Supercritical carbon dioxide closed cycle sealing test system

Abstract

The present invention discloses a supercritical carbon dioxide closed-loop sealing test system, comprising: a carbon dioxide storage tank, a heater, a static seal, a dynamic seal, a sealed chamber, a first flowmeter, a cooler, and a motor. The carbon dioxide storage tank is connected to the inlet of the sealed chamber via a first pipeline, and the heater is located in the first pipeline. The static seal is installed in a detection chamber of the sealed chamber, and the outlet of the sealed chamber is connected to a second pipeline. The cooler is located in the second pipeline and is used to cool the carbon dioxide in the second pipeline. The second pipeline is also connected to the first pipeline. The carbon dioxide cooled by the cooler can enter the first pipeline and circulate into the sealed chamber. The first flowmeter is installed at the outlet of the sealed chamber and is used to measure the amount of carbon dioxide leaked through the connection between the dynamic seal and the static seal. The sealing test can be performed under conditions where the test environment is close to the actual working conditions, and the test results are closer to the actual situation.

Description

Technical Field

[0001] The present invention relates to the field of testing, and further to a supercritical carbon dioxide closed-cycle sealing testing system. Background Art

[0002] Supercritical carbon dioxide Brayton cycle power generation technology is a closed-cycle turbine power generation technology that uses supercritical carbon dioxide as the working fluid. It mainly generates electricity by allowing high-temperature and high-pressure working fluid to enter the turbine and expand and perform work. It has many advantages such as high cycle efficiency, high energy density, and wide adaptability of heat sources.

[0003] This technology has developed rapidly in recent years and is currently a research hotspot worldwide. Supercritical CO2 sealing remains a key core technology for its application in many fields, especially in turbines operating in high-temperature, high-pressure, and high-speed environments. Guaranteed sealing performance under these conditions is crucial to minimize the impact of fluid leakage on generator set and system efficiency.

[0004] In the prior art, whether the sealing performance is qualified can only be determined after formal installation. If it is unqualified, it needs to be replaced, which affects the normal operation of the equipment. Summary of the Invention

[0005] In response to the above technical problems, the present invention aims to provide a supercritical carbon dioxide closed-circuit sealing test system, in which a motor can drive the dynamic seal to rotate relative to the static seal, simulating the operating speed of the turbine in actual use. The heater can heat the carbon dioxide to a preset temperature, simulating the temperature environment in actual operation of the turbine. The sealing test is performed under conditions close to the actual working conditions, and the test results are closer to the actual situation. In order to achieve the above objectives, the present invention provides a supercritical carbon dioxide closed-circuit sealing test system, comprising:

[0006] A carbon dioxide storage tank, a heater, a static seal, a dynamic seal, a sealed cavity, a first flowmeter, a cooler and a motor, wherein the carbon dioxide storage tank is connected to the inlet of the sealed cavity through a first pipeline, the heater is located in the first pipeline, and is used to heat the carbon dioxide in the first pipeline; the static seal is installed in the detection cavity of the sealed cavity, the dynamic seal is connected to the power output shaft of the motor, and the dynamic seal abuts the static seal, the motor is used to drive the dynamic seal to rotate, the outlet of the sealed cavity is connected to a second pipeline, the cooler is located in the second pipeline, and is used to cool the carbon dioxide in the second pipeline, and the second pipeline is also connected to the first pipeline. The carbon dioxide cooled by the cooler can enter the first pipeline and circulate into the sealed cavity, and the first flowmeter is installed at the outlet of the sealed cavity, and is used to measure the amount of carbon dioxide leaked through the connection between the dynamic seal and the static seal.

[0007] In some preferred embodiments, the supercritical carbon dioxide closed-cycle sealing test system further includes a buffer tank located in the first pipeline and a safety valve provided in the buffer tank, and the carbon dioxide after passing through the cooler enters the buffer tank.

[0008] In some preferred embodiments, the heater includes a low-temperature heater and a high-temperature heater. The low-temperature heater is located between the carbon dioxide storage tank and the buffer tank, and is used to heat the carbon dioxide to a first preset temperature; the high-temperature heater is located between the buffer tank and the sealed cavity, and is used to heat the carbon dioxide to a second preset temperature.

