CN115059526A

CN115059526A - Recompression Brayton cycle system and start-up method

Info

Publication number: CN115059526A
Application number: CN202210984338.XA
Authority: CN
Inventors: 刘秀婷; 刘光旭; 黄彦平; 昝元峰
Original assignee: Nuclear Power Institute of China
Current assignee: Nuclear Power Institute of China
Priority date: 2022-08-17
Filing date: 2022-08-17
Publication date: 2022-09-16
Anticipated expiration: 2042-08-17
Also published as: CN115059526B

Abstract

The application provides a recompression Brayton cycle system and a start-up method. The recompression Brayton cycle system comprises a storage subsystem, a cycle subsystem and a sealing subsystem, wherein the storage subsystem is responsible for storing fluid media and filling the fluid media into the cycle subsystem and the sealing subsystem; the fluid medium circulates in the circulation subsystem to complete energy conversion; the sealing subsystem comprises an air sealing system and an air sealing valve, wherein the air sealing system fills fluid media into the air sealing valve to realize dry air sealing of the circulating device; the sealing subsystem and the storage subsystem are started firstly at the starting stage of the compression Brayton cycle system, the sealing subsystem fills fluid medium into the cycle subsystem, and the sealing subsystem seals the cycle device, so that the problem that the cycle device cannot be started stably due to poor sealing effect at the starting stage is solved; and the storage subsystem is started to fill fluid medium into the circulation subsystem, and the circulation subsystem is adjusted to the target load, so that the circulation system can be started safely and stably.

Description

Recompression Brayton cycle system and starting method

Technical Field

The application relates to the technical field of power conversion, in particular to a recompression Brayton cycle system and a starting method.

Background

Supercritical carbon dioxide is carbon dioxide (chemical formula: CO2) in a critical state (temperature and pressure reach critical point), has a physical state between liquid and gas, has special physical properties of small gas viscosity and high liquid density, has typical advantages of good fluidity, high heat transfer efficiency, small dynamic viscosity and the like, and is popular. Supercritical carbon dioxide currently has a variety of cycle configurations in the power conversion field, with recompression brayton cycle being the most efficient.

The typical recompression brayton cycle system today generally includes a main compressor, a recompressor, at least one turbine, a low temperature regenerator, a high temperature regenerator, and a cooler. And a part of working medium at the hot side outlet of the low-temperature regenerator is cooled by the cooler, compressed and boosted by the main compressor and then enters the cold side channel of the low-temperature regenerator, a part of working medium flows through the secondary compressor and then is boosted and then is converged at the cold side outlet of the low-temperature regenerator, two parts of working medium enter the high-temperature regenerator and a heat source for heat exchange and temperature rise after being converged at the cold side outlet of the low-temperature regenerator, and the heated working medium sequentially flows through the turbine unit, the high-temperature regenerator and the low-temperature regenerator to form closed recompression cycle.

Because the recompression Brayton cycle system comprises a plurality of compressors with different characteristics, turbines and high-temperature and high-pressure equipment which are coupled in a matching way, accidents are easily caused and potential safety hazards are caused if the equipment cannot be normally matched in the running process, particularly in the starting stage of the system.

Disclosure of Invention

In view of the above problems, the present application provides a recompression brayton cycle system and a start method thereof to solve the problem that the system cannot be started safely and stably because each device cannot be normally matched in the start stage of the recompression brayton cycle system.

In a first aspect, the present application provides a recompression brayton cycle system comprising a storage subsystem, a circulation subsystem, and a containment subsystem; the storage subsystem is used for storing fluid media and supplying the fluid media to the circulation subsystem and the sealing subsystem, the circulation subsystem is respectively communicated with the storage subsystem and the sealing subsystem, the circulation subsystem is used for receiving the fluid media filled from the storage subsystem so as to enable the fluid media to complete energy circulation in the circulation subsystem, the circulation subsystem comprises a circulation device for circulating the fluid media, the sealing subsystem is used for sealing the circulation subsystem, the sealing subsystem comprises an air seal valve and an air seal system, the air seal valve is arranged on the circulation device, the outlet end of the air seal system is communicated with the air seal valve, and the inlet end of the air seal system is communicated with the outlet end of the storage subsystem and the connecting position of the circulation subsystem.

In the technical scheme of the embodiment of the application, the recompression Brayton cycle system comprises a storage subsystem, a cycle subsystem and a sealing subsystem, wherein the storage subsystem is responsible for storing the fluid medium and filling the fluid medium into the cycle subsystem and the sealing subsystem; the fluid medium circulates in the circulation subsystem to complete energy conversion; the sealing subsystem comprises a gas sealing system and a gas sealing valve, the gas sealing system receives fluid media from the storage subsystem and the circulation subsystem and fills the fluid media into the gas sealing valve to realize dry gas sealing of the circulation device, the dry gas sealing enables the pressure of the circulation system to be increased at a normal speed when the circulation system runs, particularly in the process of converting from a low-pressure environment to a high-pressure environment in the starting stage of the circulation system, a stable working environment suitable for running of each device can be formed in the circulation system, and the problem that the circulation system fails due to the fact that each device of the circulation system cannot normally run due to poor sealing effect of the recompression Brayton circulation system is solved.

In some embodiments, the cycle sub-system includes a main compressor unit, a recompression unit, a turbine unit, a first recuperator, a second recuperator, a cooling apparatus, a heat source apparatus, and a control valve assembly; the inlet end of the main compressor unit is communicated with the outlet end of the cooling device, and the inlet end of the secondary compressor is communicated with the inlet end of the cooling device; the first regenerator comprises a first hot side channel and a first cold side channel, the second regenerator comprises a second hot side channel and a second cold side channel, the inlet end of the second cold side channel is communicated with the outlet end of the first cold side channel, and the outlet end of the second hot side channel is communicated with the inlet end of the first hot side channel; the inlet end of the second hot side channel is communicated with the outlet end of the turbine unit, the outlet end of the first hot side channel is respectively communicated with the inlet end of the cooling device and the inlet end of the recompression unit, the inlet end of the first cold side channel is communicated with the outlet end of the main compressor unit, the outlet end of the first cold side channel and the outlet end of the recompression unit are converged and then pass through the second cold side channel, and the heat source device is communicated with the inlet end of the turbine unit; the control valve group comprises a first control valve, a second control valve and a third control valve, wherein the first control valve is arranged at the inlet end of the main compressor unit and used for controlling the inlet pressure and the flow of the main compressor unit, the second control valve is arranged at the inlet end of the recompression unit and used for controlling the inlet pressure and the flow of the recompressor, and the third control valve is arranged at the inlet end of the turbine unit and used for controlling the inlet pressure and the flow of the turbine unit.

In some embodiments, the circulation subsystem is further provided with a bypass, the bypass having a bypass control valve disposed thereon, the bypass including at least one of a first bypass, a second bypass, and a third bypass, wherein: the first bypass is connected between the outlet end of the main compressor unit and the inlet end of the cooling device, a first bypass control valve is arranged on the first bypass, and the first bypass valve is used for adjusting the inlet pressure and flow of the main compressor unit; the second bypass is connected between the outlet end of the recompression unit and the outlet end of the first hot side channel, and a second bypass control valve is arranged on the second bypass and used for adjusting the inlet pressure and the flow of the recompression unit; the third bypass is connected between the inlet end of the turbine set and the inlet end of the second hot side channel, and a third bypass control valve is arranged on the third bypass and used for adjusting the inlet pressure and the flow of the turbine set.

In some embodiments, the cycle plant includes at least one of a main compressor train, a recompression train, and a turbine train.

In some embodiments, the storage subsystem includes a first outlet port in communication with the circulation subsystem and a second outlet port in communication with the gas seal system.

In some embodiments, the gas seal system includes a mixer, a heating device, and a buffering device connected in series along a flow direction of the fluid medium; the heating device is used for adjusting the temperature of the fluid medium entering the air seal valve from the sealing subsystem; the inlet end of the mixer is connected with the connecting position of the circulating subsystem, the inlet end of the heater is connected with the inlet end of the mixer, the inlet end of the buffer device is connected with the inlet end of the heating device, and the outlet end of the buffer device is communicated with the air seal valve.

In some embodiments, the circulation system further comprises a cooling subsystem coupled to the cooling device, the cooling subsystem further coupled to at least one of the main compressor train, the recompression train, and the turbine train, the cooling subsystem for cooling the cooling device and at least one of the main compressor train, the recompression train, and the turbine train.

