A fan for heating the reactor main container

Abstract

The present invention relates to a fan for heating the reactor main container, including a fan body, a speed increasing box, a coupling, a three-phase asynchronous motor, a thin oil station, a sealing device, and a variable frequency speed control system. By designing the inlet installation angle and the outlet installation angle of the impeller blade, at least 75% of the mechanical energy is converted into heat energy, and a heating power of not less than 650kW can be provided. By designing the volute cooling water circuit and the heat insulation baffle, the working temperature at the shaft seal is reduced to ensure the reliability of the sealing device. The present invention solves the problem of stable heating of the reactor main container and the internal components at the same time, and can be promoted and applied to the preheating of large container-type equipment with complex internal structures.

Description

Technical Field

[0001] The invention belongs to the design of a fan, and in particular relates to a fan used for heating a reactor main container. Background Art

[0002] The main container of a sodium-cooled fast reactor needs to be preheated before filling with sodium to reduce the thermal shock caused to the inner wall of the main container and the components inside the reactor when the liquid metal sodium enters the main container. The commonly used heating technology currently used is to heat the object by contact heat conduction after converting electrical energy into thermal energy. This heating method is not suitable for large container-type equipment with inaccessible internal parts and complex internal structures, and cannot meet the requirements of uniform heating of internal and external structures, such as the main container of the reactor. The main container of the reactor includes the reactor body, the components inside the reactor and the protective container. The main container itself is large in size and has a complex internal structure. Traditional heating methods may cause uneven local heating and thermal stress exceeding the limit. The heating fan can blow hot air directly into the container to achieve the heating of the equipment, but the existing heating fan has insufficient efficiency in converting mechanical energy into thermal energy, and the fan outlet temperature is difficult to meet the requirements of heating the main container of the reactor. Summary of the invention

[0003] The purpose of the present invention is to provide a blower for heating the reactor main container, which can satisfy both the main container gas heating and ventilation circulation and the heating and heat preservation functions, thereby solving the problem of simultaneous heating of the reactor main container and the components inside the reactor.

[0004] The technical solution of the present invention is as follows: A fan for heating a reactor main container, comprising a fan body, a speed increaser, a coupling, a three-phase asynchronous motor, a thin oil station, a sealing device, and a variable frequency speed control system, wherein the fan body comprises a volute and an impeller, the impeller is made by integral forging and then CNC machining, the impeller blade inlet installation angle is 12.5°-13.5°, and the outlet installation angle is 60°-62°.

[0005] Furthermore, in the fan for heating the reactor main container as described above, a cooling device for reducing the bearing temperature of the speed increaser is provided between the volute of the fan body and the speed increaser; the cooling device is a two-inlet and two-outlet water cooling device, a cooling channel is formed between a water inlet and a corresponding water outlet, and a plurality of partitions are provided in the cooling channel to allow the cooling water to flow in a circuitous manner in the channel.

[0006] Furthermore, in the blower for heating the reactor main container as described above, thermal insulation coating is coated on the inner and outer surfaces of the volute of the blower body, and a thermal insulation plate is provided at the shaft hole of the back plate of the volute.

[0007] Furthermore, in the blower for heating the reactor main vessel as described above, the impeller and nut of the blower body are made of high-strength TC11 forgings.

[0008] Furthermore, in the blower for heating the reactor main container as described above, the volute and the volute ring of the blower body are cast from medium silicon-molybdenum heat-resistant ductile iron QTRS i4Mo which is resistant to high temperature creep and thermal fatigue.

[0009] Furthermore, in the above-mentioned blower for heating the reactor main container, a heat insulating cover is provided on the outside of the blower body.

[0010] Furthermore, in the above-mentioned fan for heating the reactor main container, the three-phase asynchronous motor is connected to the speed increaser via a diaphragm coupling, and the fan body is connected to the speed increaser via semi-flange stop bolts.

