CN204834063U - Active waste heat discharge heat exchanger test device of non - - Google Patents

Abstract

The utility model relates to a test device for a passive waste heat discharge heat exchanger. The test device includes a heat transfer test section, a voltage stabilizer, a shielded pump, a heater, a circulating pump, a heat exchanger, a high-level water tank, a low-level water tank, a lift pump, a water supply pump and a spray pump; wherein, the heat transfer test section, a voltage stabilizer, a shielded pump, and a heater form the main circuit system of the test device; It is connected with the inlet pipe of the shielded pump; the shielded pump is connected with the outlet pipe of the heat transfer test section, and the flow of the main circuit is adjusted by adjusting the valve and bypass valve in front of the shielded pump; the heater is installed between the shielded pump and the heat transfer test section. between heat test sections. The utility model has reasonable designs on the form, size and material of the heat transfer tube. And the problem of stress deformation is reasonably avoided, and the water consumption is also greatly reduced. The heat transfer process can be simulated more accurately and more accurate heat transfer data can be obtained.

Description

A test device for passive waste heat removal heat exchanger

technical field

The invention specifically relates to a test device for a passive waste heat discharge heat exchanger.

Background technique

Passive waste heat removal heat exchanger (PRHRHX) is an emergency core cooling system in AP1000 of the third-generation pressurized water reactor nuclear power plant, which plays an important role in alleviating heat sink loss accidents. The passive waste heat removal heat exchanger is mainly composed of heat transfer tubes and refueling water tanks in the containment. The fluid in the hot section of the reactor coolant system flows into the heat transfer tubes and is cooled by the water in the refueling water tank, thereby removing the decay heat of the core. Due to the density difference between the coolants of different temperatures, a natural circulation is formed in the heat exchanger.

The two-phase flow heat transfer phenomenon of the passive waste heat removal heat exchanger in the natural circulation process is a thermal-hydraulic phenomenon that has an important impact on the safety of the reactor. Due to the large temperature difference between the primary and secondary sides of the heat exchanger, the parameters vary widely, involving a variety of single-phase and two-phase flow heat transfer modes. Natural circulation has a low flow rate and is greatly affected by buoyancy, so the dynamics in the heat exchanger are significantly different from forced circulation. At present, there is insufficient understanding of the two-phase flow and heat transfer phenomenon inside and outside the heat transfer tube of the passive waste heat removal heat exchanger. Therefore, the experimental device of the passive waste heat removal heat exchanger is established to carry out the heat transfer behavior of the natural circulation two-phase flow Research is necessary for the development of core design and safety analysis techniques.

Westinghouse Corporation of the United States has established a heat transfer test device for the passive waste heat removal heat exchanger in AP600 to verify the heat transfer performance of the heat exchanger. The test section of the test device consisted of three parallel 304 stainless steel vertical heat transfer tubes immersed in a circular water tank to simulate the heat transfer of the vertical section of the heat exchanger tube in the refueling water tank. The device maintains the full height of the AP600 passive waste heat removal heat exchanger, and the wall thickness, inner diameter and spacing of the heat exchange tubes are similar to the real size. The operating conditions of the test device can cover the operating parameters of the AP600 passive waste heat removal heat exchanger. However, the heat transfer tube of the actual AP1000 heat exchanger is a C-shaped heat transfer tube, which is composed of upper and lower horizontal sections and vertical sections, of which the horizontal section accounts for 42% of the total surface area of the heat transfer tube, and the main heat transfer occurs in the The upper horizontal section of the heat pipe. In the test device established by Westinghouse, the heat transfer tube only includes the vertical section, and the heat transfer test research of the horizontal section cannot be carried out on this device. At the same time, the heat transfer tube of the test device is made of 304 stainless steel tube, while the material of the heat transfer tube in AP1000 is Inconel (Inconel690). Accuracy and reliability have an impact.

Contents of the invention

In view of the deficiencies of the above-mentioned test device, the purpose of the present invention is to establish a passive waste heat discharge heat exchanger heat transfer test device with the same size and similar material as the C-shaped tube of the AP1000 passive waste heat discharge heat exchanger, which is used to carry out natural circulation two-phase The flow heat transfer test provides test data for core design and safety analysis, and provides a basis for the evaluation of the passive waste heat removal heat exchanger natural circulation two-phase flow heat transfer program model.

