Voltage stabilizer and nuclear power equipment

Abstract

The invention provides a pressure stabilizing device and nuclear power equipment, and relates to the technical field of pressure stabilizing devices for nuclear power equipment.The pressure stabilizing device comprises an upper sealing head, a lower sealing head, a refrigerant source, an electric heater, a cooling coil, a nitrogen source, a main control unit and a monitoring unit, and an inner cavity of the upper sealing head and an inner cavity of the lower sealing head communicate and jointly form a pressure stabilizing cavity; the refrigerant source is used for supplying cold liquid to an inner cavity of the lower sealing head; at least parts of the electric heater and the cooling coil extend to the inner cavity of the lower sealing head and are positioned below the liquid level of the cold-state liquid; the output end of the nitrogen source is communicated with the pressure stabilizing cavity, and the nitrogen source is used for supplying nitrogen and coupling pressure and temperature in the pressure stabilizing cavity; the main control unit is electrically connected with the electric heater and the monitoring unit, and the monitoring unit is used for monitoring at least one kind of parameter information of the temperature, the pressure and the liquid level of the cold-state liquid in the pressure stabilizing cavity. According to the invention, rapid heating and cooling can be realized, and pressure and temperature coupling can be realized in the heating and cooling process, so that the debugging test requirements of nuclear power equipment under variable temperature and pressure working conditions are met.

Description

Technical Field

[0001] The present application relates to the technical field of voltage stabilizing devices for nuclear power equipment, and in particular to a voltage stabilizing device and nuclear power equipment. Background Art

[0002] Nuclear power equipment usually operates under high temperature and high pressure environment. During the operation and debugging process, the operating temperature and pressure have different requirements according to the different operating conditions. In order to achieve the corresponding temperature and pressure conditions, the operating system usually needs to be equipped with corresponding voltage stabilizing devices and temperature regulating devices to complete operations such as heating and cooling, raising and lowering the pressure.

[0003] The voltage stabilizing devices in related technologies are generally designed for steady-state conditions, and the temperature and pressure can meet the operating conditions required for nuclear power equipment. However, the temperature and pressure adjustment speed during operation is slow, and it is impossible to complete the rapid transition between different temperature and pressure environments. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of one aspect of the present invention proposes a voltage stabilizing device, which can quickly heat up and cool down, and can achieve pressure and temperature coupling during the heating and cooling process to meet the debugging test requirements of nuclear power equipment under variable temperature and pressure conditions.

[0006] Another aspect of the present invention provides a nuclear power plant.

[0007] A pressure stabilizing device according to an embodiment of the present invention includes an upper end cover, a lower end cover, a refrigerant source, an electric heater, a cooling coil, a nitrogen source, a main control unit, and a monitoring unit.

[0008] Wherein, the upper head and the lower head both extend in the vertical direction, the inner cavity of the upper head and the inner cavity of the lower head are connected and together constitute a pressure stabilizing cavity, the output end of the cold medium source is connected to the pressure stabilizing cavity, and the cold medium source is used to supply cold liquid to the inner cavity of the lower head;

[0009] Wherein, the electric heater and the cooling coil are both connected to the lower head, and at least a portion of the electric heater and the cooling coil extend to the inner cavity of the lower head and are below the liquid level of the cold liquid;

[0010] The output end of the nitrogen source is connected to the pressure stabilizing chamber, and the nitrogen source is used to supply nitrogen and couple the pressure and temperature in the pressure stabilizing chamber;

[0011] The main control unit is electrically connected to the electric heater and the monitoring unit, and the monitoring unit is used to monitor at least one parameter information of the temperature, pressure and liquid level of the cold liquid in the pressure stabilizing chamber.

[0012] According to the voltage stabilizing device of the embodiment of the present invention, the electric heater can heat the cold liquid, and the cooling coil can cool the cold liquid, and the monitoring unit can monitor the temperature and pressure in the voltage stabilizing chamber and feed back the monitoring information to the main control unit, so that the main control unit can control the working conditions of the electric heater and the cooling coil according to the temperature and pressure in the voltage stabilizing chamber, thereby realizing rapid heating and cooling of the voltage stabilizing device, and in the process of heating and cooling, the pressure and temperature in the voltage stabilizing chamber are coupled in the nitrogen environment, so that the pressure can be adjusted synchronously according to the temperature change. Therefore, the voltage stabilizing device can not only be applied to the operating environment of nuclear power equipment under steady-state conditions, but also can meet the commissioning test of nuclear power equipment under variable temperature and pressure conditions.

