Full water cooling system of high-voltage frequency converter

Abstract

The invention belongs to the technical field of water cooling systems of high-voltage frequency converters, and particularly relates to a full water cooling system of a high-voltage frequency converter. A flow regulating valve A is installed on an outlet pipeline of the power unit, a flow regulating valve B is installed on an outlet pipeline of the water-cooled transformer, an outlet loop of the flow regulating valve A is provided with a pressure transmitter A, a flow transmitter A and a temperature element A, and an outlet loop of the flow regulating valve B is provided with a pressure transmitter B, a flow transmitter B and a temperature element B; an inlet pipeline of the expansion water tank is connected with water catchment main pipes of the flow adjusting valve A and the flow adjusting valve B, a water tank heater is installed in the expansion water tank, the upper portion of the expansion water tank is connected with the first nitrogen expansion tank and the second nitrogen expansion tank, and an outlet pipeline of the expansion water tank is connected with inlet water catchment pipelines of the first circulating pump and the second circulating pump. The reliability and the stability of water-cooling operation of the high-voltage frequency converter are fundamentally and integrally improved.

Description

Technical Field

[0001] The invention belongs to the technical field of water cooling systems for high-voltage frequency converters, and in particular relates to a full water cooling system for high-voltage frequency converters. Background Art

[0002] The water cooling system technology of high-voltage inverter is an efficient heat dissipation solution designed to ensure the stable operation of the inverter under high load and high temperature environment. This technology uses the excellent thermal conductivity of cooling water to take away the heat generated by the inverter through circulation, thereby achieving effective cooling. In the water cooling system of high-voltage inverter, cooling water circulates in a closed pipe, passes through the heat dissipation part of the inverter, absorbs and takes away heat. The system adjusts the flow, temperature, conductivity, pH and dissolved oxygen of the cooling water through the intelligent control module to ensure the best cooling effect of the live equipment. At the same time, in order to ensure the purity of the water quality and prevent pipe blockage, the system will regularly perform water treatment and maintenance.

[0003] High-voltage inverters are key components for the stable operation of nuclear power plants. Overheating of the inverter or tripping due to coolant leakage will cause power failure of important loads, resulting in serious consequences such as reactor shutdown or unit shutdown. Alternatively, the coolant parameter indicators are unqualified and the loop design redundancy is insufficient to support the long-term safe and stable operation of the equipment. The most direct function of the water cooling system of traditional high-voltage inverters is to export the heat from the operation of high-power devices. The control of coolant indicators and other aspects is insufficient, and it cannot support the long-term safe and stable operation of the equipment.

[0004] In order to ensure the long-term safe and stable operation of high-voltage inverters, it is necessary to develop a full water cooling system technology for the overall control of the operating status of new high-voltage inverters, including: heat removal, coolant conductivity, pH, dissolved oxygen, full water cooling redundant circuits, etc., which is of great significance to improving the operating stability and reliability of high-voltage inverters. Summary of the invention

