A high-precision temperature control system and method

Abstract

The application relates to the technical field of temperature control systems, and discloses a high-precision temperature control system and method, which comprises a temperature control module, an efficient filter and an air purifier which are electrically connected; a temperature monitoring device is arranged at the cavity between the bottom of the first air deflector and the top of the air purifier; the temperature monitoring device comprises a temperature sensor, two metal rods and a laser range finder for measuring the deformation of the metal rods; one end of the metal rod is fixed, and the other end is free and aligned with the laser range finder; the application adopts an optical detection mode, realizes high-precision temperature control through linkage of control of the condenser temperature, adjustment of the cold storage capacity by the electric louver and the heating block, and the method of optical detection can realize 0.01 DEG's ultra-high-precision temperature stability through a differential method regardless of environmental factors.

Description

Technical Field

[0001] This invention relates to the field of temperature control system technology, and specifically to a high-precision temperature control system and method. Background Technology

[0002] Currently, temperature control systems on the market are mainly designed for optoelectronic or mechanical equipment operating in a wide temperate climate range of 40–60℃, with temperature accuracy typically ranging from 0.5 to 1℃. However, for research institutions and laboratories where the ambient temperature is already between 23℃ and 1℃, the temperature accuracy and stability of such temperature control equipment are far from sufficient.

[0003] Temperature stability is particularly important in high-precision equipment. When temperature stability is strong, the parameters of the equipment can be corrected by algorithms. However, when temperature stability is insufficient, it is difficult for the algorithm to predict the temperature fluctuation curve, resulting in a decrease in the overall robustness of the equipment.

[0004] CN109489454A discloses a precision temperature control system for temperature control equipment, aiming to provide a temperature control system that can be precisely controlled. The key technical points are: it includes a cylindrical body, with a cooling water inlet at the top, a circulating liquid outlet on the side wall, another circulating liquid inlet below the outlet, and a cooling water outlet at the bottom. A temperature control unit is also provided inside the cylindrical body, comprising an inlet end cap located near the cooling water inlet, a first partition below the inlet end cap, a heat exchange tube inside the cylindrical body, an outlet end cap located at the cooling water outlet, a second partition inside the cylindrical body near the outlet, and a heater inside the cylindrical body. However, the temperature control accuracy of this equipment still has limitations.

[0005] CN112965543A discloses an ultra-high precision temperature control system, aiming to solve the problem that existing temperature control systems cannot achieve precise temperature control. It includes a microcomputer processor, a circulating fluid system, and a plant cooling water system. The circulating fluid system includes a circulating liquid pipeline and a filter, a second heat exchange plate, a water tank, and a circulating liquid temperature sensor sequentially installed in the pipeline. The circulating liquid pipeline contains the target circulating fluid requiring precise temperature control. A water pump for circulating the target fluid is installed on the water tank, and a heating wire I with an output frequency controlled by the microcomputer processor is installed inside the water tank. The circulating liquid temperature sensor is used to collect the temperature signal of the target circulating fluid. This system is suitable for ultra-high precision temperature control systems and has high social value and application prospects. However, the equipment structure is relatively complex, occupies a large area, and is not suitable for high-precision equipment such as lithography machines. Summary of the Invention

[0006] This invention addresses the issue of higher requirements for temperature stability and control precision in equipment such as lithography machines by providing a high-precision temperature control system. It employs optical detection to achieve high-precision temperature control of the equipment and can also eliminate measurement errors caused by environmental factors such as vibration, achieving high-precision temperature adjustment within ±0.01℃.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A high-precision temperature control system includes an electrically connected temperature control module, a high-efficiency filter, and an air purifier; the high-efficiency filter is located at the air inlet of the temperature control module, and the air purifier is located at the air outlet of the temperature control module. The temperature control module contains a condenser, a first air guide plate, a second air guide plate, and a temperature monitoring device. The condenser is located at the air outlet of the high-efficiency filter, and the second air guide plate is located at the air outlet of the condenser. A ring of first air guide plates surrounds the second air guide plate. The first air guide plate has an air inlet facing the condenser and an air outlet away from the condenser. Heating blocks are located on both sides of the second air guide plate. Heated air flows out through the air outlet of the first air guide plate and enters the air inlet of the air purifier. A temperature monitoring device is installed in the cavity between the bottom of the first air guide plate and the top of the air purifier. The temperature monitoring device includes a temperature sensor, two metal rods, and a laser rangefinder for measuring the deformation of the metal rods. One end of the metal rod is fixed, and the other end is free and aligned with the laser rangefinder. The coefficient of thermal expansion of the first metal rod is 20 × 10⁻⁶. -6 At temperatures above / ℃, the coefficient of thermal expansion of the second metal rod is 5×10⁻⁶. -6 / ℃ below.