In some embodiments, a connection valve is disposed between the connection location and the inlet end of the mixer, the connection location comprising: a first position between the outlet end of the main compressor unit and the inlet end of the first cold-side passage, a first valve being provided between the first position and the inlet end of the mixer; and/or a second position, the second position is arranged between the outlet end of the heat source device and the inlet end of the turbine unit, and a second valve is arranged between the second position and the inlet end of the mixer.

In some embodiments, the exhaust subsystem is further included, an inlet end of the exhaust subsystem being in communication with the circulation subsystem, the exhaust subsystem for releasing the fluid medium within the circulation subsystem.

In some embodiments, the system further comprises a volume control subsystem comprising a storage tank, an outlet end and an inlet end of the storage tank both in communication with the circulation subsystem, the volume control subsystem for stabilizing a pressure within the circulation subsystem.

In a second aspect, the present application provides a starting method for starting the recompression brayton cycle system according to any of the embodiments of the first aspect, where the cycle subsystem includes a main compressor unit, a recompression unit, a turbine unit, a first heat regenerator, a second heat regenerator, a cooling device, a heat source device, and a control valve set, where the control valve set includes a first control valve disposed at an inlet end of the main compressor unit, a second control valve disposed at an inlet end of the recompression unit, and a third control valve disposed at an inlet end of the turbine unit, the cycle subsystem further includes a bypass, where the bypass includes a bypass control valve, the bypass is disposed between at least one of an outlet end of the main compressor unit and an inlet end of the cooling device, an outlet end of the recompression unit and an outlet end of the first hot-side passage, and an inlet end of the turbine unit and an inlet end of the second hot-side passage, and the gas sealing system includes a heating device, the heating device is used for adjusting the temperature of a fluid medium entering the air seal valve and comprises a first air seal stage, a second air seal stage and a circulation stage, wherein in the first air seal stage, the sealing subsystem and the storage subsystem are started, the first control valve, the second control valve and the bypass control valve are opened to 50% -80% of full opening, the connecting valve and the third control valve are closed, and the storage subsystem is made to fill the fluid medium into the air seal system;

in the second air sealing stage, heating the fluid medium entering the circulation subsystem from the air sealing system to 70-90 ℃ so that the fluid medium at 70-90 ℃ enters the main compressor unit, and the fluid medium enters the air sealing valve from the air sealing system to complete the sealing of the circulation device; in the circulation phase, the circulation subsystem is started to enable the storage subsystem to fill the circulation subsystem with the fluid medium, so that the circulation subsystem reaches the target load, and the system is started.

In the technical scheme of the embodiment of the application, the sealing subsystem and the storage subsystem are started firstly, so that the sealing subsystem fills fluid medium into the circulating subsystem, and the sealing subsystem seals the circulating device, thereby solving the problem that the circulating device cannot be started stably due to poor sealing effect in the starting stage; and then the storage subsystem is started to fill fluid medium into the circulation subsystem, and the circulation subsystem is continuously adjusted until the circulation subsystem reaches the target load, so that the circulation system is started stably.

In some embodiments, the cycle subsystem includes a main compressor train, a recompression train, a heat source device, and a turbine train, the cycle system further including a cooling subsystem operable to cool at least one of the main compressor train, the recompression train, and the turbine train, the cycle phase including: filling the storage subsystem with a fluid medium to the circulation subsystem, and starting the cooling subsystem; starting a main compressor unit, a recompression unit and a heat source device; adjusting the temperature of the heat source device until the turbine unit reaches a first temperature, and starting the turbine unit; when the rotating speeds of the main compressor unit and the recompression unit are increased to 30% -35% of rated rotating speed, and the rotating speed of the turbine unit is increased to 10% -20% of rated rotating speed, the main compressor unit and the recompression unit are adjusted to the rated rotating speed, and then the turbine unit is adjusted to the rated rotating speed, so that the starting of the circulating system is completed.

In some embodiments, the circulation system includes a volume control subsystem, the inlet and outlet ports of the volume control subsystem being in communication with the circulation subsystem for stabilizing the pressure within the circulation subsystem, and the step of starting the main compressor package, the recompression package, and the heat source device comprises: when the pressure of the inlet end of the main compressor unit reaches a first pressure, the main compressor unit and the recompression unit are started, and then the volume control subsystem is started, or when the pressure of the inlet end of the main compressor unit reaches the first pressure, the rotating speed of the main compressor unit is increased to 10% -25% of the rated rotating speed, the recompression unit is started, and then the volume control subsystem is started.

In some embodiments, the heat source device is started after the rotating speed of the main compressor unit and the recompressor unit is increased to 30% -35% of the rated rotating speed.

In some embodiments, the inlet end of the gas seal system is connected with a connection position of the circulation subsystem, a connection valve is arranged between the inlet end of the gas seal system and the connection position, the connection valve is used for controlling the flow rate of the fluid medium entering the gas seal system from the circulation subsystem, and the steps of starting the cooling subsystem, the main compressor unit and the recompression unit further comprise closing the storage subsystem and opening the connection valve when the pressure at the inlet end of the main compressor unit reaches 90% -95% of the rated pressure so that the fluid medium of the circulation subsystem enters the gas seal system.

In some embodiments, the recirculation subsystem includes a control valve assembly including a third control valve disposed at an inlet end of the turbine assembly, and the step of adjusting the temperature of the heat source device until the turbine assembly reaches the first temperature further includes: and adjusting the temperature of a fluid medium entering an air seal valve of the turbine unit to 80-110 ℃, opening a third control valve to 25-35% of full opening, and starting the turbine unit.

In some embodiments, the circulation subsystem further comprises a bypass, the bypass having a bypass control valve disposed thereon, the bypass control valve comprising: the first bypass control valve is arranged on a first bypass connected between the outlet end of a main compressor unit and the inlet end of a cooling device, the second bypass control valve is arranged on a second bypass between the outlet end of a recompression unit and the outlet end of a first hot side channel, and the third bypass control valve is arranged on a third bypass between the inlet end of a turbine unit and the inlet end of a second hot side channel, and the steps of adjusting the main compressor unit and the recompression unit to a rated rotating speed and then adjusting the turbine unit to the rated rotating speed comprise: adjusting a main compressor unit and a recompression unit to rated rotation speed, adjusting a first bypass control valve and a second bypass control valve to be completely closed, and adjusting a control valve group to be completely opened; adjusting the pressure difference between the outlet end and the inlet end of the turbine unit to be not more than 0.5MPa, adjusting the temperature difference between the outlet end and the inlet end of the turbine unit to be not more than 70 ℃, and increasing the rotating speed of the turbine unit to 20-30% of rated rotating speed; and after the running time t of the turbine set is 20% -30% of the rated rotating speed, closing the third bypass control valve, and increasing the rotating speed of the turbine set to the rated rotating speed.

In some embodiments, the step of adjusting the main compressor unit and the recompression unit to the rated speed includes decreasing the cooling device power to increase the inlet side temperature of the main compressor unit when the inlet side temperature of the main compressor unit is below 30 ℃, and increasing the cooling device power to decrease the inlet side temperature of the main compressor unit when the inlet side temperature of the main compressor unit is above 35 ℃.

Compared with the prior art, the method has the following beneficial effects:

the recompression Brayton cycle system comprises a storage subsystem, a cycle subsystem and a sealing subsystem, wherein the storage subsystem is responsible for storing fluid media and filling the fluid media into the cycle subsystem and the sealing subsystem; the fluid medium circulates in the circulation subsystem to complete energy conversion; the sealing subsystem comprises a gas sealing system and a gas sealing valve, the gas sealing system receives fluid media from the storage subsystem and the circulation subsystem and fills the fluid media into the gas sealing valve to realize dry gas sealing of the circulation device, the dry gas sealing enables the pressure in the circulation system to be increased at a normal speed when the circulation system runs, particularly in the process of converting from a low-pressure environment to a high-pressure environment in the starting stage of the circulation system, a stable working environment suitable for running of each device can be formed in the circulation system, and the problem that the circulation system fails due to the fact that each device of the circulation system cannot normally run due to poor sealing effect of the recompression Brayton circulation system is solved; in the starting stage of the recompression Brayton cycle system, the sealing subsystem and the storage subsystem are started firstly, so that the sealing subsystem fills the fluid medium into the circulation subsystem, the sealing subsystem seals the circulation device, the problem that the circulation device cannot be started stably in the starting stage due to poor sealing effect is solved, the first control valve, the second control valve and the bypass control valve are opened to 50% -80% of the full opening, and the situation that each device in the circulation subsystem is damaged due to too large opening degree of the valve and too high pressure in the starting stage and the fluid medium is blocked from flowing in the circulation subsystem 11 due to too small opening degree of the valve is ensured; heating the gas entering the circulation subsystem from the gas seal system to 70-80 ℃ so that the fluid medium at 70-80 ℃ enters the main compressor unit, and avoiding the damage of the main compressor unit caused by the low-temperature fluid medium flowing into the main compressor unit; and then the storage subsystem is started to fill fluid medium into the circulation subsystem, and the circulation subsystem is continuously adjusted until the circulation subsystem reaches the target load, so that the circulation system can be started safely and stably.

