A crucible cooling water supply closed circulation system and operation method thereof

Abstract

The present invention discloses a closed circulation system for cooling water supply of a crucible and an operation method thereof. The closed circulation system for cooling water supply of a crucible comprises an external circulation water supply system, an internal circulation cooling water system and a water supply tank D. The internal circulation cooling water system for cooling the crucible is a closed circulation system. The external circulation water supply system and the internal circulation cooling water system exchange heat through a heat exchanger E. The external circulation water supply system supplies water to the water supply tank D, and the water supply tank D supplies water to the internal circulation cooling water system. The water supply tank D is connected to a drain through an overflow port. The external circulation water supply system, the internal circulation cooling water system and the water pump outlet of the internal circulation cooling water system are all connected to the drain through a pipeline. The system has high operation stability and high safety.

Description

Technical Field

[0001] The invention relates to the technical field of crucible cooling, and in particular to a crucible cooling water supply closed circulation system and an operation method thereof. Background Art

[0002] In metal smelting, in order to prevent the copper crucible from chemically reacting with the liquid metal, the crucible needs a high cooling efficiency to keep the crucible surface at a very low temperature. The flow rate and temperature of the cooling water determine the cooling efficiency of the crucible. Providing a cooling water supply system with stable flow, reliable heat exchange, and constant water temperature is essential for the normal operation of the crucible. At the same time, the water storage capacity of the cooling water system is an important indicator for assessing the safe operation of the crucible system. If it is too little, it will be detrimental to the water supply cooling, and if it is too much, there will be safety hazards. Therefore, the water storage capacity of the cooling water system must meet the indicators of safe operation when the cooling water flow rate and temperature meet the cooling requirements. Summary of the invention

[0003] The purpose of the present invention is to provide a closed circulation system for cooling water of a crucible in view of the defect that the large amount of water storage for cooling the crucible in the prior art leads to safety problems.

[0004] Another object of the present invention is to provide an operating method of the crucible cooling water supply closed circulation system.

[0005] The technical solution adopted to achieve the purpose of the present invention is:

[0006] A closed circulation system for cooling water of a crucible, comprising an external circulation water supply system, an internal circulation cooling water system and a water supply tank D, wherein the internal circulation cooling water system for cooling the crucible is a closed circulation system, and the external circulation water supply system and the internal circulation cooling water system exchange heat through a heat exchanger E;

[0007] The external circulation water supply system replenishes water to the water supply tank D, and the water supply tank D replenishes water to the internal circulation cooling water system. The water supply tank D is connected to the drain outlet through an overflow port;

[0008] The external circulation water supply system, the internal circulation cooling water system and the water pump air outlet of the internal circulation cooling water system are all connected to the drain port through pipelines.

[0009] In the above technical solution, the external circulation water supply system includes an external circulation water tank, an external circulation water supply pipeline connecting the external circulation water tank with the heat exchanger E, and an external circulation water return pipeline, a valve V001 is provided on the external circulation water supply pipeline, and a valve V002 is provided on the external circulation water return pipeline;

[0010] The internal circulation cooling water system comprises a crucible water supply pipeline and a crucible water return pipeline respectively connected to the heat exchanger E, a water pump P is provided on the crucible water supply pipeline, a valve V009 is provided on the crucible water supply pipeline between the heat exchanger E and the water pump P, a normally open solenoid valve V020 and a water supply control valve are provided on the crucible water supply pipeline between the water pump P and the crucible water supply port, the crucible water return pipeline is provided between the crucible water return port and the heat exchanger E, and a water return control valve is provided on the crucible water return pipeline;

[0011] The bottom of the water replenishment tank D is connected to the water inlet of the water pump P through a water replenishment pipeline, a valve V010 is provided on the water replenishment pipeline, the external circulation water supply pipeline is connected to the water replenishment tank D through a water inlet pipeline, a water inlet control valve is provided on the water inlet pipeline, the pipeline between the water inlet control valve and the water replenishment tank D is connected to the drain through a first drain pipeline, a valve V005 is provided on the first drain pipeline, and the overflow port on the upper part of the water replenishment tank D is connected to the drain through an overflow pipeline;

[0012] A second drainage branch is connected to the pipeline between the heat exchanger E and the valve V009, the second drainage branch 9 is connected to the drain port, the exhaust port of the water pump P is connected to the drain port through a third drainage branch, an exhaust control valve is provided on the third drainage branch, the water outlet of the water pump P is connected to the drain port through a fourth drainage branch, and a drainage control valve is provided on the fourth drainage branch.

