Crystal furnace constant-temperature circulating water system capable of precisely controlling water temperature

Abstract

The invention relates to the technical field of constant-temperature water systems, in particular to a crystal furnace constant-temperature circulating water system capable of precisely controlling water temperature. In order to solve the problems that the refrigerating capacity of an original water circulation system is greatly influenced by the environment, stable operation of the system is influenced by a single fault, the stability of the water temperature at an inlet of a crystal furnace is further influenced, and finally crystal growth is limited, the following technical scheme is provided: the system comprises a circulation loop, the circulation loop comprises a first water tank, a crystal growing furnace and a first circulation pump set which are sequentially connected through a water pipeline to form a closed loop, the output end of the first circulation pump set is connected with the first water tank, and a pipeline between the first water tank and the crystal growing furnace is connected with a first heat exchanger; and a second heat exchanger is connected to a pipeline between the crystal growing furnace and the first circulating pump set. According to the invention, the influence of refrigerating capacity fluctuation on system temperature and single fault on stable operation of the system can be reduced, and stable water temperature at the inlet of the crystal growth furnace is ensured, so that the quality and uniformity of crystal growth are improved.

Description

Technical Field

[0001] The invention relates to the technical field of constant temperature water systems, and in particular to a crystal furnace circulating water system with precisely controllable water temperature. Background Art

[0002] A crystal furnace is a device used for crystal growth. It can provide a specific high-temperature environment and suitable physical and chemical conditions, so that the raw materials can grow into single crystals or polycrystals in the furnace according to certain crystallization rules. Single crystals refer to crystals with regular atomic arrangement and complete lattice structure, such as single crystal silicon; polycrystals are crystals composed of many small single crystals (grains). Because the furnace is in a high-temperature environment during the crystal growth process, if the temperature of the parts around the furnace is too high, it will affect the performance and service life of the equipment. Therefore, it is necessary to design a circulating water circuit to cool the key components of the crystal furnace, such as the furnace shell, electrodes, etc.

[0003] The existing system has basically met the functional requirements of the crystal furnace, but there are still some faults in the process of use that affect the stable operation of the entire system. The cooling tower is greatly affected by the environment, and the switching process between the refrigerator and the cooling tower brings about fluctuations in cooling capacity, which affects the system's stable control of temperature, thereby further affecting the stability of the crystal furnace inlet water temperature, and ultimately limiting crystal growth. In view of this, the present invention proposes a crystal furnace constant temperature circulating water system with precisely controlled water temperature. Summary of the invention

[0004] The purpose of the present invention is to propose a constant temperature circulating water system for a crystal furnace with precisely controlled water temperature, in order to address the problem in the background technology that the refrigeration capacity of the original water circulation system is greatly affected by the environment and a single fault affects the stable operation of the system, which further affects the stability of the water temperature at the inlet of the crystal furnace and ultimately leads to limited crystal growth.

[0005] The technical solution of the present invention is: a constant temperature circulating water system for a crystal furnace with precisely controlled water temperature, comprising a circulating circuit, wherein the circulating circuit comprises a first water tank, a crystal growth furnace and a first circulating pump group and are connected in sequence through water pipelines to form a closed loop, wherein the output end of the first circulating pump group is connected to the first water tank, a first heat exchanger is connected to the pipeline between the first water tank and the crystal growth furnace, and a second heat exchanger is connected to the pipeline between the crystal growth furnace and the first circulating pump group; an intermediate circuit, wherein the intermediate circuit is connected to the first heat exchanger and the second heat exchanger and is used to reduce the water temperature in the circulating circuit, and a third heat exchanger and a fourth heat exchanger are arranged in series on the intermediate circuit; a first refrigeration circuit, wherein the first refrigeration circuit is connected to the third heat exchanger and is used to reduce the water temperature in the intermediate circuit; and a second refrigeration circuit, wherein the second refrigeration circuit is connected to the fourth heat exchanger and is used to reduce the water temperature in the intermediate circuit.

[0006] Optionally, a heater is connected in parallel on the pipeline between the water tank and the first heat exchanger, and a plurality of groups of first temperature sensors are installed on the pipeline between the heater and the first heat exchanger.

[0007] Optionally, a plurality of groups of second temperature sensors are installed on the pipeline between the second heat exchanger and the first circulation pump group.

