A closed supercritical carbon dioxide Brayton cycle experimental device

Abstract

The present invention discloses a closed supercritical carbon dioxide Brayton cycle experimental device, including a plunger pump, an orifice flowmeter, a printed circuit board type heat exchanger, a heating section, a printed circuit board type cooler, a Coriolis mass flowmeter, a pressure reduction orifice plate, a turbine flowmeter, a water-cooled chiller, a cooling tower, an electric flow regulating valve, a carbon dioxide storage tank, a charging and discharging plunger pump and an electric charging and discharging valve group, etc.; and a data acquisition and control system is designed. The present invention is based on the supercritical carbon dioxide industrial application technology, adopts a new Brayton cycle layout, uses a plunger pump to replace a compressor, and uses a pressure reduction valve and a throttling orifice to replace a gas turbine, which saves the construction and research and development costs, and can carry out the dynamic characteristics research of the closed supercritical carbon dioxide Brayton cycle, the steady-state and dynamic characteristics research of the microchannel printed circuit board type heat exchanger, and the rod bundle flow channel supercritical carbon dioxide flow heat exchange research.

Description

Technical Field

[0001] The invention belongs to the field of energy experimental technology application, and in particular relates to a closed supercritical carbon dioxide Brayton cycle experimental device. Background Art

[0002] The supercritical carbon dioxide (S-CO2) Brayton cycle has the characteristics of small turbine machinery, simple cycle layout, high medium temperature cycle efficiency, and low dry cooling efficiency loss, making it very suitable for the power generation system of nuclear reactors to replace the existing Rankine cycle. The ideal S-CO2 Brayton cycle has the same four thermal processes as the Rankine cycle and other gas Brayton cycles, including isobaric heating process, isentropic expansion process, isobaric heat release process and isentropic compression process.

[0003] The special feature of the S-CO2 Brayton cycle is that it uses S-CO2 as a heat transfer fluid to cool the compressor inlet fluid to a temperature close to the critical point of S-CO2, and its high density helps to reduce the working consumption of the compressor. The gas Brayton cycle uses an ideal gas as a coolant and has no phase change process. Due to the special thermal properties and cycle structure of S-CO2, the S-CO2 Brayton cycle has distinct characteristics. The high density of the fluid at the compressor inlet can reduce the power consumption of the compressor. As the temperature increases, S-CO2 has no phase change, making the heating process more efficient, and the fluid temperature reaching the turbine is higher, which improves the power conversion efficiency. The turbine expansion process is always single-phase, without the danger of condensation. The gas turbine system can remove the steam-water separation reheater used in the Rankine cycle, simplifying the system configuration. The large S-CO2 density and small pressure ratio make the turbomachinery very compact. The fluid in the cooling process has a large specific heat, which improves the heat exchange efficiency. The low viscosity S-CO2 enables the system to have a lower pressure drop. The single-phase CO2 in the entire cycle eliminates the phase change process and accelerates the dynamic response. The S-CO2 power cycle has a high efficiency at medium turbine inlet temperature (about 450-600℃), which is close to the core outlet temperature of the fourth-generation reactor design. The simplicity and compactness of the S-CO2 power cycle help save costs and improve the economic efficiency of nuclear power plants.

[0004] Experimental research is the basis for conducting feasibility studies of closed S-CO2 Brayton cycles. Small integrated S-CO2 Brayton cycle experimental loops help achieve the following goals: 1) Experiment on the performance of key components such as turbines, compressors, regenerators, and precoolers; 2) Accumulate operating experience of closed S-CO2 Brayton cycles, which had no reference in the past; 3) Study control strategies for cycle startup, shutdown, and power maneuvers; 4) Accumulate experimental data for transient analysis program verification, which can be used for further design of S-CO2 Brayton cycles at higher powers. Concentrated solar power (CSP) technology based on the S-CO2 Brayton cycle was rated as one of the "Top Ten Engineering and Technical Challenges in the Field of Energy and Power" in 2018 by the China Association for Science and Technology. More and more Chinese researchers are committed to the technical development of the S-CO2 Brayton cycle. Summary of the invention

[0005] Aiming at the industrial and scientific research application requirements of supercritical carbon dioxide flow heat transfer, the present invention provides a closed supercritical carbon dioxide Brayton cycle experimental device.