[0005] The purpose of the present invention is to provide a high-voltage inverter full water cooling system to solve the problems of insufficient heat dissipation, coolant index control, circuit redundancy, etc. existing in traditional high-voltage inverters.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A high-voltage frequency converter full water cooling system, a flow regulating valve A is installed on the outlet pipeline of the power unit, a flow regulating valve B is installed on the outlet pipeline of the water-cooled transformer, a pressure transmitter A, a flow transmitter A and a temperature element A are configured on the outlet circuit of the flow regulating valve A, a pressure transmitter B, a flow transmitter B and a temperature element B are configured on the outlet circuit of the flow regulating valve B, an inlet pipeline of an expansion water tank is connected to the water collecting mother pipes of the flow regulating valve A and the flow regulating valve B, a water tank heater is installed inside the expansion water tank, the upper part of the expansion water tank is respectively connected to the No. 1 nitrogen expansion tank and the No. 2 nitrogen expansion tank, the outlet pipeline of the expansion water tank is connected to the inlet water collecting pipelines of the No. 1 circulation pump and the No. 2 circulation pump, the outlet water collecting mother pipes of the No. 1 circulation pump and the No. 2 circulation pump are respectively connected to the inlet of the three-way valve A and the three-way valve B, the outlet pipeline of one end of the three-way valve A is connected to the inlet of the plate heat exchanger A, and the outlet pipeline of the other end is connected to the outlet of the plate heat exchanger A. The outlet pipeline of one end of the three-way valve B is connected to the inlet of the plate heat exchanger B, and the outlet pipeline of the other end is connected to the outlet of the plate heat exchanger B. The outlet pipelines of the water collection pipelines of the No. 1 deionized water tank and the No. 2 deionized water tank are connected to the inlet water collection pipelines of the No. 1 circulation pump and the No. 2 circulation pump. The inlet pipelines of the water collection pipelines of the No. 1 deionized water tank and the No. 2 deionized water tank are connected to a water supply pump and connected to the three-way valve A, the three-way valve B, the plate heat exchanger A and the plate heat exchanger B. The outlet water collection pipeline of heat exchanger B is connected, and the outlet water collection pipelines of three-way valve A, three-way valve B, plate heat exchanger A and plate heat exchanger B are concentrated and converged with the inlet water collection pipelines of deionized water tank No. 1 and deionized water tank No. 2. The confluence pipeline is equipped with pH transmitter, dissolved oxygen transmitter, conductivity meter, temperature element C, flow transmitter C and pressure transmitter C, and the outlet of the confluence pipeline is respectively connected to the inlet pipeline of the power unit and the inlet pipeline of the water-cooled transformer.

[0008] The cooling water circulates inside the pipeline through the operation of the No. 1 circulation pump or the No. 2 circulation pump, passes through the water-cooling pipeline inside the power unit and the water-cooled transformer, and transfers the working heat of the power unit and the water-cooled transformer to the cooling water.

[0009] The cooling water then flows through the power unit outlet pipeline and the water-cooled transformer outlet pipeline and flows into the inlet pipeline of the No. 1 circulating pump or the No. 2 circulating pump through the main pipeline of the expansion water tank.

[0010] The inlet branch pipeline of the expansion water tank is connected with the alkali adding pump and the alkali adding water tank, and the outlet branch pipeline of the expansion water tank is connected with the outlet pipelines of the No. 1 deionized water tank and the No. 2 deionized water tank.

[0011] Then the cooling water flows through the outlet pipeline of circulating pump No. 1 or circulating pump No. 2 to the inlet pipeline of three-way valve A or three-way valve B respectively, flows out through the outlet pipeline at one end of three-way valve A or three-way valve B to the corresponding plate heat exchanger A or plate heat exchanger B, and directly flows into the outlet manifold of plate heat exchanger A or plate heat exchanger B through the outlet pipeline at the other end.

[0012] The branch pipelines and water supply pumps of the water collecting main pipe are connected to the inlet pipelines of the No. 1 deionized water tank and the No. 2 deionized water tank, and the cooling water that has undergone heat exchange flows to the internal water cooling pipelines of the power unit and the water-cooled transformer respectively.

[0013] The outlet pipeline of the power unit is installed with a flow regulating valve A, a pressure transmitter A, a flow transmitter A and a temperature element A to adjust the flow of cooling water of the power unit and monitor the pipeline pressure, actual flow and cooling water temperature in real time. The outlet pipeline of the water-cooled transformer is installed with a flow regulating valve B, a pressure transmitter B, a flow transmitter B and a temperature element B to adjust the flow of cooling water of the water-cooled transformer and monitor the pipeline pressure, actual flow and cooling water temperature in real time.

[0014] An alkali adding pump and an alkali adding water tank are connected in series to the confluence pipeline of the power unit outlet pipeline and the water-cooled transformer outlet pipeline and the inlet pipeline of the expansion water tank. The pH value and dissolved oxygen of the cooling water are adjusted online according to the pH transmitter and dissolved oxygen transmitter installed on the main pipe.

[0015] The expansion water tank is equipped with No. 1 nitrogen expansion tank, No. 2 nitrogen expansion tank and water tank heater, which are used to adjust the overall pressure of the full water cooling system according to the pressure transmitter C installed on the main pipe; the three-way valve A or three-way valve B is adjusted through the temperature element A installed on the outlet pipeline of the power unit, the temperature element B on the outlet pipeline of the water-cooled transformer and the temperature element C on the main pipe to control the cooling water temperature within the required range; the flow of the entire water system is monitored in real time through the flow transmitter C installed on the main pipe.