[0013] In the above technical solution, the liquid level of the external circulation water tank is higher than the liquid level of the water replenishment tank to realize automatic water replenishment and liquid level control of the water replenishment tank, and the water replenishment tank is higher than the height of the water pump P to replenish water by gravity of water drop.

[0014] In the above technical solution, the water supply control valve includes valve V015 and valve V016, the return water control valve includes valve V017 and valve V019, the water inlet control valve includes valve V003 and valve V004, and the drainage control valve on the fourth drainage branch includes valve V006 and valve V007.

[0015] In the above technical solution, a flow meter FE01 is provided on the crucible water supply pipeline, and a flow meter FE02 is provided on the crucible return pipeline to monitor the system cooling water flow. Furthermore, the flow meter FE01 is arranged on the crucible water supply pipeline between the water pump and the water supply control valve, and the flow meter FE02 is arranged on the crucible return pipeline between the return water control valve and the heat exchanger E.

[0016] In the above technical solution, a thermometer TT01 is provided on the crucible water supply pipeline, and a thermometer TT02 is provided on the crucible return water pipeline to monitor the system cooling water temperature. Furthermore, the thermometer TT01 is arranged on the crucible water supply pipeline between the water pump and the water supply control valve, and the thermometer TT02 is arranged on the crucible return water pipeline between the return water control valve and the heat exchanger E.

[0017] In the above technical solution, a pressure sensor PT01 and a pressure gauge PI01 are provided on the crucible water supply pipeline between the heat exchanger E and the water inlet of the water pump P, and a pressure sensor PPT02 and a PI02 pressure gauge are provided on the crucible water supply pipeline between the water outlet of the water pump P and the crucible water supply port to detect the inlet and outlet pressures of the water pump P.

[0018] In the above technical solution, the water pump P includes a water pump P1 and a water pump P2, the exhaust port of the water pump P1 is connected to the drain port through a first output pipeline, a valve V013 is provided on the first output pipeline, and the exhaust port of the water pump P2 is connected to the drain port through a second output pipeline, a valve V014 is provided on the second output pipeline.

[0019] In the above technical solution, a one-way valve V011 is provided on the water outlet of the water pump P1, and a one-way valve V012 is provided on the water outlet of the water pump P2.

[0020] In the above technical solution, a one-way valve V018 is provided on the crucible return water pipeline.

[0021] In the above technical solution, the heat exchanger E is a plate heat exchanger.

[0022] In another aspect of the present invention, the method for operating the closed circulation system for cooling and supplying water to the crucible comprises the following steps:

[0023] Before the crucible cooling water supply circulation system works, open valves V001, V002, water inlet control valves (valves V003 and V004), V009, V010, water supply control valves, and return water control valves (valves V017 and V019), and close other valves. The external circulation water tank supplies water to the internal circulation cooling water system and the water supply tank. When the liquid level in the water supply tank is higher than the overflow port 8, it is automatically discharged to the drain port through the overflow pipe;

[0024] When the crucible cooling water supply circulation system is working, valves V008, V006, V007, V013, V014, water inlet control valves (V003, V004), V005 are closed, and other valves are opened, and the water pump P1 or P2 is started. When the crucible cooling water supply circulation system just starts to work, there is always some air in the system pipeline. The air concentrated at the exhaust port of the water pump is discharged through the drain port by repeatedly switching the exhaust control valve (valves V013 and V014) on the third exhaust branch 10; when the crucible cooling water supply circulation system is abnormal, the normally open solenoid valve V020 is closed to cut off the water supply to the crucible; when the crucible cooling water supply circulation system is shut down, the water pump P is turned off. After the water pump P stops, the valves V001, V002, the water supply control valve (valves V015 and V016), and the return water control valve (valves V017 and V019) are closed to cut off the water supply to the external circulation water tank and the water supply to the crucible;

[0025] When the crucible cooling water supply circulation system is drained, open valves V005, V006, V007, and V008, close other valves, and drain the cooling water in the system.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The entire system has compact piping, small footprint, and small water storage capacity, ensuring the safety of the crucible system. It has functions such as system drainage, startup exhaust, water pump switching, cooling and heat exchange. Two pumps are connected in parallel to supply water, one for backup and one for use, ensuring stable and reliable water supply flow. Plate heat exchanger is used, with sufficient heat exchange to ensure stable water supply temperature.