[0006] The present invention is achieved by adopting the following technical solutions:

[0007] A closed supercritical carbon dioxide Brayton cycle experimental device, comprising a plunger pump, an orifice flowmeter, a printed circuit board type heat exchanger, an experimental section, a printed circuit board type cooler, a Coriolis mass flowmeter, a turbine flowmeter, a water-cooled chiller, a cooling tower, a carbon dioxide storage tank, a charging and discharging plunger pump, and a pressure-reducing orifice plate;

[0008] The outlet of the carbon dioxide storage tank is connected to the inlet of the charging and discharging plunger pump, the outlet of the charging and discharging plunger pump is connected to the inlet of the plunger pump through the electric charging and discharging valve group and the outlet of the Coriolis mass flowmeter, the outlet of the plunger pump is connected to the inlet of the orifice flowmeter, the outlet of the orifice flowmeter is connected to the high-pressure side inlet of the printed circuit board heat exchanger through the electric flow regulating valve, the high-pressure side outlet of the printed circuit board heat exchanger is connected to the inlet of the experimental section, the outlet of the experimental section is connected to the inlet of the pressure reduction orifice plate, the outlet of the pressure reduction orifice plate is connected to the low-pressure side inlet of the printed circuit board heat exchanger through the electric pressure regulating valve, the low-pressure side outlet of the printed circuit board heat exchanger is connected to the main circuit working fluid side inlet of the printed circuit board cooler, and the main circuit working fluid side outlet of the printed circuit board cooler is connected to the inlet of the Coriolis mass flowmeter; a bypass is provided between the outlet of the plunger pump and the inlet of the Coriolis mass flowmeter, and a bypass manual flow regulating valve is provided on the bypass;

[0009] The cooling water side outlet of the printed circuit board type cooler is connected to the first cooling water inlet of the water-cooled chiller through an electric flow regulating valve, the first cooling water outlet of the water-cooled chiller is connected to the inlet of the cooling tower, the outlet of the cooling tower is connected to the second cooling water inlet of the chiller, the second cooling water outlet of the water-cooled chiller is connected to the inlet of the turbine flowmeter, and the outlet of the turbine flowmeter is connected to the cooling water side inlet of the printed circuit board type cooler.

[0010] A further improvement of the present invention is that the experimental section is a vertically placed hexagonal cylinder structure containing 37 heating rods and adopts an indirect heating form.

[0011] A further improvement of the present invention is that seven heating rods in the center of the experimental section are connected to thermocouples to achieve real-time temperature measurement, the heating section length is 1.5m, the rod diameter is 9.5mm, and the rod spacing is 15mm.

[0012] A further improvement of the present invention is that the carbon dioxide storage tank is a horizontal cylinder structure, designed to withstand a pressure of 10 MPa and a volume of 2m 3 , equipped with safety valve, cooling spray and magnetic flap level gauge.

[0013] A further improvement of the present invention is that it also includes a data acquisition system, wherein the temperature signal acquisition frequency of the data acquisition system is not less than 75S / s, and the other analog signal acquisition frequencies are not less than 500S / s.

[0014] A further improvement of the present invention is that an eleventh pressure transmitter and an eleventh temperature transmitter are provided on the carbon dioxide storage tank.

[0015] A further improvement of the present invention is that a first temperature transmitter and a first pressure transmitter are provided at the outlet of the plunger pump, and a tenth temperature transmitter and a tenth pressure transmitter are provided at the inlet of the plunger pump.