To achieve the above object, the present invention adopts the following technical solutions:

A passive waste heat discharge heat exchanger test device, the test device includes a heat transfer test section, a voltage stabilizer, a shielded pump, a heater, a circulation pump, a heat exchanger, a high-level water tank, a low-level water tank, a lift pump, and a water supply pump and spray pumps;

Wherein, the heat transfer test section, voltage stabilizer, shielded pump, and heater form the main circuit system of the test device; the heat transfer test section includes 3 C-shaped heat transfer tubes and a cooling water tank, and the voltage stabilizer and The outlet pipe of the heat transfer test section is connected to the inlet pipe of the shielded pump; the shielded pump is connected to the outlet pipe of the heat transfer test section, and the flow of the main circuit is adjusted by adjusting the valve and the bypass valve in front of the shielded pump; the heating The device is installed between the shielded pump and the heat transfer test section;

The inlet of the circulating pump is connected to the tube-side outlet of the heat exchanger, and the outlet is connected to the inlet pipe of the cooling water tank;

The tube-side inlet of the heat exchanger is connected to the outlet pipe of the cooling water tank, and the tube-side outlet is connected to the inlet of the circulation pump;

The high-level water tank stores pure water for the main circuit system, and injects water into the main circuit system under the action of gravity; the low-level water tank stores pure water for the main circuit system;

The lifting pump is connected with the high-level water tank and the low-level water tank, and injects the water in the low-level water tank into the high-level water tank; Inject, increase the pressure of the regulator, and ensure that the water level in the regulator is not lower than the minimum liquid level value; the spray pump is installed between the low-level water tank and the upper nozzle of the regulator, and the water in the low-level water tank passes through the stabilized pressure The sprinkler at the top of the regulator injects water into the regulator.

Further, in the above-mentioned passive waste heat discharge heat exchanger test device, in the heat transfer test section, each C-shaped pipe 12 is connected by ferrules in three sections: the upper horizontal section, the vertical section and the lower horizontal section. The three heat transfer tubes are respectively nested in the three vertical circular tubes of the cooling water tank; the inlet and outlet of the three heat transfer tubes are respectively connected to the main circuit pipe of the test device through the upper splitter and the lower splitter.

Further, in the above-mentioned passive waste heat discharge heat exchanger test device, the cooling water tank is formed by connecting three vertical circular tubes in parallel with the upper and lower horizontal circular tubes, and each vertical circular tube contains The vertical section of a heat transfer tube; the lower horizontal circular tube at the bottom of the cooling water tank has an inlet pipe, the upper horizontal circular tube has an upper flange cover, and the upper flange cover has an outlet pipe, and the upper flange cover also has an outlet pipe. There is another outlet pipe for overflow of cooling water.

Further, in the above-mentioned passive waste heat removal heat exchanger test device, several thermocouple traps are arranged in the heat transfer tube, and the thermocouple traps are inserted into the heat transfer tube and silver-welded with the wall surface of the heat transfer tube. The bracket supports it in the center of the heat transfer tube, and the thermocouples penetrate through the opening end of the thermocouple well, and 10, 12 and 13 thermocouples are respectively arranged in the 3 heat transfer tubes; the outer walls of the 3 heat transfer tubes have The thermocouples directly welded on the outer wall surface, 10, 14 and 13 thermocouples are respectively arranged on the outer walls of the above three heat transfer tubes, and the thermocouples on the outer wall surface and the thermocouples in the heat transfer tubes are distributed alternately; 18 thermocouple wells are arranged in the water tank. The thermocouple wells are inserted into the cooling water tank and welded to the wall of the water tank. The thermocouples penetrate into the thermocouple wells, and one thermocouple is installed in each thermocouple well.

Further, in the above-mentioned passive waste heat discharge heat exchanger test device, the pressurizer adopts a vertical cylindrical structure and has upper and lower elliptical heads. During the pressure stabilization process of the pressurizer, the gas in the container The discharge is realized by the exhaust valve, which is installed on the top of the voltage stabilizer; the system pressure protection is realized by the safety valve installed on the upper end of the voltage stabilizer.