[0008] Optionally, the intermediate circuit includes a second water tank, a second circulation pump group and a first control valve, and are connected in sequence through water pipes to form a closed loop, the input end of the second circulation pump group is connected to the second water tank, the output end of the second circulation pump group is connected to the first control valve, the first control valve is connected in parallel with the first heat exchanger and the second heat exchanger through pipelines, and the water outlet end of the first heat exchanger is provided with a second control valve, and the water outlet end of the second heat exchanger is provided with a third control valve.

[0009] Optionally, the third heat exchanger and the fourth heat exchanger are both arranged in series on the pipeline between the first control valve and the second water tank, and the third heat exchanger is close to the second water tank.

[0010] Optionally, a plurality of sets of third temperature sensors are installed on the pipeline between the third heat exchanger and the second water tank, and a plurality of sets of fourth temperature sensors are installed on the pipeline between the fourth heat exchanger and the third heat exchanger.

[0011] Optionally, the first refrigeration circuit includes a refrigerator, a third circulation pump group and a fourth control valve, and are connected in sequence through water pipes to form a closed-loop basic water circulation circuit. The refrigerator is connected to the input end of the third circulation pump group, the fourth control valve is connected in parallel with the third heat exchanger through a pipeline, and a fifth control valve is provided at the water outlet of the third heat exchanger.

[0012] Optionally, the second refrigeration circuit includes a cooling tower, a fourth circulation pump group and a sixth control valve, and are connected in sequence through water pipes to form a closed-loop basic water circulation circuit. The cooling tower is connected to the input end of the fourth circulation pump group, the sixth control valve is connected in parallel with the fourth heat exchanger through a pipeline, and a seventh control valve is provided at the water outlet of the fourth heat exchanger.

[0013] Optionally, the first circulating pump group, the second circulating pump group, the third circulating pump group and the fourth circulating pump group each include at least two groups of circulating pumps arranged in parallel.

[0014] In summary, the present application includes at least one of the following beneficial technical effects:

[0015] The present invention sets a heater. If the water temperature is lower than the standard value, the heater is turned on to increase the water temperature. If the water temperature is higher than the standard value, the heater is turned off to stop heating, so as to increase the water temperature when the water temperature is too low in winter.

[0016] Further, by setting up the second heat exchanger, the inlet temperature is prevented from rising to a higher value than the standard value due to the influence of the high ambient temperature and the conversion of the output mechanical energy and thermal energy of the first circulating pump group;

[0017] Further, by adding an intermediate loop as a buffer loop, the heat exchange capacity of the first heat exchanger and the second heat exchanger is guaranteed to be stable by controlling the water temperature of the intermediate loop. At the same time, the refrigerator and the cooling tower loop are decoupled and used separately in winter and summer. The cooling tower loop is used in winter and the refrigerator loop is used in summer, thereby ensuring the cooling capacity at different ambient temperatures.

[0018] In summary, the present invention can reduce the influence of refrigeration capacity fluctuation on system temperature, ensure the stability of water temperature at the inlet of the crystal growth furnace, and thus improve the quality and uniformity of crystal growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of a constant temperature circulating water system for a crystal furnace with precisely controlled water temperature.

[0020] Reference numerals:

[0021] 1. Circulation loop; 11. First water tank; 12. Crystal growth furnace; 13. First circulation pump group; 14. Heater; 15. First temperature sensor; 16. Second temperature sensor;

[0022] 2. Intermediate circuit; 21. Second water tank; 22. Second circulation pump group; 23. First control valve; 24. Second control valve; 25. Third control valve; 26. Third temperature sensor; 27. Fourth temperature sensor;

[0023] 3. First refrigeration circuit; 31. Refrigeration machine; 32. Third circulation pump group; 33. Fourth control valve; 34. Fifth control valve;

[0024] 4. Second refrigeration circuit; 41. Cooling tower; 42. Fourth circulation pump group; 43. Sixth control valve; 44. Seventh control valve;

[0025] 5. The first heat exchanger; 6. The second heat exchanger; 7. The third heat exchanger; 8. The fourth heat exchanger. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0027] The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0028] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", "fourth", "fifth", "sixth", and "seventh" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Example

