WO2022111577A1

WO2022111577A1 - Bypass auxiliary system for closed brayton cycle heat engine system, heat engine device, and regulation method therefor

Info

Publication number: WO2022111577A1
Application number: PCT/CN2021/133088
Authority: WO
Inventors: 李亚飞; 邢继; 堵树宏; 丁亮; 于沛; 姚鸿帅; 王晰; 李�杰; 马惠昀; 黄晨; 刘亚光
Original assignee: 中国核电工程有限公司
Priority date: 2020-11-26
Filing date: 2021-11-25
Publication date: 2022-06-02
Also published as: CN112814785A; CA3202989A1; CN112814785B

Abstract

A bypass auxiliary system for a closed Brayton cycle heat engine system. The bypass auxiliary system comprises a first regulation unit and a second regulation unit, the first regulation unit comprising a first branch pipeline (30), a compressor (33), and a buffer tank (35). The compressor (33) and the buffer tank (35) are connected in series on the first branch pipeline, the compressor (33) being used for suctioning a working medium from the heat engine system, and the buffer tank (35) being used for storing the working medium suctioned by the compressor (33) and releasing the stored working medium to the heat engine system. The second regulation unit comprises a second branch pipeline (40) and a regulating valve (43), the regulating valve (43) being arranged on the second branch pipeline (40). The present system is capable of regulating the flow amount and mechanical output power of a main loop in a closed Brayton cycle heat engine system, features a fast response speed and a large regulation range, and helps to reduce power output efficiency loss. Further disclosed are a heat engine device comprising the present bypass auxiliary system, and a regulation method therefor.

Description

Bypass auxiliary system for closed Brayton cycle heat engine system, heat engine device and adjustment method thereof

The present disclosure claims the priority of a Chinese patent application with an application date of November 26, 2020, an application number of 202011346692.7, and the title of "Bypass Auxiliary System for Closed Brayton Cycle Heat Engine System, Heat Engine System".

technical field

The present disclosure belongs to the field of nuclear technology, and in particular relates to a bypass auxiliary system for a closed Brayton cycle heat engine system, a closed Brayton cycle heat engine device including the bypass auxiliary system, and an adjustment method thereof.

Background technique

In the device or system that uses the open Brayton cycle as the principle to produce power, the adjustment of its power mainly depends on the change of the flow rate of the working medium in the main circuit. In a device or system that uses the closed Brayton cycle as the principle to produce power, if it only depends on the adjustment of the circulating pressure in the main circuit, that is, the adjustment of the charging volume of the working medium in the entire main circuit, this adjustment involves the pressure pipe. It is difficult to achieve the purpose of fast response with the existing system design or equipment design, and it is difficult to produce accurate flow or power regulation capability. Therefore, the closed Brayton cycle is generally regulated by bypassing the main circuit circulation. Since part of the flow is circulated through the bypass and does not go through the turbine to do work, the bypass bypassing the main circuit circulation method is still result in a loss of efficiency.

At present, there are two main ways of bypassing the main circuit of the traditional bypass: one is to use the charging and exhausting method to adjust the charging volume of the main circuit. The advantage is that the flow or power can be adjusted in a wide range. The disadvantage is that the response speed is slow and the control ability is imprecise; the second is to use a straight-through bypass with a regulating valve for adjustment, which has the advantage of fast response speed. overall power output efficiency.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned defects in the prior art, the present disclosure provides a bypass auxiliary system for a closed Brayton cycle heat engine system, a closed Brayton cycle heat engine device including the bypass auxiliary system, and an adjustment method, which can The flow rate and mechanical output power of the main circuit in the closed Brayton cycle heat engine system are adjusted, and the response speed is fast, and at the same time, a wide range of adjustment can be realized, which is beneficial to reduce the loss of power output efficiency.

In a first aspect, the present disclosure provides a bypass auxiliary system for a closed Brayton cycle heat engine system, comprising a first regulating unit and a second regulating unit, wherein:

The first conditioning unit includes a first branch pipeline, a compressor, and a buffer tank. The inlet end of the first branch pipeline is connected to the outlet of the high-pressure compressor in the closed Brayton cycle heat engine system, and the outlet end of the first branch pipeline is connected to the outlet of the high-pressure compressor in the closed Brayton cycle heat engine system. It is connected with the inlet of the low-pressure compressor in the closed Brayton cycle heat engine system, the compressor and the buffer tank are connected in series on the first branch pipeline, and the compressor is used for extracting from the closed Brayton cycle. pumping working fluid in the Brayton cycle heat engine system, and the buffer tank is used to store the working fluid pumped by the compressor and release the stored working fluid to the closed Brayton cycle heat engine system;

The second regulating unit is connected in parallel with the first regulating unit, and the second regulating unit includes a second branch pipeline and a regulating valve, and the regulating valve is arranged on the second branch pipeline.

In a second aspect, the present disclosure also provides a heat engine device, including a closed Brayton cycle heat engine system, the closed Brayton cycle heat engine system including a main loop, and characterized in that the heat engine device further includes the above-mentioned heat engine. In the bypass auxiliary system of the closed Brayton cycle heat engine system, the bypass auxiliary system is connected in parallel with the main circuit.