Further, in the above-mentioned passive waste heat discharge heat exchanger test device, the heater is connected to the main circuit pipeline through flanges, and insulating sealing gaskets are added between the flanges; the main circuit fluid flows through the heater, and then passes through the upper The shunt flows into the heat transfer tube; the maximum working pressure of the heater is 15MPa, and the maximum working temperature is 324°C; the working medium in the heater is pure water, and the heater is made of a pipe with a diameter of 32×3mm and a length of about 4.5m. The DC low voltage and high current adjusted by the thyristor rectifier power supply is directly output to the heating pipe section for heating. The output of the rectifier power supply is 12-pulse DC DC: 50V, 0-10000A, the heating power is 300KW, and the positive pole of the indirect power supply in the pipeline , both ends are connected to the negative pole of the power supply.

Further, in the above-mentioned passive waste heat discharge heat exchanger test device, the circulation pump pumps out the water in the cooling water tank, and after being cooled by the heat exchanger, injects it into the cooling water tank to realize the circulation and temperature of the water in the cooling water tank. constant.

Further, in the above-mentioned passive waste heat discharge heat exchanger test device, the heat exchanger lowers the temperature of the fluid coming out of the cooling water tank to achieve a constant water temperature in the cooling water tank, and the heat exchanger is an evaporative heat exchanger. Shell-and-tube structure, vertical arrangement, tube side heat exchange tube adopts U-shaped arrangement, shell side is a cylindrical structure, the cylinder is connected with the upper and lower heads, the upper head is an elliptical head, and the lower head is a spherical head. Head, shell side and tube side are made of 304 stainless steel.

Furthermore, in the above-mentioned passive waste heat removal heat exchanger test device, the thermocouple trap is made of Φ3×0.5mm 304 stainless steel seamless pipe, one end of the steel pipe is closed and the other end is open.

Further, in the above-mentioned passive waste heat discharge heat exchanger test device, the high-level water tank is a cylindrical water tank with a diameter of 1m and a height of 1.2m. The working temperature of the water tank is 20-90℃, the working pressure is normal pressure, and the material of the water tank is 304 Stainless steel; the lower water tank is a cubic water tank of 1×1×1.3m, the working temperature of the water tank is 20-90°C, the working pressure is normal pressure, and the material of the water tank is 304 stainless steel.

The beneficial effects of the present invention are as follows:

The passive waste heat discharge heat exchanger test device of the present invention uses three Φ19.05×1.5mm Inconel600C-shaped tubes to simulate the heat transfer tubes of the heat exchanger in AP1000, and its size is the same as the three typical heat transfer tubes in AP1000. Compared with 304 stainless steel, the thermal conductivity of Inconel600 is closer to that of Inconel690, with a difference of only 6%.

In addition, the simplified design of the cooling water tank reasonably avoids the stress deformation problem caused by the oversized water tank, and also greatly reduces the water consumption of the cooling water tank and shortens the test preparation time.

After debugging, the test device can reach the test range of pressure 0.2-15.0MPa, heat transfer tube inlet vapor content -0.1-1.0, inlet temperature 150-324°C, heat transfer tube internal flow rate 200-2000kg/m ² s . This operating range covers the operating range of the AP1000 passive waste heat removal heat exchanger.

Therefore, carrying out the natural circulation two-phase flow heat transfer test on this device can more accurately simulate the heat transfer process of the AP1000 passive waste heat removal heat exchanger and obtain more accurate heat transfer data.

Description of drawings

Figure 1 is a flow chart of the experimental device for passive waste heat removal heat exchanger.

Figure 2 is a schematic diagram of the structure of the heat transfer test section.

Figure 3 is a schematic diagram of the structure of a thermocouple well.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, the passive waste heat removal heat exchanger test device includes a heat transfer test section 1, a voltage stabilizer 2, a shielded pump 3, a heater 4, a circulation pump 5, a heat exchanger 6, a high-level water tank 7, and a low-level water tank 8. Lifting pump 9, replenishment pump 10 and spray pump 11. Among them, the test section 1, the voltage stabilizer 2, the shielded pump 3, and the heater 4 constitute the main circuit system of the test device.

