Converter valve cooling system in high altitude area

Abstract

The utility model discloses a converter valve cooling system in a high altitude area. The system comprises an inner cooling system and an outer cooling system. The inner cooling system, the outer cooling system and the converter valve are connected through a pipeline to form closed circulation; wherein the outer cooling system comprises at least one air cooler, each air cooler comprises a fan, a heat exchange tube bundle, a divergent spray pipe and a rectification grid which are connected in sequence, and the fan is arranged on one side, close to the inner cooling system, of the air cooler; the divergent spray pipe is arranged at an air inlet of the heat exchange pipe bundle; the rectifying grating is arranged at an air inlet of the divergent spray pipe; and the flow of air entering the divergent spray pipe can be regulated and controlled by adjusting the opening degree of the rectifying grating. According to the utility model, the safety and stability of operation in high-altitude areas can be guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to cooling system technical field especially relates to a high altitude region converter valve cooling system. BACKGROUND

[0002] This section aims to provide background or context for the embodiments of the utility model set forth in the claims. The description herein does not admit to be prior art because of being included in this section.

[0003] Converter valve is one of the core equipment of high voltage direct current transmission, and plays the role of AC-DC conversion in the converter station. Because its power is large, a large amount of heat will be generated in the running process, which needs to be taken away through the converter valve cooling system to ensure its safe and stable operation. The converter valve cooling system includes an internal cooling system and an external cooling system, and the valve internal cooling system adopts a certain proportion of ethylene glycol solution to prevent freezing. Considering the climate characteristics of water shortage, long low temperature and low maximum temperature in summer in high altitude area, the external cooling system adopts air cooler for cooling.

[0004] The air density is low and the wind sand dust is large in high altitude area, so the influence of high altitude environment on the valve cooling system design needs to be considered comprehensively. UTILITY MODEL CONTENT

[0005] The utility model embodiment provides a kind of high altitude region converter valve cooling system, can guarantee the security and stability of operation in high altitude area, and the system includes:

[0006] Internal cooling system and external cooling system;The internal cooling system, external cooling system and converter valve are connected by pipeline, form closed cycle;Wherein,

[0007] The external cooling system includes at least one air cooler, and the air cooler includes sequentially connected fan, heat exchange tube bundle, gradually expanding nozzle and rectifier grid, and the fan is located at the side of air cooler close to internal cooling system;

[0008] The gradually expanding nozzle is located at the air inlet of heat exchange tube bundle;

[0009] The rectifier grid is located at the air inlet of gradually expanding nozzle;

[0010] The rectifier grid can adjust opening degree to regulate and control the air flow size entering gradually expanding nozzle.

[0011] The cooling medium in the inner cooling system can cool the converter, and the outer cooling system can exchange heat with the cooling medium flowing through by air, so that the cooling medium flowing into the converter valve finally can effectively cool the converter valve, wherein, the converging-diverging nozzle is arranged at the air inlet of the heat exchange tube bundle, after the gas flows through the converging-diverging nozzle, the pressure increases, the air density increases, the flow rate decreases, the turbulence degree decreases, and the heat exchange between the air and the heat exchange tube bundle is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows, obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained according to these drawings without creative labor. In the drawings:

[0013] Figure 1 It is a structure schematic view of the converter valve cooling system in the high-altitude area in the embodiment of the present application,

[0014] Figure 2 It is a structure schematic view of the air cooler schematic view in the embodiment of the present application,

[0015] Figure 3 It is a converging-diverging nozzle top view schematic view in the embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the drawings. Herein, the schematic embodiments of the present application and the description thereof are used to explain the present application, but not as a limitation of the present application.