In a third aspect, the present disclosure provides a method for adjusting a heat engine device, comprising:

When the closed Brayton cycle heat engine system is in normal operation and the mechanical output power of the closed Brayton cycle heat engine system needs to be reduced, the working fluid is extracted from the main circuit and stored in the buffer tank of the first regulating unit until the working fluid of the main circuit. The amount of mass charging matches the mechanical output power to be reduced, or, when the closed Brayton cycle heat engine system is operating normally and the mechanical output power of the closed Brayton cycle heat engine system needs to be increased, the first adjustment The working medium stored in the buffer tank of the unit is released into the main circuit of the closed Brayton cycle heat engine system, until the charging amount of the working medium in the main circuit matches the required mechanical output power;

At the same time, adjust the opening of the regulating valve in the second regulating unit, and change the flow bypassed by the second regulating unit, so that the real-time speed of the turbine unit in the main circuit and the rated value corresponding to the mechanical output power that needs to be lowered/raised to. speed to match.

Beneficial effects of the present disclosure compared to the prior art:

Through the bypass auxiliary system for the closed Brayton cycle heat engine system provided by the present disclosure, the first adjustment unit and the second adjustment unit can adjust the working medium flow in the main circuit of the closed Brayton cycle heat engine system, Therefore, the function of adjusting the mechanical output power of the closed Brayton heat engine is realized, so that the actual mechanical output power matches the required mechanical output power. Compared with the existing technology, it not only has a fast response speed, a large adjustment range, and an accurate adjustment. Controllable, it is beneficial to reduce the power output efficiency loss and energy consumption of the closed Brayton cycle heat engine system, and it can also filter, purify and supplement the working fluid online to reduce the impact of working fluid loss or pollution on system operation. The disclosed structure is simple and the operation is convenient.

Through the closed Brayton cycle heat engine system heat engine device and its adjustment method provided by the present disclosure, the flow rate and mechanical output power of the main circuit can be adjusted through the bypass auxiliary system, and the response speed is fast, the adjustment range is large, and the power output The efficiency loss is small, and it has the ability to filter and purify the working medium.

Description of drawings

1 is a schematic structural diagram of a bypass auxiliary system for a closed Brayton cycle heat engine system according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of another bypass auxiliary system used in a closed Brayton cycle heat engine system according to an embodiment of the present disclosure.

In the figure: 10 - high pressure compressor; 20 - low pressure compressor; 30 first branch pipeline; 31 - first stop valve; 32 - first check valve; 33 - compressor; 34 - filter purifier; 35 - Buffer tank; 36-second check valve; 37-second stop valve; 40-second branch pipeline; 41-third stop valve; 42-third check valve; 43-regulating valve; 50-third branch pipeline.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present disclosure, the present disclosure will be further described in detail below with reference to the accompanying drawings and embodiments.

Example 1

1 is a schematic structural diagram of a bypass auxiliary system for a closed Brayton cycle heat engine system in an embodiment of the disclosure; FIG. 2 is another embodiment of the disclosure for a closed Brayton cycle heat engine system Schematic diagram of the bypass auxiliary system.

As shown in FIG. 1 , the present embodiment discloses a bypass auxiliary system for a closed Brayton cycle heat engine system, including a first adjustment unit and a second adjustment unit, wherein:

The first conditioning unit includes a first branch line 30, a compressor 33, and a buffer tank 35, wherein the inlet end of the first branch line 30 is connected to the outlet of the high-pressure compressor 10 in the closed Brayton cycle heat engine system, Its outlet end is connected to the inlet of the low-pressure compressor 20 in the closed Brayton cycle heat engine system, so that the bypass auxiliary system of this embodiment is connected in parallel with the main circuit of the closed Brayton cycle heat engine system, the compressor 33 and the buffer tank 35 It is connected in series on the first branch pipeline 30, and the compressor 33 is located upstream of the buffer tank 35. The compressor 33 is used to pump the working medium (for example, helium, helium and xenon mixture) from the closed Brayton cycle heat engine system. , nitrogen, carbon dioxide, etc.), the buffer tank 35 is used to store the working fluid pumped by the compressor 33 and release the stored working fluid to the closed Brayton cycle heat engine system. During the normal operation of the main circuit of the closed Brayton cycle heat engine system, the gas working medium in the main circuit of the closed Brayton cycle heat engine system can be pumped, compressed and temporarily stored in the buffer tank 35 by using the compressor 33 , or, by releasing the compressed gas working medium temporarily stored in the buffer tank 35 into the main circuit of the closed Brayton cycle heat engine system, the above-mentioned working medium between the buffer tank 35 and the main circuit is mutually transported and circulated , the filling amount of the gas working medium in the main circuit can be changed, and the working medium filling amount of the main circuit can be controlled between 0-100%, that is, the filling amount can be continuously adjusted between the vacuum level and the rated level. Using the basic working principle that the working medium filling amount of the main circuit is proportional to the mechanical output power, the more working medium, the greater the mechanical output power. Therefore, the adjustment range of the mechanical output power of the main circuit in this embodiment can be from zero to Rated power, that is to say, a wide range of adjustment purposes can be achieved. In addition, during the start-up process of the main circuit of the closed Brayton cycle heat engine system, the compressed gas working medium temporarily stored in the buffer tank 35 can also be released to the main circuit to adapt to the working medium required when the mechanical output power of the main circuit is increased. filling volume. For the closed Brayton cycle heat engine system designed to use compressed gas energy storage to complete the startup, the compressed gas working medium temporarily stored in the buffer tank 35 can also be released to the main circuit, and the pressure difference can be used to drive the turbine unit in the main circuit to rotate. , and then slowly turn to the normal heat source of the main circuit to provide the rotational energy source, thereby reducing energy consumption.