[0016] Deionized water tank No. 1 and deionized water tank No. 2 are arranged between the outlet pipeline of the expansion water tank and the water main pipe of plate heat exchanger A and plate heat exchanger B. The ion concentration and conductivity in the cooling water are controlled according to the conductivity meter installed on the main pipe. A water replenishment pump is arranged on the inlet pipeline of deionized water tank No. 1 and deionized water tank No. 2 to replenish water when the system water volume is insufficient.

[0017] The beneficial effects achieved by the present invention are:

[0018] Compared with the traditional high-voltage inverter, the present invention integrates heat extraction with the conductivity, pH, dissolved oxygen content adjustment of the coolant and a full water-cooling redundant circuit, fundamentally improving the reliability and stability of the water-cooling operation of the high-voltage inverter as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural diagram of a high-voltage inverter full water cooling system. DETAILED DESCRIPTION

[0020] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown: The water-cooled transformer and power unit of the high-voltage inverter are important users of heat removal, and its water cooling system includes: flow control valve A, flow control valve B, alkali water tank, alkali pump, expansion water tank, water tank heater, No. 1 nitrogen expansion tank, No. 2 nitrogen expansion tank, No. 1 circulation pump, No. 2 circulation pump, three-way valve A, three-way valve B, plate heat exchanger A, plate heat exchanger B, No. 1 deionized water tank, No. 2 deionized water tank and make-up water pump. A flow regulating valve A is installed on the outlet pipeline of the power unit, a flow regulating valve B is installed on the outlet pipeline of the water-cooled transformer, the outlet circuit of the flow regulating valve A is equipped with a pressure transmitter A, a flow transmitter A and a temperature element A, the outlet circuit of the flow regulating valve B is equipped with a pressure transmitter B, a flow transmitter B and a temperature element B, the inlet pipeline of the expansion water tank is connected to the water collection pipes of the flow regulating valve A and the flow regulating valve B, a water tank heater is installed inside the expansion water tank, the upper part of the expansion water tank is connected to the No. 1 nitrogen expansion tank and the No. 2 nitrogen expansion tank respectively, the outlet pipeline of the expansion water tank is connected to the inlet water collection pipes of the No. 1 circulation pump and the No. 2 circulation pump, the outlet water collection pipes of the No. 1 circulation pump and the No. 2 circulation pump are connected to the inlet of the three-way valve A and the three-way valve B respectively, one end of the outlet pipeline of the three-way valve A is connected to the inlet of the plate heat exchanger A, and the other end of the outlet pipeline is connected to the outlet of the plate heat exchanger A, the three-way valve B One end of the outlet pipeline is connected to the inlet of plate heat exchanger B, and the other end of the outlet pipeline is connected to the outlet of plate heat exchanger B. The outlet pipelines of the water confluence pipelines of No. 1 deionized water tank and No. 2 deionized water tank are connected to the inlet confluence pipelines of No. 1 circulation pump and No. 2 circulation pump. The inlet pipelines of the water confluence pipelines of No. 1 deionized water tank and No. 2 deionized water tank are connected to a make-up pump and connected to the outlet confluence pipelines of three-way valve A, three-way valve B, plate heat exchanger A and plate heat exchanger B. The outlet confluence pipelines of three-way valve A, three-way valve B, plate heat exchanger A and plate heat exchanger B are centrally confluent with the inlet confluence pipelines of No. 1 deionized water tank and No. 2 deionized water tank. A pH transmitter, a dissolved oxygen transmitter, a conductivity meter, a temperature element C, a flow transmitter C and a pressure transmitter C are arranged on the confluence pipeline. The outlets of the confluence pipelines are respectively connected to the inlet pipelines of the power unit and the inlet pipelines of the water-cooled transformer.