When the fluid flows through the heater 4 in the main circuit, the temperature rises and the density drops, so it flows upwards into the heat transfer test section 1 . In the heat transfer test section 1, the main circuit fluid is cooled and its density increases, so it flows downward, flows out of the test section, and returns to the heater 4 through the main circuit pipe. This forms a natural circulation process in the passive waste heat removal heat exchanger test device. If the valves VAJ101 and VAJ102 are opened, and the canned pump 3 is turned on, the main circuit fluid passes through the canned pump and then enters the heater, which forms a forced circulation.

(1) Heat transfer test section

Heat transfer test section 1 is a key component in the test device, which is used to transfer the heat in the primary circuit to the secondary side system. As shown in FIG. 2 , it mainly consists of three C-shaped heat transfer tubes 12 and a cooling water tank 13 . The C-shaped pipe 12 is submerged in the cooling water tank 13, which simulates the refueling water tank in the containment.

The main technical parameters of test section 1 are shown in Table 1.

Table 1 Main technical parameters of heat transfer test section

The size of the heat transfer tube 12 is the same as that of the AP1000, with an outer diameter of 19.05 mm and a wall thickness of 1.65 mm. Every C-shaped pipe 12 is formed by connecting three sections of the upper horizontal section, the vertical section and the lower horizontal section with ferrules. The use of the ferrule connection instead of the entire C-shaped pipe is for the convenience of the installation of the test section. Because the three heat transfer tubes 12 are respectively nested in the three vertical circular tubes of the cooling water tank 13 .

The three heat transfer tubes 12 respectively simulate the shortest, longest and central heat transfer tubes in the heat transfer tube bundle of the AP1000 passive waste heat removal heat exchanger (as shown in Table 2). The heat transfer tube bundles are in the same vertical plane, and the distance between the central axes of adjacent horizontal sections is designed to be 38mm, which is the same as AP1000. The material of the heat transfer tube 12 is Inconel600, and its thermal conductivity is only 6% different from that of Inconel690.

Table 2 Heat Transfer Tube Length

Heat transfer tube number horizontal section vertical segment A (shortest) 2586mm 5284mm B (middle) 3656mm 5360mm C (longest) 4724mm 5436mm

The inlets and outlets of the three heat transfer tubes 12 are respectively connected to the main loop pipe of the test device through the upper splitter 14 and the lower splitter 15 . The fluid flows into the heat transfer tube 12 from the upper splitter 14 and flows out of the heat transfer tube 12 from the lower splitter 15 . When the high-temperature fluid flows through the heat transfer tubes 12, the water in the cooling water tank 13 is heated or even boiled, and the heat in the main circuit is transferred to the cooling water tank 13 through the heat transfer tube bundle of the heat exchanger. The difference in density between the cold water in the outlet line and the hot water in the inlet line creates a natural circulation of the fluid in the primary circuit.

The cooling water tank 13 is formed by connecting three vertical round pipes in parallel with the upper and lower horizontal round pipes. Each vertical circular tube contains a vertical section of the heat transfer tube 12 respectively. The size of the horizontal round tube is Φ325×3.5mm, and the size of the vertical round tube is Φ219×3.5mm. According to Westinghouse's experimental research on the AP600 passive waste heat removal heat exchanger, it is shown that when the axial distance between adjacent heat transfer tubes is large, the thermal effects between the tube bundles are independent of each other. Typical heat exchanger tube spacing and diameter ratio P/D is 1.3-1.5, and P/D=2 in AP600. When the distance between the wall of the cooling water tank and the heat transfer tube is large enough, the influence of the distance change of the wall of the water tank on the heat transfer inside and outside the heat transfer tube can be ignored. In this device, the distance between the wall of the cooling water tank 13 and the heat transfer tube 12 is greater than 38mm, which will not affect the heat transfer between the main circuit and the cooling water, so it is feasible to reasonably simplify the cooling water tank.

The main technical parameters of the cooling water tank 13 are shown in Table 3. The cooling water on the secondary side flows in from the inlet pipe 16 at the bottom of the cooling water tank 13 and flows out from the outlet pipe 18 on the upper flange cover 17 . There is also another outlet pipe 19 on the upper flange cover for the overflow of cooling water.