[0017] Figure 1 It is a structure schematic view of the converter valve cooling system in the high-altitude area in the embodiment of the present application, Figure 2 It is a structure schematic view of the air cooler schematic view in the embodiment of the present application, referring to Figure 1 and Figure 2 The converter valve cooling system in the high-altitude area comprises an inner cooling system 1 and an outer cooling system 2; the inner cooling system 1, the outer cooling system 2 and the converter valve 18 are connected through pipelines to form a closed circulation; wherein,

[0018] The outer cooling system 2 comprises at least one air cooler 12, the air cooler 12 comprises sequentially connected fan 13, heat exchange tube bundle 14, divergent nozzle 15 and rectification grid 16, and the fan 13 is arranged at the air cooler 12 close to the inner cooling system 1;

[0019] The divergent nozzle 15 is arranged at the air inlet of the heat exchange tube bundle 14;

[0020] The rectification grid 16 is arranged at the air inlet of the divergent nozzle 15;

[0021] The rectification grid 16 can adjust the air flow entering the divergent nozzle 15 by adjusting the opening degree.

[0022] The air density is low at high altitude, which leads to poor heat exchange effect. In order to achieve ideal heat exchange effect, the conventional air cooler at high altitude increases the rotating speed, which leads to larger gas pressure loss, enhanced turbulence degree, cannot fully exchange heat with the heat exchange tube bundle, and generates larger noise and vibration. Compared with the low altitude area, the air density has greater influence on the heat exchange effect than the flow rate. The divergent nozzle is arranged at the air inlet of the heat exchange tube bundle, the pressure is increased after the gas flows through the divergent nozzle, the air density is increased, the flow rate is reduced, the turbulence degree is reduced, and the heat exchange between the air and the heat exchange tube bundle is enhanced. The opening degree of the rectification grid can be adjusted, on the one hand, the power of the air cooler is adjusted together with the rotating speed of the fan, and on the other hand, the wind sand dust in the high altitude area is blocked, and the maintenance frequency of the air cooler is reduced.

[0023] In an embodiment, the air cooler 12 further comprises an air cooler support 17 for supporting the air cooler 12;

[0024] The height of the air inlet of the air cooler 12 from the ground is not less than the height of the divergent nozzle 15.

[0025] Specifically, the height of the air inlet of the air cooler from the ground is greater than or equal to the height of the divergent nozzle, so that the uniformity of the air entering the divergent nozzle is good.

[0026] Figure 3 The air cooler 12 adopts the air induction type structure in an embodiment.

[0027] The cross section shape of the divergent nozzle 15 is square.

[0028] The arrangement direction of the rectification grid 16 is consistent with the heat exchange tube bundle 14.

[0029] Specifically, the cross-sectional shape of the divergent nozzle is square, and the arrangement direction of the rectifier grid 16 is consistent with the heat exchange tube bundle 14, so that the air flow entering the divergent nozzle is more uniform, the resistance of the air flowing through the heat exchange tube bundle is smaller, and the heat exchange between the air and the heat exchange tube bundle is further enhanced.

[0030] In an embodiment, the outer cooling system 2 further comprises an outer cooling electric heater for adjusting the temperature of the air flowing into the air cooler 12.

[0031] Specifically, the outer cooling electric heater can adjust the water temperature according to the cooling medium temperature group classification, so as to achieve the purpose of preventing freezing.

[0032] In an embodiment, the motor of the fan 13 is provided with a protection circuit breaker for overload protection of the fan 13.

[0033] In an embodiment, at least one air cooler 12 is connected in parallel, and each air cooler 12 is provided with a butterfly valve for independent control.

[0034] In an embodiment, the inner cooling system 1 comprises a main circulating pump 3, two electric three-way valves 4, a water supplement pump 5, a raw water pump 6, an inner cooling electric heater 7, an expansion tank 8, a degassing tank 9, an ion tank 10, and a water supplement tank 11.