[0022] The full water cooling system of this high-voltage inverter mainly uses cooling water as the medium for heat transfer. The cooling water inside the full water cooling system circulates in the pipeline through the operation of No. 1 circulating pump or No. 2 circulating pump, passes through the water cooling pipeline inside the power unit and the water-cooled transformer, and transfers the working heat of the power unit and the water-cooled transformer to the cooling water. Then the cooling water is concentrated and converged through the outlet pipeline of the power unit and the outlet pipeline of the water-cooled transformer and flows into the inlet pipeline of No. 1 circulating pump or No. 2 circulating pump through the main pipeline of the expansion water tank. The inlet branch pipeline of the expansion water tank is connected to the alkali pump and the alkali water tank, and the outlet branch pipeline of the expansion water tank is connected to the outlet pipeline of No. 1 deionized water tank and No. 2 deionized water tank. Then the cooling water is discharged through the No. 1 circulating pump or The outlet pipeline of No. 2 circulation pump flows to the inlet pipeline of three-way valve A or three-way valve B respectively, flows out to the corresponding plate heat exchanger A or plate heat exchanger B through one end outlet pipeline of three-way valve A or three-way valve B, and directly flows into the outlet water collection pipe of plate heat exchanger A or plate heat exchanger B through the other end outlet pipeline. The branch pipeline and water supply pump of the water collection pipe are connected with the inlet pipeline of No. 1 deionized water tank and No. 2 deionized water tank, and the cooling water that has undergone heat exchange flows to the power unit and the internal water cooling pipeline of the water-cooled transformer respectively; the outlet pipeline of the power unit is installed with a flow regulating valve A, a pressure transmitter A, a flow transmitter A and a temperature element A, which are used to adjust the flow of cooling water of the power unit and to monitor the pipeline pressure, actual flow and cooling water. The cooling water temperature is monitored in real time. The outlet pipeline of the water-cooled transformer is equipped with a flow regulating valve B, a pressure transmitter B, a flow transmitter B and a temperature element B to adjust the flow of cooling water of the water-cooled transformer and monitor the pipeline pressure, actual flow and cooling water temperature in real time. An alkali pump and an alkali water tank are connected in series in the confluence pipeline of the power unit outlet pipeline and the water-cooled transformer outlet pipeline and the inlet pipeline of the expansion water tank. The pH value and dissolved oxygen of the cooling water are adjusted online according to the pH transmitter and dissolved oxygen transmitter installed on the mother pipe. The expansion water tank is equipped with a No. 1 nitrogen expansion tank, a No. 2 nitrogen expansion tank and a water tank heater to adjust the full water cooling system according to the pressure transmitter C installed on the mother pipe. Overall pressure; the three-way valve A or three-way valve B is adjusted by the temperature element A installed on the outlet pipeline of the power unit, the temperature element B on the outlet pipeline of the water-cooled transformer and the temperature element C on the main pipe to control the cooling water temperature within the required range; the flow of the entire water system is monitored in real time by the flow transmitter C installed on the main pipe; No. 1 deionized water tank and No. 2 deionized water tank are configured between the outlet pipeline of the expansion water tank and the water confluence main pipe of the plate heat exchanger A and the plate heat exchanger B, and the ion concentration and conductivity in the cooling water are controlled according to the conductivity meter installed on the main pipe; a water replenishment pump is configured on the inlet pipeline of the No. 1 deionized water tank and the No. 2 deionized water tank to replenish water when the system water volume is insufficient.

[0023] The circulating water pump, plate heat exchanger, deionized water tank, nitrogen expansion tank, three-way valve and other components are configured in a one-in-one configuration, which are mutually standby. When working normally, their flow is constant. The flow is distributed between the high-voltage inverter power unit and the transformer through the flow control valves of different calibers. The branch water system of the power unit and the transformer is monitored by the pressure transmitter, flow transmitter and temperature element installed in the outlet circuit of the flow control valve. The deionization circuit is connected in parallel with the main circulation circuit, and the purpose of maintaining extremely low conductivity for a long time is achieved by continuously removing ions from the cooling medium. The ion exchange resin uses imported non-regenerated resin as raw material for special proportioning, with an operating temperature of ≤60℃ and a maximum flow rate of 120m / h. It is a non-regenerated resin specially used for the removal of trace ions. By adding a water supply pump to the deionization circuit, the purified cooling water is added to the high-voltage inverter water system to increase the water capacity of the entire system. The alkali water tank and alkali pump are connected in series to the main circulation loop. The anhydrous sodium sulfite solution pre-stored in the water tank is added to the main circulation loop through the alkali pump to change the pH value of the cooling water so that it can be kept between 7.5-8.5 as much as possible to protect the copper pipes in the system from corrosion for a long time. The expansion water tank is pressurized by the nitrogen expansion tank to meet the water system pressure during the normal operation of the high-voltage inverter, and when the water system temperature is low, the electric heater installed inside the expansion water tank can be started to heat the cooling water to balance the operating temperature of the entire water system. By installing pH transmitters, dissolved oxygen transmitters, temperature elements, flow transmitters and pressure transmitters in the main pipeline, the overall performance indicators of the water cooling circuit coolant can be monitored in real time.