Table 3 Main technical parameters of cooling water tank

In order to obtain the test data of natural circulation two-phase flow heat transfer, many temperature measuring points were arranged in the test section 1, including the temperature of the fluid in the center of the heat transfer tube 12, the temperature of the outer wall, and the temperature of the pool water in the cooling water tank 13.

As shown in FIG. 3 , in order to measure the temperature of the fluid at the center of the heat transfer tube 12 , several thermocouple traps 20 are arranged in the heat transfer tube 12 . The thermocouple trap is inserted into the heat transfer tube 12 and is silver-welded with the wall surface of the heat transfer tube 12 , and is supported at the center of the heat transfer tube 12 by a tripod bracket 21 . An armored thermocouple with a diameter of 0.5 mm is threaded through the open end of the thermocouple well 20 . According to the test data requirements, the test device needs to arrange 10 thermocouples in the A heat transfer tube 12, 12 thermocouples in the B heat transfer tube 12, and 13 thermocouples in the C heat transfer tube 12. The selection of the size of the thermocouple trap should not only ensure that a sufficient number of thermocouples can be penetrated, but also minimize its influence on the fluid flow in the heat transfer tube. At the same time, it must also meet the design conditions of 20MPa and 350°C. Therefore, the thermocouple well 20 is made of Φ3×0.5 mm 304 stainless steel seamless pipe, one end of the steel pipe is closed and the other end is open.

The temperature of the outer wall surface of the heat transfer tube 12 is measured by a thermocouple directly welded on the outer wall surface. There are 10 thermocouples arranged on the surface of tube A, 14 thermocouples on tube B, and 13 thermocouples on tube C. Wall temperature thermocouples and central fluid temperature thermocouples are distributed alternately.

In addition, in order to measure the pool water temperature of the cooling water tank 13, 18 thermocouple traps are arranged in the cooling water tank 13. The thermocouple trap is inserted into the cooling water tank 13 and welded with the wall of the water tank. Armored thermocouples with a diameter of 0.5mm penetrate into the thermocouple wells, and one thermocouple is installed in each thermocouple well.

(2) Regulator

In the test device, the pressurizer 2 is connected to the outlet pipe of the heat transfer test section 1 and the inlet pipe of the shielded pump 3, and its function is to maintain a constant pressure in the main loop system and provide sufficient volume compensation for the loop system, thereby ensuring the stability of the main loop system. Pressure stability and safety.

The voltage stabilizer adopts a vertical cylindrical structure, and has upper and lower oval heads, and the container shell is made of 304 stainless steel. During the voltage stabilization process of the voltage stabilizer, the gas discharge in the container is realized by the exhaust valve, which is installed on the top of the voltage stabilizer; the system pressure protection is realized by the safety valve installed on the upper end of the voltage stabilizer. When the pressure exceeds 19MPa, The safety valve opens, and when the pressure drops to 18MPa, the safety valve will automatically return to its seat and seal to keep the pressure of the main circuit system operating within the rated range. The main technical parameters of the regulator are shown in Table 4.

Table 4 main technical parameters of the regulator

(3) Canned pump

The shielded pump 3 is connected to the outlet pipe of the heat transfer test section 1, and is the main power equipment of the main circuit circulation system, providing the required fluid flow under different test conditions. When carrying out the cyclic heat transfer test with a large flow rate, if the natural circulation cannot reach the required flow rate of the test working condition, it is necessary to turn on the canned pump 3 to carry out the forced cycle heat transfer test. By adjusting the valve VAJ102 and the bypass valve VAJ101 in front of the canned pump 3, the flow of the main circuit is adjusted.

According to the design capacity orientation of the test device, the circulation system of the main loop is required to have a circulation flow capacity of 15m ³ /h. Therefore, the main technical parameters of the selected canned pump 3 are shown in Table 5. The canned pump 3 is connected to the main circuit pipeline by welding. The bearing lubrication of the pump and the cooling of the shielding sleeve are guaranteed by the secondary water circulation cooling system. The cooling water used for lubricating the bearings of the pump and cooling the shielding sleeve must ensure continuous supply. When the cooling water is interrupted, the control system will alarm and cut off the power supply of the shielding pump 3.

