A waste heat exhaust heat exchanger having a thermoelectric conversion function
By introducing thermoelectric panels into the waste heat exhaust heat exchanger, waste heat can be converted into electricity using thermoelectric power generation technology, which solves the problem of low waste heat utilization rate, provides emergency power after emergency shutdown, and improves the safety and thermal energy utilization rate of nuclear power plants.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2023-12-05
- Publication Date
- 2026-07-03
AI Technical Summary
In existing nuclear power plant waste heat removal systems, low-grade heat is difficult to utilize, resulting in low thermal energy utilization and a lack of emergency power supply after emergency shutdown.
Thermoelectric conversion technology is introduced into the waste heat discharge heat exchanger. The thermoelectric power generation plate uses the water in the heat exchange tank as the heat source and the cooling water of the power generation device as the cold source to form thermoelectric power generation and realize the power generation function.
It improves the thermal energy utilization rate of nuclear power plants, provides emergency power after a nuclear reactor has been shut down, and enhances system safety.
Smart Images
Figure CN117612751B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of waste heat removal technology in nuclear power plants, and specifically to a waste heat removal heat exchanger with thermoelectric conversion function. Background Technology
[0002] Passive safety is a key concern in advanced pressurized water reactor (PWR) design. Passive residual heat removal systems are crucial safety systems in nuclear power plants, enabling the timely removal of core residual heat through natural circulation after an emergency reactor shutdown, ensuring reactor safety. The residual heat removal heat exchanger is a key component of the passive residual heat removal system. It typically employs a C-tube design, where water from the primary or secondary side carries residual heat released from the reactor core into the C-tube bundle, transferring the heat to the cooling water in the heat exchanger tank. Natural circulation within the heat exchanger tank provides continuous cooling of the primary or secondary water within the C-tube bundle. During an emergency reactor shutdown, the water in the heat exchanger tank absorbs a significant amount of heat during the residual heat removal process, causing its temperature to rise continuously. However, this heat is low-grade and difficult to utilize, ultimately being released into the environment.
[0003] Since the mid-20th century, thermoelectric conversion technology has undergone continuous development and has been widely applied in fields such as aviation and military. Thermoelectric conversion technology has advantages such as simple structure, no moving parts, and long service life. It can generate electricity using low-grade energy sources such as solar energy, geothermal energy, and industrial waste heat, making it a green and environmentally friendly power generation method. Based on the Seebeck effect, an electromotive force is generated when there is a temperature difference across the thermoelectric conversion device. With the development of thermoelectric materials, the application of thermoelectric conversion technology in the low-temperature range (300-500K) has been widely practiced. In waste heat removal heat exchangers, the water in the heat exchange tank absorbs a large amount of waste heat from the reactor core, causing its temperature to rise. If this heat can be used to generate electricity, it can not only improve the utilization rate of thermal energy but also provide emergency power after an emergency shutdown of the nuclear reactor. By applying thermoelectric conversion technology to waste heat removal heat exchangers, using the water in the heat exchange tank as a heat source and providing additional cooling water for the power generation devices as a cold source, a stable temperature difference can be maintained across the thermoelectric conversion device, thus continuously generating electricity and achieving the above objectives. Summary of the Invention
[0004] The purpose of this invention is to provide a waste heat discharge heat exchanger with thermoelectric conversion function. This heat exchanger has both nuclear reactor waste heat discharge and power generation functions, and can generate electricity using nuclear reactor waste heat, thereby improving the utilization rate of thermal energy in nuclear power plants.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A waste heat discharge heat exchanger with thermoelectric conversion function is characterized in that: the heat exchanger includes a left C-shaped heat exchange tube bundle 1, a right C-shaped heat exchange tube bundle 2, a left thermoelectric generator plate 3, a right thermoelectric generator plate 4, a lower waste heat discharge water tank 5, an upper waste heat discharge water tank 6, a lower cooling water tank 7 for the power generation device, and an upper cooling water tank 8 for the power generation device; the left C-shaped heat exchange tube bundle 1 and the right C-shaped heat exchange tube bundle 2 are located in the lower waste heat discharge water tank 5, and the inlet and outlet of the left C-shaped heat exchange tube bundle 1 and the right C-shaped heat exchange tube bundle 2 are located on the same side wall of the lower waste heat discharge water tank 5; the lower waste heat discharge water tank 5 and the upper waste heat discharge water tank 6 are connected to each other to form the waste heat discharge water tank; the left thermoelectric generator plate 3 and the right thermoelectric generator plate 4 are connected to each other to form the upper waste heat discharge water tank; the left thermoelectric generator plate 3 and the right thermoelectric generator plate 4 are connected to each other to form the upper waste heat discharge water tank. The differential temperature generator plate 4 is closely attached to both sides of the lower cooling water tank 7 of the power generation device. The left and right differential temperature generator plates 3 and 4 are both located within the lower waste heat discharge water tank 5 in the vertical direction, and are located between the left C-type heat exchange tube bundle 1 and the right C-type heat exchange tube bundle 2 in the horizontal direction. The lower cooling water tank 7 of the power generation device is connected to the upper cooling water tank 8 of the power generation device to form the power generation device cooling water tank. The left and right differential temperature generator plates 3 and 4 use the water in the waste heat discharge water tank that has absorbed the waste heat of the reactor core as the heat source and the water in the power generation device cooling water tank as the cold source, forming a stable temperature difference on both sides of the differential temperature generator plate, and generating electricity using the waste heat of the reactor core, thereby improving the utilization rate of thermal energy in the nuclear power plant.