[0028] 2. The water supply tank of the crucible cooling water supply system is connected to the external circulation water tank. The higher liquid level of the external circulation water tank is used to realize automatic water replenishment and liquid level control of the water supply tank. At the same time, the normal temperature water in the water supply tank automatically flows to the water inlet of the water pump by gravity, which saves energy and ensures the stability of the system flow.

[0029] 3. The crucible cooling water supply system adopts a closed loop, and the heat exchange between the normal temperature water in the external water supply tank and the high temperature water in the crucible cooling water supply system is realized through a heat exchanger, so as to obtain cooling water below 30°C to cool the crucible. The system isolates the high temperature crucible from the external water supply tank to avoid the potential harm of a large amount of external water supply contacting the crucible. At the same time, the closed loop is adopted to realize the controllable water storage capacity of the system. The water storage capacity of the system is controlled within a safe range through the selection of pipelines and accessories, so as to prevent the cooling water from entering the test space where the crucible is located and possibly causing an accident when the crucible cooling water flow channel is damaged.

[0030] 4. A valve is installed at the vent of the water pump in the crucible cooling water supply system to connect it to the drainage pipeline. When the water pump starts running, the gas in the pipeline system is discharged by switching the valve, which facilitates rapid and stable system flow.

[0031] 5. A one-way valve is installed at the water pump outlet of the crucible cooling water supply system and the crucible return water port to prevent cooling water from flowing back. A normally open solenoid valve is installed at the crucible water supply port. When the system is abnormal, the solenoid valve is closed to cut off the water supply to the crucible and improve the safety of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Shown is a schematic structural diagram of a crucible cooling and water supply closed circulation system.

[0033] In the figure: 1-external circulation water supply pipeline, 2-external circulation return pipeline, 3-crucible water supply pipeline, 4-crucible return pipeline, 5-water replenishment pipeline, 6-water inlet pipeline, 7-first drainage pipeline, 8-overflow port, 9-second drainage branch, 10-third discharge branch, 11-fourth drainage branch. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] Example 1

[0036] A closed circulation system for cooling water of a crucible, comprising an external circulation water supply system, an internal circulation cooling water system and a water supply tank D, wherein the internal circulation cooling water system for cooling the crucible is a closed circulation system, and the external circulation water supply system and the internal circulation cooling water system exchange heat through a heat exchanger E;

[0037] The external circulation water supply system replenishes water to the water supply tank D, and the water supply tank D replenishes water to the internal circulation cooling water system. The water supply tank D is connected to the drain outlet through an overflow port;

[0038] The external circulation water supply system, the internal circulation cooling water system and the water pump air outlet of the internal circulation cooling water system are all connected to the drain port through pipelines.

[0039] The temperature of cooling water in the internal circulation cooling water system (crucible cooling water supply system) is ≤30°C. After cooling the high-temperature crucible, the temperature at the crucible return port can reach 55°C. The normal-temperature water in the external water supply tank is used to cool the high-temperature water in the crucible cooling water supply system through the heat exchanger E, so that its temperature is reduced to below 30°C, and the high-temperature crucible is circulated and cooled by the water supply pump. The water supply tank D plays the role of replenishing water to the internal circulation cooling water system, and also plays the role of exhausting and draining.

[0040] More preferably, the external circulation water supply system includes an external circulation water tank (not shown in the figure), an external circulation water supply pipeline 1 and an external circulation water return pipeline 2 connecting the external circulation water tank with the heat exchanger E, a valve V001 is provided on the external circulation water supply pipeline 1, and a valve V002 is provided on the external circulation water return pipeline 2;

[0041] The internal circulation cooling water system comprises a crucible water supply pipeline 3 and a crucible water return pipeline 4 respectively connected to the heat exchanger E, a water pump P is provided on the crucible water supply pipeline 3, a valve V009 is provided on the crucible water supply pipeline 3 between the heat exchanger E and the water pump P, a normally open solenoid valve V020 and a water supply control valve are provided on the crucible water supply pipeline 3 between the water pump P and the crucible water supply port, the crucible water return pipeline 4 is arranged between the crucible water return port and the heat exchanger E, and a water return control valve is provided on the crucible water return pipeline 4;