Table 5 Main Circulation Pump Technical Parameters

serial number name unit value 1 set tempreture ℃ 350 2 design pressure MPa 20 3 Limited Data m ³ /h 25 4 Rated head m 25 5 Motor efficiency % 60 6 Rotating speed r/min 3000

(4) Heater

The heater 4 is installed between the shielded pump 2 and the heat transfer test section 1 , the main circuit fluid flows through the heater 4 , and then flows into the heat transfer pipe 12 through the upper splitter 14 . By adjusting the power of the heater 4, the inlet temperature of the heat transfer tube 12 can meet the test requirements.

The maximum working pressure of the heater 4 is 15MPa, and the maximum working temperature is 324°C. The working fluid in the heater is pure water. The heater 4 is made of a pipe with a diameter of Φ32×3mm and a length of about 4.5m. The heater 4 is connected to the main circuit pipeline through flanges, and insulating sealing gaskets are added between the flanges. The heater 4 adopts a heating method in which the DC low voltage and high current regulated by the silicon controlled rectifier power supply are directly output to the heating pipe section. The output of the rectified power supply is 12-pulse DC: 50V, 0-10000A. The heating electric power is 300KW. The middle of the pipeline is connected to the positive pole of the power supply, and the two ends are connected to the negative pole of the power supply.

(5) Circulation pump

The circulation pump 5 is a centrifugal pump, its inlet is connected to the outlet of the tube side of the heat exchanger 6, and its outlet is connected to the inlet pipe 16 of the cooling water tank 13. , and then injected into the cooling water tank 13 to realize the circulation and constant temperature of the water in the cooling water tank 13 .

(6) Heat exchanger

The tube-side inlet of the heat exchanger 6 is connected to the outlet pipe 18 of the cooling water tank 13, and the tube-side outlet is connected to the inlet of the circulation pump 5, and its function is to reduce the temperature of the fluid coming out of the cooling water tank 13, so as to realize constant water temperature in the cooling water tank 13 . The heat exchanger is an evaporative heat exchanger with a shell-and-tube structure and a vertical arrangement, and the tube-side heat exchange tubes are arranged in a U-shape. The shell side is a cylinder structure, the cylinder is connected with the upper and lower heads, the upper head is an elliptical head, and the lower head is a spherical head. Shell side and tube side are made of 304 stainless steel. The main technical parameters of the heat exchanger 6 are shown in Table 6.

Table 6 Heat Exchanger Technical Parameters

(7) High water tank

The function of the high level water tank 7 is to store the pure water for the main circuit system, and inject water to the main circuit system under the action of gravity. The high-level water tank is a cylindrical water tank with a diameter of 1m and a height of 1.2m. The working temperature of the water tank is 20-90°C, the working pressure is normal pressure, and the material of the water tank is 304 stainless steel.

(8) Low water tank

The function of the low water tank 8 is to store pure water for the main circuit system. The low-level water tank is a cubic water tank of 1×1×1.3m. The working temperature of the water tank is 20-90°C, the working pressure is normal pressure, and the material of the water tank is 304 stainless steel.

(9) lift pump

The lifting pump 9 is connected with the high water tank 7 and the low water tank 8, and its effect is to inject the water in the low water tank 8 into the high water tank 7. The liquid level difference between the high level water storage tank and the low level water storage tank is about 10m. Therefore, a vertical stainless steel centrifugal pump HS50-250A is adopted, with a rated head of 70m and a rated flow of 20m ³ /h.

(10) Make-up water pump

The supplementary water pump 10 is installed between the lower water tank 8 and the lower nozzle of the pressurizer 2, and its effect is to inject the water in the lower water tank from the bottom of the pressurizer 2 to enhance the pressure of the pressurized tank and ensure the water in the pressurizer 2. The water level is not lower than the minimum liquid level value. The flow rate of the supplementary water pump 10 is 60L/h.