[0013] In some embodiments, the cooling coil is provided with heat transfer oil, the cooling coil comprises an inlet section, a cooling section and an outlet section which are connected in sequence, and the cooling section is provided below the liquid level of the cold liquid;

[0014] The voltage stabilizing device also includes a cooling pump and a heat sink. The cooling pump is connected between the inlet section and the outlet section and is electrically connected to the main control unit. The heat sink is arranged at a portion of the outlet section away from the cooling section. The heat sink is used to cool the heat transfer oil in the outlet section.

[0015] In some embodiments, there are multiple cooling coils, and the multiple cooling coils all extend spirally along the vertical direction and are sequentially sleeved in the inner cavity of the lower head from the inside to the outside;

[0016] The pressure stabilizing device further comprises a first main pipe and a second main pipe, the inlet sections of the plurality of cooling coils are all connected to the first main pipe, and the outlet sections of the plurality of cooling coils are all connected to the second main pipe.

[0017] In some embodiments, the pressure stabilizing device further includes a sleeve penetrating the bottom wall of the lower head and extending along the vertical direction and two penetration interfaces;

[0018] The electric heater is fitted in the sleeve;

[0019] The first manifold is fitted in one of the penetration interface, and the second manifold is fitted in the other penetration interface.

[0020] In some embodiments, the electric heater and the cooling coil are spaced apart in a portion of the inner cavity of the lower head.

[0021] In some embodiments, there are multiple electric heaters, and the multiple electric heater arrays are arranged on the bottom wall of the lower head.

[0022] In some embodiments, the voltage stabilizing device further includes an electric heating tape, which is disposed on the upper head and electrically connected to the main control unit.

[0023] In some embodiments, the upper head is formed to communicate with the spray port, the liquid filling port, the gas charging port and the exhaust port of the pressure stabilizing chamber, the spray port and the liquid filling port are both communicated with the refrigerant source, the spray port, the gas charging port and the exhaust port are respectively connected to a valve and are controlled to be on and off by the valve, the valve is electrically connected to the main control unit, and the gas charging port is communicated with the nitrogen source;

[0024] The lower end cover is formed with a liquid discharge port connected to the pressure stabilizing chamber.

[0025] In some embodiments, the monitoring unit includes a safety valve, a thermocouple, a pressure gauge and a liquid level gauge. The safety valve and the pressure gauge are both installed on the upper head. There are at least two thermocouples and at least two liquid level gauges. The upper head and the lower head are both installed with at least one thermocouple and one liquid level gauge at the same time. The thermocouple is used to monitor the temperature in the pressure stabilizing chamber, the pressure gauge is used to monitor the pressure in the pressure stabilizing chamber, and the liquid level gauge is used to monitor the liquid level of the cold liquid.

[0026] In some embodiments, the pressure stabilizing device also includes a circulation pump installed outside the lower head, the lower head is formed with a liquid outlet and a liquid inlet, the circulation pump is connected between the liquid outlet and the liquid inlet and is electrically connected to the main control unit, and the circulation pump is used to pump cold liquid to circulate in the inner cavity of the lower head.

[0027] In some embodiments, the pressure stabilizing device further comprises a concrete column, which extends along the vertical direction and is connected to the bottom wall of the lower head.

[0028] A nuclear power device according to an embodiment of the present invention includes the voltage stabilizing device as described above.

[0029] The technical advantages of the nuclear power equipment according to the embodiment of the present invention are the same as the technical advantages of the above-mentioned voltage stabilizing device, which will not be repeated here.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 2 is a schematic diagram of a vertical cross-sectional structure of a voltage stabilizing device according to an embodiment of the present invention.

[0032] Figure 2 It is a partial cross-sectional schematic diagram of the connection structure of the sleeve and the penetration interface on the lower head in the pressure stabilizing device according to an embodiment of the present invention.

[0033] Figure 3 It is a schematic diagram of the cross-sectional structure of the lower head in the pressure stabilizing device according to an embodiment of the present invention.

[0034] Figure 4 It is a schematic diagram of the arrangement structure of the cooling coil in the lower head in the pressure stabilizing device according to an embodiment of the present invention.

[0035] Figure 5 The present invention is a block diagram of the control relationship between the main control unit and various electrical components in the voltage stabilizing device according to an embodiment of the present invention.

