A water temperature control system for MOCVD machine

Abstract

The utility model relates to a kind of MOCVD machine water temperature control system, including water inlet route and backwater route;Water inlet route includes water tank, water tank is equipped with heater for heating and temperature controller and relay for control, circulating pump is connected water tank and upper cover by pipeline;Backwater route includes the plate heat exchanger connected by pipeline with upper cover, plate heat exchanger first branch is connected to the water tank on water inlet route, the inlet of second branch is connected cooling circulating water pipe, and proportional control valve is installed on the pipeline of cooling circulating water pipe;The outlet of second branch is connected backwater pipe, backwater pipe is connected with the cooling circulating water pipe of the inlet of second branch after being connected with the cold water area of plant affairs end again to communicate;Proportional control valve is coupled with temperature controller, the utility model simplifies system, removes complex and expensive three-way mixing valve, and pipeline connection is simpler.

Description

Technical Field

[0001] This utility model relates to a water temperature control system for an MOCVD machine, belonging to the technical field of MOCVD equipment. Background Technology

[0002] During the growth process of metal-organic chemical vapor deposition (MOCVD), the top cover needs to be connected to 50-degree hot water to maintain a circulating water temperature of 50 degrees Celsius. This is to prevent the top cover from deforming due to high cavity temperature and to meet the process requirements for water temperature.

[0003] Currently, the water temperature control system that supplies hot water to the lid includes an inlet water path and a return water path. Please see... Figure 1 ; The water inlet route includes a water tank 4, which is equipped with a heater 3 for heating, a thermostat 1 for control, and a relay 2. The circulation pump 5 is connected to the water tank 4 and the top cover 6 through a pipe. The return water route includes a plate heat exchanger 7 connected to the top cover 6 via a pipe. The first branch of the plate heat exchanger 7 is connected to the water tank 4 on the inlet water route. The inlet of the second branch is connected to the cooling circulating water pipe 8. The outlet of the second branch is connected to the three-way mixing valve 10 via the return water pipe 11. The water flows from the mixing valve 10 to the cold water area at the plant end and then returns to the cooling circulating water pipe 8 at the inlet of the second branch. A branch pipe 9 is provided on the cooling circulating water pipe 8 of the second branch. The branch pipe 9 is connected to a three-way mixing valve 10. The mixing valve 10 is coupled to the thermostat 1, so that the circulation is divided into two paths: one path goes through the plate heat exchanger 7 and then into the mixing valve 10; the other path goes directly from the mixing valve 10. The water temperature control system uses a three-way mixing valve 10 to regulate the water temperature. This method results in higher spare parts costs and the mixing valve 10 is prone to damage. The main issues are: the three-way mixing valve 10 is connected in series with the cooling water inlet and outlet. If the outlet water temperature is too high, the valve core will be damaged due to prolonged open-angle movement. Furthermore, the valve core is made of copper and is easily corroded, which can cause the valve core to jam, resulting in abnormal water temperature control and affecting process data. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a water temperature control system for MOCVD machines.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a water temperature control system for an MOCVD machine, comprising an inlet water route and a return water route; The water inlet route includes a water tank, which is equipped with a heater for heating and a thermostat and relay for control. The circulation pump is connected to the water tank and the top cover through a pipe. The return water route includes a plate heat exchanger connected to the top cover via a pipe. The first branch of the plate heat exchanger is connected to the water tank on the inlet water route, and the inlet of the second branch is connected to a cooling circulating water pipe. A proportional control valve is installed on the cooling circulating water pipe. The outlet of the second branch is connected to the return water pipe, which is connected to the cold water area at the plant end and then back to the cooling circulating water pipe at the inlet of the second branch. The proportional control valve is coupled to the temperature controller.

[0006] Furthermore, a flow meter is installed on the return water pipe at the outlet of the second branch of the plate heat exchanger. The flow meter is used for real-time monitoring and provides flow protection.

[0007] Furthermore, a buffer valve is provided on the cooling circulating water pipe at the inlet of the second branch of the plate heat exchanger and upstream of the proportional control valve. The buffer valve is used to ensure that the pressure in front of the proportional control valve is constant and to avoid flow fluctuations affecting temperature control. The buffer valve is coupled to the temperature controller.

[0008] Compared with the prior art, the advantages and positive effects of this utility model are as follows: 1. System simplification: The complex and expensive three-way mixing valve has been removed, making pipe connections simpler.

[0009] 2. Lower cost: A two-way proportional control valve is typically 50% cheaper than a three-way mixing valve.