[0035] The first end of the parallel air cooler 12 is connected to the first end of the electric three-way valve 4 connected to each other, the second end of each electric three-way valve 4 is connected to the first end of the main circulating pump 3, the second end of the main circulating pump 3 is connected to the degassing tank 9, the degassing tank 9 is connected to the converter valve 18 through the first path after the inner cooling electric heater 7, the second path of the degassing tank 9 is connected to the expansion tank 8, the first end of the expansion tank 8 is filled with nitrogen, the second end of the expansion tank 8 is connected to the first end of the ion tank 10 through a precision filter, the second end of the ion tank 10 is connected to the water supplement tank 11, the water supplement tank 11 is connected to the water supplement pump 5; the second end of the parallel air cooler 12 is connected to the converter valve 18.

[0036] The cooling medium flows from the main circulating pump 3, passes through the electric three-way valve 4, exchanges heat with the air through the air cooler 12, and then flows into the converter valve 18.

[0037] Specifically, the electric three-way valve 4 is designed to adjust the cooling water temperature during low outdoor environment temperature and low load operation or shutdown of the converter valve 18. In addition, after the electric three-way valve is configured, the bypass pipe is opened when the outdoor environment temperature is low, the cooling medium flow through the outdoor air cooler is reduced, the heat dissipation of the outdoor cooling equipment is reduced, and the medium temperature of the converter valve is prevented from being too low. The inner cooling electric heater can adjust the water temperature according to the cooling medium temperature group classification, so as to achieve the purpose of preventing freezing.

[0038] In an embodiment, the main circulating pump 3 adopts a motor whose power exceeds a threshold power value.

[0039] Specifically, in a high-altitude environment, the air is thin, the heat dissipation performance of the motor is reduced, the temperature rise will be increased, and thus the rated power output of the motor is directly affected. Therefore, the main circulating pump 3 adopts a motor whose power exceeds a threshold power value, for example, a high-power motor with a power of 110 kW is selected for the main circulating pump.

[0040] In an embodiment, the cooling medium of the inner cooling system 1 is a glycol solution with a preset concentration, and the outdoor pipeline of the outer cooling system 2 is provided with an electric heating tape and a heat preservation tape.

[0041] Specifically, the outdoor pipeline includes a pipeline from the valve cooling equipment room to the air cooler. The preset concentration can be 48%, and the above design is a freeze-proof measure taken considering the extreme minimum temperature in high-altitude areas. The electric heating tape and the heat preservation tape can prevent the outdoor pipeline from freezing.

[0042] In an embodiment, the inner cooling system 1 and the outer cooling system 2 contain low-voltage components, electrical control current-carrying conductor components, water cooling system pressure instruments, flow transmitters, temperature transmitters, and liquid level transmitters.

[0043] The selection of the low-voltage components and all the electrical control current-carrying conductor components meets the requirements of component derating use;

[0044] The selection of the water cooling system pressure instruments meets the requirements of the influence of atmospheric pressure changes;

[0045] The flow transmitter adopts a vortex flowmeter, the temperature transmitter selects an instrument with a linear relationship between the resistance value of the metal PT100 and the temperature, and the liquid level transmitter selects a capacitive liquid level meter.

[0046] Specifically, the low-voltage components include circuit breakers, contactors, and relays, etc., which have air-insulated parts in the internal electric circuit, and the withstand voltage capacity is affected by the altitude. Therefore, the low-voltage components such as circuit breakers, contactors, and relays are designed with reduced capacity. The electrical control current-carrying conductor components mainly include conductive copper bars, wires and cables, and electrical component main contacts, etc. The current-carrying conductor is used in high-altitude areas. Due to the thin air in high-altitude environments, the convection is poor, and the heat dissipation condition is deteriorated. Under the same allowable temperature rise condition, the current-carrying capacity will be reduced. When the altitude exceeds 1000 m, the conductor temperature rise increases by 0.5°C for every 100 m. Therefore, all the electrical control current-carrying conductor components are designed with reduced capacity.

[0047] The selection of the water-cooled system pressure instrument meets the requirement of the influence of the change of atmospheric pressure, so as to ensure the normal operation of the instrument. Therefore, the instrument operated in the high altitude environment is affected by the change of atmospheric pressure, when the altitude is increased by 1000 meters, the atmospheric pressure will be decreased by 10 kPa. According to the characteristics of the high altitude environment, the water-cooled system pressure instrument can be selected as the high-precision instrument, so as to avoid the increase of the detection error and ensure the normal operation of the instrument.