[0036] Figure 6 This is a graph of water temperature and pressure test data obtained when the voltage stabilizing device according to an embodiment of the present invention was subjected to the 310th temperature rise and fall test. In the graph, curve a is the water temperature curve (in ° C), and curve b is the pressure curve (in MPa).

[0037] Figure 7 3 is a pressure-temperature variation curve obtained when the voltage stabilizing device according to an embodiment of the present invention was subjected to the 310th temperature rise and fall test. The solid line in the figure is the temperature rise curve, and the dotted line is the standard pressure-temperature curve.

[0038] Figure numerals: 1. upper head, 11. spray port, 12. filling port, 13. inflation port, 14. exhaust port, 2. lower head, 21. casing, 22. penetration interface, 23. drain port, 3. electric heater, 4. cooling coil, 5. main control unit, 6. monitoring unit, 7. first main pipe, 8. second main pipe, 9. concrete column. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0040] like Figures 1 to 5 As shown, a pressure stabilizing device according to an embodiment of the present invention includes an upper head 1, a lower head 2, a refrigerant source, an electric heater 3, a cooling coil 4, a nitrogen source, a main control unit 5 and a monitoring unit 6.

[0041] Among them, the upper head 1 and the lower head 2 both extend in the vertical direction, the inner cavity of the upper head 1 and the inner cavity of the lower head 2 are connected and together constitute a pressure-stabilizing cavity, the output end of the refrigerant source is connected to the pressure-stabilizing cavity, and the refrigerant source is used to supply cold liquid to the inner cavity of the lower head 2.

[0042] The electric heater 3 and the cooling coil 4 are both connected to the lower head 2, and at least parts of the electric heater 3 and the cooling coil 4 extend to the inner cavity of the lower head 2 and are below the liquid level of the cold liquid.

[0043] The output end of the nitrogen source is connected to the pressure stabilizing chamber, and the nitrogen source is used to supply nitrogen and couple the pressure and temperature in the pressure stabilizing chamber.

[0044] The main control unit 5 is electrically connected to the electric heater 3 and the monitoring unit 6, and the monitoring unit 6 is used to monitor at least one parameter information of the temperature, pressure and liquid level of the cold liquid in the pressure stabilizing chamber.

[0045] According to the voltage stabilizing device of the embodiment of the present invention, the electric heater 3 can heat the cold liquid, the cooling coil 4 can cool the cold liquid, and the monitoring unit 6 can monitor the temperature and pressure in the voltage stabilizing chamber and feed back the monitoring information to the main control unit 5, so that the main control unit 5 can control the working conditions of the electric heater 3 and the cooling coil 4 according to the temperature and pressure in the voltage stabilizing chamber, thereby realizing the rapid heating and cooling of the voltage stabilizing device, and in the heating and cooling process, the pressure and temperature in the voltage stabilizing chamber are coupled in the nitrogen environment, so that the pressure can be adjusted synchronously according to the temperature change. Therefore, the voltage stabilizing device can not only be applied to the operating environment of nuclear power equipment under steady-state conditions, but also can meet the commissioning test of nuclear power equipment under variable temperature and pressure conditions.

[0046] Specifically, the cold liquid can be water at room temperature, and the nitrogen source can be a nitrogen bottle group. The output end of the nitrogen bottle group is connected to the pressure stabilizing chamber. Before the commissioning test of the nuclear power equipment under variable temperature and pressure conditions, nitrogen is introduced into the pressure stabilizing chamber from the nitrogen bottle group to stabilize the pressure of the pressure stabilizing device.

[0047] like Figure 1 , Figure 4 and Figure 5 As shown, in some embodiments, heat transfer oil is provided in the cooling coil 4, and the cooling coil 4 includes an inlet section, a cooling section and an outlet section which are connected in sequence, and the cooling section is provided below the liquid level of the cold liquid.

[0048] The voltage stabilizing device also includes a cooling pump and a heat sink. The cooling pump is connected between the inlet section and the outlet section and is electrically connected to the main control unit 5. The heat sink is arranged at the part of the outlet section away from the cooling section. The heat sink is used to cool the heat transfer oil in the outlet section.

[0049] Since the pressure stabilizing device operates in a high temperature and high pressure environment, heat transfer oil is used as the coolant in the cooling coil 4. When the cooling coil 4 cools the cold liquid, it can avoid the generation of steam in the tube and the increase of pressure in the tube, which poses a safety hazard. The coordinated design of the cooling pump and the heat sink allows the heat transfer oil in the cooling coil 4 to circulate and cool down, so as to achieve the cooling of the cold liquid in the pressure stabilizing device by the cooling coil 4.