[0009] In some preferred embodiments, the supercritical carbon dioxide closed-cycle sealing test system also includes a first temperature transmitter arranged at the outlet of the high-temperature heater, which is used to measure the temperature of the outlet of the high-temperature heater and feed back to the controller of the high-temperature heater to automatically adjust the operating temperature of the high-temperature heater.

[0010] In some preferred embodiments, the supercritical carbon dioxide closed-cycle sealing test system also includes a flow regulating valve and a second flow meter sequentially arranged between the buffer tank and the high-temperature heater, and the flow regulating valve can adjust the flow of carbon dioxide entering the sealed cavity, and the second flow meter is used to measure the flow of carbon dioxide flowing through and feed back to the flow regulating valve, and the flow regulating valve can be automatically adjusted based on the measurement results of the second flow meter.

[0011] In some preferred embodiments, the supercritical carbon dioxide closed-cycle sealing test system further includes a filter located between the buffer tank and the flow regulating valve, for filtering impurities in the flowing carbon dioxide.

[0012] In some preferred embodiments, the supercritical carbon dioxide closed-cycle sealing test system also includes a first booster pump and a first one-way valve. The first booster pump is arranged between the carbon dioxide storage tank and the low-temperature heater, and is used to pressurize the carbon dioxide to a preset pressure. The first one-way valve is arranged between the low-temperature heater and the buffer tank.

[0013] In some preferred embodiments, the supercritical carbon dioxide closed-loop sealing test system also includes a second booster pump and a second one-way valve, and the second booster pump and the second one-way valve are arranged in sequence between the cooler and the buffer tank, and the second booster pump is used to pressurize the carbon dioxide flowing out of the cooler to a preset pressure.

[0014] In some preferred embodiments, the supercritical carbon dioxide closed-loop sealing test system also includes a pressure regulating valve and a pressure transmitter. The pressure transmitter is arranged in the sealed cavity and is used to detect the pressure of the sealed cavity. The pressure regulating valve is arranged between the cooler and the second one-way valve. The pressure regulating valve can automatically adjust the opening based on the measurement result of the pressure transmitter to adjust the pressure in the sealed cavity.

[0015] In some preferred embodiments, the supercritical carbon dioxide closed-cycle sealing test system further includes a second temperature transmitter installed in the sealed cavity, and the second temperature transmitter is used to measure the temperature of the sealed cavity.

[0016] Compared with the prior art, the supercritical carbon dioxide closed-cycle sealing test system provided by the present invention has at least one of the following beneficial effects:

[0017] 1. The supercritical carbon dioxide closed-cycle seal testing system provided by the present invention has a motor that can drive the dynamic seal to rotate relative to the static seal, simulating the actual operating speed of the turbine. The heater can heat the carbon dioxide to a preset temperature, simulating the temperature environment in actual turbine operation. This allows the seal test to be conducted under conditions close to actual operating conditions, resulting in test results that are closer to reality.

[0018] 2. In the supercritical carbon dioxide closed-loop sealing test system provided by the present invention, the carbon dioxide leaving the sealed cavity can re-enter the sealed cavity through the second pipeline and the first pipeline, thereby realizing the recycling of the carbon dioxide;

[0019] 3. The supercritical carbon dioxide closed-cycle sealing test system provided by the present invention can simulate a high-temperature, high-pressure, and high-speed working environment to test the sealing performance of supercritical carbon dioxide seals under conditions close to actual working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The preferred embodiments will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0021] Figure 1 It is a block diagram of a supercritical carbon dioxide closed-cycle sealing test system according to a preferred embodiment of the present invention.

[0022] Description of Figure Numbers:

[0023] Carbon dioxide storage tank 11, heater 12, low-temperature heater 121, high-temperature heater 122, static seal 13, dynamic seal 131, sealing chamber 14, first flow meter 15, cooler 16, motor 17, buffer tank 18, safety valve 19, first temperature transmitter 21, flow regulating valve 22, second flow meter 23, filter 24, first boosting pump 25, first check valve 26, second boosting pump 27, second check valve 28, pressure regulating valve 31, pressure transmitter 32, second temperature transmitter 33. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other embodiments can be obtained based on these drawings without inventive work.