[0016] A further improvement of the present invention is that a third differential pressure transmitter is arranged between the main circuit working fluid side outlet and the main circuit working fluid side inlet of the printed circuit board type cooler, a fourth differential pressure transmitter is arranged between the cooling water side outlet and the cooling water side inlet of the printed circuit board type cooler, and a ninth temperature transmitter and a ninth pressure transmitter are arranged at the main circuit working fluid side outlet of the printed circuit board type cooler.

[0017] A further improvement of the present invention is that a fourth temperature transmitter and a fourth pressure transmitter are provided at the inlet of the experimental section, a fifth temperature transmitter and a fifth pressure transmitter are provided at the inlet of the pressure reducing orifice plate, and a sixth temperature transmitter and a sixth pressure transmitter are provided at the outlet of the pressure reducing orifice plate.

[0018] A further improvement of the present invention is that a second temperature transmitter and a second pressure transmitter are provided at the high-pressure side inlet of the printed circuit board type heat exchanger, a third temperature transmitter and a third pressure transmitter are provided at the high-pressure side outlet of the printed circuit board type heat exchanger, a seventh temperature transmitter and a seventh pressure transmitter are provided at the low-pressure side inlet of the printed circuit board type heat exchanger, an eighth temperature transmitter and an eighth pressure transmitter are provided at the low-pressure side outlet of the printed circuit board type heat exchanger, a first differential pressure transmitter is provided between the high-pressure side inlet and the high-pressure side outlet of the printed circuit board type heat exchanger, and a second differential pressure transmitter is provided between the low-pressure side inlet and the low-pressure side outlet of the printed circuit board type heat exchanger.

[0019] The present invention has at least the following beneficial technical effects:

[0020] A closed supercritical carbon dioxide Brayton cycle experimental device provided by the present invention adopts a new Brayton cycle layout and a microchannel printed circuit board heat exchanger (PCHE) design, which greatly reduces the construction space and saves costs. On this basis, a 100-kilowatt-level closed supercritical carbon dioxide Brayton cycle experimental device capable of studying complete cycle characteristics is built, which can meet the flow heat transfer experiment of carbon dioxide under a supercritical state and ensure good sealing of the system; meet multiple system parameters and flow state parameters, have a wide test range and advanced means; can carry out a variety of research work not limited to the verification of key experimental components, the flow channel heat transfer characteristics of the experimental section, and the overall cycle characteristics; the design of the data acquisition and control system can more fully study the dynamic characteristics of the system, and has great application prospects for the verification and improvement of the system analysis program, providing a safe and reliable platform for domestic supercritical carbon dioxide flow heat transfer research.

[0021] The invention can be used in scientific research units of universities and engineering practice to meet the scientific research needs of different units for the application of supercritical carbon dioxide, and to design a complete set of closed supercritical carbon dioxide Brayton cycle experimental devices. The invention is a closed Brayton cycle, which is a new type of efficient structural form with great development potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a closed supercritical carbon dioxide Brayton cycle experimental device of the present invention.

[0023] Figure 2 It is a structural schematic diagram of the present invention including temperature and pressure measuring points.

[0024] In the figure: 1 plunger pump, 2 orifice flowmeter, 3 printed circuit board heat exchanger (PCHE), 4 experimental section, 5 printed circuit board cooler (PCHE), 6 Coeur mass flowmeter, 7 turbine flowmeter, 8 water-cooled chiller, 9 cooling tower, 10 carbon dioxide storage tank, 11 charging and discharging plunger pump; V01 electric flow regulating valve, V02 pressure reduction orifice plate, V03 electric pressure regulating valve, V04 electric flow regulating valve, V05 bypass manual flow regulating valve, V06-11 electric charging and discharging valve group;

[0025] The first temperature transmitter to the tenth temperature transmitter T101-T110, the eleventh temperature transmitter T401; the first pressure transmitter to the tenth pressure transmitter P101-P110, the eleventh pressure transmitter P401; the first differential pressure transmitter to the fourth differential pressure transmitter P201-204.