[0050] Specifically, the cooling pump and the heat sink are both arranged outside the lower head 2. The heat sink is not limited to external cooling water. To ensure the cooling effect on the cold liquid and reduce energy waste, the cooling section of the cooling coil 4 is completely arranged below the liquid level of the cold liquid.

[0051] like Figure 1 and Figure 4 As shown, in some embodiments, there are multiple cooling coils 4, and the multiple cooling coils 4 all extend spirally in the vertical direction and are sequentially sleeved in the inner cavity of the lower head 2 from the inside to the outside.

[0052] The pressure stabilizing device further includes a first main pipe 7 and a second main pipe 8 . The inlet sections of the plurality of cooling coils 4 are all connected to the first main pipe 7 , and the outlet sections of the plurality of cooling coils 4 are all connected to the second main pipe 8 .

[0053] Multiple cooling coils 4 are arranged in the inner cavity of the lower head 2 in a manner of being sequentially sleeved from the inside to the outside, so that the multiple cooling coils 4 can cooperate with each other to achieve rapid cooling of the cold liquid, and can fully utilize the inner cavity space of the lower head 2, ensuring the cooling efficiency while making the overall structure compact. The first main pipe 7 and the second main pipe 8 can integrate the inlet section and the outlet section of the multiple cooling coils 4, which is convenient for uniformly pumping out and cooling the heat transfer oil in the cooling coils 4, so that the temperature of the heat transfer oil in each cooling coil 4 is basically the same, so as to ensure uniform cooling of the cold liquid, and at the same time simplify and organize the structure of this part.

[0054] Preferably, in order to achieve uniform cooling of the cold liquid and increase the cooling rate, multiple cooling coils 4 are sequentially arranged in the inner cavity of the lower head 2 from the inside to the outside and are coaxial with the lower head 2. This layout method also reduces the difficulty of laying out the cooling coils 4.

[0055] It can be understood that multiple cooling coils 4 are sequentially arranged from the inside to the outside, which means that the cooling coils 4 can be arranged sequentially from the inside to the outside according to the specifications of the spiral inner diameter formed after the cooling coils 4 are extended along the vertical direction, that is, the cooling coil 4 with a larger spiral inner diameter is arranged outside the cooling coil 4 with a smaller spiral inner diameter.

[0056] It should be noted that multiple cooling coils 4 can also be mutually nested in the inner cavity of the lower head 2, that is, multiple cooling coils 4 can be nested in sequence from the inside to the outside, or a part of the cooling coils 4 can be nested in the same or several cooling coils 4 and other cooling coils 4 can be nested in the aforementioned part of the cooling coils 4 in sequence from the inside to the outside. The specific layout of the multiple cooling coils 4 can comprehensively consider the inner cavity specifications of the lower head 2, the difficulty of layout construction, the cooling rate and cost, etc., which will not be elaborated here.

[0057] like Figures 1 to 4 As shown, in some embodiments, the pressure stabilizing device further includes a sleeve 21 penetrating the bottom wall of the lower head 2 and extending in the vertical direction and two penetration interfaces 22 .

[0058] The electric heater 3 is fitted in the sleeve 21 .

[0059] The first manifold 7 is fitted into one of the penetration interface 22 , and the second manifold 8 is fitted into the other penetration interface 22 .

[0060] The sleeve 21 and the penetration interface 22 facilitate the disassembly and assembly of the electric heater 3 and the cooling coil 4 on the lower head 2. At the same time, the use of the first main pipe 7 and the second main pipe 8 can also avoid the construction difficulty of the sealing of the pressure stabilizing chamber increased by respectively penetrating the inlet section and outlet section of multiple cooling coils 4 on the bottom wall of the lower head 2.

[0061] like Figures 1 to 4 As shown, in some embodiments, the electric heater 3 and the cooling coil 4 are spaced apart in part of the inner cavity of the lower head 2 .

[0062] In order to reduce the mutual interference between the electric heater 3 and the cooling coil 4 during operation, the two can be arranged at intervals in a part of the inner cavity of the lower head 2 .

[0063] like Figures 1 to 3 As shown, in some embodiments, there are multiple electric heaters 3, and the multiple electric heaters 3 are arranged in an array on the bottom wall of the lower head 2.