[0007] Preferably, the water flow in both the waste heat discharge tank and the power generation device cooling water tank is natural circulation.
[0008] Preferably, the electrical energy generated by the left thermoelectric generator 3 and the right thermoelectric generator 4 can serve as an emergency power source after the nuclear reactor is shut down.
[0009] Preferably, the lower cooling water tank 7 of the power generation device is partially located in the lower waste heat discharge water tank 5 and partially located in the upper waste heat discharge water tank 6 in the vertical direction; the upper cooling water tank 8 of the power generation device is entirely located in the upper waste heat discharge water tank 6 in the vertical direction.
[0010] Preferably, the waste heat discharge water tank has a T-shaped structure; the power generation device cooling water tank has a T-shaped structure.
[0011] Preferably, the left C-type heat exchange tube bundle 1 and the right C-type heat exchange tube bundle 2 have the same geometry and are arranged symmetrically in the heat exchanger; the left thermoelectric generator plate 3 and the right thermoelectric generator plate 4 have the same geometry and are arranged symmetrically in the heat exchanger.
[0012] Preferably, the cold side surfaces of the left thermoelectric generator plate 3 and the right thermoelectric generator plate 4 both face the cooling water tank 7 of the power generation device.
[0013] Preferably, the cooling water tank 7 of the power generation device is provided with heat insulation material on its outer surface that is not in contact with the thermoelectric plate.
[0014] Compared with the prior art, the present invention has the following advantages:
[0015] 1. The heat exchanger of the present invention has a thermoelectric power generation plate installed next to the C-type heat exchange tube bundle. The water in the waste heat discharge tank that has absorbed the waste heat of the reactor core is used as the heat source, and the water in the cooling water tank of the power generation device is used as the cold source. A stable temperature difference is formed on both sides of the thermoelectric power generation plate, and the waste heat of the reactor core is used to generate electricity, thereby improving the utilization rate of thermal energy in the nuclear power plant.
[0016] 2. In the heat exchanger of the present invention, the water flow in both the waste heat discharge tank and the cooling water tank of the power generation device is natural circulation, which reduces the dependence of the thermoelectric conversion device on the external environment.
[0017] 3. The heat exchanger of the present invention generates electrical energy from the thermoelectric plate, which can be used as an emergency power source after the nuclear reactor is shut down, thereby improving the safety of the nuclear power plant. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of a waste heat discharge heat exchanger with thermoelectric conversion function according to the present invention.
[0019] Figure 2 (a) and (b) are schematic diagrams of the structure and principle of the waste heat discharge water tank of a waste heat discharge heat exchanger with thermoelectric conversion function according to the present invention.