[0011] The beneficial effects of the present invention are as follows: The present invention solves the problem of uniform heating of the main container and internal components of a large-scale pool-type sodium-cooled fast reactor. The new fan provides a heating power of no less than 650kW for heating the main container of the reactor, and at the same time serves as a power source for gas circulation and a heat source for heating. The maximum outlet temperature of the fan can reach 435°C, and the strength and thermal deformation of the volute and impeller meet the design requirements, and the leakage is no more than 0.6Nm 3 / h, providing conditions for sodium feeding into the pool-type sodium-cooled fast reactor. At the same time, the fan body is designed with a cooling water circuit and a heat-insulating baffle to reduce the working temperature of the shaft seal. It has been verified by experiments that when the external shaft temperature is 496°C, the shaft temperature at the shaft seal is up to 182°C, which meets the heat-resistant temperature of the sealing ring and ensures the reliability of the sealing device. The present invention can be widely applied to the preheating of large container-type equipment with complex internal structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the overall structure of the fan used for heating the reactor main container of the present invention;

[0013] Figure 2 It is a structural schematic diagram of the fan impeller of the present invention;

[0014] Figure 3a It is a schematic diagram of the volute structure of the fan of the present invention;

[0015] Figure 3b A schematic diagram of the cooling channel of the cooling device on one side of the volute;

[0016] Figure 4 Schematic diagram of the volute and ring structure of the fan body. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0018] The blower for heating the reactor main container provided by the present invention is to connect the blower inlet and outlet to the reactor main container to form a closed loop, and the blower does work on the medium gas to increase the kinetic energy and internal energy of the medium gas, wherein the kinetic energy keeps the gas circulating in the heating system pipeline, and the internal energy increases the temperature of the circulating medium gas. When the high-temperature gas flows in the main container and the protective container interlayer, the main container and its components are continuously heated, so as to achieve the purpose of uniformly increasing the temperature of the main container and its components.

[0019] The fan structure type is a single-stage high-speed centrifugal blower, such as Figure 1 As shown in the figure, it is mainly composed of a fan body 1, a speed increaser 2, a diaphragm coupling, a three-phase asynchronous motor 3, a thin oil station 4, a dry gas composite sealing device 5, a variable frequency speed control system, etc. The fan is a combined structure as a whole. The oil station tank is integrated with the fan body and the motor base. The base is the oil station tank. All components are installed on a common base, and the oil circuit system and the sealed gas circuit system are placed on both sides of the base. The motor and the speed increaser are connected by a diaphragm coupling, and the fan body and the speed increaser are connected by a semi-flange stop bolt. The impeller is directly suspended at the output end of the high-speed shaft. A dry gas sealing device is installed between the fan shaft hole and the high-speed shaft. The speed increaser is divided into upper and lower halves for easy installation and maintenance.

[0020] The fan volute is connected by a semi-flange stop. At the same time, free supports are provided on both sides of the horizontal center line of the volute to prevent the uneven gap between the casing and the impeller caused by thermal expansion and contraction stress, resulting in scratches and damage. A stainless steel expansion joint is installed at the inlet and outlet of the fan to prevent external components from exerting additional force on the fan.

[0021] The volute 6 and the ring 7 are made of medium silicon-molybdenum heat-resistant ductile iron QTRSi4Mo, which is resistant to high temperature creep and thermal fatigue. Figure 4 In order to reduce the high temperature of the fan medium being transferred to the output side bearing and sealing device of the speed increaser, the volute design is improved, and a two-inlet and two-outlet water cooling device is provided between the volute and the speed increaser, as shown in the figure. Figure 3a As shown, the bearing temperature of the speed increaser is kept below 110℃ when the fan outlet is 420℃. Heat insulation coating is applied on the inner and outer surfaces of the volute, and heat insulation board is added at the shaft hole of the back plate to prevent heat loss during heating.

[0022] The two-inlet and two-outlet water cooling device is in an annular shape as a whole, and includes two semi-circular cooling channels, each of which is provided with a water inlet A and a water outlet B. Figure 3a The cooling channel is shown in the following figure. Figure 3b As shown, each cooling channel is provided with a plurality of partitions to allow the cooling water to flow in a circuitous manner in the channel.