Drawings

Other features, objects and advantages of the invention will become apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings in which like or similar reference characters refer to the same or similar parts.

FIG. 1 is a schematic structural diagram of a circulation system provided in an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a circulation subsystem provided in an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a storage subsystem provided in an embodiment of the present application;

FIG. 4 is a schematic structural diagram of a gas seal system provided in an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a circulation system provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of a volume subsystem according to an embodiment of the present disclosure;

FIG. 7 is a schematic flow chart illustrating a method for starting a circulation system according to an embodiment of the present disclosure;

FIG. 8 is a schematic flow chart diagram illustrating a method for starting a circulation system according to another embodiment of the present disclosure;

fig. 9 is a schematic flowchart of a method for starting a circulation system according to another embodiment of the present disclosure.

The reference numbers in the detailed description are as follows:

the system comprises a circulating system 1, a circulating subsystem 11, a sealing subsystem 12, a storage subsystem 13, a cooling subsystem 14, a volume subsystem 15, an exhaust subsystem 16, a circulating device 110, a gas seal valve 120 and a gas seal system 121;

a main compressor unit 111, a recompression unit 112, a turbine unit 113, a first heat regenerator 114, a second heat regenerator 115, a cooling device 116, a heat source device 117, a control valve group 118, a bypass control valve 119, a first hot side passage 114a, a first cold side passage 114b, a second hot side passage 115a, a second cold side passage 115b, a first control valve 118a, a second control valve 118b, a third control valve 118c, a first bypass control valve 119a, a second bypass control valve 119b, a third bypass control valve 119c, a mixer 121a, a heating device 121b, a buffer device 121c, a storage device 131, a pressure boosting device 132, a heater 133, a vacuum pump 134, a connecting valve 122, a first valve 122a, a second valve 122b, a first position 11a, a second position 11b, a storage tank 151, and a heating device 152.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are merely used to more clearly illustrate the technical solutions of the present application, and therefore are only examples, and the protection scope of the present application is not limited thereby.

It should be noted that technical terms or scientific terms used in the embodiments of the present application should be understood as having a common meaning as understood by those skilled in the art to which the embodiments of the present application belong, unless otherwise specified.

The brayton cycle is a typical thermodynamic cycle which is firstly proposed by brayton, an american scientist and takes gas as a working medium. The simple Brayton cycle gas working medium realizes high-efficiency energy conversion through four processes of isentropic compression, isobaric heat absorption, isentropic expansion and isobaric cooling. When the working medium is in a supercritical state, the change of the phase state of the working medium is avoided, the consumption of compression work is reduced, and the cycle efficiency of the working medium can be greatly improved.

When the temperature and the pressure of the carbon dioxide reach the critical temperature of 31.1 ℃ and the critical pressure of 7.38Mpa respectively, the carbon dioxide is in a supercritical state, namely, the carbon dioxide becomes supercritical carbon dioxide, and the supercritical CO2 is CO2 between liquid CO2 and gaseous CO2 and has the special physical characteristics of small gas viscosity and large liquid density, so the supercritical CO2 has the typical advantages of good fluidity, high heat transfer efficiency, small compressibility and the like.

The dry gas seal is the same as the balance cartridge type structure of the common mechanical seal, but the end face design is different, the surface is provided with a groove with the depth of several microns to more than ten microns, and the width of the end face is wider. In general, the operating temperature of a dry gas seal does not exceed 200 ℃, and unlike a conventional lubricated mechanical seal, the dry gas seal generates a stable gas film on two sealing surfaces. The air film has strong rigidity to completely separate two sealing end faces and keep a certain sealing gap, the existence of the air film not only effectively separates the end faces but also cools the two end faces which run oppositely, and the two end faces are not in contact, so that the friction and the abrasion are greatly reduced, the sealing has the characteristic of long service life, and the service life of a host is prolonged.

The typical existing Brayton cycle system comprises a recompression Brayton cycle system, and compared with a simple regenerative Brayton cycle system, the recompression Brayton cycle system can effectively reduce the occurrence of pinch point problem. Recompression brayton cycle systems typically include a main compressor, a recompressor, at least one turbine, a low temperature regenerator, a high temperature regenerator, and a cooler. And a part of working medium at the hot side outlet of the low-temperature regenerator is cooled by the cooler, compressed and boosted by the main compressor and then enters the cold side channel of the low-temperature regenerator, a part of working medium flows through the secondary compressor and is boosted and then is converged at the cold side outlet of the low-temperature regenerator, two parts of working medium enter the high-temperature regenerator and a heat source for heat exchange and temperature rise after being converged at the cold side outlet of the low-temperature regenerator, and the heated working medium sequentially flows through the turbine, the high-temperature regenerator and the low-temperature regenerator to form closed recompression cycle.

The inventor of the present application has noticed that there are multiple devices operating at high temperature or high pressure in the recompression brayton cycle system, so that during the operation of the cycle system, especially during the start-up phase of the cycle system, each device undergoes the transition from low pressure to high pressure, and from low temperature to high temperature, and if the sealing efficiency between the devices is not good at this time, and the devices cannot be normally matched, the cycle system is prone to accidents.

Based on the above problems found by the inventors, the inventors have made intensive studies to improve a circulation system and a starting method of the circulation system in order to start the circulation system safely and smoothly.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a circulation system 1 according to an embodiment of the present disclosure.

In some alternative embodiments, as shown in fig. 1, the recompression brayton cycle system 1 includes a storage subsystem 13, a circulation subsystem 11, and a containment subsystem 12; the storage subsystem 13 is used for storing fluid media and supplying the fluid media to the circulation subsystem 11 and the sealing subsystem 12, the circulation subsystem 11 is respectively communicated with the storage subsystem 13 and the sealing subsystem 12, the circulation subsystem 11 is used for receiving fluid media filling from the storage subsystem 13 so that the fluid media can complete energy circulation in the circulation subsystem 11, the circulation subsystem 11 comprises a circulation device 110 used for circulating the fluid media, the sealing subsystem 12 is used for sealing the circulation subsystem 11, the sealing subsystem 12 comprises a gas seal valve 120 and a gas seal system 121, the gas seal valve 120 is arranged on the circulation device 110, the outlet end of the gas seal system 121 is communicated with the gas seal valve 120, and the inlet end of the gas seal system 121 is communicated with the outlet end of the storage subsystem 13 and the connection position of the circulation subsystem 11.

Alternatively, the fluid medium may be supercritical carbon dioxide or other suitable fluid.

Optionally, the sealing subsystem 12 seals the circulation subsystem 11 in a dry gas seal.

In these alternative embodiments, the recompression brayton cycle system includes a storage subsystem 13, a circulation subsystem 11, and a containment subsystem 12, the storage subsystem 13 being responsible for storing the fluid medium and filling the circulation subsystem 11 and the containment subsystem 12 with the fluid medium; the fluid medium circulates in the circulation subsystem 11 to complete energy conversion; the sealing subsystem 12 comprises a gas sealing system 121 and a gas sealing valve 120, the gas sealing system 121 receives fluid media from the storage subsystem 13 and the circulation subsystem 11, and the fluid media are filled into the gas sealing valve 120 to realize dry gas sealing of the circulation device 110, so that the problem that the recompression Brayton cycle system 1 is abnormal in operation because the devices of the cycle system 1 cannot be normally matched due to poor sealing effect is solved.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a circulation subsystem according to an embodiment of the present disclosure.