[0025] To simplify the drawings, only portions relevant to the invention are schematically depicted in each figure; they do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one component with the same structure or function is schematically depicted or labeled. In this document, "one" not only means "only one" but also "more than one."

[0026] It should be further understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0027] It should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0028] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0029] refer to Figure 1 The supercritical carbon dioxide closed-cycle sealing test system of a preferred embodiment of the present invention includes: a carbon dioxide storage tank 11, a heater 12, a static seal 13, a dynamic seal 131, a sealed cavity 14, a first flowmeter 15, a cooler 16 and a motor 17. The carbon dioxide storage tank 11 is connected to the inlet of the sealed cavity 14 through a first pipeline. The heater 12 is located in the first pipeline and is used to heat the carbon dioxide in the first pipeline. The static seal 13 is installed in the detection cavity of the sealed cavity 14, the dynamic seal 131 is connected to the power output shaft of the motor 17, and the dynamic seal 131 is connected to the power output shaft of the motor 17. The seal 131 abuts against the static seal 13, and the motor 17 is used to drive the dynamic seal 131 to rotate. The outlet of the sealed cavity 14 is connected to the second pipeline. The cooler 16 is located in the second pipeline and is used to cool the carbon dioxide in the second pipeline. The second pipeline is also connected to the first pipeline. The carbon dioxide cooled by the cooler 16 can enter the first pipeline and circulate into the sealed cavity 14. The first flowmeter 15 is installed at the outlet of the sealed cavity 14 and is used to measure the amount of carbon dioxide leaked through the connection between the dynamic seal 131 and the static seal 13.

[0030] In this preferred embodiment, the motor 17 can drive the dynamic seal 131 of the sealed chamber 14 to rotate, simulating the actual operating speed of the turbine. The heater 12 can heat the carbon dioxide to a preset temperature, simulating the temperature environment of the actual operation of the turbine. The sealing test is performed under conditions close to actual operating conditions, and the test results are more realistic. The carbon dioxide leaving the sealed chamber 14 can re-enter the sealed chamber 14 through the second pipeline and the first pipeline, realizing the recycling of the carbon dioxide.

[0031] Furthermore, the supercritical carbon dioxide closed-loop leak-tightness testing system also includes a buffer tank 18 located in the first pipeline and a safety valve 19 disposed in the buffer tank 18. Carbon dioxide entering the buffer tank 18 after passing through the cooler 16 serves to temporarily store carbon dioxide and stabilize pressure. Opening the safety valve 19 allows the carbon dioxide in the buffer tank 18 to be discharged, thereby improving safety.

[0032] The heater 12 includes a low-temperature heater 121 and a high-temperature heater 122. The low-temperature heater 121 is located between the carbon dioxide storage tank 11 and the buffer tank 18, and is used to heat the carbon dioxide to a first preset temperature; the high-temperature heater 122 is located between the buffer tank 18 and the sealed cavity 14, and is used to heat the carbon dioxide to a second preset temperature. Preferably, the first preset temperature range is 31.1°C to 60°C, preferably 50°C. The second preset temperature range is 500°C to 600°C. Carbon dioxide can be better heated by a two-stage step-by-step heating method. After passing through the cooler 16, the temperature of the carbon dioxide can be reduced to the first preset temperature, preferably 50°C.

[0033] refer to Figure 1 Furthermore, the supercritical carbon dioxide closed-cycle sealing test system also includes a first temperature transmitter 21 located at the outlet of the high-temperature heater 122. The first temperature transmitter 21 is configured to measure the outlet temperature of the high-temperature heater 122 and provide feedback to the controller of the high-temperature heater 122 to automatically adjust the operating temperature of the high-temperature heater 122. The first temperature transmitter 21 can provide feedback to the controller of the high-temperature heater 122 regarding the actual outlet temperature of the high-temperature heater 122, automatically adjusting the heating power of the high-temperature heater 122 to adjust the outlet temperature of the high-temperature heater 122. For example, when the temperature measured by the first temperature transmitter 122 is higher than a desired temperature, the controller reduces the heating power of the high-temperature heater 122; when the temperature measured by the first temperature transmitter 122 is lower than the desired temperature, the controller increases the heating power of the high-temperature heater 122.