The second regulating unit and the first regulating unit are arranged in parallel, and the second regulating unit includes a second branch pipeline 40 and a regulating valve 43 , and the regulating valve 43 is arranged on the second branch pipeline 40 . The second regulating unit bypasses the high pressure section and the low pressure section of the closed Brayton cycle heat engine system. During the normal operation of the main circuit of the closed Brayton cycle heat engine system, by controlling the opening and closing and the opening degree of the regulating valve 43, the Complete the distribution of the working fluid in the main loop and the bypass, so that the flow resistance of the bypass auxiliary system changes, so as to quickly change the working fluid flow in the bypass auxiliary system and the main loop, and then quickly change the mechanical output power of the main loop, and , the structure of the second adjustment unit is simpler, and the state change of the second adjustment unit has a faster impact on the change of the state of the working medium in the main circuit, which can improve the adjustment response speed and realize the flow rate of the main circuit of the closed Brayton cycle heat engine system. , The purpose of rapid adjustment of mechanical output power.

When the main circuit is in normal operation, the first adjustment unit and the second adjustment unit are in a ready-to-use state at the same time. Using the respective characteristics of the two adjustment units, the first adjustment unit is mainly responsible for tracking a wide range of mechanical output power due to its wide adjustable range. When the output changes, the second adjustment unit can be used to make up for the lack of adjustment accuracy of the first adjustment unit because of its fast response, and maintain the stability of the turbine unit operation, especially the mechanical output power, in the closed Brayton cycle heat engine system.

It should be noted that the first adjustment unit and the second adjustment unit in this embodiment can also be used independently. However, since it is difficult to realize the two necessary functions of wide-range adjustment and fast and precise adjustment at the same time by using any adjustment unit alone, so , under normal circumstances, two adjustment units are required to be used in conjunction.

Next, the details of this embodiment will be described in further detail.

In some embodiments, the first regulating unit may further include a first shut-off valve 31 and a second shut-off valve 37 to control the opening and closing of the first branch line 30 . Wherein, the first shut-off valve 31 is provided on the first branch line 30 between the inlet end of the first branch line 30 and the compressor 33 , and is used to control the inlet end of the first branch line 30 and the compressor 33 . The on-off of the first branch pipeline between the machines 33; the second shut-off valve 37 is arranged on the first branch pipeline 30, and is between the buffer tank 33 and the outlet end of the first branch pipeline 30, used to control On-off of the first branch line between the buffer tank 33 and the outlet end of the first branch line 30 .

During the process of the compressor 33 sucking, compressing and temporarily storing the gas working medium in the circuit in the closed Brayton cycle heat engine system to the buffer tank 35, the first shut-off valve 31 is opened; the compressed air in the buffer tank 35 is opened. During the process of releasing the gas working medium to the main circuit of the closed Brayton cycle heat engine system, the second shut-off valve 37 is opened.

In some embodiments, the number of buffer tanks 35 may be one or multiple, and when the number of buffer tanks 35 is multiple, each buffer tank 35 may be arranged on the first branch pipeline 30 in parallel.

In some embodiments, the first regulating unit may further include a first check valve 32 and a second check valve 36 to prevent backflow of the gas working medium in the first branch line 30 . Wherein, the first check valve 32 is arranged on the first branch pipeline 30 and is between the first shut-off valve 31 and the compressor 33; the second check valve 36 is arranged on the first branch pipeline 30 and is located between the first stop valve 31 and the compressor 33; Between the buffer tank 353 and the second shut-off valve 37 .

Of course, on the premise that the functions of the first check valve 32 and the second check valve 36 are maintained, the first check valve 32 and the second check valve 36 can also be arranged on the first branch pipeline 30 as required. other positions, for example, the first check valve 32 can also be provided on the first branch pipeline 30 between the high-pressure compressor 10 and the first shut-off valve 31, and is not limited to the above position, which is not limited in this embodiment. Repeat them one by one.

In some embodiments, the first conditioning unit may further include a filter purifier 34 to remove impurities such as dust in the gaseous working medium.

Specifically, the filter and purifier 34 can be provided on the first branch pipeline 30 and between the compressor 33 and the buffer tank 35 (as shown in FIG. 1 ). After filtering and purifying in the filter purifier 34, it is passed into the buffer tank 35 for storage; or, as shown in FIG. 2, the bypass auxiliary system can also include a third branch pipeline 50, and the third branch pipeline 50 and The part of the first branch pipeline 30 provided with the first check valve 32, the compressor 33, the buffer tank 35, and the second check valve 36 is connected in parallel, and the filter purifier 34 can be arranged on the third branch pipeline 50, through The filter purifier on the third branch line 50 can continuously or intermittently filter the gas working medium in the main circuit without adjusting the flow rate and mechanical output power of the main circuit of the closed Brayton cycle heat engine system For purification, it is not necessary to separately set a circuit for filtering and purification on the main circuit, which is beneficial to improve the space utilization rate, reduce the pressure loss of the main circuit, and is beneficial to improve the circulation efficiency. The specific number of filter purifiers 34 can be selected according to actual needs, and for different gas working medium components, matching filter purifiers and combinations thereof can be selected. When the number of filter purifiers 34 is multiple, the multiple filter purifiers may be only provided on the first branch pipeline 30 between the compressor 33 and the buffer tank 35, or may be a part of the filter purifiers 34 in series Connected to the first branch pipeline 30 between the compressor 33 and the buffer tank 35 , and another filter purifier 34 is provided on the third branch pipeline 50 .