In some embodiments, as shown in fig. 2, the circulation subsystem 11 includes a main compressor unit 111, a recompression unit 112, a turbine unit 113, a first regenerator 114, a second regenerator 115, a cooling device 116, a heat source device 117, and a control valve set 118; the inlet end of the main compressor unit 111 is communicated with the outlet end of the cooling device 116, and the inlet end of the recompression unit 112 is communicated with the inlet end of the cooling device 116; the first regenerator 114 includes a first hot side passage 114a and a first cold side passage 114b, the second regenerator 115 includes a second hot side passage 115a and a second cold side passage 115b, an inlet end of the second cold side passage 115b communicates with an outlet end of the first cold side passage 114b, and an outlet end of the second hot side passage 115a communicates with an inlet end of the first hot side passage 114 a; an inlet end of a second hot side channel 115a is communicated with an outlet end of the turbine unit 113, an outlet end of a first hot side channel 114a is respectively communicated with an inlet end of a cooling device 116 and an inlet end of a recompression unit 112, an inlet end of a first cold side channel 114b is communicated with an outlet end of a main compressor unit 111, an outlet end of the first cold side channel 114b and an outlet end of the recompression unit 112 are converged and then pass through a second cold side channel 115b, and a heat source device 117 is communicated with an inlet end of the turbine unit 113; the control valve group 118 includes a first control valve 118a, a second control valve 118b, and a third control valve 118c, the first control valve 118a is disposed at an inlet end of the main compressor group 111 and controls an inlet pressure and a flow rate of the main compressor group 111, the second control valve 118b is disposed at an inlet end of the recompression group 112 and controls an inlet pressure and a flow rate of the recompression group 112, and the third control valve 118c is disposed at an inlet end of the turbine group 113 and controls an inlet pressure and a flow rate of the turbine group 113.

Optionally, the regenerator may be divided into a high temperature regenerator and a low temperature regenerator according to the temperature of the two sides of the regenerator, in this application, the first regenerator 114 is a low temperature regenerator, and the second regenerator 115 is a high temperature regenerator.

Optionally, the main compressor unit 111 and the recompression unit 112 include a compressor, a bearing, and a driving motor.

Optionally, the turbine assembly 113 includes a turbine, a bearing, and a generator.

Optionally, the bearing may be an electromagnetic bearing, the electromagnetic bearing is a sliding bearing that suspends the shaft by using an electric field force and a magnetic field force, the electromagnetic bearing does not need to be lubricated because the shaft does not directly contact the bearing, can work in vacuum and in a very wide temperature range, has small frictional resistance, is not limited by speed, and has a long service life.

Optionally, the control valve set 118 may be a dual valve design, i.e., the same control valve set 118 includes two control valves, which improves the safety of the pipeline.

In these alternative embodiments, the fluid medium is divided into two paths before entering the cooling device 116, and one path enters the cooling device 116 for cooling, so that the fluid medium enters the main compressor set 111 for compression after the temperature and pressure of the fluid medium are reduced. The fluid medium then enters the first heat regenerator 114 to absorb a portion of the heat, and the other fluid medium directly enters the recompression unit 112 for compression. The two paths of fluid media are mixed in front of the second heat regenerator 115, then enter the heat source device 117 together for heating, then enter the turbine unit 113 for applying work, and the fluid media after applying work flow back to the second heat regenerator 115 to complete the whole circulation process.

In these alternative embodiments, the fluid medium circulates among the main compressor unit 111, the recompressor unit 112, the turbine unit 113, the first regenerator 114, the second regenerator 115, the cooling device 116, and the heat source device 117, thereby completing the energy conversion process. The control valve set 118 is used to control the flow and pressure of the fluid medium within the circulation subsystem.

In the technical solution of some optional embodiments, as shown in fig. 2, the circulation subsystem 11 is further provided with a bypass, on which a bypass control valve 119 is provided, the bypass including at least one of a first bypass, a second bypass, and a third bypass, wherein: the first bypass is connected between the outlet end of the main compressor unit 111 and the inlet end of the cooling device 116, a first bypass control valve 119a is arranged on the first bypass, and the first bypass control valve 119a is used for adjusting the inlet pressure and the flow of the main compressor unit 111; the second bypass is connected between the outlet end of the recompression unit 112 and the outlet end of the first hot side passage 114a, a second bypass control valve 119b is arranged on the second bypass, and the second bypass control valve 119b is used for adjusting the inlet pressure and the flow rate of the recompression unit 112; a third bypass is connected between the inlet side of turbine set 123 and the inlet side of second hot side duct 115a, and a third bypass control valve 119c is provided on the third bypass, and third bypass control valve 119c is used to regulate the inlet pressure and flow of turbine set 113.

In these alternative embodiments, by providing bypass and bypass control valves 119 in the circulation sub-system 11, it is possible to regulate the flow into each device and to change the flow path of the fluid medium in the circulation sub-system 11, and to protect the device in case of emergency by regulating the bypass control valve 119.

In some alternative embodiments, the circulation device 110 includes at least one of a main compressor unit 111, a recompression unit 112, and a turbine unit 113 as shown in fig. 2.

Optionally, a mechanical sealing valve may be further disposed on the circulation device 110 to further enhance the sealing capability.

In these alternative embodiments, the circulation device 110 includes at least one of the main compressor unit 111, the recompressor unit 112 and the turbine unit 113, that is, at least one of the main compressor unit 111, the recompressor unit 112 and the turbine unit 113 is provided with a gas seal valve, and a gas seal system is connected to the gas seal valve, and the gas seal system can provide dry gas seal for at least one of the main compressor unit 111, the recompressor unit 112 and the turbine unit 113.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a storage subsystem 13 according to an embodiment of the present disclosure.

In the solutions of some optional embodiments, the storage subsystem 13 includes a first outlet end and a second outlet end, and the first outlet end is communicated with the circulation subsystem 11; the second outlet port is in communication with a gas seal system 121.

In these alternative embodiments, the storage subsystem 13 includes a first outlet port and a second outlet port, which ensure that whether the storage subsystem 13 fills the circulation subsystem 11 and the gas seal system 121 with fluid media, respectively, can be controlled.

Optionally, valves are provided between the first outlet port and the circulation subsystem 13 and between the second outlet port and the gas seal system 121 for controlling the flow of the fluid medium through the first outlet port and the second outlet port.

Optionally, a pressurization device 132 is disposed within the storage subsystem 13 for pressurizing fluid medium charged from the storage subsystem 13 into the circulation subsystem 11 or the containment subsystem 12.

Optionally, a heater 133 is provided within the storage subsystem 12 for preheating the fluid medium charged from the storage subsystem 12 into the circulation subsystem 11 or the containment subsystem 12.

Optionally, the storage subsystem 13 comprises a storage device 131 and a vacuum pump 134, the storage device 131 being used for storing the fluid medium, the vacuum pump 134 being used for pumping the fluid medium.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a gas sealing system 121 according to an embodiment of the present disclosure.

In some alternative embodiments, as shown in fig. 4, the gas seal system 121 includes a mixer 121a, a heating device 121b, and a buffer device 121c connected in series in the flow direction of the fluid medium; the heating device 121b is used for adjusting the temperature of the fluid medium entering the air seal valve 120 from the air seal system 121; the inlet end of the mixer 121a is connected with the connection position of the circulation subsystem 11, the inlet end of the heating device 121b is connected with the inlet end of the mixer 121a, the inlet end of the buffer device 121c is connected with the inlet end of the heating device 121b, and the outlet end of the buffer device 121c is communicated with the air seal valve 120.

Alternatively, the second outlet port communicates with the inlet port of the mixer 121a, or the second outlet port communicates with the inlet port of the heating device 121 b.

In these alternative embodiments, a mixer 121a, a heating device 121b, and a buffering device 121c are included in the gas seal system 121. The mixer 121a is used to mix the fluid media entering the gas seal system 121, balancing the pressure and temperature of the fluid media. The heating device 121b is used for adjusting the temperature of the fluid medium filled into the circulation subsystem 11 by the air seal system 121, and the purpose of preheating the circulation subsystem 11 is achieved. The buffer device 121c can adjust the pressure of the fluid medium entering the air seal valve 120 in the air seal system 121, and prevent the air seal valve 120 from being damaged by excessive pressure.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a circulation system according to an embodiment of the present disclosure.

In some alternative embodiments, as shown in fig. 5, the circulation system 1 further includes a cooling subsystem 14, the cooling subsystem 14 is connected to the cooling device 116, the cooling subsystem 14 is further connected to at least one of the main compressor unit 111, the recompressor unit 112 and the turbine unit 113, and the cooling subsystem 14 is configured to cool the cooling device 116 and at least one of the main compressor unit 111, the recompressor unit 112 and the turbine unit 113.