[0034] Furthermore, the supercritical carbon dioxide closed-cycle sealing test system also includes a flow control valve 22 and a second flow meter 23, which are sequentially arranged between the buffer tank 18 and the high-temperature heater 122. The flow control valve 22 can adjust the flow of carbon dioxide entering the sealed cavity 14. The second flow meter 23 is used to measure the flow of carbon dioxide flowing through and feedback it to the flow control valve 22. The flow control valve 22 can automatically adjust based on the measurement results of the second flow meter 23. The flow of carbon dioxide flowing through can be measured by the second flow meter 23. After feedback is provided to the flow control valve 22, the flow control valve 22 can adjust its opening based on the measurement results of the second flow meter 23. When the flow measured by the second flow meter 23 is less than a preset flow rate, the flow control valve 22 increases its opening to allow more carbon dioxide to pass through. When the flow measured by the second flow meter 23 is greater than the preset flow rate, the flow control valve 22 decreases its opening to reduce the flow of carbon dioxide passing through, thereby achieving automatic flow control.

[0035] Furthermore, the supercritical carbon dioxide closed-loop leak-tightness testing system also includes a filter 24 located between the buffer tank 18 and the flow regulating valve 22 for filtering impurities from the flowing carbon dioxide. The carbon dioxide filtered by the filter 24 meets the system's operating requirements and avoids affecting normal system operation.

[0036] The supercritical carbon dioxide closed-cycle sealing test system also includes a first booster pump 25 and a first one-way valve 26. The first booster pump 25 is arranged between the carbon dioxide storage tank 11 and the low-temperature heater 121, and is used to pressurize the carbon dioxide to a preset pressure. The first one-way valve 26 is arranged between the low-temperature heater 121 and the buffer tank 18. Preferably, the carbon dioxide storage tank 11 stores low-temperature and low-pressure liquid carbon dioxide. The first booster pump 25 can increase the pressure of non-supercritical carbon dioxide to above the critical pressure (7.38 MPa) to the pressure required for the sealing test, so as to simulate the actual pressure when the turbine is working. The first one-way valve 26 allows the gas in the carbon dioxide storage tank 11 to enter the buffer tank 18, preventing the carbon dioxide in the buffer tank 18 from flowing back into the carbon dioxide storage tank 11.

[0037] Furthermore, the supercritical carbon dioxide closed-loop sealing test system also includes a second booster pump 27 and a second one-way valve 28. The second booster pump 27 and the second one-way valve 28 are sequentially arranged between the cooler 16 and the buffer tank 18. The second booster pump 27 is used to pressurize the carbon dioxide flowing out of the cooler 16 to a preset pressure. The second booster pump 27 is a circulation pump that can pressurize the carbon dioxide flowing out of the cooler 16 and re-enter the buffer tank 18 to form a circulation system. It only needs to replenish the carbon dioxide leaking through the connection between the dynamic seal 131 and the static seal 13.

[0038] The supercritical carbon dioxide closed-cycle sealing test system also includes a pressure regulating valve 31 and a pressure transmitter 32. The pressure transmitter 32 is provided in the sealed cavity 14 and is used to detect the pressure within the sealed cavity 14. The pressure regulating valve 32 is provided between the cooler 16 and the second one-way valve 28. The pressure regulating valve 32 can automatically adjust its opening based on the measurement result of the pressure transmitter 32 to adjust the pressure within the sealed cavity 14. For example, when the pressure of the pressure transmitter 32 is within the normal pressure range, the pressure regulating valve 32 remains closed; when the pressure value of the pressure transmitter 32 is higher than a preset pressure value, the pressure regulating valve 32 opens to release a preset amount of carbon dioxide to reduce the pressure within the sealed cavity 14.

[0039] Furthermore, the supercritical carbon dioxide closed-cycle sealing test system also includes a second temperature transmitter 33 installed in the sealed cavity 14. The second temperature transmitter 33 is used to measure the temperature of the sealed cavity 14. The second temperature transmitter 33 can transmit the measured temperature value to the control system of the flow control valve 22. Based on the measurement result of the second temperature transmitter 33, the set value of the flow control valve 22 is adjusted to maintain the temperature in the sealed cavity 14 between 500°C and 600°C.