[0026] Figure 3 It is an overall view of the experimental section of the present invention. DETAILED DESCRIPTION

[0027] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] like Figure 1 and Figure 2As shown, a closed supercritical carbon dioxide Brayton cycle experimental device provided by the present invention includes a main loop flow heat transfer circulation system, a cold side refrigeration system and a working fluid charging and exhausting system, and is designed with a data acquisition and control system; the main loop flow heat transfer circulation system includes a plunger pump 1, an orifice flowmeter 2, a printed circuit board heat exchanger (PCHE) 3, an experimental section 4, a printed circuit board cooler (PCHE) 5, a Coriolis mass flowmeter 6, an electric flow regulating valve V01, a pressure reducing orifice V02, an electric pressure regulating valve V03 and a bypass manual flow regulating valve V0 5; the cold side refrigeration system includes a turbine flowmeter 7, a water-cooled chiller 8, a cooling tower 9 and an electric flow regulating valve V04; the working fluid charging and discharging system includes a carbon dioxide storage tank 10, a charging and discharging plunger pump 11 and an electric charging and discharging valve group V06-11; the entire system also includes the first temperature transmitter to the tenth temperature transmitter T101-T110, the eleventh temperature transmitter T401, the first pressure transmitter to the tenth pressure transmitter P101-P110, the eleventh pressure transmitter P401 and the first differential pressure transmitter to the fourth differential pressure transmitter P201-204.

[0029] The carbon dioxide working fluid is stored in the carbon dioxide storage tank 10. The carbon dioxide storage tank 10 is equipped with the eleventh temperature transmitter T401 and the eleventh pressure transmitter P401. The carbon dioxide storage tank 10 is also equipped with a cooling spray and a magnetic flap level gauge. The carbon dioxide storage tank has a pressure resistance of 10MPa and maintains the temperature in the tank no higher than 10°C to ensure that the carbon dioxide is stored in liquid form. In addition, in order to realize the working fluid charging and discharging function of the main circuit, an electric charging and discharging valve group V06-11 is designed and connected to the main circuit. The main function of the valve group is to realize the switching of charging and discharging working fluid.