[0008] This invention addresses the temperature accuracy and stability requirements of equipment such as lithography machines by providing a high-precision temperature control system that employs optical detection, resulting in higher accuracy in temperature stability detection. High-precision temperature control is achieved through a combination of condenser temperature control, electric louver adjustment of cold storage capacity, and heating block linkage. The optical detection method, utilizing a differential approach, ignores the influence of environmental factors and can achieve an ultra-high temperature stability of 0.01°C.

[0009] Preferably, the first metal rod is made of aluminum alloy 6061, and the second metal rod is made of Invar round bar. Aluminum alloy 6061 has a high coefficient of thermal expansion, which can produce large deformation at lower temperature changes, thus improving measurement accuracy. Invar has a low coefficient of thermal expansion, which results in smaller deformation when the temperature changes. This deformation is then deducted as an environmental disturbance, such as deformation caused by vibration, pressure, and wind speed.

[0010] Preferably, the second air guide plate is arranged parallel to the condenser. This parallel arrangement effectively increases the effective path of the air duct and the contact surface between the heater and the vertical airflow, achieving uniform and stable heating.

[0011] Preferably, behind the second air guide plate, there are two guide rails, one above the other, on which heating blocks are installed to heat the air above and below, making the gas heating distribution more uniform.

[0012] Preferably, the condenser is equipped with an external water pipe and an industrial chiller. After the water undergoes initial temperature control by the industrial chiller, it is conducted to the condenser through the water pipe for heat exchange. The external industrial chiller reduces the number of internal condensing components, thereby avoiding vibrations caused by condensing components such as air compressors and improving the stability of the equipment.

[0013] The condenser serves two purposes: filtering the air and insulating it with fiberglass paper and plywood to reduce heat loss and improve refrigeration efficiency.

[0014] Preferably, one or more vibration dampers are provided at any position on the housing of the temperature control system. Preferably, 2-6 flexible spring vibration dampers are provided to reduce the impact of external environmental vibrations on the equipment.

[0015] Preferably, the temperature control module uses a stainless steel shell, which has a low thermal conductivity, reducing heat exchange with the outside environment and enabling precise temperature control of the airflow throughout the duct.

[0016] Preferably, the air purifier is an FFU (Fluorescent Filter Unit) Class 100 air purifier, comprising a silent variable-speed fan, an air distribution duct, and a high-efficiency filter. It draws in cool air from the condenser through negative pressure, and after passing through the air distribution duct and the high-efficiency filter, it discharges the air, thus cooling or heating the load equipment to achieve temperature regulation. The airflow after passing through the FFU Class 100 air purifier is more uniform and stable.

[0017] Preferably, the first air guide plate is provided with a sloping air duct facing the air outlet of the condenser, which plays a role in temperature buffering for bottom cold storage.

[0018] Preferably, the temperature control module is further provided with an electric louver device, which is located between the condenser and the heating block, and controls the amount of cold air entering by controlling the opening and closing angle of the louvers.

[0019] Preferably, the heating block is a quick-release heating block; the second air guide plate is equipped with a guide rail for installing the quick-release heating block, and the heating block is equipped with guide rail buckles for easy and quick disassembly and assembly.

[0020] Preferably, the temperature monitoring device is positioned directly above the air purifier to reduce the impact of wind resistance. The smaller the wind influence at the center of the fan, the more accurate the temperature measurement. By measuring the temperature, feedback can be simultaneously sent to the heating block and the electric louver device for high-precision temperature adjustment.