[0020] Figure 3 (a) and (b) are schematic diagrams of the cooling water tank structure and principle of a waste heat discharge heat exchanger with thermoelectric conversion function according to the present invention. Detailed Implementation
[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments:
[0022] like Figure 1As shown, this invention discloses a waste heat discharge heat exchanger with thermoelectric conversion function, comprising a left C-shaped heat exchange tube bundle 1, a right C-shaped heat exchange tube bundle 2, a left thermoelectric generator plate 3, a right thermoelectric generator plate 4, a lower waste heat discharge water tank 5, an upper waste heat discharge water tank 6, a lower cooling water tank 7 for the power generation device, and an upper cooling water tank 8 for the power generation device. The left C-shaped heat exchange tube bundle 1 and the right C-shaped heat exchange tube bundle 2 are located inside the lower waste heat discharge water tank 5, and their inlets and outlets are located on the same side wall of the lower waste heat discharge water tank 5. The lower waste heat discharge water tank 5 and the upper waste heat discharge water tank 6 are connected to each other to form the waste heat discharge water tank. The left thermoelectric generator plate 3 and the right thermoelectric generator plate 4 are connected to each other to form the upper waste heat discharge water tank. Plate 4 is closely attached to both sides of the lower cooling water tank 7 of the power generation device. The left thermoelectric power generation plate 3 and the right thermoelectric power generation plate 4 are both located inside the waste heat discharge lower water tank 5 in the vertical direction, and are located between the left C-type heat exchange tube bundle 1 and the right C-type heat exchange tube bundle 2 in the horizontal direction. The lower cooling water tank 7 of the power generation device is connected to the upper cooling water tank 8 of the power generation device to jointly form the power generation device cooling water tank. The left thermoelectric power generation plate 3 and the right thermoelectric power generation plate 4 use the water in the waste heat discharge water tank that has absorbed the waste heat of the reactor core as the heat source and the water in the power generation device cooling water tank as the cold source, forming a stable temperature difference on both sides of the thermoelectric power generation plate, and using the waste heat of the reactor core to generate electricity, thereby improving the utilization rate of thermal energy in the nuclear power plant.
[0023] The waste heat discharge water tank has a T-shaped structure; the power generation device cooling water tank has a T-shaped structure; the T-shaped structure is beneficial to increasing the water volume above the heat exchanger and improving the cooling capacity of the heat exchanger.
[0024] The left C-type heat exchange tube bundle 1 and the right C-type heat exchange tube bundle 2 have the same geometry and are arranged symmetrically within the heat exchanger; the left thermoelectric generator plate 3 and the right thermoelectric generator plate 4 have the same geometry and are arranged symmetrically within the heat exchanger. This symmetrical arrangement helps reduce the unevenness of the horizontal temperature distribution of the cooling water in the waste heat discharge tank and the power generation device cooling water tank; it also helps maintain the consistency of the power generation output of the left thermoelectric generator plate 3 and the right thermoelectric generator plate 4.
[0025] The cold side surfaces of the left thermoelectric plate 3 and the right thermoelectric plate 4 both face the cooling water tank 7 of the power generation device. The cooling water of the power generation device plays a cooling role between the two thermoelectric plates and is not affected by external heat sources.
[0026] The cooling water tank 7 of the power generation device is provided with heat insulation material on the surface that does not contact the thermoelectric plate, so as to prevent the hot water in the water tank from directly heating the cold water in the cooling water tank of the thermoelectric device, which is conducive to maintaining the stability of the cold source of the thermoelectric plate.
[0027] The structure and working principle of the waste heat discharge water tank are as follows: Figure 2 As shown in (a) and (b), the waste heat discharge tank contains two sets of C-type heat exchange tube bundles. Coolant from the primary or secondary side carries the waste heat released from the reactor core and flows through the C-type heat exchange tube bundles, heating the water in the lower waste heat discharge tank 5. A temperature gradient exists between the upper and lower parts of the waste heat discharge tank, forming natural convection. Some of the heat is transferred to the water in the upper waste heat discharge tank 6 through natural convection, and some heat is transferred to the hot side of the thermoelectric generator.
[0028] The structure and working principle of the cooling water tank for power generation devices are as follows: Figure 3 As shown in (a) and (b), the outer surface of the lower cooling water tank 7 of the power generation device is divided into two regions along the axial direction. The lower region is in close contact with the thermoelectric plate, where the cooling water in the power generation device's cooling water tank continuously cools the cold side of the thermoelectric plate. The upper region is equipped with heat insulation material. Within this height range, the water temperature in the upper water tank 6, where waste heat is discharged, is higher. The heat insulation material effectively prevents the water in the waste heat discharge tank from heating the water in the power generation device's cooling water tank, maintaining the cooling capacity of the cold side of the thermoelectric plate. Inside the power generation device's cooling water tank, the lower cooling water absorbs the heat released from the cold side of the thermoelectric plate, causing its temperature to rise. A temperature gradient exists between the upper and lower cooling water tanks of the power generation device, forming natural convection, and heat is transferred to the water in the upper cooling water tank 8. A stable temperature difference exists on both sides of the thermoelectric plate, enabling power generation based on the principle of thermoelectric conversion.