It should be noted that the series sequence of the compressor 33, the filter purifier 34, the buffer tank 35 and other equipment in the first adjustment unit can also be adjusted according to actual needs, not limited to the above sequence. In this embodiment, they are not one by one. Repeat.

In some embodiments, the second regulating unit may further include a third shut-off valve 41 . The third shut-off valve 41 is provided on the second branch pipeline 40 and is located at one end close to the high-pressure compressor 10 , that is, at an end of the regulating valve 43 . upstream to prevent backflow of gaseous working medium in the second branch pipeline.

In some embodiments, the second regulating unit may further include a third check valve 42, the third check valve 42 is provided on the second branch line 40, and the regulating valve 43 is located between the third check valve 43 and the third check valve 42. between the shut-off valves 41 to control the opening and closing of the second branch pipeline 40 .

It should be noted that the series sequence of the regulating valve 43, the third stop valve 41, and the third check valve 42 in the second regulating unit can also be adjusted according to actual needs, and is not limited to the above sequence, which is not limited in this embodiment. Repeat them one by one.

It should be noted that, in actual operation, when some process conditions allow, for example, when there is no reverse flow of air flow caused by pressure difference, or when part of the pipeline allows reverse flow of air flow caused by pressure difference, The third stop valve 41 , the first check valve 32 , the second check valve 36 , and the third check valve 42 in this embodiment can be deleted according to requirements, and are not limited to include the third stop valve 41 , the third A check valve 32 , a second check valve 36 , and a third check valve 42 .

In some embodiments, the bypass assist system further includes a control assembly, which may include a pressure sensor, a rotational speed sensor, and a controller, wherein:

The pressure sensor is electrically connected with the controller for detecting the pressure of the main circuit in the closed Brayton cycle heat engine system, and transmitting the detected pressure value to the controller; the controller is connected with the first shut-off valve, the compressor, and the second The shut-off valves are respectively electrically connected, and a calibrated pressure value is set therein. The controller is used to compare the pressure value transmitted by the pressure sensor with the corresponding calibrated pressure value, and control the first shut-off valve and the compressor according to the comparison result. , and the opening and closing of the second shut-off valve to adjust the real-time pressure of the closed Brayton cycle heat engine system to the calibration pressure range, so as to ensure that the output of the closed Brayton cycle heat engine system is basically stable and realize the closed Brayton cycle heat engine. Coarse adjustment of system mechanical output power;

The speed sensor is electrically connected with the controller, and is used to detect the real-time speed of the turbine unit (also referred to as the unit in this paper) in the main circuit of the closed Brayton cycle heat engine system, and transmit the detected real-time speed value to the controller; control The controller is also electrically connected with the third cut-off valve and the regulating valve, and a rated speed value is also set therein. The controller is also used to compare the real-time speed value with the rated speed value, and control the first speed value according to the comparison result. The opening and closing of the three-stop valve and the opening degree of the control valve are used to stabilize the unit speed of the closed Brayton cycle heat engine system and realize the fine adjustment of the mechanical output power, thereby making up for the lack of the adjustment accuracy of the first adjustment unit and improving the Adjustment accuracy.

Specifically, the calibration pressure value is determined according to the mechanical output power required by the turbine unit in the main circuit of the closed Brayton cycle heat engine system, which is preset in the controller, and the target control range is 100%-102% of the calibration pressure value. Since the second regulating unit has a certain loss of mechanical output power, the charging volume of the main circuit should not be lower than the theoretical charging volume of the working medium, that is, the lower limit of the pressure of the main circuit is 100% of the calibrated pressure value, and the upper limit of the pressure of the main circuit It should be slightly higher than 100% of the nominal pressure value, for example, it can be 102%, which can provide a certain downward adjustment margin for the use of the second adjustment unit. When the pressure value detected by the pressure sensor is greater than 102% of the calibrated pressure value, the first shut-off valve 31 and the compressor 33 in the first regulating unit are opened, and the working medium is extracted from the main circuit and stored in the buffer tank 35, so that the main circuit When the working medium charging capacity of the main circuit decreases to 100% of the theoretical working medium charging capacity corresponding to the required mechanical output power W1, the first shut-off valve is closed. 31 and compressor 33, at the same time, the real-time speed of the unit is detected by the speed sensor. When the real-time speed is greater than 99%-101% of the rated speed, the third stop valve 41 in the second adjustment unit is opened, and by increasing the Adjust the opening of valve 43 to increase the flow of working medium through the second adjustment unit, thereby bypassing and reducing the flow of working medium through the main circuit, so that the real-time speed of the unit decreases until the real-time speed of the unit drops to 99% of the rated speed. When it is within -101%, the third shut-off valve 41 is closed. When the pressure value detected by the pressure sensor is less than 100% of the calibrated pressure value, the second shut-off valve 37 in the first regulating unit is opened, and the working fluid stored in the buffer tank 35 is released into the main circuit, so that the working fluid in the main circuit is released. When the filling volume increases, the mechanical output power of the unit increases. When the working medium filling volume of the main circuit increases to 102% of the theoretical working medium filling volume corresponding to the required mechanical output power W2, close the second stop valve 37 , at the same time, the real-time speed of the unit is detected by the speed sensor. When the real-time speed is less than 99%-101% of the rated speed, the opening of the regulating valve 43 in the second regulating unit is reduced, or the second regulating unit is closed. The third cut-off valve 41 in the middle of the valve reduces the flow rate of the working medium that bypasses the second adjustment unit or does not pass through the second adjustment unit, so that the real-time rotational speed of the unit increases until the real-time rotational speed of the unit detected by the rotational speed sensor increases When the speed is within 99-101% of the rated speed, stop adjusting the regulating valve 43; when the pressure value detected by the pressure sensor is slightly different from the calibration pressure, for example, when the pressure value detected by the pressure sensor is 100%-102% of the calibration pressure, The first adjustment unit does not respond, that is, the first adjustment unit remains in the original state.