[0021] More preferably, the metal rod is polished toward the surface of the laser rangefinder, and the roughness Ra of the polished metal surface is ≤0.02.

[0022] Preferably, the two metal rods are installed as close as possible to ensure that their detection environments are as similar as possible; the laser rangefinder is positioned as close as possible to the metal rods within its measurement range to improve the accuracy of the measurement results. The laser rangefinder measures the displacement changes caused by the thermal expansion of the two metal rods using reflected light to calculate the temperature change data, which is then fed back to the relevant control unit to achieve high-precision temperature control.

[0023] This invention also provides a high-precision temperature control method, which uses a laser rangefinder to measure the length change of a metal rod, calculates the temperature change based on the length change, and feeds the temperature change back to the relevant control unit to achieve high-precision temperature control. The metal rods include a first metal rod made of aluminum alloy 6061 and a second metal rod made of Invar steel. The displacement change value of the second metal rod is considered as an environmental disturbance item.

[0024] When the threshold is exceeded, the relevant control unit performs temperature control to reduce the temperature change value below the threshold. ; This represents the temperature change of the first metal rod. This represents the temperature change of the second metal rod. To set a threshold, the specific temperature change value is calculated using the following formula: , Where △L1 is the change in length of the first metal rod, and L1 is the initial length of the first metal rod. Let L1 be the coefficient of thermal expansion of the first metal rod; ΔL2 is the change in length of the second metal rod, and L2 is the initial length of the second metal rod. ΔL1 and ΔL2 are the coefficients of thermal expansion of the second metal rod; ΔL1 and ΔL2 are measured by a laser rangefinder.

[0025] Compared with the prior art, the present invention has the following beneficial effects: (1) In view of the requirements of temperature accuracy and stability of equipment such as lithography machines, the high-precision temperature control system provided by the present invention adopts optical detection method, which makes the temperature stability detection accuracy higher. Its function is equivalent to the grating ruler during the operation of the machine tool to detect the accuracy and stability. (2) In this invention, the temperature control system adopts a method of controlling the condenser temperature, adjusting the cold storage capacity by electric louvers, and linking the heating block to achieve high-precision temperature control.

[0026] (3) In this invention, an external water cooler is used to cool the condenser, reducing the vibration caused by the internal condenser. The external connection uses a flexible spring shock absorber to reduce the impact of the entire equipment on the environment, further improving the stability of temperature and the accuracy of monitoring. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the high-precision temperature control system in the embodiment.

[0028] Figure 2 This is a schematic diagram of the internal structure of the high-precision temperature control system in the embodiment.

[0029] Figure 3 This is a side sectional view of the high-precision temperature control system in the embodiment.

[0030] Figure 4 This is a schematic diagram of the internal structure of the high-precision temperature control system in the embodiment after removing the outer shell of the temperature control module.

[0031] Figure 5 This is a schematic diagram of the air duct of the high-precision temperature control system in the embodiment.

[0032] Figure 6 This is a schematic diagram of the metal rod and laser rangefinder in the temperature monitoring device of the embodiment. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention, without departing from the spirit and scope of the invention, should be covered within the protection scope of this invention.

[0034] The raw materials used in the following specific embodiments were all purchased from the market. The length change of the metal rod was determined according to the method and calculation formula for the linear thermal expansion coefficient in ISO 11359-1:2014 "Plastics - Thermomechanical analysis (TMA) - Part 1: General". Where ΔL: length change (m), L0: initial length (m), α: coefficient of thermal expansion ( / ℃), ΔT: temperature change (℃).