[0029] The above description is a further detailed explanation of the present invention in conjunction with specific preferred embodiments. It should not be construed that the specific embodiments of the present invention are limited to these. For those skilled in the art, any changes and modifications to the above embodiments that are within the essential spirit and scope of the present invention should be considered as being within the scope of the claims of the present invention.
Claims
1. A waste heat discharge heat exchanger with thermoelectric conversion function, characterized in that: The heat exchanger includes a left C-type heat exchange tube bundle (1), a right C-type heat exchange tube bundle (2), a left thermoelectric generator plate (3), a right thermoelectric generator plate (4), a lower waste heat discharge water tank (5), an upper waste heat discharge water tank (6), a lower cooling water tank for the power generation device (7), and an upper cooling water tank for the power generation device (8). The left C-type heat exchange tube bundle (1) and the right C-type heat exchange tube bundle (2) are located inside the lower waste heat discharge water tank (5), and the inlet and outlet of the left C-type heat exchange tube bundle (1) and the right C-type heat exchange tube bundle (2) are located on the same side wall of the lower waste heat discharge water tank (5). The lower waste heat discharge water tank (5) and the upper waste heat discharge water tank (6) are connected to each other and together form the waste heat discharge water tank. The left thermoelectric generator plate (3) and the right thermoelectric generator plate (4) are closely attached to each other. On both sides of the lower cooling water tank (7) of the power generation device, the left thermoelectric generator plate (3) and the right thermoelectric generator plate (4) are all located in the lower waste heat discharge water tank (5) in the vertical direction, and the left thermoelectric generator plate (3) and the right thermoelectric generator plate (4) are located between the left C-type heat exchange tube bundle (1) and the right C-type heat exchange tube bundle (2) in the horizontal direction; the lower cooling water tank (7) of the power generation device and the upper cooling water tank (8) of the power generation device are connected to form the power generation device cooling water tank; the left thermoelectric generator plate (3) and the right thermoelectric generator plate (4) use the water in the waste heat discharge water tank that has absorbed the waste heat of the reactor core as the heat source and the water in the power generation device cooling water tank as the cold source, forming a stable temperature difference on both sides of the thermoelectric generator plate, and using the waste heat of the reactor core to generate electricity, thereby improving the utilization rate of thermal energy in the nuclear power plant; The water in both the waste heat discharge tank and the power generation device cooling water tank flows through natural circulation. The lower water tank (7) for cooling the power generation device is partially located in the lower water tank (5) for waste heat discharge in the vertical direction, and partially located in the upper water tank (6) for waste heat discharge; the upper water tank (8) for cooling the power generation device is entirely located in the upper water tank (6) for waste heat discharge in the vertical direction. The cold side surfaces of the left thermoelectric plate (3) and the right thermoelectric plate (4) both face the cooling water tank (7) of the power generation device. The cooling water tank (7) of the power generation device is provided with heat insulation material on its outer surface that is not in contact with the thermoelectric plate; The outer surface of the cooling water tank (7) of the power generation device is divided into two areas along the axial direction. The lower area is in close contact with the thermoelectric plate, and the upper area is equipped with heat insulation material.
2. A waste heat discharge heat exchanger with thermoelectric conversion function according to claim 1, characterized in that: The electrical energy generated by the left thermoelectric generator (3) and the right thermoelectric generator (4) can serve as an emergency power source after the nuclear reactor is shut down.
3. A waste heat discharge heat exchanger with thermoelectric conversion function according to claim 1, characterized in that: The waste heat discharge water tank has a T-shaped structure; the power generation device cooling water tank has a T-shaped structure.
4. A waste heat discharge heat exchanger with thermoelectric conversion function according to claim 1, characterized in that: The left C-type heat exchange tube bundle (1) and the right C-type heat exchange tube bundle (2) have the same geometric structure and are arranged symmetrically in the heat exchanger; the left thermoelectric generator plate (3) and the right thermoelectric generator plate (4) have the same geometric structure and are arranged symmetrically in the heat exchanger.