Alternatively, the cooling subsystem 14 may be liquid nitrogen, water, freon, or the like.

In these alternative embodiments, the circulation system 1 further includes a cooling subsystem 14, the cooling subsystem 14 is connected to the cooling device 116 for cooling the cooling device 116, and the cooling subsystem 14 is connected to at least one of the main compressor unit 111, the recompressor unit 112 and the turbine unit 113 for cooling the above-mentioned devices to prevent the above-mentioned devices from malfunctioning due to high temperature.

In some alternative embodiments, as shown in fig. 4 and 5, a connection valve is disposed between the connection position and the inlet end of the mixer 121a, and the connection position includes: a first position 11a, the first position 11a being located between the outlet end of the main compressor block 111 and the inlet end of the first cold-side duct 114b, a first valve being arranged between the first position 11a and the inlet end of the mixer 121 a; and/or a second position 11b, the second position 11b being arranged between the outlet end of the heat source device 117 and the inlet end of the turbine unit 113, a second valve being arranged between the second position 11b and the inlet end of the mixer 121 a.

In these alternative embodiments, the circulation subsystem 11 fills the gas seal system 121 with gas through the connection locations so that the gas seal system 121 can continuously provide a dry gas seal effect to the circulation device. The first position 11a, arranged at the outlet end of the main compressor unit 111, makes it possible to obtain a fluid medium of lower temperature in the main compressor unit 111 for sealing against the dry gas of the circulation device. The second position 11b is arranged at the outlet of the heat source device 117 for obtaining a fluid medium of higher temperature in the heat source device 117 for sealing the dry gas of the circulation device.

Optionally, the connection position includes a first position 11a and a second position 11b, the fluid medium at a lower temperature in the first position 11a and the fluid medium at a higher temperature in the second position 11b enter the air seal valve 120 of the turbine unit 113 after being mixed in the mixer 121a of the air seal system 121 to reach the equilibrium temperature, and therefore, the loss of the turbine unit 113 due to the too low temperature of the fluid medium flowing into the turbine unit 113 is avoided, and the air seal performance of the air seal valve 120 is not affected due to the too high temperature of the fluid medium flowing into the air seal valve 120.

In the solution of some alternative embodiments, as shown in fig. 5, the exhaust subsystem 16 is further included, an inlet end of the exhaust subsystem 16 is communicated with the circulation subsystem 11, and the exhaust subsystem 16 is used for releasing the fluid medium in the circulation subsystem 11.

Optionally, an exhaust subsystem 16 is disposed between the first outlet port and the circulation subsystem 11, and the exhaust subsystem 16 may release the fluid medium in the circulation subsystem 11 while releasing the fluid medium in the storage subsystem 13.

In these alternative embodiments, the exhaust subsystem 16 is in communication with the recirculation subsystem 11 for releasing the fluid medium within the recirculation subsystem 11 when the pressure within the recirculation subsystem 11 is too high or when the recirculation subsystem 11 is shut down, ensuring safe operation of the recirculation subsystem 11.

Referring to fig. 6, fig. 6 is a schematic structural diagram of a volume subsystem according to an embodiment of the present disclosure.

In some alternative embodiments, as shown in fig. 5 and 6, the system further comprises a volume control subsystem 15, the volume control subsystem 15 comprises a storage tank 151, an outlet end and an inlet end of the storage tank 151 are both communicated with the circulation subsystem 11, and the volume control subsystem 15 is used for stabilizing the pressure in the circulation subsystem 11.

Optionally, the outlet and inlet ends of the containment subsystem 15 are disposed across the first cold-side channel 114 b.

Optionally, a tank heating device 152 is further connected to the tank 151 for heating the fluid medium in the tank 151.

Optionally, the reservoir 151 is in communication with the storage subsystem 13, and the storage subsystem 13 may draw or fill fluid media into the reservoir 151.

In these alternative embodiments, the inlet end and the outlet end of the volume subsystem 15 are both communicated with the circulation subsystem 11, and the volume subsystem 15 can stabilize the pressure of the circulation subsystem 11 when the pressure in the circulation subsystem 11 fluctuates, so as to prevent the equipment from being damaged due to overhigh pressure in the circulation subsystem 11, and also avoid the efficiency of the circulation system from being reduced due to overlow pressure in the circulation subsystem 11.

Referring to fig. 7, fig. 7 is a schematic flowchart illustrating a starting method of a circulation system according to an embodiment of the present application.

As shown in fig. 7, the present embodiment further provides a start-up method, which may be used to start up any recompression brayton cycle system 1 according to the embodiment of the first aspect. The circulation subsystem 11 comprises a main compressor unit 111, a recompression unit 112, a turbine unit 113, a first heat regenerator 114, a second heat regenerator 115, a cooling device 116, a heat source device 117 and a control valve group 118, wherein the control valve group 118 comprises a first control valve 118a arranged at the inlet end of the main compressor unit 111, a second control valve 118b arranged at the inlet end of the recompression unit 112 and a third control valve 118c arranged at the inlet end of the turbine unit 123, the circulation subsystem 11 is further provided with a bypass, a bypass control valve 119 is arranged on the bypass, the bypass is arranged between at least one of the outlet end of the main compressor unit 111 and the inlet end of the cooling device 116, the outlet end of the recompression unit 112 and the outlet end of the first hot-side passage 114a, the inlet end of the turbine unit 123 and the inlet end of the second hot-side passage 115a, the air-seal system 121 comprises a heating device 121b, and the heating device 121b is used for regulating the temperature of the fluid medium entering the air-seal valve 120, referring to fig. 1 to 7, the starting method includes:

step S11: in the first air sealing stage, the sealing subsystem 12 and the storage subsystem 13 are started, the first control valve 118a, the second control valve 118b and the bypass control valve 119 are opened to 50% -80% of full opening, the connecting valve 122 and the third control valve 118c are closed, and the storage subsystem 13 is made to fill fluid media into the air sealing system 121;

step S12: in the second air sealing stage, the fluid medium entering the circulation subsystem 11 from the air sealing system 121 is heated to 70-90 ℃ so that the fluid medium at 70-90 ℃ enters the main compressor unit 111, and the fluid medium enters the air sealing valve 120 from the air sealing system 121 to complete the sealing of the circulation device 110;

step S2: in the circulation phase, the circulation subsystem 11 is started to enable the storage subsystem 13 to fill the circulation subsystem 11 with the fluid medium, so that the circulation subsystem 11 reaches the target load, and the system is started.

Alternatively, in step S11, the first control valve 118a, the second control valve 118b, and the bypass control valve 119 are opened to 60% of full opening, and the connecting valve 122 and the third control valve 118c are closed.

Alternatively, in step S12, the fluid medium entering the main compressor group 111 is maintained above 80 ℃.

In these alternative embodiments, the sealing subsystem 12 and the storage subsystem 13 are started first, so that the sealing subsystem 12 fills the circulation subsystem 11 with the fluid medium, and the sealing subsystem 12 seals the circulation device 110, which improves the problem that the circulation device 110 cannot be started smoothly due to poor sealing effect in the starting stage. The first control valve 118a, the second control valve 118b and the bypass control valve 119 are opened to 50-80% of full opening, so that damage to each device in the circulation subsystem at the starting stage due to overlarge valve opening and overhigh pressure is avoided, and fluid media are prevented from flowing in the circulation subsystem 11 due to undersize valve opening; the gas entering the circulation subsystem 11 from the gas seal system 121 is heated to 70-80 ℃, so that the fluid medium at 70-80 ℃ enters the main compressor unit 111, and the low-temperature fluid medium is prevented from flowing into the main compressor unit 111 and damaging the main compressor unit 111. The restart storage subsystem 13 fills the circulation subsystem 11 with fluid medium, and continuously adjusts the circulation subsystem 11 until the circulation subsystem 11 reaches a target load, so that the circulation system 1 starts smoothly.

Referring to fig. 8, fig. 8 is a schematic flow chart illustrating a starting method of the circulation system 1 according to another embodiment of the present disclosure.

In some alternative embodiments, as shown in fig. 1 to 8, the circulation subsystem 11 includes a main compressor unit 111, a recompression unit 112, a heat source device 117, and a turbine unit 113, the circulation system 1 further includes a cooling subsystem 14, the cooling subsystem 14 may cool at least one of the main compressor unit 111, the recompression unit 112, and the turbine unit 113, and step S2 includes:

step S21: the storage subsystem 13 is caused to fill the circulation subsystem 11 with fluid medium and the cooling subsystem 14 is activated.