[0035] Example A high-precision temperature control system, such as Figures 1-5 As shown, it includes a temperature control module 1, a high-efficiency filter 2, and an air purifier 3 that are electrically connected; the high-efficiency filter 2 is located at the air inlet of the temperature control module 1, and the air purifier 3 is located at the air outlet of the temperature control module 1. The temperature control module 1 has a stainless steel shell and internally houses a condenser 4, a first air guide plate 5, a second air guide plate 6, and a temperature monitoring device 7. The condenser 4 is located at the air outlet of the high-efficiency filter 2, and the second air guide plate 6 is located at the air outlet of the condenser 4, arranged parallel to the condenser 4 to increase the contact surface for all airflow and achieve uniform heating. A ring of first air guide plates 5 surrounds the second air guide plate 6. The first air guide plate 5 has a sloping air inlet facing the condenser 4 and an air outlet away from the condenser 4. Quick-release heating blocks 8 are located on both sides of the second air guide plate 6, which is equipped with guide rails for installing the quick-release heating blocks. The heating blocks 8 are fitted with guide rail clips for easy and quick installation and removal. The heated air flows out through the air outlet of the first air guide plate 6 and then enters the air inlet of the air purifier 3.

[0036] The temperature control module 1 has a shock absorber 9 on its outer shell, which can be suspended and connected to any equipment to achieve vibration reduction. The air purifier 3 is an FFU (Fan Filter Unit) Class 100 air purifier, including a silent variable-speed fan, an air distribution duct, and a high-efficiency filter. It draws in cool air from the condenser through negative pressure, and after passing through the air distribution duct and the high-efficiency filter, it discharges the air to cool or heat the load equipment, thus achieving temperature regulation. The airflow after passing through the FFU Class 100 air purifier is more uniform and stable.

[0037] The condenser 4 is equipped with an external water pipe and an industrial chiller. After the water is initially temperature-controlled by the industrial chiller, it is conducted to the condenser through the water pipe for heat exchange, thereby reducing the number of internal condensing components and avoiding vibrations caused by condensing components such as air compressors, thus improving the stability of the equipment.

[0038] An electric louver device 10 is provided between the condenser 4 and the heating block 8. The electric louver device 10 adjusts the opening and closing angle of the louvers according to the temperature change value monitored by the temperature monitoring device 7, thereby controlling the amount of cold air entering and achieving precise temperature control.

[0039] A temperature monitoring device 11 is installed in the cavity between the bottom of the first air guide plate 5 and the top of the air purifier 3, directly above the air purifier. The smaller the influence of the wind at the center of the fan, the more accurate the temperature measurement. By measuring its temperature, it can be synchronously fed back to the heating block and the electric louver device for high-precision temperature adjustment.

[0040] The temperature monitoring device 11 includes a temperature sensor, two metal rods, and a laser rangefinder for measuring the deformation of the metal rods. Figure 6 As shown, one end of the metal rod is fixed, while the other end is free and aligned with the laser rangefinder. The distance between the first and second metal rods is as small as possible to achieve the same result in the same environment. The laser rangefinder used is the Zero-Wide LK-PD08, and the distance between its test port and the metal rod is as small as possible within the detection range to improve accuracy.

[0041] The first and second metal rods are polished towards the surface of the laser rangefinder, and the roughness Ra of the polished metal surface is ≤0.02.

[0042] Temperature control is performed using the system described above. The length change of the metal rod is measured using a laser rangefinder, and the result is determined by the length change value. Calculate the temperature change value; when the temperature change value Once the threshold is exceeded, the condenser 4, the electric louver device 10, and the quick-release heating block 8 are electrically connected to control the temperature of the equipment, thereby achieving precise and stable temperature control.

[0043] In this embodiment, a threshold is set. The temperature is 0.01℃, and the first metal rod is made of aluminum alloy 6061 with a coefficient of thermal expansion of 0.01℃. The initial length is 23.6 × 10⁻⁶ / ℃. The length is 0.2m; the second metal rod is made of Invar round bar with a thermal expansion coefficient of 0.2m. 2×10 -6 / ℃, initial length It is 0.2m.

[0044] When the temperature changes by 0.01℃, ΔL1= =0.2×23.6×10 -6 ×0.01=0.0472μm;△L2= =0.2×2×10 -6 ×0.01=0.004μm; It can be seen that aluminum alloy 6061 has a high coefficient of thermal expansion, which can produce large deformation at low temperature changes, which is beneficial to improving measurement accuracy; Invar steel has a low coefficient of thermal expansion, and its deformation is small when the temperature changes. Its deformation is used as an environmental interference term to be deducted, such as deformation caused by vibration, pressure, wind speed, etc.