[0024] Due to the different lengths and diameters of the pipelines of the high-voltage inverter power unit and the transformer, the flow resistance and pressure loss of the two are different. Under the operation condition of a single circulating water pump, two water supply pipelines are designed to provide cooling water sources to the power unit and the transformer respectively to ensure the water flow required for the heat dissipation of each load; since the cooling water needs to be in direct contact with the live parts, the water cooling system is designed with anion and cation resin tanks to control the ion concentration and conductivity of the cooling water; in order to protect the copper pipes in the water system from corrosion to the maximum extent, the water cooling system is equipped with an alkalizing device (mainly anhydrous sodium sulfite) to Maintain the pH value between 7.5-8.5; to enhance the sealing of the water cooling system, use an airbag expansion tank pressure stabilization system to keep the system pipelines full of cooling medium and isolate the air, reduce the amount of oxygen dissolved, and extend the service life of copper pipelines of key components such as transformers and power units in high-voltage inverters; to improve the reliability of the water cooling system operation, in addition to valves and pipelines as single failure points, other equipment, such as water pumps, heat exchangers, deionization tanks, expansion tanks, etc., are designed with double redundancy. When a device fails, it can automatically switch, and the faulty equipment can be safely isolated and repaired.

Claims

1. A high-voltage inverter full water cooling system, characterized in that: A flow regulating valve A is installed on the outlet pipeline of the power unit, a flow regulating valve B is installed on the outlet pipeline of the water-cooled transformer, the outlet circuit of the flow regulating valve A is equipped with a pressure transmitter A, a flow transmitter A and a temperature element A, the outlet circuit of the flow regulating valve B is equipped with a pressure transmitter B, a flow transmitter B and a temperature element B, the inlet pipeline of the expansion water tank is connected to the water collection pipes of the flow regulating valve A and the flow regulating valve B, a water tank heater is installed inside the expansion water tank, the upper part of the expansion water tank is connected to the No. 1 nitrogen expansion tank and the No. 2 nitrogen expansion tank respectively, the outlet pipeline of the expansion water tank is connected to the inlet water collection pipes of the No. 1 circulation pump and the No. 2 circulation pump, the outlet water collection pipes of the No. 1 circulation pump and the No. 2 circulation pump are connected to the inlet of the three-way valve A and the three-way valve B respectively, one end of the outlet pipeline of the three-way valve A is connected to the inlet of the plate heat exchanger A, and the other end of the outlet pipeline is connected to the outlet of the plate heat exchanger A, the three-way valve B One end of the outlet pipeline is connected to the inlet of plate heat exchanger B, and the other end of the outlet pipeline is connected to the outlet of plate heat exchanger B. The outlet pipelines of the water confluence pipelines of No. 1 deionized water tank and No. 2 deionized water tank are connected to the inlet confluence pipelines of No. 1 circulation pump and No. 2 circulation pump. The inlet pipelines of the water confluence pipelines of No. 1 deionized water tank and No. 2 deionized water tank are connected to a make-up pump and connected to the outlet confluence pipelines of three-way valve A, three-way valve B, plate heat exchanger A and plate heat exchanger B. The outlet confluence pipelines of three-way valve A, three-way valve B, plate heat exchanger A and plate heat exchanger B are centrally confluent with the inlet confluence pipelines of No. 1 deionized water tank and No. 2 deionized water tank. A pH transmitter, a dissolved oxygen transmitter, a conductivity meter, a temperature element C, a flow transmitter C and a pressure transmitter C are arranged on the confluence pipeline. The outlets of the confluence pipelines are respectively connected to the inlet pipelines of the power unit and the inlet pipelines of the water-cooled transformer.