Step S22: the main compressor unit 111, the recompressor unit 112 and the heat source device 117 are started.

Step S23: the heat source device 117 is adjusted until the turbine set reaches the first temperature, and the turbine set 113 is started.

Step S24: when the rotating speeds of the main compressor unit 111 and the recompressor unit 112 are increased to 30% -35% of rated rotating speeds, and the rotating speed of the turbine unit 113 reaches 10% -20% of rated rotating speeds, the main compressor unit 111 and the recompressor unit 112 are adjusted to the rated rotating speeds, and then the turbine unit 113 is adjusted to the rated rotating speeds, so that the circulating system 1 is started.

Alternatively, in step S23, the temperature of the heat source device 117 is heated to 100 ℃ before the turbine unit 113 is started.

Optionally, in step S23, the first temperature of the turbine set 113 is the temperature at which the outer cylinder wall of the turbine in the turbine set 113 reaches the predetermined starting temperature, and the first temperature value may be determined by a user according to actual conditions, for example, the first temperature value may be determined by the user according to the device specification, because different turbines have different performances and specifications.

Optionally, in step S23, the temperature of the heat source device 117 is adjusted until the temperature of the turbine unit 113 reaches the first temperature; the temperature of the heat source device 117 is continuously increased to the rated temperature at the first temperature increasing rate.

Alternatively, in step S23, the user may decide the specific value of the first temperature-increasing rate according to the actual situation due to the specification difference between the heat source device 117 and the circulation system 1.

Optionally, in step S23, the first temperature-increasing rate may be 40 ℃/h to 60 ℃/h. Optionally, when the rotating speed of the turbine unit 113 reaches 10% -20% of the rated rotating speed, the turbine unit 113 maintains the rotating speed to operate, whether the system can stably operate or not is observed, and the rotating speed of the turbine unit 113 is gradually increased after the turbine unit 113 stably operates for 5 min.

Optionally, in step S24, the barring motor drives the turbine unit 113 to barring, and the rotation speed of the turbine unit 113 is increased to above 10% of the rated rotation speed.

In these alternative embodiments, in step S23, the temperature of heat source device 117 is heated to a first temperature of turbine unit 113 before turbine unit 113 is started to avoid damage to turbine unit 113 from the cryogenic fluid medium. Firstly, when the rotating speeds of the main compressor unit 111 and the recompressor unit 112 are increased to 30% -35% of rated rotating speeds, and the rotating speed of the turbine unit 113 is increased to 10% -20% of rated rotating speeds, whether the main compressor unit 111, the recompressor unit 112 and the turbine unit 113 can stably operate or not in a low-speed state is tested, then the main compressor unit 111 and the recompressor unit 112 are adjusted to the rated rotating speeds, and then the turbine unit 113 is adjusted to the rated rotating speeds. The rotating speeds of the main compressor unit 111, the recompression unit 112 and the turbine unit 113 are regulated in stages, so that the equipment pressure is reduced, and the safety and stability of the main compressor unit 111, the recompression unit 112 and the turbine unit 113 in the starting stage are ensured.

In some alternative embodiments, as shown in fig. 1 to 7, the circulation system 1 includes a volume control subsystem 15, and an inlet end and an outlet end of the volume control subsystem 15 are both communicated with the circulation subsystem 11 to stabilize the pressure in the circulation subsystem 11, in step S22: when the pressure at the inlet end of the main compressor unit 111 reaches a first pressure, the main compressor unit 111 and the recompression unit 112 are started, and then the volume control subsystem 15 is started, or when the pressure at the inlet end of the main compressor unit 111 reaches the first pressure, the rotating speed of the main compressor unit 111 is increased to 10% -25% of the rated rotating speed, the recompression unit 112 is started, and then the volume control subsystem 15 is started.

Optionally, in the above step, the first pressure is a specified starting pressure value of the main compressor unit 111, and due to differences in performance and specification of different compressors, a user may determine the first pressure value according to an actual situation, for example, the user may determine the first pressure value through an equipment specification.

Optionally, in the above step, when the pressure at the inlet end of the main compressor unit 111 reaches 3MPa to 3.5MPa, the main compressor unit 111 is started.

Optionally, in the above step, the rotation speeds of the main compressor unit 111 and the recompression unit 112 are increased at an increasing rate of 2000rpm/min to 5000 rpm/min.

Optionally, in the above step, when the main compressor unit 111 and the recompression unit 112 reach 10% to 25% of rated rotation speeds, the main compressor unit 111 and the recompression unit 112 stably operate for no less than 5min, whether the main compressor unit 111 and the recompression unit 112 are abnormal or not is observed, the rotation speeds of the main compressor unit 111 and the recompression unit 112 are increased to 30% to 35% of rated rotation speeds, the stable operation of the main compressor unit 111 and the recompression unit 112 is ensured through a sectional speed increasing mode, and the pressure in the circulation subsystem 11 is stabilized through the pressure regulation effect of the volume subsystem 15, so that the pressure fluctuation in the circulation subsystem 11 is avoided, and the working efficiency of the circulation system 1 is not affected.

Optionally, the abnormal conditions include whether the abnormal sound and vibration of the compressor, the bearing and the motor are within limit values, whether the rotating speed of the compressor, the shaft vibration and the temperature of the bearing bush are within design limit values, whether the rotating speed of the motor, the winding temperature, the frequency and the current of the bearing are within design limit values, and whether the leakage pressure of the gas seal branch of the compressor and the three-phase current of the driving motor are within design limit values.

In these optional embodiments, when the inlet end pressure of the main compressor unit 111 reaches the first pressure, the main compressor unit 111 is started, so that the ineffective work of the main compressor unit 111 is reduced, and the damage of idling to the main compressor unit 111 is also reduced, and the recompression unit 112 and the main compressor unit 111 are started synchronously, so that the operation steps are simplified, or the recompression unit 112 can be started when the main compressor unit 111 reaches 10% -25% of the rated rotation speed, so that the inlet end pressure of the recompression unit 112 is not too low to cause the ineffective work of the recompression unit 112, and the boosting time of the circulation subsystem 11 is not prolonged because the recompression unit 112 is started too late.

In some technical solutions of alternative embodiments, as shown in fig. 1 to 7, in step S22, the heat source device 117 is started after the rotation speeds of the main compressor unit 111 and the recompressor unit 112 are increased to 30% to 35% of the rated rotation speed.

Optionally, in the above step, the heat source device 117 is started when the inlet air temperature of the air seal valve 120 of the main compressor unit 111 and the recompression unit 112 is in a stable temperature range.

Optionally, in the above step, the heat source device 117 is started when the inlet air temperature of the air seal valve 120 of the main compressor unit 111 and the recompression unit 112 is 95-105 ℃.

In these alternative embodiments, when the rotational speeds of the main compressor unit 111 and the recompressor unit 112 are increased to 30% -35% of the rated rotational speed, the circulation subsystem 11 already has sufficient fluid medium therein, and the heat source device 117 is restarted, so that the risk of dry burning of the heat source device 117 is reduced.

In some alternative embodiments, as shown in fig. 1 to 7, an inlet end of the gas seal system 121 is connected to a connection position of the circulation subsystem 11, a connection valve 122 is disposed between the inlet end of the gas seal system 121 and the connection position, the connection valve 122 is used for controlling a flow rate of the fluid medium entering the gas seal system 121 from the circulation subsystem 11, in step S22, when an inlet end pressure of the main compressor unit 111 reaches 90% to 95% of a rated pressure, the storage subsystem 13 is closed, and the connection valve 122 is opened, so that the fluid medium of the circulation subsystem 11 enters the gas seal system 121.

Optionally, in the above step, the fluid medium enters the mixer 121a of the gas seal system 121 from the connection position of the circulation subsystem 11 after the connection valve 122 is opened.

In these alternative embodiments, when the inlet pressure of the main compressor unit 111 reaches 90% -95% of the rated pressure, the storage subsystem 13 is closed to prevent accidents caused by excessive pressure in the circulation system 1, and the connecting valve 122 is opened, so that the fluid medium in the circulation subsystem 11 enters the gas seal system 121 and enters the gas seal valve 120 through the gas seal system 121, and the circulation device 110 is sealed continuously.