[0030] The tenth temperature transmitter T110 and the tenth pressure transmitter P110 are set before the plunger pump 1; in the main loop closed cycle, the plunger pump 1 is used as a power drive to increase the system pressure and maintain the working medium circulation. The nominal mass flow rate of the plunger pump 1 is 1kg / s, and the first temperature transmitter T101 and the first pressure transmitter P101 are set in its outlet pipeline and connected to the bypass manual regulating valve V05 and the main loop orifice flowmeter 2 to divide the experimental system into a main loop and a bypass, and the main loop electric regulating valve V01 and the bypass manual regulating valve V05 are set respectively; the bypass finally flows back to the outlet pipeline of the cooler 5, the Coriolis mass flowmeter 6 and the plunger pump 1 in front of the inlet, the main loop electric regulating valve V01 and the orifice flowmeter 2 cooperate with the bypass manual regulating valve V05 to realize the main loop flow calibration; Afterwards, in the main circuit, the rear end of the electric regulating valve V01 is connected to the high-pressure side of the heat exchanger 3. The second temperature transmitter T102 and the second pressure transmitter P102 are set at the inlet of the high-pressure side of the heat exchanger 3, the third temperature transmitter T103 and the third pressure transmitter P103 are set at the outlet of the high-pressure side of the heat exchanger 3, and the first differential pressure transmitter P201 is set at the inlet and outlet of the high-pressure side of the heat exchanger 3; the front end of the experimental section 4 is connected to the outlet of the high-pressure side of the heat exchanger 3, and the rear end is connected to the pressure-reducing orifice V02 and the electric pressure regulating valve V03; the fourth temperature transmitter T104 and the fourth pressure transmitter P104 are set at the inlet of the experimental section 4, and the fifth temperature transmitter T105 and the fifth pressure transmitter P105 are set between the experimental section 4 and the pressure-reducing orifice V02. The experimental section 4 is a vertically placed hexagonal cylinder. The structure contains 37 heating rods and adopts indirect heating. The hexagonal flow channel is designed to better exert the cooling characteristics of the coolant. The upper and lower top cover heads are designed in consideration of the high-pressure bearing function of the experimental section, and are completed by one-piece molding and precision cutting processes; the pressure reducing device after the experimental section 4 is a pressure reducing orifice plate V02 and an electric pressure regulating valve V03, which are used to reduce the fluid pressure. The pressure reducing orifice plate cannot be accurately regulated, so the electric regulating valve is used to achieve precise and controllable pressure regulation; the sixth temperature transmitter T106 and the sixth pressure transmitter P106 are set between the pressure reducing orifice plate V02 and the electric pressure regulating valve V03; then it is connected to the low-pressure side inlet pipeline of the heat exchanger 3, and the seventh temperature transmitter T107 and the seventh pressure transmitter P10 are set at the low-pressure side inlet of the heat exchanger 3. 7. The outlet of the low-pressure side of the heat exchanger 3 is connected to the inlet of the working fluid side of the main circuit of the cooler 5. The eighth temperature transmitter T108 and the eighth pressure transmitter P108 are arranged at the outlet of the low-pressure side of the heat exchanger 3. The second differential pressure transmitter P202 is arranged at the inlet and outlet of the low-pressure side of the heat exchanger 3; the outlet of the working fluid side of the main circuit of the cooler 5 is connected to the inlet of the Coriolis mass flowmeter 6 by intersecting with the rear end pipeline of the bypass manual flow regulating valve V05. The outlet of the working fluid side of the main circuit of the cooler 5 is connected to the ninth temperature transmitter T109 and the ninth pressure transmitter P109; the inlet and outlet of the working fluid side of the main circuit of the cooler 5 are provided with the third differential pressure transmitter P203; the outlet pipeline of the Coriolis mass flowmeter 6 is connected to the rear end of the electric charging and discharging valve group V06-11 for controlling the charging and discharging of the tank by intersecting with the inlet of the plunger pump 1, and the main circuit is closed and connected.

[0031] The cooling water side of cooler 5 serves as the final heat sink of the main circuit, and is mainly responsible for circulating cooling water to take away the heat on the main circuit side. The turbine flowmeter 7 is connected to the inlet pipeline of the cooling water side of cooler 5, and the electric flow regulating valve V04 is placed at the outlet of the cooling water side of cooler 5, and then connected to the water-cooled chiller 8 and the cooling tower 9 to realize the closed loop on the cooling side; the fourth differential pressure transmitter P204 is set at the inlet and outlet of the cooling water side of cooler 5, and the chiller 8 has its own temperature measurement function and can provide cold water at 4°C. The chiller 8 finally takes away the heat of the circuit through heat exchange with the cooling tower 9.

[0032] The closed supercritical carbon dioxide Brayton cycle experimental device of the present invention adopts a Brayton cycle configuration layout for the main circuit. The high-pressure pipe section adopts a DN32 specification, the low-pressure pipe section adopts a DN40 specification, and the pipe material is S316L material, designed to withstand a pressure of 22MPa; the heat exchanger 3 and the cooler 5 are both designed with a microchannel printed circuit board heat exchanger (PCHE), which greatly reduces the size of the equipment and saves construction space. There are two flow channels inside that can carry different pressure working fluids or heat exchange between different working fluids, and the research and application prospects are broad; the experimental section 4 is a vertically placed hexagonal cylinder structure, precisely cut, and integrally formed. It contains 37 heating rods, which adopt indirect heating. The seven central heating rods are connected to thermocouples to achieve temperature measurement. The length of the heating section is 1.5m, the rod diameter is 9.5mm, and the rod spacing is 15mm. The carbon dioxide storage tank 10 is a horizontal cylinder design, designed to withstand a pressure of 10MPa, and a volume of 2m 3 , equipped with safety valve, cooling spray and magnetic flap level gauge, equipped with electric filling and exhaust valve group V06-11 to realize the switching function of working fluid filling and exhaust. The data acquisition system collects and transforms data such as temperature, pressure transmitter, flow meter, electric valve opening, heating rod power, etc. in the loop and transmits them in real time. The temperature signal acquisition frequency is not less than 75S / s, and the other analog signal acquisition frequency is not less than 500S / s. The control system refers to converting the collected data into 4-20mA signal, summarizing it in the main control computer, and writing PID control module based on NI system and LabVIEW software to realize the control function of key parameters such as loop temperature.