2. The high-voltage inverter full water cooling system according to claim 1 is characterized in that: The cooling water circulates inside the pipeline through the operation of the No. 1 circulation pump or the No. 2 circulation pump, passes through the water-cooling pipeline inside the power unit and the water-cooled transformer, and transfers the working heat of the power unit and the water-cooled transformer to the cooling water.

3. The high-voltage inverter full water cooling system according to claim 2 is characterized in that: The cooling water then flows through the power unit outlet pipeline and the water-cooled transformer outlet pipeline and flows into the inlet pipeline of the No. 1 circulating pump or the No. 2 circulating pump through the main pipeline of the expansion water tank.

4. The high-voltage inverter full water cooling system according to claim 3 is characterized in that: The inlet branch pipeline of the expansion water tank is connected with the alkali adding pump and the alkali adding water tank, and the outlet branch pipeline of the expansion water tank is connected with the outlet pipelines of the No. 1 deionized water tank and the No. 2 deionized water tank.

5. The high-voltage inverter full water cooling system according to claim 4 is characterized in that: Then the cooling water flows through the outlet pipeline of circulating pump No. 1 or circulating pump No. 2 to the inlet pipeline of three-way valve A or three-way valve B respectively, flows out through the outlet pipeline at one end of three-way valve A or three-way valve B to the corresponding plate heat exchanger A or plate heat exchanger B, and directly flows into the outlet manifold of plate heat exchanger A or plate heat exchanger B through the outlet pipeline at the other end.

6. The high-voltage inverter full water cooling system according to claim 5, characterized in that: The branch pipelines and water supply pumps of the water collecting main pipe are connected to the inlet pipelines of the No. 1 deionized water tank and the No. 2 deionized water tank, and the cooling water that has undergone heat exchange flows to the internal water cooling pipelines of the power unit and the water-cooled transformer respectively.

7. The high voltage inverter full water cooling system according to claim 6, characterized in that: The outlet pipeline of the power unit is installed with a flow regulating valve A, a pressure transmitter A, a flow transmitter A and a temperature element A to adjust the flow of cooling water of the power unit and monitor the pipeline pressure, actual flow and cooling water temperature in real time. The outlet pipeline of the water-cooled transformer is installed with a flow regulating valve B, a pressure transmitter B, a flow transmitter B and a temperature element B to adjust the flow of cooling water of the water-cooled transformer and monitor the pipeline pressure, actual flow and cooling water temperature in real time.

8. The high-voltage inverter full water cooling system according to claim 7, characterized in that: An alkali adding pump and an alkali adding water tank are connected in series to the confluence pipeline of the power unit outlet pipeline and the water-cooled transformer outlet pipeline and the inlet pipeline of the expansion water tank. The pH value and dissolved oxygen of the cooling water are adjusted online according to the pH transmitter and dissolved oxygen transmitter installed on the main pipe.

9. The high-voltage inverter full water cooling system according to claim 8, characterized in that: The expansion water tank is equipped with No. 1 nitrogen expansion tank, No. 2 nitrogen expansion tank and water tank heater, which are used to adjust the overall pressure of the full water cooling system according to the pressure transmitter C installed on the main pipe; the three-way valve A or three-way valve B is adjusted through the temperature element A installed on the outlet pipeline of the power unit, the temperature element B on the outlet pipeline of the water-cooled transformer and the temperature element C on the main pipe to control the cooling water temperature within the required range; The flow of the entire water system is monitored in real time through the flow transmitter C installed on the main pipe.

10. The high voltage inverter full water cooling system according to claim 9, characterized in that: Deionized water tank No. 1 and deionized water tank No. 2 are arranged between the outlet pipeline of the expansion water tank and the water main pipe of plate heat exchanger A and plate heat exchanger B. The ion concentration and conductivity in the cooling water are controlled according to the conductivity meter installed on the main pipe. A water replenishment pump is arranged on the inlet pipeline of deionized water tank No. 1 and deionized water tank No. 2 to replenish water when the system water volume is insufficient.

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