[0032] like Figure 1As shown, a crystal furnace constant temperature circulating water system with precisely controlled water temperature proposed by the present invention comprises a circulating loop 1, wherein the circulating loop 1 comprises a first water tank 11, a crystal growth furnace 12 and a first circulating pump group 13, which are connected in sequence through water pipelines to form a closed loop. The output end of the first circulating pump group 13 is connected to the first water tank 11, so that the water in the pipeline can circulate. The pipeline between the first water tank 11 and the crystal growth furnace 12 is connected with a first heat exchanger 5, which is used to reduce the water temperature entering the crystal growth furnace 12 so that the water temperature is maintained at 20±0.1°C. The pipeline between the crystal growth furnace 12 and the first circulating pump group 13 is connected with a second heat exchanger 6, which is used to reduce the water temperature output from the crystal growth furnace 12 to prevent the water temperature in the circulating loop 1 from being too high. A heater 14 is connected in parallel to the pipeline between the water tank and the first heat exchanger 5, and the heater 14 is turned on when the water temperature is lower than 20°C to increase the water temperature. If the water temperature is higher than 21°C, the heater 14 is turned off and the heating is stopped. Among them, the margin of 1°C is set to prevent the heater 14 from being repeatedly turned on and off due to temperature fluctuations, which affects its service life. Three groups of first temperature sensors 15 are installed on the pipeline between the heater 14 and the first heat exchanger 5. The three first temperature sensors 15 measure the temperature together and take the average value to set it as the outlet water temperature of the first water tank 11. If the measurement results of one group of first temperature sensors 15 differ greatly from those of the other two groups of first temperature sensors 15, they play a mutual correction function. Multiple groups of second temperature sensors 16 are installed on the pipeline between the second heat exchanger 6 and the first circulation pump group 13. The three second temperature sensors 16 measure the temperature together and take the average value to set it as the outlet water temperature of the second heat exchanger 6. If the measurement results of one group of second temperature sensors 16 differ greatly from those of the other two groups of second temperature sensors 16, they play a mutual correction function.

[0033] The first heat exchanger 5 is provided with a PID flow control module at the outlet end of the circulation loop 1, and the flow feedback adjustment through the first heat exchanger 5 is realized by collecting the temperature data results of the three groups of first temperature sensors 15 to ensure that the inlet temperature of the crystal growth furnace 12 is maintained at 20°C. At the same time, the three groups of second temperature sensors 16 are also connected to the PID flow control module to adjust the flow through the second heat exchanger 6 in the pipeline of the intermediate loop 2, so as to adjust the cooling effect of the second heat exchanger 6.

[0034] Specifically, the above-mentioned circulating water system also includes an intermediate loop 2, which is connected to the first heat exchanger 5 and the second heat exchanger 6, and is used to reduce the water temperature in the circulating loop 1. The third heat exchanger 7 and the fourth heat exchanger 8 are arranged in series on the intermediate loop 2. The intermediate loop 2 includes a second water tank 21, a second circulating pump group 22 and a first control valve 23, and they are connected in sequence through a water pipeline to form a closed loop. The input end of the second circulating pump group 22 is connected to the second water tank 21, and the output end of the second circulating pump group 22 is connected to the first control valve 23, and the water is driven to circulate in the pipeline by the second circulating pump group 22. The first control valve 23 is connected in parallel with the first heat exchanger 5 and the second heat exchanger 6 through pipelines, and the water outlet end of the first heat exchanger 5 is provided with a second control valve 24, and the second control valve 24 is used to control whether water in the intermediate loop 2 passes through the first heat exchanger 5. The water outlet end of the second heat exchanger 6 is provided with a third control valve 25, and the third control valve 25 is used to control whether water in the intermediate loop 2 passes through the second heat exchanger 6. The third heat exchanger 7 and the fourth heat exchanger 8 are both arranged in series on the pipeline between the first control valve 23 and the second water tank 21. The third heat exchanger 7 and the fourth heat exchanger 8 are used to reduce the water temperature in the pipeline of the intermediate loop 2, so that the water in the pipeline of the intermediate loop 2 can be heat exchanged and cooled when passing through the first heat exchanger 5 and the second heat exchanger 6. The third heat exchanger 7 is close to the second water tank 21. Two groups of third temperature sensors 26 are installed on the pipeline between the third heat exchanger 7 and the second water tank 21. The third temperature sensors 26 are used to detect the water temperature after passing through the third heat exchanger 7. Multiple groups of fourth temperature sensors 27 are installed on the pipeline between the fourth heat exchanger 8 and the third heat exchanger 7. The fourth temperature sensors 27 are used to monitor the water temperature after passing through the fourth heat exchanger 8.