[0064] To ensure the heating efficiency, multiple electric heaters 3 may be arranged on the bottom wall of the lower head 2 .

[0065] Specifically, the electric heater 3 is not limited to an electric heating rod, and a plurality of electric heaters 3 may be arranged at equal intervals or at unequal intervals. In order to allow the cold liquid to be heated evenly, it is preferred that the plurality of electric heaters 3 are arranged at equal intervals.

[0066] like Figure 1 and Figure 5 As shown, in some embodiments, the voltage stabilizing device further includes an electric heating tape, which is disposed on the upper head 1 and electrically connected to the main control unit 5 .

[0067] Since the upper end cover 1 itself has a certain heat storage capacity, in order not to affect the working efficiency of the electric heater 3, an electric heating tape can be installed on the upper end cover 1 to ensure the temperature in the pressure stabilizing chamber.

[0068] like Figure 1 , Figure 3 and Figure 5 As shown, in some embodiments, the upper head 1 is formed with a spray port 11, a liquid filling port 12, an air charging port 13 and an exhaust port 14 connected to the pressure stabilizing chamber, the spray port 11 and the liquid filling port 12 are both connected to a refrigerant source, the spray port 11, the air charging port 13 and the exhaust port 14 are respectively connected to a valve and are controlled on and off by the valve, the valve is electrically connected to the main control unit 5, and the air charging port 13 is connected to a nitrogen source.

[0069] The lower end cover 2 is formed with a drain port 23 connected to the pressure stabilizing chamber.

[0070] When the pressure in the pressure stabilizing chamber is higher than the required pressure requirement, the cold liquid can be supplied from the refrigerant source to the spray port 11 for spraying, so that the steam in the pressure stabilizing chamber is partially condensed, thereby reducing the pressure and realizing auxiliary adjustment of the pressure in the pressure stabilizing chamber. The cold liquid can be supplied to the inner cavity of the lower head 2 through the liquid filling port 12, and the cold liquid needs to be replenished through the liquid filling port 12 when the pressure stabilizing chamber is in a low temperature and low pressure state. In addition, the use of valves at the spray port 11, the air filling port 13 and the exhaust port 14 further improves the degree of automation during the working process of the pressure stabilizing device.

[0071] Specifically, a nitrogen pipeline connected to the pressure stabilizing chamber is formed at the gas filling port 13 of the upper head 1, and the output end of the nitrogen cylinder group passes nitrogen from the gas filling port 13 into the pressure stabilizing chamber through the nitrogen pipeline.

[0072] like Figure 1 and Figure 5 As shown, in some embodiments, the monitoring unit 6 includes a safety valve, a thermocouple, a pressure gauge and a liquid level gauge. The safety valve and the pressure gauge are both installed on the upper head 1. There are at least two thermocouples and liquid level gauges, and the upper head 1 and the lower head 2 are both installed with at least one thermocouple and one liquid level gauge at the same time. The thermocouple is used to monitor the temperature in the pressure stabilizing chamber, the pressure gauge is used to monitor the pressure in the pressure stabilizing chamber, and the liquid level gauge is used to monitor the liquid level of the cold liquid.

[0073] To ensure the reliability of temperature and liquid level monitoring, thermocouples and liquid level gauges are installed on both the upper head 1 and the lower head 2.

[0074] Specifically, the upper head 1 can form a pressure measuring pipeline connected to the pressure stabilizing chamber, and the detection end of the pressure gauge can be matched in the pressure measuring pipeline. The upper head 1 and the lower head 2 can both form liquid level measuring pipelines, and the detection end of the liquid level gauge can be matched in the liquid level measuring pipeline. The specific layout positions and layout quantities of the thermocouples and liquid level gauges on the upper head 1 and the lower head 2 can be determined according to the corresponding pressure stabilizing device.

[0075] like Figure 1 and Figure 5 As shown, in some embodiments, the pressure stabilizing device also includes a circulation pump installed outside the lower head 2, the lower head 2 is formed with a liquid outlet and a liquid inlet, the circulation pump is connected between the liquid outlet and the liquid inlet and is electrically connected to the main control unit 5, and the circulation pump is used to pump the cold liquid to circulate in the inner cavity of the lower head 2.

[0076] The use of an external circulation pump can cause the cold liquid in the inner cavity of the lower head 2 to circulate, so as to ensure uniform heating and cooling of the cold liquid.