It should be noted that in the above example, 102% of the calibrated pressure value is selected as the upper limit of the pressure of the main circuit, which only describes a situation of the bypass auxiliary system in this embodiment. The actual upper limit of the pressure of the main circuit can also be calibrated 101%, 103%, 104% of the pressure value does not exceed any value of 120%.

It should be noted that, in the above-mentioned adjustment process, the flow rate of inflation or exhaust through the first adjustment unit (that is, releasing the working medium to the main circuit or pumping the working medium to the buffer tank 35) preferably does not exceed the flow rate of the main circuit 0.5%-1% to ensure the relatively stable charging and discharging of the main circuit working medium and prevent too much thermal shock. In addition to using the threshold controller (herein referred to as the control according to the rated speed) adopted above to perform the opening and closing control of the first shut-off valve 41 and the opening degree adjustment of the regulating valve 43, the second adjustment unit can also use a PID controller for control, In addition, no matter which control method is adopted, the maximum flow rate through the second adjustment unit should not be too large to avoid excessive loss of efficiency, and it should not be smaller than the ratio between the pressure range adjusted by the first adjustment unit and the maximum rated pressure. Specifically, , which cannot be less than two to three times the pressure interval adjusted by the first adjustment unit, so as not to be unable to form a sufficient supplement for the coarse adjustment of the first adjustment unit (relative to the first adjustment unit). In this embodiment, the maximum flow rate of the second regulating unit is preferably no more than 2%-3% of the flow rate of the main circuit.

The bypass auxiliary system for the closed Brayton cycle heat engine system in this embodiment can adjust the working fluid flow in the main circuit of the closed Brayton cycle heat engine system through the first adjustment unit and the second adjustment unit, thereby Realize the function of adjusting the mechanical output power of the closed Brayton heat engine, so that the actual mechanical output power matches the required mechanical output power, and compared with the existing technology, it not only has a fast response speed, a large adjustment range, and an accurate adjustment Controllable, it is beneficial to reduce the power output efficiency loss and energy consumption of the closed Brayton cycle heat engine system, and it can also filter, purify and supplement the working fluid online, and reduce the loss or pollution of the working fluid to the operation of the closed Brayton cycle heat engine system. In addition, the system has a simple structure and is easy to operate.

Example 2

As shown in FIG. 1 , this embodiment discloses a heat engine device, including a closed Brayton cycle heat engine system, the closed Brayton cycle heat engine system includes a main loop, and the device further includes the bypass auxiliary system in Embodiment 1 , the bypass auxiliary system and the main circuit are connected in parallel.

Specifically, the main circuit includes a high-pressure compressor 10 and a low-pressure compressor 20, wherein the outlet of the high-pressure compressor 10 is connected to the inlet end of the first branch pipeline 30, and the inlet of the low-pressure compressor 20 is connected to the first branch pipeline 30. The outlet end of the main circuit is connected to adjust by circulating the working fluid in the main circuit to the bypass auxiliary system and releasing the working fluid (such as helium, helium-xenon mixture, nitrogen, carbon dioxide, etc.) in the bypass auxiliary system to the main circuit The flow rate of the working medium in the main circuit can be quickly and widely adjusted to the mechanical output power of the main circuit.

This embodiment also discloses an adjustment method using the above-mentioned heat engine device, which includes:

When the closed Brayton cycle heat engine system is running normally and the mechanical output power of the closed Brayton cycle heat engine system needs to be reduced, the working medium is extracted from the main circuit of the closed Brayton cycle heat engine system and stored in the buffer of the first regulating unit tank until the working medium filling of the main circuit matches the mechanical output power to be reduced to, or, when the closed Brayton cycle heat engine system is operating normally, and it is necessary to raise the mechanical power of the closed Brayton cycle heat engine system. When outputting power, the working medium stored in the buffer tank of the first regulating unit is released into the main circuit of the closed Brayton cycle heat engine system, until the filling amount of the working medium in the main circuit and the required mechanical output power are increased. match;

At the same time, a part of the working medium in the main circuit is bypassed through the second adjustment unit, and the opening of the adjustment valve is adjusted according to the real-time speed of the turbine unit in the main circuit, the bypass flow of the second adjustment unit is changed, and the flow rate of the main circuit is adjusted. The output of the unit makes the real-time rotational speed of the turbine unit match the rated rotational speed corresponding to the mechanical output power to be lowered/raised, so that the actual filling amount of the working medium in the main circuit has been adjusted by the aforementioned first adjustment unit. Under the premise of adjusting to approximately match the theoretical working medium filling amount, the output of the closed Brayton cycle heat engine system can be adjusted in a small range to increase or decrease the output, thereby maintaining the speed of the turbine unit stable within a certain range.

