion unit and a high-pressure gas intake line Connecting, the high pressure gas enters the piston expansion unit through the high pressure gas intake line; the exhaust port of the piston expansion unit is connected to the intake port of the turboexpander unit, and the exhaust gas is supplied to the turboexpander unit; The device is disposed on the intake pipe of the piston expansion unit and the turboexpander unit for heating the work gas in the system; the valve is disposed on the intake pipe of the piston expansion unit for controlling the flow direction of the gas, thereby controlling The flow of the high pressure gas in the piston expansion unit; the turbo expansion unit is located downstream of the piston expansion unit, and uses the exhaust of the piston expansion unit as a power source to perform work.

Preferably, the piston expansion unit adopts a multi-cylinder structure, and each stage of the cylinder is connected to the main shaft through a crank link.

Preferably, the piston expansion unit comprises at least one piston expander in a multi-stage series or parallel configuration.

Preferably, the piston expansion unit is provided with a clutch, and the clutch is mounted on the main shaft of the piston expansion unit to realize the connection and disengagement of the piston connecting rod of each stage and the main shaft, thereby realizing the series control of the piston expansion unit.

Preferably, the turboexpander unit adopts a multi-stage series structure to output power through a main shaft.

Preferably, the turboexpander unit comprises at least one centripetal turbine expander in a multi-stage series or parallel configuration.

Preferably, the inlet pressure of the centripetal turboexpander is 0.2 to 5 MPa.

Preferably, the piston expansion unit is provided with an expansion control system to achieve control of the expansion condition.

Preferably, the heat source of the reheater comprises a solar heat source, a biomass energy heat source, an external waste heat waste heat source or a compressed heat source of the compressor.

In order to utilize the energy of the high pressure gas reasonably, the present invention organically couples the piston expansion unit and the centripetal turbine expansion unit. When the high-pressure gas needs to perform expansion work, it first enters the piston expansion unit to expand the high-pressure section, and the high-pressure gas expands and works in it, reduces the pressure of the gas to a certain low pressure, and simultaneously outputs the corresponding expansion work. In order to further improve the efficiency of the system, the corresponding gas pipeline valve is configured to control the number of stages of the piston expander according to the pressure of the high pressure gas. After the high pressure gas expands through the piston expansion unit, the pressure temperature decreases, and then continues to enter the centripetal turbine expansion unit, where the gas further expands to perform work. At the same time, in order to improve the function and efficiency of the system, the reheating process is used to heat the gas working medium through the reheater.

Compared with the traditional system using the centrifugal turboexpander unit alone, the system has adopted the piston expansion unit, replacing the throttle valve, and eliminating the throttling loss, thereby effectively improving the efficiency of the system. Taking a compressed air energy storage system with a gas storage pressure of 15 MPa and a gas storage volume of 500 m3 as an example, a combined expansion power system using high-pressure gas expansion power generation is more than 10% more efficient than a conventional system.

DRAWINGS

1 is a schematic structural view of a specific embodiment of a combined expansion power system for high pressure gas power generation according to the present invention.

In the picture:

1. First valve 2. Second valve 3. Third valve 4. Fourth valve 5. Fifth valve 6. Sixth valve 11. First cylinder 12. Second cylinder 13. Third cylinder 21. First clutch 22. Second clutch 31. First spindle 32. Second spindle 41. First reheater 42. Second reheater 43. Third reheater 44. Fourth reheater 51. First centripetal Flat expander 52. Second radial turboexpander

detailed description

The present invention will be further described in detail below in conjunction with the drawings and embodiments.

Please refer to FIG. 1. FIG. 1 is a schematic structural view of a specific embodiment of a combined expansion power system applied to high-pressure gas power generation according to the present invention.

In a specific embodiment, the combined expansion power system provided by the present invention is mainly composed of a piston expansion unit and a centripetal turbine expansion unit.

The piston expansion unit is connected to the intake of the high pressure gas for performing the expansion work of the high pressure section, mainly by the first valve 1, the second valve 2, the third valve 3, the fourth valve 4, the fifth valve 5, and the sixth valve. 6. The first cylinder 11, the second cylinder 12, the third cylinder 13, the first clutch 21, the second clutch 22, the first main shaft 31, and the like, in addition to the first cylinder 11, the second cylinder 12 and the third cylinder The first reheater 41 and the second reheater 42 are respectively disposed on the intake pipe of the 13th. The above components are sequentially connected through the pipeline as shown in the figure, and the flow direction of the high pressure gas is controlled by the opening and closing of the valve, and expansion is realized. The first cylinder 11, the second cylinder 12, and the third cylinder 13 are connected to the first main shaft 31 via a crank-link mechanism, and the first clutch 21 and the second clutch 22 are disposed on the first main shaft 31 for The main shaft of the first stage and second stage expansion pistons are coupled.

The centripetal turboexpander unit is connected to the exhaust of the piston expansion system to perform the expansion work of the low pressure section, mainly by the first centripetal turboexpander 51, the second centripetal turboexpander 52, the second main shaft 32, etc. The third reheater 43 and the fourth reheater 44 are respectively disposed on the intake lines of the respective centripetal turboexpanders, and the above components are sequentially connected through the pipelines as illustrated.