[0077] like Figure 1As shown, in some embodiments, the pressure stabilizing device further includes a concrete column 9 , which extends in the vertical direction and is connected to the bottom wall of the lower head 2 .

[0078] The concrete column 9 can not only support the lower head 2, but also reserve an operating space at the bottom of the lower head 2, so as to facilitate the staff to disassemble and assemble the electric heater 3 and the cooling coil 4 and inspect the drain port 23.

[0079] like Figures 1 to 7 As shown, a nuclear power equipment according to an embodiment of the present invention includes the voltage stabilizing device as described above.

[0080] The technical advantages of the nuclear power equipment according to the embodiment of the present invention are the same as the technical advantages of the above-mentioned voltage stabilizing device, which will not be repeated here.

[0081] Now, combined with the specific structure of the voltage stabilizing device, its working process is described, including the temperature increase operation and the temperature decrease operation, specifically:

[0082] Heating steps:

[0083] 1) Open the inlet and outlet of the cooling coil 4, and fill the cooling coil 4 with heat transfer oil;

[0084] 2) Close the drain port 23 and open the filling port 12 to fill the inner cavity of the lower head 2 with cold liquid;

[0085] 3) The liquid level of the cold liquid is monitored by a liquid level gauge until the set liquid level is reached, and then the filling port 12 is closed;

[0086] 4) Close the valve at the exhaust port 14, and open the valve at the charging port 13, and fill the pressure stabilizing chamber with nitrogen from the nitrogen source until the pressure in the pressure stabilizing chamber rises to the test pressure, and then close the valve at the charging port 13 to stop the nitrogen filling;

[0087] 5) The main control unit 5 controls the electric heater 3 to heat the cold liquid. During the heating process, the heating rate of the cold liquid can be controlled by adjusting the power of the electric heater 3, and the heating rate is maintained at ≥ 60°C / h. The temperature is continuously raised until the temperature of the cold liquid is raised to 262°C and the pressure in the pressure stabilizing chamber is raised to 5.7MPa.

[0088] Cooling operation steps:

[0089] The main control unit 5 controls the electric heater 3 to stop working and turns on the cooling pump, so that the heat transfer oil in the cooling coil 4 cools down the cold liquid. During the cooling process, the cooling rate of the cold liquid can be controlled by adjusting the flow rate of the heat transfer oil, and the cooling rate is maintained at ≥60℃ / h. The cooling is continued until the temperature of the cold liquid drops to 60℃ and the pressure in the pressure stabilizing chamber drops to 0.45MPa. During this process, the heat transfer oil is cooled by external cooling water at the same time.

[0090] Taking the test No. 310 as an example, the technical solution of the present application was used to perform the temperature rise and fall operation, wherein the cold liquid was water, the voltage stabilizer was heated from 60°C, 0.4MPa to 262°C, 5.7MPa, and it took 3h 22min, and the heating rate was 60.2°C / h; the voltage stabilizer was cooled from 262°C, 5.7MPa to 60°C, 0.4MPa, and it took 3h 17min, and the cooling rate was 61.7°C / h. The test data obtained are as follows: Figure 6 shown.

[0091] In addition, according to the temperature and pressure curves required by the test, the temperature and pressure of the voltage stabilizer keep changing synchronously during the heating and cooling process. Specifically, by using nitrogen to adjust the initial pressure of the voltage stabilizer chamber to 0.4MPa at 60℃, the pressure and temperature can be self-coupled during the heating and cooling process. The test results are as follows: Figure 7 shown.

[0092] The heat transfer calculation instructions for the above test are as follows:

[0093] The cooling liquid is water. Preliminary calculation shows that the mass of water in the pressure stabilizing device is about 2500kg. The materials of the upper head 1 and the lower head 2 are both 304 stainless steel, weighing about 14000kg.

[0094] For the cooling process from 120℃ to 60℃ during the test, the cooling rate is required to reach 60℃ / h, and the heat exchange power is calculated.

[0095] 1. Calculation of heat exchange power of water in the pressure stabilizing device

[0096] According to the test conditions, the specific enthalpy of water at 0.39 MPa and 120 °C is h1 = 503.92 kJ / kg;

[0097] The specific enthalpy of water at 0.16 MPa and 60 ° C is h2 = 251.27 kJ / kg;

[0098] When the cooling rate reaches 60℃ / h, calculate the heat exchange power:

[0099]

[0100] 2. Calculation of wall heat transfer power of upper head 1 and lower head 2

[0101] The mass of the upper head 1 and the lower head 2 is about 14000kg, and the specific heat of 304 stainless steel is about 0.46kJ / (kg·℃). The cooling rate reaches 60℃ / h. The heat exchange power is calculated as follows:

[0102] Q2=Mc p ×60℃ / h=107.33kW

[0103] According to calculations, the heat exchange power required for cooling is Q=Q1+Q2=282.78kW.