[0033] Example

[0034] Figure 1 and Figure 2 This is a diagram of the closed supercritical carbon dioxide Brayton cycle experimental device

[0035] After the experimental device is built, a series of preparatory work needs to be carried out before the formal experiment to ensure that no accidents occur during the experiment and to ensure the accuracy of the experimental data.

[0036] The material used to build the experimental bench is S316L stainless steel pipe. There will be some attachments on the surface of the stainless steel pipe, as well as a protective layer added to its surface during production. When carbon dioxide enters the supercritical state, it will be extractable. If the pipe is not treated, the attachments on the pipe will be extracted during the experiment, polluting the carbon dioxide working fluid and damaging the instrument. Therefore, before the experiment, soak the pipe in dilute hydrochloric acid or acetone for 12 hours to extract the attachments on its surface.

[0037] Secondly, a sufficient amount of deionized water is passed into the carbon dioxide storage tank 10, the plunger pump 1 is turned on, and the system is run for 20 minutes, then the valve group V06-11 is switched to discharge the deionized water in the pipeline, and the above flushing process is repeated until no obvious impurities appear. Then nitrogen is passed to dry the pipeline to ensure that there is no excess water in the pipeline. Subsequently, anhydrous ethanol with a concentration of 95% is passed into the carbon dioxide storage tank 10, and the pipeline is cleaned again until no obvious impurities are observed in the anhydrous ethanol. After the anhydrous ethanol flushing is completed, it is also necessary to purge the pipeline with nitrogen to ensure the dryness of the pipeline.

[0038] On this basis, the experiment can be carried out according to the following steps:

[0039] (1) Observe the temperature display on the carbon dioxide storage tank 10. If the temperature is higher than 10°C, open the spray device for precooling to maintain the carbon dioxide in liquid state. Monitor the working fluid level through the magnetic flap level gauge until the experimental requirements are met.

[0040] (2) Check the entire circuit and switch to ensure that the wires of the entire system are connected correctly, without short circuit or leakage, and the switch can work normally. Confirm whether all valves of the entire system are open to prevent the pressure from being blocked and causing damage to the plunger pump 1. Confirm whether the main power switch is connected intact, then turn on the main power switch to power the circuit, and then turn on the control switches of the transformer, DC power supply and other experimental equipment as needed.

[0041] (3) Turn on plunger pump 1, start the circuit running at the set mass flow rate, and check whether there is obvious air leakage in the circuit.

[0042] (4) Then turn on the water cooling machine 8 and set the water cooling temperature at 8°C.

[0043] (5) Turn on the computer, start the data acquisition program, and set up the acquisition file.

[0044] (6) Open the flow control valve V01 and adjust it in real time. If necessary, adjust the manual control valve V05 to calibrate the flow, and then adjust the pressure control valve V03 to make the circuit pressure meet the experimental requirements.