In some alternative embodiments, as shown in fig. 1 to 7, the recycling sub-system 11 includes a control valve set 118, the control valve set 118 includes a third control valve 118c, the third control valve 118c is disposed at an inlet end of the turbine unit 113, and the step S23 includes, after adjusting the temperature of the heat source device 117 until the temperature of the turbine unit 113 reaches the first temperature:

and adjusting the temperature of the fluid medium entering the air seal valve 120 of the turbine unit 113 to 80-110 ℃, opening the third control valve 118c to 25-35% of full opening, and starting the turbine unit 113.

Optionally, in the above step, the third control valve 118c is opened to 30% of full open.

In the optional embodiments, the temperature of the fluid medium entering the air seal valve 120 of the turbine unit 113 is adjusted to 80-110 ℃, so that a turbine warming effect is achieved, the fluid medium with too high or too low temperature is prevented from damaging the turbine unit 113, the third control valve 118c is opened to 25% -35% of full opening, the fluid medium with too high pressure entering the turbine unit 113 is prevented from damaging the turbine unit 113, and the condition that the valve opening is too low and the turbine unit 113 cannot obtain enough flow is also avoided.

Referring to fig. 9, fig. 9 is a schematic flowchart illustrating a starting method of the circulation system 1 according to another embodiment of the present disclosure.

In some solutions of alternative embodiments, as shown in fig. 1 to 9, the circulation subsystem 11 further includes a bypass, a bypass control valve 119 is disposed on the bypass, and the bypass control valve 119 includes: a first bypass control valve 119a provided on a first bypass connected between the outlet end of the main compressor group 111 and the inlet end of the cooling device 116, a second bypass control valve 119b provided on a second bypass between the outlet end of the recompressor group 112 and the outlet end of the first hot side path 114a, and a third bypass control valve 119c provided on a third bypass between the inlet end of the turbine group 113 and the inlet end of the second hot side path 115a, in step 24, including:

step S241: adjusting the main compressor unit 111 and the recompression unit 112 to rated speeds, adjusting the first bypass control valve 119a and the second bypass control valve 119b to be fully closed, and adjusting the first control valve 118a and the second control valve 118b to be fully open;

step S242: adjusting the pressure difference between the outlet end and the inlet end of the turbine unit 113 to be not more than 0.5MPa, adjusting the temperature difference between the outlet end and the inlet end of the turbine unit 113 to be not more than 70 ℃, adjusting the third control valve 118c to be fully opened, and increasing the rotating speed of the turbine unit 113 to 20-30% of rated rotating speed;

step S243: and after the turbine unit 113 runs for more than 5min at the rated rotating speed of 20-30%, closing the third bypass control valve 119c and increasing the rotating speed of the turbine unit 113 to the rated rotating speed.

Alternatively, in step S241, the opening degree of the third control valve 118c is increased to full opening while the rotation speed of the main compressor unit 111 is increased.

Optionally, in step S243, after the turbine unit 113 reaches the rated rotation speed of 10%, the turning gear motor is turned off, the turbine unit 113 is turned at the rated rotation speed of 20% to 30%, the operation is performed for more than 5min, whether the turbine unit 113 normally operates is checked, then the rotation speed of the turbine unit 113 is increased to the rated rotation speed of 50% to 60%, the operation is performed for more than 5min, and whether the turbine unit 113 normally operates is checked.

In these alternative embodiments, the first bypass control valve 119a and the second bypass control valve 119b are closed, all the control valve sets 118 are opened, the main compressor set 111 and the recompressor set 112 are raised to the rated rotation speed, so that the fluid medium can completely reach the inlet end of the turbine set 113, the pressure difference between the outlet end and the inlet end of the turbine set 113 is regulated to be not more than 0.5MPa, the temperature difference between the outlet end and the inlet end of the turbine set 113 is regulated to be not more than 70 ℃, and the turbine set 113 is prevented from being damaged due to the overlarge pressure difference and temperature difference between the outlet end and the inlet end of the turbine set 113; after the turbine unit 113 runs for more than 5min at the rated rotation speed of 20% -30%, the third bypass control valve 119c is closed, all fluid media enter the turbine unit 113, and the turbine unit 113 reaches the rated rotation speed.

In some alternative embodiments, as shown in fig. 1 to 7, step S24 includes decreasing the power of the cooling device 116 to increase the inlet temperature of the main compressor group 111 when the inlet temperature of the main compressor group 111 is lower than 30 ℃, and increasing the power of the cooling device 116 to decrease the inlet temperature of the main compressor group 111 when the inlet temperature of the main compressor group 111 is higher than 40 ℃.

In these alternative embodiments, the inlet end temperature of the main compressor set 111 is adjusted by adjusting the power of the cooling device 116 to assist in adjusting the inlet end temperature of the main compressor set 111 to prevent damage to the main compressor set 111 due to fluctuations in fluid medium temperature.

It will be appreciated by persons skilled in the art that the above embodiments are illustrative and not restrictive. Different features which are present in different embodiments may be combined to advantage. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art upon studying the drawings, the specification, and the claims. In the claims, the term "comprising" does not exclude other means or steps; the indefinite article "a" does not exclude a plurality; the terms "first" and "second" are used to denote a name and not to denote any particular order. Any reference signs in the claims shall not be construed as limiting the scope. The functions of the parts appearing in the claims may be implemented by one single hardware or software module. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A recompression brayton cycle system comprising a storage subsystem, a circulation subsystem, and a containment subsystem, wherein:

the storage subsystem is used for storing fluid medium and supplying the fluid medium to the circulation subsystem and the sealing subsystem;

the circulation subsystem is communicated with the storage subsystem and the sealing subsystem respectively, the circulation subsystem is used for receiving filling of fluid medium from the storage subsystem so as to enable the fluid medium to complete energy circulation in the circulation subsystem, and the circulation subsystem comprises a circulation device used for circulating the fluid medium;

the sealing subsystem is used for sealing the circulating subsystem and comprises an air seal valve and an air seal system, the air seal valve is arranged on the circulating device, the outlet end of the air seal system is communicated with the air seal valve, and the inlet end of the air seal system is communicated with the outlet end of the storage subsystem and the connecting position of the circulating subsystem.

2. A recompression brayton cycle system as set forth in claim 1, wherein said cycle subsystem comprises a main compressor train, a recompression train, a turbine train, a first recuperator, a second recuperator, a cooling apparatus, a heat source apparatus, and a control valve train;

the inlet end of the main compressor unit is communicated with the outlet end of the cooling device, and the inlet end of the recompression unit is communicated with the inlet end of the cooling device;

the first regenerator comprises a first hot side channel and a first cold side channel, the second regenerator comprises a second hot side channel and a second cold side channel, an inlet end of the second cold side channel is communicated with an outlet end of the first cold side channel, and an outlet end of the second hot side channel is communicated with an inlet end of the first hot side channel;

the inlet end of the second hot side channel is communicated with the outlet end of the turbine unit, the outlet end of the first hot side channel is respectively communicated with the inlet end of the cooling device and the inlet end of the recompression unit, the inlet end of the first cold side channel is communicated with the outlet end of the main compressor unit, the outlet end of the first cold side channel and the outlet end of the recompression unit are converged and then pass through the second cold side channel, and the heat source device is communicated with the inlet end of the turbine unit;

the control valve group comprises a first control valve, a second control valve and a third control valve, the first control valve is arranged at the inlet end of the main compressor group and used for controlling the inlet pressure and the flow of the main compressor group, the second control valve is arranged at the inlet end of the recompression group and used for controlling the inlet pressure and the flow of the recompression group, and the third control valve is arranged at the inlet end of the turbine group and used for controlling the inlet pressure and the flow of the turbine group.

3. A recompression brayton cycle system as set forth in claim 2, wherein said recirculation sub-system is further provided with a bypass having a bypass control valve disposed thereon, said bypass comprising at least one of a first bypass, a second bypass, and a third bypass, wherein:

the first bypass is connected between the outlet end of the main compressor unit and the inlet end of the cooling device, a first bypass control valve is arranged on the first bypass, and the first bypass valve is used for adjusting the inlet pressure and the flow of the main compressor unit;

the second bypass is connected between the outlet end of the recompression unit and the outlet end of the first hot side channel, and a second bypass control valve is arranged on the second bypass and used for adjusting the inlet pressure and the flow of the recompression unit;

the third bypass is connected between the inlet end of the turbine unit and the inlet end of the second hot side channel, and a third bypass control valve is arranged on the third bypass and used for adjusting the inlet pressure and the flow of the turbine unit.