[0048] The flow transmitter selects the vortex flowmeter, the instrument calculates the amount of flow by means of the number of Karman vortex formed by the baffle; the temperature transmitter selects the instrument with the linear relationship between the resistance value of the metal PT100 and the temperature; the liquid level transmitter selects the capacitive liquid level meter, the instrument is composed of the probe and the grounding pipe to form two plates of the capacitor, the liquid level height is measured by measuring the capacitance value, and the change of the temperature and pressure of the environment in the measurement process of the selected instrument does not affect the measurement value of the instrument.

[0049] In addition, with the increase of the altitude, the solar radiation is increased accordingly, and the thermal radiation has a heating effect on the object. For the outdoor electrical products, the increase of the solar thermal radiation causes a large surface additional temperature rise, reduces the material properties of the organic insulating material, deforms the material, and causes the mechanical thermal stress and other influences. The increase rate of the ultraviolet radiation irradiance with the increase of the altitude is much larger than that of the total solar radiation irradiance, and when the altitude is 3000m, it is more than 1.6 times of the corresponding value at low altitude. The ultraviolet causes the accelerated aging of the organic insulating material, easily ionizes the air, and causes the reduction of the outdoor insulation strength and the corona starting voltage, and the special selection and design of the key components of the outdoor equipment such as the sealing material.

[0050] In conclusion, the high-altitude region converter valve cooling system can guarantee the safety and stability of the valve cooling system in high-altitude region, and is important for guaranteeing the heat dissipation and reliable operation of the high-altitude region converter valve. The outer cooling part is provided with a gradually expanding nozzle at the air cooler inlet, so that the air pressure, density, flow rate and turbulence degree are increased, and the heat exchange of the air heat exchange tube bundle is enhanced; the gradually expanding nozzle is provided with a flow regulation grid at the inlet, so that the air flow is more uniform, and the resistance of the heat exchange tube bundle is smaller, and the heat exchange of the air and the heat exchange tube bundle is further enhanced; the opening of the flow regulation grid is adjusted, so that the power of the air cooler is adjusted, and the wind and dust are blocked, and the maintenance frequency of the air cooler is reduced. The inner cooling part is provided with a main circulating pump with increased motor power, so that the load capacity of the water pump in high-altitude region is improved; the low-voltage electrical elements and all electrical control current conductor elements of the valve cooling system are designed with reduced capacity, so that the reliability of the system in high-altitude region is improved; a protection circuit breaker is configured for each fan motor of the air cooler, so that the fault diagnosis is simplified, and the maintenance efficiency of the system is improved; high-precision pressure instruments are selected, and the change of atmospheric pressure is considered in the selection of the instruments except the pressure, so that the accuracy of the instruments of the system in high-altitude region is guaranteed; the air cooler frame structure and the wear allowance of the external connection are increased, and the key components of the outdoor equipment are specially selected and designed, so that the service life of the equipment in high-altitude region is improved; the cooling medium of the inner cooling system is 48% ethylene glycol solution, the temperature of the cooling medium is adjusted by an electric three-way valve and an electric heater, and the outdoor pipeline (from the valve cooling equipment room to the air cooler) is provided with an electric heating band and an insulation band, so that the valve cooling system can withstand the extremely low temperature environment in high-altitude region.