[0010] 3. Intuitive control logic: Directly controls the water flow of the PCW, reducing energy consumption by 10%; 4. A flow meter is installed on the return water pipe to monitor the water flow rate; 5. A buffer valve is installed on the cooling water circulation pipe. The buffer valve and the proportional control valve form a dual-valve cooperative working mode. a. Normal operating conditions: Buffer valve: Maintains the pressure before the proportional control valve at the set value (e.g., 4.0 bar). Proportional control valve: Precisely adjusts PCW flow rate according to temperature requirements; Heater: Compensatory heating to eliminate undercooling; b. Pressure fluctuation condition: When the PCW inlet pressure fluctuates, the buffer valve responds quickly; Ensure constant pressure before the proportional control valve to avoid flow fluctuations affecting temperature control; c. Operating conditions with rapid temperature changes: Proportional control valves rapidly adjust flow rate in response to temperature changes; The buffer valve provides a stable pressure environment, ensuring the control accuracy of the proportional control valve. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the water temperature control system before the improvement. Figure 2 A schematic diagram of the improved water temperature control system; Figure 3 A schematic diagram of a further embodiment of the improved water temperature control system; Figure 4 A schematic diagram of another embodiment of the improved water temperature control system; Legend: 1-Thermostat, 2-Relay, 3-Heater, 4-Water tank, 5-Circulating pump, 6-Top cover, 7-Plate heat exchanger, 8-Cooling circulating water pipe, 9-Branch pipe, 10-Mixing valve, 11-Return water pipe, 12-Flow meter, 13-Proportional control valve, 14-Buffer valve. Detailed Implementation

[0012] Please see Figure 2 This utility model provides a technical solution: a water temperature control system for an MOCVD machine, including an inlet water route and a return water route; The water inlet route includes a water tank 4, which is equipped with a heater 3 for heating, a thermostat 1 for control, and a relay 2. The circulation pump 5 is connected to the water tank 4 and the top cover 6 through a pipe. The return water route includes a plate heat exchanger 7 connected to the upper cover 6 via a pipe. The plate heat exchanger 7 has two branches, wherein the first branch is connected to the water tank 4 on the inlet water route, and the inlet of the second branch is connected to the cooling circulating water pipe 8. A proportional control valve 10 is installed on the cooling circulating water pipe 8. The outlet of the second branch is connected to the return water pipe 11, which is connected to the cold water area at the plant end and then back to the cooling circulating water pipe 8 at the inlet of the second branch. The proportional control valve 13 is coupled to the temperature controller 1; After adopting the above solution, the entire system is simplified: the complex and expensive three-way mixing valve 10 is removed, making the pipe connection simpler; the cost may be lower: a two-way proportional control valve 13 is typically 50% cheaper than a three-way mixing valve 10, and has a longer service life; at the same time, the control logic is intuitive: the water flow of the PCW is directly controlled, reducing energy consumption by 10%.

[0013] Please see Figure 3A buffer valve 14 is provided on the cooling circulating water pipe 8 at the inlet of the second branch of the plate heat exchanger 7 and upstream of the proportional control valve 13. The buffer valve 14 is coupled to the temperature controller 1. The buffer valve 14 is used to ensure that the pressure in front of the proportional control valve 13 is constant and to avoid flow fluctuations affecting temperature control. The buffer valve 14 provides a stable pressure environment to ensure the control accuracy of the control valve 13. The buffer valve 14 is an automatic pressure reducing valve with its own pressure regulation function. It does not require PID controller control; only the pressure needs to be set.

[0014] A buffer valve 14 is installed on the cooling water circulation pipe 8 to enable the buffer valve 14 and the proportional control valve 13 to work together in a dual-valve cooperative mode. a. Normal operating conditions: Buffer valve: Maintains the pressure before the proportional control valve at the set value (e.g., 4.0 bar). Proportional control valve: Precisely adjusts PCW flow rate according to temperature requirements; Heater: Compensatory heating to eliminate undercooling; b. Pressure fluctuation condition: When the PCW inlet pressure fluctuates, the buffer valve responds quickly; Ensure constant pressure before the proportional control valve to avoid flow fluctuations affecting temperature control; c. Operating conditions with rapid temperature changes: Proportional control valves rapidly adjust flow rate in response to temperature changes; The buffer valve provides a stable pressure environment, ensuring the control accuracy of the proportional control valve.

[0015] Please see Figure 4 In order to monitor the water output, a flow meter 12 is provided on the return water pipe 11 at the outlet of the second branch of the plate heat exchanger 7. The flow meter 12 is used for real-time monitoring and provides flow protection.

[0016] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Variations and modifications made without departing from the spirit and scope of this utility model fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A water temperature control system for an MOCVD machine, characterized in that: Including the water inlet route and the water return route; The water inlet route includes a water tank, which is equipped with a heater for heating and a thermostat and relay for control. The circulation pump is connected to the water tank and the top cover through a pipe. The return water route includes a plate heat exchanger connected to the top cover via a pipe. The first branch of the plate heat exchanger is connected to the water tank on the inlet water route, and the inlet of the second branch is connected to a cooling circulating water pipe. A proportional control valve is installed on the cooling circulating water pipe. The outlet of the second branch is connected to the return water pipe, which is connected to the cold water area at the plant end and then back to the cooling circulating water pipe at the inlet of the second branch. The proportional control valve is coupled to the temperature controller.

2. The MOCVD machine water temperature control system according to claim 1, characterized in that: A flow meter is installed on the return water pipe at the outlet of the second branch of the plate heat exchanger. The flow meter is used for real-time monitoring and provides flow protection.

3. The MOCVD machine water temperature control system according to claim 2, characterized in that: A buffer valve is provided on the cooling circulating water pipe at the inlet of the second branch of the plate heat exchanger and upstream of the proportional control valve. The buffer valve is used to ensure that the pressure in front of the proportional control valve is constant and to avoid flow fluctuations affecting temperature control. The buffer valve is coupled to the temperature controller.

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