Thermal balance calculation method, adjustment method and system of electric heating device under cooling state

Abstract

The present invention belongs to the technical field of temperature control for chip processing, and specifically relates to a method for calculating the thermal balance of an electric heating device under cooling conditions, an adjustment method and a system. The method for calculating the thermal balance of an electric heating device under cooling conditions of the present invention firstly realizes the calculation function of the output percentage of the electric heating device and the surface cooler inverter under cooling conditions based on the processing characteristics of high-temperature sensitive chips. The calculation has high real-time performance, and the calculation results are efficient and accurate. Through the coordinated control of the electric heating device and the surface cooler inverter, it can provide a basic guarantee for the research of high-precision cooling control strategies for high-temperature sensitive chips. Subsequently, the present invention also provides a corresponding system and adjustment method, so as to concretely realize the purpose of high-precision cooling control.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature control for chip processing, and in particular relates to a heat balance calculation method, an adjustment method and a system for an electric heating device in a cooling state. Background Art

[0002] The key equipment for chip manufacturing is the photolithography machine; the photolithography machine is an ultra-precision processing equipment with high requirements for the working environment, especially the temperature. The stability of the internal gas temperature is an important factor affecting the resolution and imaging quality of the photolithography machine; among the many micro-environmental parameters, the temperature fluctuation has the greatest impact on the photolithography accuracy. Therefore, a reasonable temperature range, accurate temperature measurement and control are important to ensure the three key indicators of the photolithography machine, namely resolution, overlay accuracy and output. The thermal control device used in the photolithography machine belongs to a sub-field of precision environmental control. Its ideal temperature control accuracy is required to reach ±0.05℃, and the higher temperature control requirement needs to reach ±0.02℃; at present, the temperature control accuracy of peer products in the industry can reach ±1℃, and manufacturers with high temperature control levels can reach ±0.5℃, which is still a certain distance from the above ideal temperature control accuracy. In this regard, the patent document with application number 202110647092.2 discloses a high-precision temperature control device for cross-radiation convection, which can adjust the flow rate of the cross-radiation convection device by water pump frequency conversion, automatically adapt to the changes in the heat source on the measurement platform, improve the heat exchange efficiency, and accurately control the temperature of the water collector by fine-tuning the heating device to achieve the purpose of controllable and adjustable temperature of the measurement platform. However, the above scheme does not provide enough details of radiation convection temperature control. According to the description of its content, the convection and radiation power of the device cannot be completely decoupled, and the advantages of high-precision temperature control of thermal radiation and rapid temperature control of thermal convection cannot be brought into play. In particular, for the current chip processing field, some chips are extremely sensitive to high temperatures during processing; that is, when the working environment temperature is lower than the set temperature for a certain period of time, it will not have a significant impact on the lithography accuracy of the chip, but once the working environment temperature is higher than the set temperature for a long time, due to the high temperature sensitivity of the chip, it is bound to lead to the appearance of defective products, affecting the final yield. Obviously, although there are onboard PIDs that can achieve self-temperature control, the above-mentioned existing temperature control technology still cannot quickly make up for the gap between the actual temperature control temperature and the ideal temperature control accuracy, and is difficult to apply to the processing of high-temperature sensitive chips that require rapid and accurate temperature reduction so that the temperature can be controlled as much as possible within the set temperature range. Therefore, it is urgent to solve this problem. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art. Firstly, based on the processing characteristics of high-temperature sensitive chips, a method for calculating the thermal balance of an electric heating device under a cooling state is provided, thereby realizing the calculation function of the output percentage of the electric heating device and the surface cooler inverter under the cooling state. The calculation has high real-time performance, and the calculation results are efficient and accurate. Through the coordinated control of the electric heating device and the surface cooler inverter, a basic guarantee can be provided for the research on high-precision cooling control strategies for high-temperature sensitive chips. Subsequently, the present invention also provides a corresponding system and adjustment method, thereby concretely realizing the purpose of high-precision cooling control.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The heat balance calculation method of the electric heating device under cooling state is characterized by:

[0006] when hour,

[0007] The real-time inverter output percentage of the surface cooler is calculated by the following formula: outc The real-time output percentage of the electric heating device in the cooling state out :

[0008] ,

[0009] ;

[0010] when hour,

[0011] Pick outc =0%, and the output percentage of the real-time electric heating device in the cooling state is calculated by the following formula out :

[0012] ;

[0013] Where:

[0014] h tin is the air enthalpy value corresponding to the real-time return air dry-bulb temperature, unit: kJ / kg;

[0015] h tout It is the air enthalpy value corresponding to the real-time outlet dry-bulb temperature, unit: kJ / kg;

[0016] Q m is the air supply volume of the air conditioning box, unit: m 3 / h;

[0017] Vssout is the air specific volume at the real-time outlet dry-bulb temperature, unit: m 3 / kg;

[0018] Xssout is the absolute humidity of air at the real-time outlet dry-bulb temperature, unit: kg / kg;

[0019] R is the lowest load node value of the electric heating device;

[0020] The cooling capacity overflow of the surface cooler, unit: %;

[0021] t cout The real-time outlet temperature of chilled water, unit: °C;

[0022] t cin The real-time inlet temperature of chilled water, unit: °C;

[0023] F cm100% The chilled water flow rate of the inverter of the surface cooler at 100% output, unit: m 3 / h;

[0024] r is the calculation constant;

[0025] Q 出风电加热100% It is the heating capacity of the electric heating device of the air conditioner at 100% output, unit: W.