[0042] The bottom of the water replenishment tank D is connected to the water inlet of the water pump P through a water replenishment pipeline 5, and a valve V010 is provided on the water replenishment pipeline 5. The external circulation water supply pipeline 1 is connected to the water replenishment tank D through a water inlet pipeline 6, and a water inlet control valve is provided on the water inlet pipeline 6. The pipeline between the water inlet control valve and the water replenishment tank D is connected to the drain through a first drain pipeline 7, and a valve V005 is provided on the first drain pipeline 7. The overflow port 8 on the upper part of the water replenishment tank D is connected to the drain through an overflow pipeline;

[0043] A second drainage branch 9 is connected to the pipeline between the heat exchanger E and the valve V009, and the second drainage branch 9 is connected to the drain port. The exhaust port of the water pump P is connected to the drain port through a third drainage branch 10, and the third drainage branch 10 is provided with an exhaust control valve. The water outlet of the water pump P is connected to the drain port through a fourth drainage branch 11, and the fourth drainage branch 11 is provided with a drainage control valve.

[0044] Preferably, the water supply control valve includes valve V015 and valve V016, the return water control valve includes valve V017 and valve V019, the water inlet control valve includes valve V003 and valve V004, and the drainage control valve on the fourth drainage branch 11 includes valve V006 and valve V007. The setting of double valves can improve safety performance and ensure that the pipeline where it is located can be cut off when there is a water leak.

[0045] Example 2

[0046] The method for operating the closed circulation system for cooling and supplying water to the crucible as described in the embodiment comprises the following steps:

[0047] Before the crucible cooling water supply circulation system works, open valves V001, V002, water inlet control valves (valves V003 and V004), V009, V010, water supply control valves (valves V015 and V016), and return water control valves (valves V017 and V019), and close other valves. The external circulation water tank supplies water to the internal circulation cooling water system and the water supply tank. When the liquid level in the water supply tank is higher than the overflow port 8, it is automatically discharged to the drain port through the overflow pipe;

[0048] When the crucible cooling water supply circulation system is working, valves V008, V006, V007, V013, V014, water inlet control valves (V003, V004), V005 are closed, and other valves are opened, and water pump P1 or P2 is started. When the crucible cooling water supply circulation system just starts to work, there is always some air in the system pipeline. The air concentrated at the exhaust port of the water pump is discharged through the drain port by repeatedly switching the exhaust control valve (valves V013 and V014) on the third exhaust branch 10; when the crucible cooling water supply circulation system is abnormal, the normally open solenoid valve V020 is closed, the crucible water supply is cut off, and the crucible safety is ensured. When the crucible cooling water supply circulation system is shut down, the water pump P is turned off. After the water pump P stops, valves V001, V002, water supply control valves (valves V015 and V016), and return water control valves (valves V017 and V019) are closed to cut off the water supply of the external circulation water tank and the crucible.

[0049] When the crucible cooling water supply circulation system is drained, open valves V005, V006, V007, and V008, close other valves, and drain the cooling water in the system.

[0050] Example 3

[0051] Preferably, the crucible water supply pipeline 3 is provided with a flowmeter FE01, and the crucible return water pipeline 4 is provided with a flowmeter FE02 to monitor the system cooling water flow. Furthermore, the flowmeter FE01 is arranged on the crucible water supply pipeline 3 between the water pump and the water supply control valve, and the flowmeter FE02 is arranged on the crucible return water pipeline 4 between the return water control valve and the heat exchanger E.

[0052] Preferably, a thermometer TT01 is provided on the crucible water supply pipeline 3, and a thermometer TT02 is provided on the crucible return water pipeline 4 to monitor the system cooling water temperature. Furthermore, the thermometer TT01 is arranged on the crucible water supply pipeline 3 between the water pump and the water supply control valve, and the thermometer TT02 is arranged on the crucible return water pipeline 4 between the return water control valve and the heat exchanger E.