Specifically, when the closed Brayton cycle heat engine system needs to adjust the mechanical output power, it is assumed that the rated speed of the unit (that is, the turbine unit) of the closed Brayton cycle heat engine system is R0, and the mechanical output power at this time is set as W0:

(1) If it is necessary to reduce the mechanical output power to W1 (W1 is the required mechanical output power, the signal of the required mechanical output power comes from the electrical system supporting the closed Brayton cycle heat engine system, this method generally only corresponds to 30%- 100% of the rated power range), first open the first shut-off valve 31 in the first adjustment unit, extract the working medium from the main circuit and store it in the buffer tank 35, so that the working medium filling amount of the main circuit is reduced, mechanical The output power drops. When the working medium filling amount of the main circuit is reduced to 100% of the theoretical working medium filling amount of the required mechanical output power W1, the first shut-off valve 31 is closed. The charging capacity of the main circuit is always higher than the charging capacity of the working medium corresponding to the required mechanical output power W1. Without the intervention of the second adjustment unit, the mechanical output of the unit will be higher than the actual consumption, and the real-time speed R of the unit will be Continuous and irreversible increase, that is, R>R0, therefore, the second regulating unit needs to respond (open) to an excessively high rotational speed, that is, open the third shut-off valve 41 in the second regulating unit, and adjust by increasing The opening of valve 43 increases the flow of working medium through the second adjustment unit, thereby bypassing and reducing the flow of working medium through the main circuit, so that the real-time speed of the unit decreases, and the speed sensor detects the real-time speed R of the unit. When the real-time rotational speed R of the unit drops to 99-101% of the rated rotational speed range, the third shut-off valve 41 is closed.

(2) If it is necessary to increase the mechanical output power to W2, first open the second shut-off valve 37 in the first adjustment unit, release the working fluid stored in the buffer tank 35 into the main circuit, and fill the working fluid in the main circuit When the working medium filling amount of the main circuit increases to 102% of the theoretical working medium filling amount of the required mechanical output power W2, the second shut-off valve 37 is closed, and at the same time, Since the main circuit working medium filling volume in this process is always lower than the working medium filling volume corresponding to the required mechanical output power W2, without the intervention of the second adjustment unit, the mechanical output of the unit will be lower than the actual consumption. , the real-time rotational speed R of the unit will continuously and irreversibly decrease, that is, R<R0. Therefore, the second regulating unit needs to respond (open) to the too low rotational speed, that is, reduce the speed of the regulating valve 43 in the second regulating unit. opening, or close the third shut-off valve 41 in the second adjustment unit, so that the flow rate of the working fluid bypassed through the second adjustment unit is reduced or does not pass through the second adjustment unit, so that the real-time rotational speed R of the unit increases, when When the real-time rotational speed R of the unit detected by the rotational speed sensor increases to 99-101% of the rated rotational speed range, the adjustment of the regulating valve 43 is stopped.

In some embodiments, the method may also include:

During the startup process of the closed Brayton cycle heat engine system, the second shut-off valve 37 is first opened to release the working fluid stored in the buffer tank 35 of the first adjustment unit into the main circuit, so as to push the turbine unit in the main circuit to rotate, Until the mechanical output power of the closed Brayton cycle heat engine system reaches 1-30% of the rated power (that is, when the charging volume of the working medium released to the main circuit reaches 1-30% of the rated power of the closed Brayton cycle heat engine system) The required working medium filling amount), preferably reaching 30% of the rated power, and then slowly switching to the normal heat source of the main circuit to drive the turbine unit to rotate, which can effectively reduce energy consumption.

Specifically, in the process of releasing the working fluid stored in the buffer tank 35 of the first regulating unit into the main circuit to push the turbine unit in the main circuit to rotate and make the mechanical output power reach 30% of the rated power, the main The thermal power of the normal heat source of the loop rises, and the temperature of its outlet working fluid increases, so that the mechanical output power of the unit will also rise. When the temperature of the working fluid at the outlet of the heat source reaches the rated temperature, the mechanical output power of the unit will reach 30% rated At the same time, the second adjustment unit participates in the control of the unit speed of the heat engine in the whole process as shown in the previous method. The target speed that the unit needs to adjust to can be the rated speed, or it can be any stable speed lower than the rated speed. speed to ensure that the compressor does not generate surge. Wherein, the adjustment process of the second adjustment unit is specifically: detecting the real-time rotational speed of the unit, judging the magnitude relationship between the real-time rotational speed and the rated rotational speed, if the real-time rotational speed is less than the rated rotational speed, then reduce the opening of the regulating valve 43 or close the regulating valve 43, The flow bypassed by the second regulating unit is sent back to the main circuit, so that the speed of the unit increases; if the real-time speed is greater than the rated speed, the third stop valve 37 is opened and the opening of the regulating valve 43 is increased, and a part of the flow of the main circuit is The bypass passes through the second regulating unit, so that the speed of the unit decreases.

It should be noted that, in the above example, 30% of rated power and 30% of working medium filling volume are selected as the boundary between the startup process and normal operation, which only describes a situation of the method in this embodiment, and the actual selection value can also be Any value from 1% to 50%, for example, can also be 5%, 10%, 15%, 20%, 25%, 35%, 40%, 45%, etc. The selection of specific values should be comprehensively considered to start Process energy consumption, compressor surge and other issues will not be repeated here.