[0045] (7) Turn on the heating system of experimental section 4. Figure 3As shown, the experimental section 4 is a vertically placed hexagonal cylinder structure with a hexagonal flow channel, precision cutting, and one-piece molding. It can be built-in with 37 heating rods, using indirect heating, and the heating power can reach hundreds of kilowatts. The seven central heating rods are connected to thermocouples to achieve real-time temperature measurement. The heating section length is 1.5m, the rod diameter is 9.5mm, and the rod spacing is 15mm. The control voltage adjusts the power of the 37 internal heating rods for heating. The 7 central heating rods of the experimental section 4 are connected to thermocouples for real-time temperature measurement. After the temperature reaches 500℃ and meets the required working conditions of the experiment, the heating power is adjusted to wait for the temperature to stabilize and collect data for 100s.

[0046] (8) After the experimental data collection is completed, first turn off the heating system, then adjust the pressure regulating valve V03 to reduce the pipeline pressure, turn off the plunger pump 1, and finally turn off the cooling system and data acquisition system.

[0047] (9) Before leaving the laboratory, ensure that the main power supply of the experimental system is turned off.

[0048] In addition, the experimental operation process must be strictly carried out in accordance with the operating specifications to avoid safety accidents. The precautions are as follows: 1) When the temperature transmitter, pressure transmitter, and differential pressure transmitter are not working properly, the experiment should be stopped to check the power supply and transmission signal system. If there is no problem with the two, check the PLC system and programming code. 2) There should be no air residue in the chiller. In winter, the temperature can reach below zero degrees. The chiller should be emptied after the experiment to avoid freezing of the evaporator and pipes of the chiller. 3) The carbon dioxide storage tank is a pressure vessel in the experimental system, so the carbon dioxide storage tank should be checked regularly. If the carbon dioxide storage tank has problems such as deformation or leakage, first stop the experiment, then open the exhaust valve to empty the carbon dioxide in the carbon dioxide storage tank, and finally inspect the carbon dioxide storage tank.

[0049] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A closed supercritical carbon dioxide Brayton cycle experimental device, characterized in that: It includes a plunger pump (1), an orifice flowmeter (2), a printed circuit board type heat exchanger (3), an experimental section (4), a printed circuit board type cooler (5), a Coriolis mass flowmeter (6), a turbine flowmeter (7), a water-cooled chiller (8), a cooling tower (9), a carbon dioxide storage tank (10), a charging and discharging plunger pump (11) and a pressure reducing orifice plate (V02); The outlet of the carbon dioxide storage tank (10) is connected to the inlet of the charging and discharging plunger pump (11), the outlet of the charging and discharging plunger pump (11) is connected to the inlet of the plunger pump (1) through the electric charging and discharging valve group (V06-11) and the outlet of the Coriolis mass flowmeter (6), the outlet of the plunger pump (1) is connected to the inlet of the orifice flowmeter (2), the outlet of the orifice flowmeter (2) is connected to the high-pressure side inlet of the printed circuit board type heat exchanger (3) through the electric flow regulating valve (V01), the high-pressure side outlet of the printed circuit board type heat exchanger (3) is connected to the inlet of the experimental section (4), and the outlet of the experimental section (4) is connected to the inlet of the experimental section (4). The inlet of the pressure reducing orifice plate (V02) is connected to the outlet of the pressure reducing orifice plate (V02) through the electric pressure regulating valve (V03), the outlet of the low-pressure side of the printed circuit board type heat exchanger (3) is connected to the main circuit working fluid side inlet of the printed circuit board type cooler (5), and the main circuit working fluid side outlet of the printed circuit board type cooler (5) is connected to the inlet of the Coriolis mass flow meter (6); a bypass is provided between the outlet of the plunger pump (1) and the inlet of the Coriolis mass flow meter (6), and a bypass manual flow regulating valve (V05) is provided on the bypass; The cooling water side outlet of the printed circuit board type cooler (5) is connected to the first cooling water inlet of the water-cooled chiller (8) through an electric flow regulating valve (V04), the first cooling water outlet of the water-cooled chiller (8) is connected to the inlet of the cooling tower (9), the outlet of the cooling tower (9) is connected to the second cooling water inlet of the water-cooled chiller (8), the second cooling water outlet of the water-cooled chiller (8) is connected to the inlet of the turbine flowmeter (7), and the outlet of the turbine flowmeter (7) is connected to the cooling water side inlet of the printed circuit board type cooler (5).