[0035] Furthermore, the above-mentioned circulating water system includes a first refrigeration loop 3, which is connected to the third heat exchanger 7 and is used to reduce the water temperature in the intermediate loop 2. The first refrigeration loop 3 includes a refrigerator 31, a third circulation pump group 32 and a fourth control valve 33, and they are connected in sequence through a water pipeline to form a closed-loop basic water circulation loop 1. The refrigerator 31 is connected to the input end of the third circulation pump group 32, and the third circulation pump group 32 drives the water in the pipeline of the first refrigeration loop 3 to circulate. The fourth control valve 33 is connected in parallel with the third heat exchanger 7 through a pipeline, and a fifth control valve 34 is provided at the water outlet of the third heat exchanger 7. The amount of water in the first refrigeration loop 3 passing through the third heat exchanger 7 is controlled jointly by the fourth control valve 33 and the fifth control valve 34.

[0036] Furthermore, the above-mentioned circulating water system also includes a second refrigeration circuit 4, which is connected to the fourth heat exchanger 8 and is used to reduce the water temperature in the intermediate circuit 2. The second refrigeration circuit 4 includes a cooling tower 41, a fourth circulation pump group 42 and a sixth control valve 43, and is connected in sequence through a water pipeline to form a closed-loop basic water circulation circuit 1. The cooling tower 41 is connected to the input end of the fourth circulation pump group 42, and the fourth circulation pump group 42 is used to drive the water in the pipeline of the second refrigeration circuit 4 to circulate. The sixth control valve 43 is connected in parallel with the fourth heat exchanger 8 through a pipeline, and the water outlet end of the fourth heat exchanger 8 is provided with a seventh control valve 44, and the amount of water in the second refrigeration circuit 4 passing through the fourth heat exchanger 8 is jointly controlled by the sixth control valve 43 and the seventh control valve 44.

[0037] Finally, the first circulation pump group 13, the second circulation pump group 22, the third circulation pump group 32 and the fourth circulation pump group 42 all include two groups of circulation pumps arranged in parallel to prevent water from being unable to circulate due to damage to one group of circulation pumps. The two groups of circulation pumps can still drive water to circulate through the other group even if one group is damaged, thereby avoiding losses caused by system shutdown.

[0038] In this embodiment, when the ambient temperature is high in summer, the refrigerator 31 is started, and the water in the first refrigeration loop 3 pipeline is driven to circulate and cool down through the third circulation pump group 32, and passes through the third heat exchanger 7 at the same time. At the same time, under the influence of the ambient temperature, the water temperature in the circulation loop 1 is higher than 20°C, and multiple first temperature sensors 15 detect the water temperature and feed it back to the PID flow control module. The PID flow control module controls the opening and closing size of the first control valve 23, the second control valve 24 and the third control valve 25 according to the water temperature. When the temperature detected by the first temperature sensor 15 is higher than 20°C by a large amount, the amount of water passing through the first heat exchanger 5 in the intermediate loop 2 is increased; when the temperature detected by the first temperature sensor 15 is higher than 20°C by a small amount, the amount of water passing through the first heat exchanger 5 in the intermediate loop 2 is reduced. Therefore, while the second circulation pump group 22 drives the water to pass through the first heat exchanger 5, the water temperature entering the crystal growth furnace 12 is reduced to maintain it at 20°C. When the high-temperature water passing through the crystal growth furnace 12 is discharged, it is cooled when passing through the second heat exchanger 6.

[0039] When the ambient temperature is low in winter, the cooling tower 41 is started, and the water in the second refrigeration loop 4 pipeline is driven to circulate and cool down through the fourth circulation pump group 42, and passes through the fourth heat exchanger 8 at the same time. At the same time, under the influence of the ambient temperature, the water temperature in the circulation loop 1 is lower than 20°C, and multiple first temperature sensors 15 detect the water temperature and feed it back to the PID flow control module. The heater 14 is started to heat the water passing through the heater 14, and the heating power of the heater 14 is self-adjusted according to the water temperature detected by the first temperature sensor 15, so that the water temperature is maintained at 20°C. At the same time, the second control valve 24 is in a closed state, and the water in the intermediate loop 2 pipeline does not pass through the first heat exchanger 5, but only passes through the second heat exchanger 6, and the high-temperature water discharged from the crystal growth furnace 12 is cooled.

[0040] According to the water temperature detected by the second temperature sensor 16, the opening and closing of the first control valve 23 and the third control valve 25 can also be adjusted by the PID flow control module to adjust the amount of water passing through the second heat exchanger 6, thereby adjusting the heat exchange effect of the second heat exchanger 6 and achieving the adjustment of the water temperature in the circulation loop 1.

[0041] The above specific embodiment is only an optional embodiment of the present invention. Based on the technical solution of the present invention and the relevant inspiration of the above embodiment, those skilled in the art can make various alternative improvements and combinations to the above specific embodiment.