(11)Spray pump

The spray pump 11 is installed between the low-level water tank 8 and the upper nozzle of the pressurizer 2, and its function is to inject water from the low-level water tank into the pressurizer 2 through the spray device on the top of the pressurizer 2 to reduce the steam temperature . The spray pump 11 flow rate is 60L/h.

The operation method of the present invention is as follows: before the natural circulation test starts, the valves VAJ101 and VAJ102 are closed to isolate the canned pump from the test circuit. Make sure the VCO103 valve is open. Open the valves VHO202 and VHO203, start the lift pump to lift the water in the low water tank to the high water tank. When the high water tank overflows, close the lift pump and valves VHO203 and VHO201. Open the valves VHO105, VHO104 and VHO204, and fill the test circuit including the surge tank, cooling water tank and main pipeline with water.

When the test circuit is full of water, close the valve VHO105. Fill nitrogen into the surge tank, and then turn on the make-up water pump to pressurize the main circuit until the pressure required for the test is reached. Turn on the heater to heat the water in the main circuit. As the water in the main circuit flows through the heater, the temperature rises causing the density to drop and it flows up into the test section. Adjust the heater power and the opening of VCO103 so that the inlet water temperature of the test section reaches the test conditions. When hot water flows through the test section, it is cooled by the cooling water tank, and its density increases, so it flows downward, out of the test section, and returns to the heater through the main pipe. This process forms a natural cycle in the main loop.

At the same time, turn on the circulation pump to make the water in the cooling water tank circulate through the heat exchanger, and open the valves VHO303 and VHO304 to make the secondary water of the heat exchanger circulate to cool the water in the water tank.

When the system reaches a steady state, the computer starts to record the test data every second, including the temperature inside the heat transfer tube, the temperature of the tube wall, the temperature of the water tank, the flow rate and the heating power, etc.

If forced circulation test is required, open valves VAJ101 and VAJ102. Other operating methods are the same as those of the natural circulation test. Turn on the canned pump, and adjust the flow of the main circuit by adjusting the opening of VAJ101 and VAJ102 to meet the flow requirements of the test conditions.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (10)