[0045] Temperature change value ;in This represents the temperature change of the first metal rod. This represents the temperature change of the second metal rod; specifically, the temperature change is calculated using the following formula: , Where △L1 is the change in length of the first metal rod, and L1 is the initial length of the first metal rod. Let L1 be the coefficient of thermal expansion of the first metal rod; ΔL2 is the change in length of the second metal rod, and L2 is the initial length of the second metal rod. ΔL1 and ΔL2 are the coefficients of thermal expansion of the second metal rod; ΔL1 and ΔL2 are measured by a laser rangefinder.

Claims

1. A high-precision temperature control system, characterized in that, It includes a temperature control module, a high-efficiency filter, and an air purifier that are electrically connected; the high-efficiency filter is located at the air inlet of the temperature control module, and the air purifier is located at the air outlet of the temperature control module. The temperature control module contains a condenser, a first air guide plate, a second air guide plate, and a temperature monitoring device. The condenser is located at the air outlet of the high-efficiency filter, and the second air guide plate is located at the air outlet of the condenser. A ring of first air guide plates surrounds the second air guide plate. The first air guide plate has an air inlet facing the condenser and an air outlet away from the condenser. Heating blocks are located on both sides of the second air guide plate. Heated air flows out through the air outlet of the first air guide plate and enters the air inlet of the air purifier. A temperature monitoring device is installed in the cavity between the bottom of the first air guide plate and the top of the air purifier. The temperature monitoring device includes a temperature sensor, two metal rods, and a laser rangefinder for measuring the deformation of the metal rods. One end of the metal rod is fixed, and the other end is free and aligned with the laser rangefinder. The coefficient of thermal expansion of the first metal rod is 20 × 10⁻⁶. -6 At temperatures above / ℃, the coefficient of thermal expansion of the second metal rod is 5×10⁻⁶. -6 / ℃ below.

2. The high-precision temperature control system according to claim 1, characterized in that, The first metal rod is made of aluminum alloy 6061, and the second metal rod is made of Invar round bar.

3. The high-precision temperature control system according to claim 1, characterized in that, The second air guide plate is arranged parallel to the condenser.

4. The high-precision temperature control system according to claim 1, characterized in that, The condenser is equipped with an external water pipe and an industrial chiller. After the water is initially temperature-controlled by the industrial chiller, it is conducted to the condenser through the water pipe for heat exchange.

5. The high-precision temperature control system according to claim 1, characterized in that, One or more vibration dampers are provided at any position on the outer casing of the temperature control system.

6. The high-precision temperature control system according to claim 1, characterized in that, The air purifier is an FFU (Fluid Filter Unit) Class 100 air purifier, which includes a silent speed-adjustable fan, an air distribution duct, and a high-efficiency filter.

7. The high-precision temperature control system according to claim 1, characterized in that, The temperature control module is also equipped with an electric louver device, which is located between the condenser and the heating block. The amount of cold air entering is controlled by controlling the opening and closing angle of the louvers.

8. The high-precision temperature control system according to claim 1, characterized in that, The heating block is a quick-release heating block.

9. The high-precision temperature control system according to claim 1, characterized in that, The metal rod is polished toward the surface of the laser rangefinder, and the roughness Ra of the polished metal surface is ≤0.

02.

10. A high-precision temperature control method, characterized in that, A laser rangefinder is used to measure the length change of a metal rod, and the temperature change is calculated from the length change. The temperature change is then fed back to the relevant control unit to achieve high-precision temperature regulation. The metal rod includes a first metal rod and a second metal rod, wherein the coefficient of thermal expansion of the first metal rod is 20 × 10⁻⁶. -6 At temperatures above / ℃, the coefficient of thermal expansion of the second metal rod is 5×10⁻⁶. -6 Below / ℃, the displacement change of the second metal rod is considered as an environmental disturbance.

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