In some embodiments, the method may also include:

When the closed Brayton cycle heat engine system operates normally and does not need to adjust the mechanical output power, if it is detected that the working medium filling amount corresponding to the pressure of the main circuit is lower than the theoretical working medium filling amount corresponding to the pressure, the The buffer tank of the first regulating unit releases the working fluid to the main circuit to supplement the working fluid reduced by leakage in the closed Brayton cycle heat engine system.

Specifically, because the closed Brayton cycle heat engine system will inevitably leak working fluid, although this leakage is a small amount, when a certain amount of working fluid leakage is accumulated, a cumulative effect will occur, resulting in a large deviation Under rated operating conditions, this deviation is mainly reflected in the deviation of pressure. In this method, the pressure sensor is used to detect the pressure somewhere in the main circuit (such as the inlet of the low-pressure compressor) in real time. The magnitude relationship of the corresponding calibrated pressure determines the leakage of the working medium. If the pressure detected in real time is lower than the lower limit of the calibrated pressure (such as the pressure corresponding to the theoretical working medium filling amount under 100% of the mechanical output power), open the The second shut-off valve 37 in the first adjustment unit releases the working medium from the buffer tank 35 of the first adjustment unit to the main circuit to supplement the working medium reduced by leakage to the main circuit, and the pressure of the main circuit rises. When the pressure sensor detects When the obtained pressure reaches the upper limit of the calibration pressure (for example, it returns to the pressure corresponding to the theoretical working medium filling amount under the mechanical output power of 102%), the second stop valve 37 is closed and the release is stopped.

It should be noted that, by utilizing the characteristics of the rapid response of the second adjusting unit, when various unpredictable small-amplitude changes occur in the closed Brayton cycle heat engine system unit, the method may further include: maintaining the closed braying through the second adjusting unit. The output and speed of the unit of the heat-cycle heat engine system.

Specifically, during the operation of the closed Brayton cycle heat engine system, the unit will inevitably be affected by the disturbance of the working conditions. This change is unavoidable in engineering, and the trend cannot be predicted. The influence of the system operation is limited, but if it is not intervened for a long time, it may produce a cumulative effect and deviate from the rated operating conditions greatly. This deviation is mainly reflected in the deviation of the unit speed in the early stage of deviation. In this embodiment, the second adjustment unit can be used for intervention. If the rotational speed of the unit exceeds the rated rotational speed, the flow through the second adjustment unit can be increased by increasing the opening of the adjustment valve 43, bypassing and reducing the flow through the main circuit. reduce the mechanical output power generated by the main circuit appropriately, alleviate the rising trend of the speed, or even turn it into a downward trend, until the speed is stable within the rated speed range; if the unit speed is lower than the rated speed, it can be adjusted by reducing the regulating valve 43 The opening of the main circuit reduces the flow through the second adjustment unit, and re-passes part of the flow originally bypassed by the second adjustment unit into the main circuit, appropriately increases the mechanical output power generated by the main circuit, alleviates the trend of speed decline, and even turns into a upward trend until the speed stabilizes within the rated speed range.

It should be noted that, in the above-mentioned adjustment process, the flow rate of inflation or exhaust through the first adjustment unit (ie, releasing the working medium to the main circuit or pumping the working medium to the buffer tank 35) is preferably not more than the main circuit. 0.5%-1% of the flow rate to ensure the relatively stable charging and discharging of the main circuit working medium and prevent too much thermal shock. The maximum flow rate through the second regulating unit should not be too large to avoid excessive loss of efficiency, nor should it be less than the ratio of the pressure range regulated by the first regulating unit to the maximum rated pressure, specifically, it should not be less than the pressure range regulated by the first regulating unit Two to three times the pressure range, so as not to fail to form a sufficient supplement for the rough adjustment of the first adjustment unit. In this embodiment, the maximum flow rate of the second regulating unit is preferably no more than 2%-3% of the flow rate range of the main circuit.

The heat engine device of this embodiment adopts the bypass auxiliary system for the closed Brayton cycle heat engine system described in Embodiment 1, so that the flow rate and mechanical output power of the main circuit can be adjusted, and the response speed is fast , The adjustment range is large, the power output efficiency loss is small, and the working medium filtration and purification ability.

It should be understood that the above embodiments are merely exemplary implementations adopted to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also regarded as the protection scope of the present disclosure.

Claims

A bypass auxiliary system for a closed Brayton cycle heat engine system, characterized in that it comprises a first adjustment unit and a second adjustment unit,

The first conditioning unit includes a first branch pipeline, a compressor, and a buffer tank. The inlet end of the first branch pipeline is connected to the outlet of the high-pressure compressor in the closed Brayton cycle heat engine system, and the outlet end of the first branch pipeline is connected to the outlet of the high-pressure compressor in the closed Brayton cycle heat engine system. connected to the inlet of the low-pressure compressor in the closed Brayton cycle heat engine system, the compressor and the buffer tank are connected in series on the first branch pipeline, and the compressor is located upstream of the buffer tank , the compressor is used for pumping working fluid from the closed Brayton cycle heat engine system, and the buffer tank is used for storing the working fluid pumped by the compressor and releasing the stored working fluid to the closed-circuit Brayton cycle heat engine system. Brayton cycle heat engine system;