1. A passive waste heat discharge heat exchanger test device, characterized in that: The test device includes a heat transfer test section, a voltage stabilizer, a shielded pump, a heater, a circulation pump, a heat exchanger, a high-level water tank, a low-level water tank, a lift pump, a water supply pump and a spray pump; Wherein, the heat transfer test section, voltage stabilizer, shielded pump, and heater form the main circuit system of the test device; the heat transfer test section includes 3 C-shaped heat transfer tubes and a cooling water tank, and the voltage stabilizer and The outlet pipe of the heat transfer test section is connected to the inlet pipe of the shielded pump; the shielded pump is connected to the outlet pipe of the heat transfer test section, and the flow of the main circuit is adjusted by adjusting the valve and the bypass valve in front of the shielded pump; the heating The device is installed between the shielded pump and the heat transfer test section; The inlet of the circulating pump is connected to the tube-side outlet of the heat exchanger, and the outlet is connected to the inlet pipe of the cooling water tank; The tube-side inlet of the heat exchanger is connected to the outlet pipe of the cooling water tank, and the tube-side outlet is connected to the inlet of the circulation pump; The high-level water tank stores pure water for the main circuit system, and injects water into the main circuit system under the action of gravity; the low-level water tank stores pure water for the main circuit system; The lifting pump is connected with the high-level water tank and the low-level water tank, and injects the water in the low-level water tank into the high-level water tank; Inject, increase the pressure of the regulator, and ensure that the water level in the regulator is not lower than the minimum liquid level value; the spray pump is installed between the low-level water tank and the upper nozzle of the regulator, and the water in the low-level water tank passes through the stabilized pressure The sprinkler at the top of the regulator injects water into the regulator. 2. The passive waste heat discharge heat exchanger test device as claimed in claim 1, characterized in that: In the heat transfer test section, each C-shaped tube 12 is formed by connecting the upper horizontal section, the vertical section and the lower horizontal section with ferrules, and the three heat transfer tubes are respectively nested in the cooling water tank. In the vertical circular tube; the inlet and outlet of the three heat transfer tubes are connected to the main circuit pipe of the test device through the upper splitter and the lower splitter respectively. 3. The passive waste heat discharge heat exchanger test device according to claim 1 or 2, characterized in that: The cooling water tank is formed by connecting three vertical circular tubes in parallel with the upper and lower horizontal circular tubes, and each vertical circular tube contains a vertical section of a heat transfer tube; the lower horizontal circular tube at the bottom of the cooling water tank There is an inlet pipe on the pipe, and an upper flange cover on the upper horizontal circular pipe, and an outlet pipe on the upper flange cover, and another outlet pipe on the upper flange cover for the overflow of cooling water. 4. The passive waste heat discharge heat exchanger test device as claimed in claim 1 or 2, characterized in that: Several thermocouple traps are arranged in the heat transfer tube, the thermocouple traps are inserted into the heat transfer tube and are silver-welded with the wall surface of the heat transfer tube, supported on the center of the heat transfer tube with a tripod, and the thermocouple is connected from the thermocouple trap The open end goes through, and 10, 12 and 13 thermocouples are respectively arranged in the three heat transfer tubes; the outer walls of the three heat transfer tubes have thermocouples directly welded on the outer walls, and the outer walls of the above three heat transfer tubes are respectively 10, 14 and 13 thermocouples are arranged, and the thermocouples on the outer wall surface and the thermocouples in the heat transfer tubes are arranged alternately; 18 thermocouple wells are arranged in the cooling water tank, and the thermocouple wells are inserted into the cooling water tank. And welded with the wall of the water tank, the thermocouple penetrates into the thermocouple well, and one thermocouple is installed in each thermocouple well. 5. The passive waste heat discharge heat exchanger test device as claimed in claim 1 or 2, characterized in that: The voltage stabilizer adopts a vertical cylindrical structure and has upper and lower oval heads. During the voltage stabilization process of the voltage stabilizer, the gas discharge in the container is realized by the exhaust valve, which is installed on the top of the voltage stabilizer ; System pressure protection is achieved through a safety valve installed on the upper end of the regulator. 6. The passive waste heat discharge heat exchanger test device as claimed in claim 1 or 2, characterized in that: The heater and the main circuit pipeline are connected by flanges, and insulating sealing gaskets are added between the flanges; the main circuit fluid flows through the heater, and then flows into the heat transfer tube through the upper diverter; the maximum working pressure of the heater is 15MPa, and the maximum working pressure The temperature is 324°C; the working medium in the heater is pure water, and the heater is made of a pipe with a diameter of 32×3mm and a length of about 4.5m. The heating method on the heating pipe section, the rectified power output is 12-pulse DC: 50V, 0~10000A, the heating power is 300KW, the positive pole of the power supply is indirect in the pipeline, and the negative pole of the power supply is connected at both ends. 7. The passive waste heat discharge heat exchanger test device as claimed in claim 2, characterized in that: The circulating pump pumps out the water in the cooling water tank, and after being cooled by the heat exchanger, injects it into the cooling water tank to realize the circulation and constant temperature of the water in the cooling water tank. 8. The passive waste heat discharge heat exchanger test device as claimed in claim 1, characterized in that: The heat exchanger reduces the temperature of the fluid coming out of the cooling water tank to achieve a constant water temperature in the cooling water tank. The heat exchanger is an evaporative heat exchanger with a shell-and-tube structure and a vertical arrangement. The tube-side heat exchange tube adopts U-shaped Arrangement, the shell side is a cylindrical cylinder structure, the cylinder body is connected with the upper and lower heads, the upper head is an oval head, the lower head is a spherical head, and the material of the shell side and the tube side is 304 stainless steel. 9. The passive waste heat discharge heat exchanger test device as claimed in claim 4, characterized in that: The thermocouple well is made of Φ3×0.5mm 304 stainless steel seamless pipe, one end of the steel pipe is closed and the other end is open. 10. The passive waste heat removal heat exchanger test device according to claim 1, characterized in that: The high-level water tank is a cylindrical water tank with a diameter of 1m and a height of 1.2m. The working temperature of the water tank is 20-90℃, the working pressure is normal pressure, and the material of the water tank is 304 stainless steel. The temperature is 20-90°C, the working pressure is normal pressure, and the water tank is made of 304 stainless steel.