[0053] Preferably, a pressure sensor PT01 and a pressure gauge PI01 are provided on the crucible water supply pipeline 3 between the heat exchanger E and the water inlet of the water pump P, and a pressure sensor PPT02 and a PI02 pressure gauge are provided on the crucible water supply pipeline 3 between the water outlet of the water pump P and the crucible water supply port to detect the inlet and outlet pressures of the water pump P.

[0054] When the crucible cooling water supply circulation system is working, flow meters FE01 and FE02 monitor the cooling water flow of the internal circulation cooling water system, thermometers TT01 and TT02 monitor the cooling water temperature of the internal circulation cooling water system, and pressure sensors PT01 and PT02 and pressure gauges PI01 and PI02 detect the inlet and outlet pressures of the water pump.

[0055] Preferably, the water pump P includes a water pump P1 and a water pump P2, the exhaust port of the water pump P1 is provided with a valve V013, and the exhaust port of the water pump P2 is provided with a valve V014. During normal operation, one water pump is started, and when the flow rate monitored by the crucible cooling water supply circulation system flowmeters FE01 and FE02 drops to a set value, the other water pump is quickly started to ensure the stability of the crucible cooling water supply flow rate. In this way, the system continues to supply water stably, and the water pump can be switched under working conditions such as the shutdown of the water pump due to a fault but without stopping the system water supply for maintenance or the life balance of the water pump, thereby ensuring continuous water supply to the system and improving the stability and reliability of the water supply system.

[0056] Preferably, a one-way valve V011 is provided on the water outlet of the water pump P1, and a one-way valve V012 is provided on the water outlet of the water pump P2 to prevent the cooling water from flowing back.

[0057] Preferably, a one-way valve V018 is provided on the crucible return water pipeline 4 to prevent cooling water from flowing back.

[0058] Preferably, the heat exchanger E is a plate heat exchanger. The plate heat exchanger is used to exchange heat with the normal temperature water in the external water supply tank. It has high heat transfer efficiency, a large heat transfer coefficient, a compact structure, and a specific surface area of ​​1000m 2 / m 3 , with a larger heat exchange area and smaller water storage capacity, which is more conducive to the safety of the entire system. At the same time, the plate heat exchanger has a high degree of standardization and serialization, has strong interchangeability, and is easy to repair and replace.

[0059] For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right" and the like are used in the embodiments to illustrate the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientation shown in the figure, the spatial terms are intended to refer to different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "on" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0060] Furthermore, relational terms such as “first” and “second” and the like are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0061] The above description is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A crucible cooling water supply closed circulation system, characterized in that: It includes an external circulation water supply system, an internal circulation cooling water system and a water supply tank D. The internal circulation cooling water system for cooling the crucible is a closed circulation system. The external circulation water supply system and the internal circulation cooling water system exchange heat through a heat exchanger E. The external circulation water supply system replenishes water to the water supply tank D, and the water supply tank D replenishes water to the internal circulation cooling water system. The water supply tank D is connected to the drain outlet through an overflow port; The external circulation water supply system, the internal circulation cooling water system and the water pump air outlet of the internal circulation cooling water system are all connected to the drain port through pipelines; The external circulation water supply system includes an external circulation water tank, an external circulation water supply pipeline connecting the external circulation water tank with the heat exchanger E, and an external circulation water return pipeline, a valve V001 is provided on the external circulation water supply pipeline, and a valve V002 is provided on the external circulation water return pipeline; The internal circulation cooling water system comprises a crucible water supply pipeline and a crucible water return pipeline respectively connected to the heat exchanger E, a water pump P is provided on the crucible water supply pipeline, a valve V009 is provided on the crucible water supply pipeline between the heat exchanger E and the water pump P, a normally open solenoid valve V020 and a water supply control valve are provided on the crucible water supply pipeline between the water pump P and the crucible water supply port, the crucible water return pipeline is provided between the crucible water return port and the heat exchanger E, and a water return control valve is provided on the crucible water return pipeline; A second drainage branch is connected to the pipeline between the heat exchanger E and the valve V009, and the second drainage branch is connected to the drain port. The exhaust port of the water pump P is connected to the drain port through a third drainage branch, and an exhaust control valve is provided on the third drainage branch. The water outlet of the water pump P is connected to the drain port through a fourth drainage branch, and a drainage control valve is provided on the fourth drainage branch.

2. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: The bottom of the water replenishment tank D is connected to the water inlet of the water pump P through a water replenishment pipeline, a valve V010 is provided on the water replenishment pipeline, the external circulation water supply pipeline is connected to the water replenishment tank D through a water inlet pipeline, a water inlet control valve is provided on the water inlet pipeline, the pipeline between the water inlet control valve and the water replenishment tank D is connected to the drain through a first drain pipeline, a valve V005 is provided on the first drain pipeline, and the overflow port on the upper part of the water replenishment tank D is connected to the drain through an overflow pipeline.

3. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: The liquid level of the external circulation water tank is higher than the liquid level of the water replenishment tank to achieve automatic water replenishment and liquid level control of the water replenishment tank. The water replenishment tank is higher than the height of the water pump P to replenish water by gravity due to water drop.

4. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: The water supply control valve includes valve V015 and valve V016, the return water control valve includes valve V017 and valve V019, the water inlet control valve includes valve V003 and valve V004, and the drainage control valve on the fourth drainage branch includes valve V006 and valve V007.

5. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: A flowmeter FE01 is provided on the crucible water supply pipeline, and a flowmeter FE02 is provided on the crucible return pipeline to monitor the system cooling water flow. Furthermore, the flowmeter FE01 is arranged on the crucible water supply pipeline between the water pump and the water supply control valve, and the flowmeter FE02 is arranged on the crucible return pipeline between the return water control valve and the heat exchanger E.

6. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: A thermometer TT01 is provided on the crucible water supply pipeline, and a thermometer TT02 is provided on the crucible return water pipeline to monitor the system cooling water temperature. Furthermore, the thermometer TT01 is arranged on the crucible water supply pipeline between the water pump and the water supply control valve, and the thermometer TT02 is arranged on the crucible return water pipeline between the return water control valve and the heat exchanger E.

7. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: A pressure sensor PT01 and a pressure gauge PI01 are provided on the crucible water supply pipeline between the heat exchanger E and the water inlet of the water pump P, and a pressure sensor PPT02 and a PI02 pressure gauge are provided on the crucible water supply pipeline between the water outlet of the water pump P and the crucible water supply port to detect the inlet and outlet pressures of the water pump P.

8. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: The water pump P includes a water pump P1 and a water pump P2. The exhaust port of the water pump P1 is connected to the drain port via a first output pipeline, and a valve V013 is provided on the first output pipeline. The exhaust port of the water pump P2 is connected to the drain port via a second output pipeline, and a valve V014 is provided on the second output pipeline.

9. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: A one-way valve V011 is provided at the water outlet of the water pump P1, and a one-way valve V012 is provided at the water outlet of the water pump P2.

10. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: A one-way valve V018 is arranged on the crucible water pipeline.

11. The crucible cooling water supply closed circulation system according to claim 1, characterized in that: The heat exchanger E is a plate heat exchanger.

12. The method for operating the closed circulation system for cooling and supplying water to a crucible according to any one of claims 2 to 11, comprising the following steps: Before the crucible cooling water supply circulation system works, open valves V001, V002, water inlet control valve, V009, V010, water supply control valve, and return water control valve. All other valves are closed. The external circulation water tank supplies water to the internal circulation cooling water system and the water supply tank. When the liquid level in the water supply tank is higher than the overflow port, it is automatically discharged to the drain port through the overflow pipe. When the crucible cooling water supply circulation system is working, valves V008, V006, V007, V013, V014, water inlet control valve, V005 are closed, other valves are opened, and water pump P1 or P2 is started. When the crucible cooling water supply circulation system just starts to work, there is always some air in the system pipeline. The air concentrated at the exhaust port of the water pump is discharged through the drain port by repeatedly opening and closing the exhaust control valve on the third discharge branch. When the crucible cooling water supply circulation system is abnormal, the normally open solenoid valve V020 is closed to cut off the water supply to the crucible. When the crucible cooling water supply circulation system is shut down, the water pump P is turned off. After the water pump P stops, valves V001, V002, water supply control valve, and return water control valve are closed to cut off the water supply to the external circulation water tank and the crucible. When the crucible cooling water supply circulation system is drained, valves V005, V006, V007, and V008 are opened, and other valves are closed to discharge the cooling water in the system.

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