The second regulating unit is connected in parallel with the first regulating unit, and the second regulating unit includes a second branch pipeline and a regulating valve, and the regulating valve is arranged on the second branch pipeline.
The bypass auxiliary system for a closed Brayton cycle heat engine system according to claim 1, wherein the first regulating unit further comprises a first shut-off valve and a second shut-off valve,

The first shut-off valve is arranged on the first branch pipeline, and is located between the inlet end of the first branch pipeline and the compressor;

The second shut-off valve is arranged on the first branch pipeline, and is located between the buffer tank and the outlet end of the first branch pipeline.
The bypass auxiliary system for a closed Brayton cycle heat engine system according to claim 2, wherein the first regulating unit further comprises a first check valve and a second check valve,

The first check valve is arranged on the first branch pipeline, and is located between the first shut-off valve and the compressor;

The second check valve is arranged on the first branch pipeline and between the buffer tank and the second shut-off valve.
The bypass auxiliary system for a closed Brayton cycle heat engine system according to claim 3, wherein the first adjustment unit further comprises a filter purifier,

The filter purifier is arranged on the first branch pipeline, and is between the compressor and the buffer tank; or,

The bypass auxiliary system further includes a third branch line, the third branch line is connected with the first check valve, the compressor, the buffer tank and the second check valve. Some of the first branch pipelines are connected in parallel, and the filter and purifier are arranged on the third branch pipeline.
The bypass auxiliary system for a closed Brayton cycle heat engine system according to any one of claims 2-4, wherein the second regulating unit further comprises a third shut-off valve, the third shut-off valve It is arranged on the second branch line and is upstream of the regulating valve.
The bypass auxiliary system for a closed Brayton cycle heat engine system according to claim 5, wherein the second regulating unit further comprises a third check valve, and the third check valve is provided at the on the second branch pipeline, and the regulating valve is located between the third check valve and the third shut-off valve.
The bypass auxiliary system for a closed Brayton cycle heat engine system according to claim 6, further comprising a control component, the control component comprising a pressure sensor, a rotational speed sensor, and a controller,

the pressure sensor, electrically connected with the controller, is used to detect the pressure of the main circuit in the closed Brayton cycle heat engine system, and transmit the detected pressure value to the controller;

The controller is electrically connected to the first shut-off valve, the compressor, and the second shut-off valve, respectively, and has a calibration pressure value therein, and the controller is used to compare the received pressure value with the calibration pressure value comparing, and controlling the opening and closing of the first shut-off valve, the compressor, and the second shut-off valve according to the comparison result;

The rotational speed sensor, electrically connected to the controller, is used to detect the real-time rotational speed of the turbine unit of the main circuit in the closed Brayton cycle heat engine system, and transmit the detected real-time rotational speed value to the controller,

The controller is also electrically connected to the third cut-off valve and the regulating valve, and is also provided with a rated rotational speed value, and the controller is also used to compare the received real-time rotational speed value with the rated rotational speed value, And control the opening and closing of the third shut-off valve and the opening degree of the regulating valve according to the comparison result.
A heat engine device, comprising a closed Brayton cycle heat engine system, the closed Brayton cycle heat engine system comprising a main loop, characterized in that, the heat engine device further comprises the method described in any one of claims 1-7 for A bypass auxiliary system of a closed Brayton cycle heat engine system, the bypass auxiliary system is connected in parallel with the main circuit.
The heat engine device according to claim 8, wherein the main circuit comprises a high-pressure compressor and a low-pressure compressor,

The outlet of the high pressure compressor is connected with the inlet end of the first branch line, and the inlet of the low pressure compressor is connected with the outlet end of the first branch line.
A method for adjusting a heat engine device using any one of claims 8-9, comprising:

When the closed Brayton cycle heat engine system is in normal operation and the mechanical output power of the closed Brayton cycle heat engine system needs to be reduced, the working fluid is extracted from the main circuit and stored in the buffer tank of the first regulating unit until the working fluid of the main circuit is exhausted. The mass charging amount matches the mechanical output power to be reduced, or, when the closed Brayton cycle heat engine system is operating normally and the mechanical output power of the closed Brayton cycle heat engine system needs to be increased, the first adjustment The working medium stored in the buffer tank of the unit is released into the main circuit of the closed Brayton cycle heat engine system, until the charging amount of the working medium in the main circuit matches the required mechanical output power;

At the same time, the opening of the regulating valve in the second regulating unit is adjusted so that the real-time rotational speed of the turbine unit in the main circuit matches the rated rotational speed corresponding to the mechanical output power to be reduced/increased.
The method for adjusting a heat engine device according to claim 10, further comprising:

During the startup process of the closed Brayton cycle heat engine system, the working fluid stored in the buffer tank of the first adjustment unit is first released into the main circuit to drive the turbine unit in the main circuit to rotate until the closed Brayton cycle heat engine system When the mechanical output power reaches 30% of the rated power, it switches to the normal heat source of the main circuit to drive the turbine unit to rotate.
The method for adjusting a heat engine device according to claim 10 or 11, further comprising:

When the closed Brayton cycle heat engine system operates normally and does not need to adjust the mechanical output power, if it is detected that the working medium filling amount corresponding to the pressure of the main circuit is lower than the theoretical working medium filling amount corresponding to the pressure, the The buffer tank of the first regulating unit releases the working fluid to the main circuit to supplement the working fluid reduced by leakage in the closed Brayton cycle heat engine system.