[0104] 3. Calculation of thermal oil flow

[0105] The cooling coil 4 uses a DN40 pipe, stainless steel pipe, with an outer diameter of 48.3 mm and a wall thickness of 3.5 mm. The thermal oil is thermal55, assuming that the inlet temperature of the thermal oil is 38°C and the outlet temperature is 55°C.

[0106] According to the heat transfer power Q = 282.78kW, we can get Cp = 2.01kJ / (kg·℃) by looking up the table, and calculate the heat transfer oil flow rate:

[0107] M=Q / (Cp·Δt)=8.4kg / s

[0108] According to the arrangement of cooling coils 4 (there are five cooling coils 4, which are sequentially sleeved in the inner cavity of the lower head 2 from the inside to the outside and coaxial with the lower head 2), the heat transfer oil enters through 5 cooling pipelines, and the heat transfer oil flow rate is:

[0109] v=M / 5(ρ·S)=1.5m / s

[0110] 4. Calculation of heat transfer coefficient

[0111] The heat transfer of the cooling coil 4 in the pressure stabilizing device can be regarded as the third type of boundary condition, and the heat transfer coefficient is:

[0112]

[0113] Where h1 is the convection heat transfer coefficient in the tube, is the heat transfer coefficient of the tube wall, and h2 is the natural convection heat transfer coefficient outside the tube.

[0114] 5. Calculation of convection heat transfer coefficient in tube

[0115] The calculation formula of convection heat transfer coefficient in the tube is as follows:

[0116]

[0117] Nu f =f(Re,Pr)

[0118]

[0119] The cooling coil 4 uses a DN40 pipe, stainless steel pipe, with an outer diameter of 48.3 mm and a wall thickness of 3.5 mm. The heat transfer oil inlet temperature is 38°C, the outlet temperature is 55°C, the average temperature is 46.5°C, the pipe wall temperature is 60°C, and the heat transfer oil flow rate v=1.5m / s.

[0120] By looking up the table, we can get:

[0121] Re f =4530.78

[0122] Pr f =185.90

[0123] At 2300 <Re f Under the condition of <10000, the heat transfer oil flow belongs to the transition stage, and the formula is:

[0124]

[0125] in:

[0126] f=(1.82lgRe-1.64) -2

[0127] have to:

[0128] Nu f =111.28

[0129] So the convection heat transfer coefficient in the tube is:

[0130]

[0131] 6. Calculation of tube wall heat transfer coefficient

[0132] The cooling coil 4 uses DN40 pipe, stainless steel pipe, outer diameter 48.3mm, wall thickness 3.5mm. So the pipe wall heat transfer coefficient is:

[0133]

[0134] 7. Calculation of natural convection heat transfer coefficient outside the tube

[0135] The natural convection heat transfer outside the tube selects the natural convection heat transfer calculation formula of the horizontal cylinder:

[0136]

[0137] Nu m =C(GrPr) n

[0138]

[0139] The cooling coil 4 is made of DN40 stainless steel pipe with an outer diameter of 48.3 mm and a wall thickness of 3.5 mm. The water temperature in the pressure stabilizing device is 120°C, the pipe wall temperature is 60°C, and the average temperature is 90°C.

[0140] After calculation, we can get:

[0141] Gr=2.13×10 8

[0142] Pr=1.95

[0143] Gr<5.76×108 belongs to the laminar flow section, take C=0.48, n=1 / 4

[0144] Nu m =0.48(GrPr) 1 / 4 =68.55

[0145] So the natural convection heat transfer coefficient outside the tube is:

[0146]

[0147] The heat transfer coefficient of the cooling coil 4 in the pressure stabilizing device is:

[0148]

[0149] 8. Calculation of cooling coil 4 length

[0150] The cooling coil 4 uses a DN40 pipe, stainless steel pipe, with an outer diameter of 48.3mm and a wall thickness of 3.5mm. The average temperature of the heat transfer oil is 46.5℃, and the average temperature of the water in the pressure stabilizing device is 90℃.