[0051] The above specific embodiments further illustrate the purpose, technical scheme and advantages of the utility model, and it should be understood that the above description is only a specific embodiment of the utility model, and is not used to limit the protection scope of the utility model, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A high altitude converter valve cooling system, characterized by, The application relates to a cooling system for a high-voltage direct-current converter, which comprises an inner cooling system (1) and an outer cooling system (2); the inner cooling system (1), the outer cooling system (2) and a converter valve (18) are connected through pipelines to form a closed circulation; wherein, the outer cooling system (2) comprises at least one air cooler (12), the air cooler (12) comprises a fan (13), a heat exchange pipe bundle (14), a converging nozzle (15) and a rectifying grid (16) which are sequentially connected, and the fan (13) is arranged on the air cooler (12) close to the inner cooling system (1); the converging nozzle (15) is arranged at the air inlet of the heat exchange pipe bundle (14); the rectifying grid (16) is arranged at the air inlet of the converging nozzle (15); the rectifying grid (16) can adjust the air flow entering the converging nozzle (15) by adjusting the opening degree. the air cooler (12) further comprises an air cooler support (17) for supporting the air cooler (12); 2. The high altitude inverter cooling system of claim 1, wherein, the height of the air inlet of the air cooler (12) from the ground is not less than the height of the converging nozzle (15). the air cooler (12) adopts an air induction structure; 3. The high altitude inverter valve cooling system of claim 1, wherein, the cross section shape of the converging nozzle (15) is square; the arrangement direction of the rectifying grid (16) is consistent with that of the heat exchange pipe bundle (14). the outer cooling system (2) further comprises an outer cooling electric heater which is used for adjusting the temperature of the air flowing into the air cooler (12).

4. The high altitude inverter cooling system of claim 1, wherein, the motor of the fan (13) is provided with a protection circuit breaker which is used for overload protection of the fan (13).

5. The high altitude inverter cooling system of claim 1, wherein, The at least one air cooler (12) is connected in parallel, and each air cooler (12) is provided with a butterfly valve for independent control.

6. The high altitude inverter cooling system of claim 1, wherein, the inner cooling system (1) comprises a main circulating pump (3), two electric three-way valves (4), a water supplementing pump (5), an original water pump (6), an inner cooling electric heater (7), an expansion tank (8), a degassing tank (9), an ion tank (10) and a water supplementing tank (11); 7. The high altitude inverter cooling system of claim 1, wherein, the first ends of the parallel air coolers (12) are respectively connected to the first ends of the electric three-way valves (4) which are connected to each other, the second ends of each electric three-way valve (4) are connected to the first end of the main circulating pump (3), the second end of the main circulating pump (3) is connected to the degassing tank (9), the degassing tank (9) is connected to the converter valve (18) through the first path after the inner cooling electric heater (7), the second path of the degassing tank (9) is connected to the expansion tank (8), the first end of the expansion tank (8) is filled with nitrogen, the second end of the expansion tank (8) is connected to the first end of the ion tank (10) through a precision filter, the second end of the ion tank (10) is connected to the water supplementing tank (11), the water supplementing tank (11) is connected to the water supplementing pump (5); and the second ends of the parallel air coolers (12) are connected to the converter valve (18). wherein the cooling medium flows from the main circulating pump (3), passes through the electric three-way valve (4), exchanges heat with air through the air cooler (12), and then flows into the converter valve (18). the main circulating pump (3) adopts a motor with a power exceeding a threshold power value.

8. The high altitude inverter cooling system of claim 7, wherein, ​ 9. The high altitude inverter cooling system of claim 1, wherein, The cooling medium of the inner cooling system (1) is a glycol solution with a preset concentration, and the outdoor pipeline of the outer cooling system (2) is provided with an electric heating tape and an insulation tape.

10. The high altitude inverter cooling system of claim 1, wherein, The inner cooling system (1) and the outer cooling system (2) comprise low-voltage components, electrically controlled current-carrying conductor components, water cooling system pressure instruments, flow transmitters, temperature transmitters and liquid level transmitters. The selection of the low-voltage components and all the electrically controlled current-carrying conductor components meets the requirements of device capacity reduction use; The selection of the water cooling system pressure instruments meets the requirements of the influence of atmospheric pressure changes; The flow transmitter adopts a vortex flowmeter, the temperature transmitter selects an instrument with a linear relationship between the resistance value of a metal PT100 and temperature, and the liquid level transmitter selects a capacitive liquid level meter.

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