During operation, the high-pressure gas enters the first cylinder 11 through the first valve 1 through the pipeline to perform the first-stage expansion work, and the expansion work is output through the first spindle 31 through the crank link; the temperature of the expanded gas pressure is lowered, and the first step is entered. The reheater 41 heats the gas by using an external heat source, and the heated gas enters the second cylinder 12 through the fourth valve 4 to perform the second-stage expansion work, and the expansion work is output through the first spindle 31 through the crank link. The expanded gas pressure temperature is further lowered, enters the second reheater 42, and the gas is heated by the external heat source, and the heated gas enters the third cylinder 13 through the sixth valve 6, and performs the third-stage expansion work. The crank link outputs the expansion work through the first spindle 31. After three stages of expansion in the piston expander, the pressure of the high pressure gas is reduced to a range of pressures that can enter the centripetal turboexpander.

The exhaust gas of the third cylinder 13 is heated by the third reheater 43 to enter the first centripetal turbine. The expander 51 performs expansion work, and outputs expansion work through the second main shaft 32. The gas pressure temperature after the work is reduced, enters the fourth reheater 44, and heats the gas by the external heat source, and the heated gas enters the second centripetal center. The turboexpander 52 is further expanded to perform work, and after the expansion, the gas is discharged to complete the cycle.

The first valve 1, the second valve 2, the third valve 3, the fourth valve 4, the fifth valve 5 and the sixth valve 6 constitute a pneumatic control system of the piston expansion system, and the piston expander is adjusted by closing and opening the valve The number of expansion stages.

The inlet pressure of the above-mentioned centripetal turboexpander is between 5 MPa and 0.2 MPa, and the heat source of the reheater may be solar energy, biomass energy, waste heat of external heat, compression heat of the compressor, and the like.

When the air flow is small, the centripetal turbine has high efficiency, and the design and manufacture are relatively simple. The piston expander can adapt to the high pressure air expansion condition, and the operating condition is easy to control and the efficiency is high. Therefore, by combining a piston expander and a centripetal turboexpander, a new combined power expansion system having the above advantages is formed.

The above embodiments are only preferred embodiments of the present invention, and are not limited thereto. On this basis, targeted adjustments can be made according to actual needs, thereby obtaining different implementation manners. For example, the piston expansion unit includes at least one piston expander, which may be in the form of multiple stages of series or parallel connection of multiple piston expanders; or the radial turboexpander unit includes at least one radial turboexpander, which may be multiple Levels in series or in parallel, and so on. Since there are many ways to implement, there is no longer an example here.

The joint expansion power system for high-pressure gas power generation provided by the present invention has been described in detail above. The principles and embodiments of the present invention have been described herein with reference to specific examples. The description of the above embodiments is only for the purpose of understanding the core concepts of the present invention. It should be noted that those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the invention.

Claims

A combined expansion power system applied to high-pressure gas power generation, comprising: a piston expansion unit, a turbo expansion unit and a reheater; the intake port of the piston expansion unit is connected to a high-pressure gas intake line, and the high-pressure gas Entering a piston expansion unit through a high-pressure gas intake line; an exhaust port of the piston expansion unit is connected to an intake port of the turboexpander unit, and an exhaust gas is supplied to the turboexpander unit; the reheater is disposed on the piston The air inlet of the expansion unit and the turboexpander unit is used for heating the gas in the system; the inlet pipe of the piston expansion unit is provided with a valve for controlling the flow direction of the gas, thereby controlling the high pressure gas in the piston expansion unit The process of the turboexpander is located downstream of the piston expansion unit, and the exhaust gas of the piston expansion unit is used as a power source for work.
The combined expansion power system for high-pressure gas power generation according to claim 1, wherein the piston expansion unit adopts a multi-cylinder structure, and each stage of the cylinder is connected to the main shaft through a crank link.
A combined expansion power system for high-pressure gas power generation according to claim 1, wherein said piston expansion unit comprises at least one piston expander in a multi-stage series or parallel configuration.
A combined expansion power system for high-pressure gas power generation according to claim 2 or 3, wherein said piston expansion unit is provided with a clutch, and said clutch is mounted on a main shaft of the piston expansion unit to realize each stage of the piston The connection and disengagement of the crank connecting rod and the main shaft realize the series control of the piston expansion unit.
The combined expansion power system for high-pressure gas power generation according to claim 1, wherein the turboexpander unit adopts a multi-stage series structure to output power through a main shaft.
A combined expansion power system for high pressure gas power generation according to claim 1, wherein said turboexpander unit comprises at least one centripetal turbine expander in a multi-stage series or parallel configuration.
The combined expansion power system for high-pressure gas power generation according to claim 6, wherein the inlet pressure of the centripetal turboexpander is 0.2 to 5 MPa.
A combined expansion power system for high-pressure gas power generation according to any one of claims 1 to 7, wherein said piston expansion unit is provided with an expansion control system for achieving expansion Control of working conditions.
The combined expansion power system for high-pressure gas power generation according to claim 8, wherein the heat source of the reheater comprises a solar heat source, a biomass energy heat source, an external waste heat waste heat source or a compressed heat source of the compressor.