[0151] The heat transfer power calculation is:

[0152] Q=kAΔt=kπdlΔt=281.77kW

[0153] Calculation shows that l=205.30m, so take l=210m.

[0154] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0155] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0156] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0157] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0158] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0159] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A voltage stabilizing device, characterized in that: include: An upper end cap, a lower end cap and a refrigerant source, wherein the upper end cap and the lower end cap both extend in a vertical direction, the inner cavity of the upper end cap and the inner cavity of the lower end cap are connected and together form a pressure stabilizing cavity, the output end of the refrigerant source is connected to the pressure stabilizing cavity, and the refrigerant source is used to supply cold liquid to the inner cavity of the lower end cap; An electric heater and a cooling coil, wherein the electric heater and the cooling coil are both connected to the lower end cover, and at least a portion of the electric heater and the cooling coil extend into the inner cavity of the lower end cover and are below the liquid level of the cold liquid; A nitrogen source, the output end of which is connected to the pressure stabilizing chamber, and the nitrogen source is used to supply nitrogen and couple the pressure and temperature in the pressure stabilizing chamber; as well as A main control unit and a monitoring unit, wherein the main control unit is electrically connected to the electric heater and the monitoring unit, and the monitoring unit is used to monitor at least one parameter information of the temperature, pressure and liquid level of the cold liquid in the pressure stabilizing chamber.

2. The voltage stabilizing device according to claim 1, characterized in that: The cooling coil is provided with heat transfer oil, and the cooling coil comprises an inlet section, a cooling section and an outlet section which are connected in sequence, and the cooling section is arranged below the liquid level of the cold liquid; The voltage stabilizing device also includes a cooling pump and a heat sink. The cooling pump is connected between the inlet section and the outlet section and is electrically connected to the main control unit. The heat sink is arranged at a portion of the outlet section away from the cooling section. The heat sink is used to cool the heat transfer oil in the outlet section.

3. The voltage stabilizing device according to claim 2, characterized in that: There are a plurality of cooling coils, and the plurality of cooling coils all extend spirally along the vertical direction and are sequentially sleeved in the inner cavity of the lower head from the inside to the outside; The pressure stabilizing device further comprises a first main pipe and a second main pipe, the inlet sections of the plurality of cooling coils are all connected to the first main pipe, and the outlet sections of the plurality of cooling coils are all connected to the second main pipe.

4. The voltage stabilizing device according to claim 3, characterized in that: The pressure stabilizing device further comprises a sleeve penetrating the bottom wall of the lower head and extending along the vertical direction and two penetration interfaces; The electric heater is fitted in the sleeve; The first manifold is fitted in one of the penetration interface, and the second manifold is fitted in the other penetration interface.

5. The voltage stabilizing device according to any one of claims 1 to 4, characterized in that: The electric heater and the cooling coil are spaced apart in a portion of the inner cavity of the lower head.

6. The voltage stabilizing device according to claim 5, characterized in that: There are multiple electric heaters, and the multiple electric heater arrays are arranged on the bottom wall of the lower head.

7. The voltage stabilizing device according to claim 1, characterized in that: The voltage stabilizing device also includes an electric heating tape, which is arranged on the upper head and is electrically connected to the main control unit.

8. The voltage stabilizing device according to claim 1, characterized in that: The upper end cap is formed to be connected to a spray port, a liquid filling port, an air charging port and an exhaust port of the pressure stabilizing chamber, the spray port and the liquid filling port are both connected to the refrigerant source, the spray port, the air charging port and the exhaust port are respectively connected to a valve and are controlled to be on and off by the valve, the valve is electrically connected to the main control unit, and the air charging port is connected to the nitrogen source; The lower end cover is formed with a liquid discharge port connected to the pressure stabilizing chamber.

9. The voltage stabilizing device according to claim 1, characterized in that: The monitoring unit includes a safety valve, a thermocouple, a pressure gauge and a liquid level gauge. The safety valve and the pressure gauge are both installed on the upper head. There are at least two thermocouples and at least two liquid level gauges. The upper head and the lower head are both installed with at least one thermocouple and at least one liquid level gauge. The thermocouple is used to monitor the temperature in the pressure stabilizing chamber, the pressure gauge is used to monitor the pressure in the pressure stabilizing chamber, and the liquid level gauge is used to monitor the liquid level of the cold liquid.

10. A nuclear power plant, characterized in that: The nuclear power equipment includes the voltage stabilizing device according to any one of claims 1 to 9.

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