4. A recompression brayton cycle system according to claim 2, wherein said cycle device comprises at least one of said main compressor train, said recompression train and said turbine train.

5. A recompression brayton cycle system as set forth in claim 2, wherein said storage subsystem comprises a first outlet port and a second outlet port, said first outlet port communicating with said circulation subsystem; the second outlet end is communicated with the gas seal system.

6. A recompression brayton cycle system as set forth in claim 2, wherein said gas seal system comprises a mixer, a heating device and a buffer device connected in series in the direction of flow of said fluid medium;

the mixer is used for mixing the fluid medium filled in the air sealing system by the circulation subsystem;

the heating device is used for adjusting the temperature of the fluid medium entering the air sealing valve from the air sealing system;

the inlet end of the mixer is connected with the connecting position of the circulating subsystem, the inlet end of the heating device is connected with the outlet end of the mixer, the inlet end of the buffer device is connected with the outlet end of the heating device, and the outlet end of the buffer device is communicated with the air seal valve.

7. A recompression brayton cycle system as set forth in claim 2, further comprising a cooling subsystem coupled to said cooling device, said cooling device further coupled to at least one of said main compressor train, said recompression train, and said turbine train, said cooling subsystem for cooling said cooling device and at least one of said main compressor train, said recompression train, and said turbine train.

8. A recompression Brayton cycle system as claimed in claim 6, wherein a connecting valve is provided between the connection location and the inlet end of the mixer, the connection location comprising:

a first location between an outlet end of the main compressor train and an inlet end of the first cold-side passage, a first valve disposed between the first location and an inlet end of the mixer;

and/or a second position, wherein the second position is arranged between the outlet end of the heat source device and the inlet end of the turbine unit, and a second valve is arranged between the second position and the inlet end of the mixer.

9. A recompression brayton cycle system as set forth in claim 1, further comprising an exhaust subsystem, an inlet port of said exhaust subsystem being in communication with said circulation subsystem, said exhaust subsystem for releasing said fluid medium from within said circulation subsystem.

10. A recompression brayton cycle system as claimed in any one of claims 1-9, further comprising a volume control subsystem, said volume control subsystem comprising a storage tank, an outlet port and an inlet port of said storage tank both communicating with said circulation subsystem, said volume control subsystem for stabilizing pressure within said circulation subsystem.

11. A starting method for starting a recompression brayton cycle system as claimed in any one of claims 1-10, wherein the cycle subsystem comprises a main compressor set, a recompression set, a turbine set, a first regenerator, a second regenerator, a cooling device, a heat source device and a control valve set, the control valve set comprises a first control valve disposed at an inlet end of the main compressor set, a second control valve disposed at an inlet end of the recompression set, and a third control valve disposed at an inlet end of the turbine set, the cycle subsystem further comprises a bypass, the bypass is provided with a bypass control valve, the bypass is disposed between at least one of an outlet end of the main compressor set and an inlet end of the cooling device, an outlet end of the recompression set and an outlet end of the first hot-side passage, an inlet end of the turbine set and an inlet end of the second passage, the gas seal system includes a heating device for regulating the temperature of the fluid medium entering the gas seal valve, including:

a first air sealing stage, wherein the sealing subsystem and the storage subsystem are started, the first control valve, the second control valve and the bypass control valve are opened to 50% -80% of full opening, the connecting valve and the third control valve are closed, and the storage subsystem is filled with the fluid medium to the air sealing subsystem;

in the second air sealing stage, the fluid medium entering the circulation subsystem from the air sealing system is heated to 70-90 ℃ so that the fluid medium at 70-90 ℃ enters the main compressor unit, and the fluid medium enters the air sealing valve from the air sealing system to complete the sealing of the circulation device;

and a circulation phase, wherein the circulation subsystem is started to enable the storage subsystem to fill the fluid medium into the circulation subsystem, so that the circulation subsystem reaches a target load, and system starting is completed.

12. The start-up method of claim 11, wherein the cycle sub-system includes a main compressor train, a recompression train, a heat source device, and a turbine train, the cycle system further including a cooling sub-system that cools at least one of the main compressor train, the recompression train, and the turbine train, the cycle phase including:

causing the storage subsystem to fill the circulation subsystem with the fluid medium, activating the cooling subsystem;

starting the main compressor unit, the recompression unit and the heat source device;

adjusting the temperature of the heat source device until the turbine unit reaches a first temperature, and starting the turbine unit;

when the rotating speeds of the main compressor unit and the recompression unit are increased to 30% -35% of rated rotating speeds, and the rotating speed of the turbine unit is increased to 15% -20% of rated rotating speeds, after the main compressor unit and the recompression unit reach the rated rotating speeds, the turbine unit is adjusted to the rated rotating speeds, and therefore the starting of the circulating system is completed.

13. A method of starting up according to claim 12, wherein the circulation system includes a volume control sub-system, an inlet end and an outlet end of the volume control sub-system being in communication with the circulation sub-system for stabilizing the pressure within the circulation sub-system, and wherein the steps of starting up the main compressor unit, the recompression unit, and the heat source device are as follows:

when the pressure at the inlet end of the main compressor unit reaches a first pressure, starting the main compressor unit and the recompression unit, and then starting the volume control subsystem, or when the pressure at the inlet end of the main compressor unit reaches the first pressure and the rotating speed of the main compressor unit is increased to 10% -25% of the rated rotating speed, starting the recompression unit, and then starting the volume control subsystem.

14. The starting method according to claim 13, wherein the heat source device is started after the rotational speeds of the main compressor unit and the recompressor unit are increased to the 30% -35% rated rotational speed.

15. The method of starting up according to claim 12, wherein an inlet end of a gas seal system is connected to a connection point of the circulation sub-system, a connection valve is provided between the inlet end of the gas seal system and the connection point, the connection valve is used for controlling the flow rate of the fluid medium entering the gas seal system from the circulation sub-system, and the steps of starting up the cooling sub-system, the main compressor unit and the recompression unit further comprise closing the storage sub-system and opening the connection valve to allow the fluid medium of the circulation sub-system to enter the gas seal system when the inlet end pressure of the main compressor unit reaches 90% -95% of a rated pressure.

16. The method of starting of claim 12, wherein the recirculation subsystem includes a control valve assembly including a third control valve disposed at an inlet end of the turbine block, and wherein the step of starting the turbine block after adjusting the heat source device to the turbine block temperature to reach the first temperature further comprises:

and adjusting the temperature of the fluid medium entering an air seal valve of the turbine unit to 80-110 ℃, and starting the turbine unit after opening the third control valve to 25-35% of the full opening.

17. The startup method of claim 12, wherein the circulation subsystem further comprises a bypass having a bypass control valve disposed thereon, the bypass control valve comprising: the first bypass control valve disposed on a first bypass connected between an outlet end of the main compressor unit and an inlet end of the cooling device, the second bypass control valve disposed on a second bypass between an outlet end of the recompression unit and an outlet end of the first hot side passage, the third bypass control valve disposed on a third bypass between an inlet end of the turbine unit and an inlet end of the second hot side passage, adjusting a temperature of the heat source device until the turbine unit reaches a first temperature, and the step of starting the turbine unit includes:

adjusting the main compressor unit and the recompression unit to rated rotation speed, adjusting the first bypass control valve and the second bypass control valve to be completely closed, and adjusting the control valve group to be completely opened;

adjusting the pressure difference between the outlet end and the inlet end of the turbine unit to be not more than 0.5MPa, adjusting the temperature difference between the outlet end and the inlet end of the turbine unit to be not more than 70 ℃, and increasing the rotating speed of the turbine unit to 20-30% of rated rotating speed;

and after the running time t of the turbine set is 20% -30% of the rated rotating speed, closing the third bypass control valve, and increasing the rotating speed of the turbine set to the rated rotating speed.

18. The method of starting according to claim 17 wherein adjusting said main compressor package and said recompression package to rated speeds, adjusting said first bypass control valve and said second bypass control valve to full close, and adjusting said set of control valves to full open comprises:

and when the temperature of the inlet end of the main compressor unit is lower than 30 ℃, reducing the power of the cooling device to improve the temperature of the inlet end of the main compressor unit, and when the temperature of the inlet end of the main compressor unit is higher than 35 ℃, improving the power of the cooling device to reduce the temperature of the inlet end of the main compressor unit.