[0040] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that those skilled in the art can make several improvements and modifications without departing from the principles of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. Supercritical carbon dioxide closed cycle sealing test system, characterized by: include: A carbon dioxide storage tank, a buffer tank, a heater, a static seal, a dynamic seal, a sealed cavity, a first flow meter, a cooler, and a motor. The carbon dioxide storage tank is connected to the inlet of the sealed cavity through a first pipeline. The buffer tank and the heater are sequentially arranged in the first pipeline, and the heater includes a low-temperature heater and a high-temperature heater. The low-temperature heater is located between the carbon dioxide storage tank and the buffer tank and is used to heat the carbon dioxide to a first preset temperature. The high-temperature heater is used to heat the carbon dioxide in the first pipeline to a second preset temperature. A first booster pump is provided between the carbon dioxide storage tank and the low-temperature heater. The first booster pump is used to pressurize the carbon dioxide to a preset pressure. The static seal The seal is installed in the detection cavity of the sealed cavity, the dynamic seal is connected to the power output shaft of the motor, and the dynamic seal abuts the static seal. The motor is used to drive the dynamic seal to rotate. The outlet of the sealed cavity is connected to the second pipeline. The cooler is located in the second pipeline and is used to cool the carbon dioxide in the second pipeline. The second pipeline is also connected to the first pipeline. The carbon dioxide cooled by the cooler can be circulated into the buffer tank through the second pipeline. A second one-way valve is provided between the cooler and the buffer tank. The first flowmeter is installed at the outlet of the sealed cavity and is used to measure the amount of carbon dioxide leaked through the connection between the dynamic seal and the static seal. The device further comprises a flow regulating valve and a second flow meter disposed between the buffer tank and the high-temperature heater, wherein the flow regulating valve is used to regulate the flow of carbon dioxide entering the sealed cavity, and the second flow meter is used to measure the flow of carbon dioxide flowing through the sealed cavity and feed back the flow to the flow regulating valve, and the flow regulating valve can automatically adjust based on the measurement result of the second flow meter; The device further comprises a pressure regulating valve and a pressure transmitter, wherein the pressure transmitter is provided in the sealed cavity and is used to detect the pressure of the sealed cavity; the pressure regulating valve is provided between the cooler and the second one-way valve, and the pressure regulating valve can automatically adjust the opening based on the measurement result of the pressure transmitter to adjust the pressure in the sealed cavity; Also included is a second temperature transmitter installed in the sealed cavity, the second temperature transmitter being used to measure the temperature of the sealed cavity; The second temperature transmitter can send the measured temperature value to the control system of the flow control valve, and adjust the set value of the flow control valve based on the measurement result of the second temperature transmitter to maintain the temperature in the sealed cavity between 500°C and 600°C.

2. The supercritical carbon dioxide closed cycle sealing test system according to claim 1, characterized in that: It also includes a safety valve arranged on the buffer tank.

3. The supercritical carbon dioxide closed cycle sealing test system according to claim 2, characterized in that: The high-temperature heater is located between the buffer tank and the sealed cavity.

4. The supercritical carbon dioxide closed-cycle sealing test system according to claim 3, characterized in that: It also includes a first temperature transmitter provided at the outlet of the high temperature heater, which is used to measure the temperature of the outlet of the high temperature heater and feed it back to the controller of the high temperature heater to automatically adjust the operating temperature of the high temperature heater.

5. The supercritical carbon dioxide closed cycle sealing test system according to claim 4, characterized in that: The flow regulating valve and the second flow meter are sequentially arranged between the buffer tank and the high-temperature heater.

6. The supercritical carbon dioxide closed-cycle sealing test system according to claim 5, characterized in that: The device further comprises a filter located between the buffer tank and the flow regulating valve, for filtering impurities in the carbon dioxide flowing therethrough.

7. The supercritical carbon dioxide closed-cycle sealing test system according to claim 6, characterized in that: The device further includes a first one-way valve, which is provided between the low-temperature heater and the buffer tank.

8. The supercritical carbon dioxide closed-cycle sealing test system according to claim 7, characterized in that: It also includes a second booster pump, which is sequentially arranged between the cooler and the buffer tank with the second booster pump and the second one-way valve. The second booster pump is used to pressurize the carbon dioxide flowing out of the cooler to a preset pressure.

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