Claims

1. A crystal furnace constant temperature circulating water system with precisely controlled water temperature, characterized in that: include: A circulation loop (1), the circulation loop (1) comprising a first water tank (11), a crystal growth furnace (12) and a first circulation pump group (13) which are connected in sequence through a water pipeline to form a closed loop, the output end of the first circulation pump group (13) being connected to the first water tank (11), the pipeline between the first water tank (11) and the crystal growth furnace (12) being connected to a first heat exchanger (5), and the pipeline between the crystal growth furnace (12) and the first circulation pump group (13) being connected to a second heat exchanger (6); An intermediate loop (2), the intermediate loop (2) being in communication with the first heat exchanger (5) and the second heat exchanger (6) and being used to reduce the water temperature in the circulation loop (1), and the intermediate loop (2) being provided with a third heat exchanger (7) and a fourth heat exchanger (8) in series; A first refrigeration circuit (3), the first refrigeration circuit (3) being in communication with a third heat exchanger (7) and being used to reduce the water temperature in the intermediate circuit (2); A second refrigeration circuit (4), the second refrigeration circuit (4) is connected to the fourth heat exchanger (8) and is used to reduce the water temperature in the intermediate circuit (2).

2. A crystal furnace constant temperature circulating water system with precisely controlled water temperature according to claim 1, characterized in that: A heater (14) is connected in parallel on the pipeline between the water tank and the first heat exchanger (5), and a plurality of groups of first temperature sensors (15) are installed on the pipeline between the heater (14) and the first heat exchanger (5).

3. A crystal furnace circulating water system with precisely controlled water temperature according to claim 2, characterized in that: A plurality of groups of second temperature sensors (16) are installed on the pipeline between the second heat exchanger (6) and the first circulation pump group (13).

4. A crystal furnace circulating water system with precisely controlled water temperature according to claim 3, characterized in that: The intermediate circuit (2) comprises a second water tank (21), a second circulation pump group (22) and a first control valve (23), which are connected in sequence through a water pipeline to form a closed loop. The input end of the second circulation pump group (22) is connected to the second water tank (21), and the output end of the second circulation pump group (22) is connected to the first control valve (23). The first control valve (23) is connected in parallel with the first heat exchanger (5) and the second heat exchanger (6) through pipelines, and the water outlet end of the first heat exchanger (5) is provided with a second control valve (24), and the water outlet end of the second heat exchanger (6) is provided with a third control valve (25).

5. A crystal furnace constant temperature circulating water system with precisely controlled water temperature according to claim 4, characterized in that: The third heat exchanger (7) and the fourth heat exchanger (8) are both arranged in series on the pipeline between the first control valve (23) and the second water tank (21), and the third heat exchanger (7) is close to the second water tank (21).

6. A crystal furnace constant temperature circulating water system with precisely controlled water temperature according to claim 5, characterized in that: A plurality of sets of third temperature sensors (26) are installed on the pipeline between the third heat exchanger (7) and the second water tank (21), and a plurality of sets of fourth temperature sensors (27) are installed on the pipeline between the fourth heat exchanger (8) and the third heat exchanger (7).

7. A crystal furnace constant temperature circulating water system with precisely controlled water temperature according to claim 6, characterized in that: The first refrigeration circuit (3) comprises a refrigerator (31), a third circulation pump group (32) and a fourth control valve (33), and are connected in sequence through a water pipeline to form a closed-loop basic water circulation circuit (1), the refrigerator (31) is connected to the input end of the third circulation pump group (32), the fourth control valve (33) is connected in parallel with the third heat exchanger (7) through a pipeline, and a fifth control valve (34) is provided at the water outlet end of the third heat exchanger (7).

8. A crystal furnace constant temperature circulating water system with precisely controlled water temperature according to claim 7, characterized in that: The second refrigeration circuit (4) comprises a cooling tower (41), a fourth circulation pump group (42) and a sixth control valve (43) and is connected in sequence through a water pipeline to form a closed-loop basic water circulation circuit (1), the cooling tower (41) is connected to the input end of the fourth circulation pump group (42), the sixth control valve (43) is connected in parallel with the fourth heat exchanger (8) through a pipeline, and a seventh control valve (44) is provided at the water outlet of the fourth heat exchanger (8).

9. A crystal furnace constant temperature circulating water system with precisely controlled water temperature according to claim 7, characterized in that: The first circulation pump group (13), the second circulation pump group (22), the third circulation pump group (32) and the fourth circulation pump group (42) each comprise at least two groups of circulation pumps arranged in parallel.

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