2. A closed supercritical carbon dioxide Brayton cycle experimental device according to claim 1, characterized in that: The experimental section (4) is a vertically placed hexagonal cylinder structure containing 37 heating rods and adopts indirect heating.

3. A closed supercritical carbon dioxide Brayton cycle experimental device according to claim 2, characterized in that: The seven heating rods in the center of the experimental section (4) are connected to thermocouples to achieve real-time temperature measurement. The heating section length is 1.5m, the rod diameter is 9.5mm, and the rod spacing is 15mm.

4. A closed supercritical carbon dioxide Brayton cycle experimental device according to claim 1, characterized in that: The carbon dioxide storage tank (10) is a horizontal cylinder structure with a designed pressure of 10 MPa and a volume of 2m 3 , equipped with safety valve, cooling spray and magnetic flap level gauge.

5. A closed supercritical carbon dioxide Brayton cycle experimental device according to claim 1, characterized in that: It also includes a data acquisition system, the temperature signal acquisition frequency of the data acquisition system is not less than 75S / s, and the other analog signal acquisition frequencies are not less than 500S / s.

6. A closed supercritical carbon dioxide Brayton cycle experimental device according to claim 1, characterized in that: The carbon dioxide storage tank (10) is provided with an eleventh pressure transmitter (P401) and an eleventh temperature transmitter (T401).

7. A closed supercritical carbon dioxide Brayton cycle experimental device according to claim 1, characterized in that: A first temperature transmitter (T101) and a first pressure transmitter (P101) are arranged at the outlet of the plunger pump (1), and a tenth temperature transmitter (T110) and a tenth pressure transmitter (P110) are arranged at the inlet of the plunger pump (1).

8. A closed supercritical carbon dioxide Brayton cycle experimental device according to claim 1, characterized in that: A third differential pressure transmitter (P203) is provided between the main circuit working fluid side outlet and the main circuit working fluid side inlet of the printed circuit board type cooler (5), a fourth differential pressure transmitter (P204) is provided between the cooling water side outlet and the cooling water side inlet of the printed circuit board type cooler (5), and a ninth temperature transmitter (T109) and a ninth pressure transmitter (P109) are provided at the main circuit working fluid side outlet of the printed circuit board type cooler (5).

9. A closed supercritical carbon dioxide Brayton cycle experimental device according to claim 1, characterized in that: A fourth temperature transmitter (T104) and a fourth pressure transmitter (P104) are provided at the inlet of the experimental section (4), a fifth temperature transmitter (T105) and a fifth pressure transmitter (P105) are provided at the inlet of the pressure reducing orifice (V02), and a sixth temperature transmitter (T106) and a sixth pressure transmitter (P106) are provided at the outlet of the pressure reducing orifice (V02).

10. A closed supercritical carbon dioxide Brayton cycle experimental device according to claim 1, characterized in that: A second temperature transmitter (T102) and a second pressure transmitter (P102) are provided at the high-pressure side inlet of the printed circuit board type heat exchanger (3); a third temperature transmitter (T103) and a third pressure transmitter (P103) are provided at the high-pressure side outlet of the printed circuit board type heat exchanger (3); a seventh temperature transmitter (T107) and a seventh pressure transmitter (P107) are provided at the low-pressure side inlet of the printed circuit board type heat exchanger (3); an eighth temperature transmitter (T108) and an eighth pressure transmitter (P108) are provided at the low-pressure side outlet of the printed circuit board type heat exchanger (3); a first differential pressure transmitter (P201) is provided between the high-pressure side inlet and the high-pressure side outlet of the printed circuit board type heat exchanger (3); and a second differential pressure transmitter (P202) is provided between the low-pressure side inlet and the low-pressure side outlet of the printed circuit board type heat exchanger (3).

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