[0023] The impeller and nut of the fan are made of high-strength TC11 forgings to reduce the centrifugal force of the impeller and ensure that the impeller has high mechanical strength at a high temperature of 500°C. The impeller blank is forged as a whole and directly processed by a CNC machining center without internal welding defects. The aerodynamic design of the fan and the flow field analysis of the whole machine are carried out according to the ventilation and heating requirements. The inlet installation angle and outlet installation angle of the impeller are determined by repeated iterative calculations, so that the inlet and outlet pressure and temperature differences of the fan meet the design requirements. The present invention adopts a brand-new blade design, such as Figure 2 As shown, the blade inlet installation angle β 1A Designed to be 12.5°-13.5°, the preferred value is 13.4°, the outlet installation angle β 2A Designed to be 60°-62°, with an optimal value of 60.68°, at least 75% of mechanical energy can be converted into thermal energy to achieve the heating function. This fan can provide a heating power of no less than 650kW. The blade inlet installation angle refers to the angle between the tangent of the blade airfoil bone line at the inlet and the circumferential direction, and the outlet installation angle refers to the angle between the tangent of the bone line at the water outlet and the circumferential direction.

[0024] The present invention can set a heat insulation cover on the outside of the fan body to ensure that the outer surface temperature of the insulation layer is not higher than 50°C. In addition, all lubricating oil circuits, gas pipelines and flanges are made of stainless steel. The system is equipped with vibration measurement, temperature measurement, displacement measurement and other devices in different parts. The whole machine bearing vibration, temperature, displacement, anti-surge control, startup interlock protection, fault alarm, lubrication system oil pressure, oil temperature and other parameters are all monitored in real time, and equipped with an on-site integrated control cabinet, with local and remote communication functions.

[0025] The maximum outlet temperature of the fan of the present invention can reach 435°C, the strength and thermal deformation of the volute and impeller meet the design requirements, and the leakage is no more than 0.6Nm 3 / h. The fan body is designed with cooling water circuit and heat insulation baffle to reduce the working temperature of the shaft seal. Tests have verified that when the external shaft temperature is 496℃, the shaft temperature at the shaft seal is up to 182℃, which meets the heat resistance temperature of the seal ring and ensures the reliability of the sealing device.

[0026] Through the verification test of the test prototype, all the data of the present invention can meet the design requirements. The maximum temperature of the fan outlet is 435°C, the external leakage rate of the medium is 0 when the fan is running, and it can run stably for 48 hours at an outlet temperature of 420°C. Various indicators such as oil temperature and bearing temperature are normal.

[0027] 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 their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A fan for heating the reactor main container, comprising a fan body, a speed increasing box, a diaphragm coupling, a three-phase asynchronous motor, a thin oil station, a sealing device, and a variable frequency speed control system, characterized in that: The inlet and outlet of the fan are connected to the main container of the reactor to form a closed loop. The fan works on the medium gas to increase the kinetic energy and internal energy of the medium gas, wherein the kinetic energy keeps the gas circulating in the heating system pipeline, and the internal energy increases the temperature of the circulating medium gas; the fan body includes a volute and an impeller, the impeller is made by integral forging and then CNC machining, the impeller blade inlet installation angle is 12.5°-13.5°, and the outlet installation angle is 60°-62°, so that at least 75% of the mechanical energy is converted into thermal energy to achieve the heating function; a cooling device for reducing the bearing temperature of the speed increaser is provided between the volute of the fan body and the speed increaser, the cooling device is a two-inlet and two-outlet water cooling device, a cooling channel is formed between a water inlet and a corresponding water outlet, a plurality of partitions are provided in the cooling channel, so that the cooling water flows circuitously in the channel.

2. The fan for heating the reactor main container according to claim 1, characterized in that: The impeller blades have an inlet installation angle of 13.4° and an outlet installation angle of 60.68°.

3. The fan for heating the reactor main container according to claim 1, characterized in that: Heat-insulating paint is coated on the inner and outer surfaces of the volute of the fan body, and a heat-insulating plate is arranged at the shaft hole of the back plate of the volute.

4. The fan for heating the reactor main container according to claim 1, characterized in that: The impeller and nut of the fan body are made of high-strength TC11 forgings.

5. The blower for heating the reactor main container according to claim 1, characterized in that: The volute and the volute ring of the fan body are cast from medium silicon-molybdenum heat-resistant ductile iron QTRSi4Mo which is resistant to high temperature creep and thermal fatigue.

6. The blower for heating the reactor main container according to claim 1, characterized in that: A heat insulation cover is arranged on the outer side of the fan body.

7. The blower for heating the reactor main container according to claim 1, characterized in that: The three-phase asynchronous motor is connected to the speed increasing box through a diaphragm coupling, and the fan body and the speed increasing box are connected with semi-flange stop bolts.

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