[0026] Preferably, the adjustment method is characterized by comprising the following steps:

[0027] S1.T sd To set the outlet dry bulb temperature, t out It is the real-time outlet dry bulb temperature;

[0028] When t sd >t out When t sd <t out When t is on, the air conditioner is in cooling state; in these two states, the system PLC uses the built-in PID to adjust the real-time dry-bulb temperature until t sd =t out Or the difference between the two is within the tolerance range;

[0029] S2. When the air-conditioning box is found to be in cooling state after two consecutive monitorings during the set time period, and the difference exceeds the tolerance zone, the real-time output percentage of the electric heating device is calculated according to the heat balance calculation method of the electric heating device in the cooling state, and the inverter output percentage of the surface cooler is adjusted to achieve the purpose of active temperature control, and then repeat step S1.

[0030] Preferably, the tolerance zone = ±0.3°C.

[0031] Preferably, when t sd >t outWhen , the temperature control logic of PID is:

[0032] A1. Calculate the real-time heat quantity Q based on the real-time outlet dry-bulb temperature, real-time return air dry-bulb temperature and air supply volume q ;

[0033] A2. The electric heating capacity of the electric heating device of the air conditioner is Q Z , the maximum cooling capacity of the surface cooler is Q C ,but:

[0034] Q q -Q Z When <0, the output percentage of the electric heating device is: [(Q Z -Q q ) / Q C ]×100%, the inverter output percentage of the cooler is 0%;

[0035] Q q -Q Z When > 0, the output percentage of the electric heating device is 0%, and the output percentage of the inverter of the surface cooler is:

[0036] [(Q Z -Q q ) / Q C ]×100%;

[0037] Q q -Q Z =0, the output percentage of the electric heating device is 40%, and the output percentage of the inverter of the surface cooler is 50%;

[0038] Preferably, when t sd <t out When , the temperature control logic of PID is:

[0039] Q q -Q Z When <0, the output percentage of the electric heating device is 0%, and the output percentage of the inverter of the surface cooler is:

[0040] [(Q C -Q q ) / Q C ]×100%;

[0041] Q q -Q Z >0, the output percentage of the electric heating device is 0%, and the inverter output percentage of the surface cooler is 100%;

[0042] Q q -Q Z =0, the output percentage of the electric heating device is 0%, and the inverter output percentage of the surface cooler is 100%.

[0043] Preferably, when t sd =t out When , the temperature control logic of PID is:

[0044] Q q -Q Z When <0, the output percentage of the electric heating device is 0%, and the inverter output percentage of the surface cooler is 100%;

[0045] Q q -Q Z >0, the output percentage of the electric heating device is 0%, and the inverter output percentage of the surface cooler is 100%;

[0046] Q q -Q Z =0, the output percentage of the electric heating device is 40%, and the output percentage of the inverter of the surface cooler is 50%.

[0047] Preferably, a system, which applies the above-mentioned method for calculating the thermal balance of an electric heating device under a cooling state, is characterized in that: it includes a temperature control box and an air supply box constituting an air-conditioning box, a circulating air path is formed between the temperature control box and the air supply box through an air supply channel and a return air channel, a mixer and a high-efficiency filter are arranged in sequence along the wind flow direction at the top of the temperature control box, and the high-efficiency filter and the inner wall and side wall of the top of the temperature control box are jointly enclosed to form a static pressure cavity; the space below the mixer constitutes a temperature control cavity, and an electric heating device and a surface cooler are arranged adjacent to each other from top to bottom in the temperature control cavity, a fan for blowing air to the mixer is arranged above the electric heating device, and a primary filter is arranged in the return air channel; wherein, an outlet wet-bulb temperature measuring point and an outlet dry-bulb temperature measuring point are arranged in the supply air channel, and a return air dry-bulb temperature measuring point is arranged in the return air channel.

[0048] Preferably, the water in the constant temperature water tank is transported to the surface cooler through a circulating pump located on the water inlet transmission pipeline, and flows back to the constant temperature water tank through the water outlet transmission pipeline to meet the heat exchange requirements; a water regulating valve V1 is also arranged on the water inlet transmission pipeline for accurately adjusting the amount of water entering the surface cooler; a group of electromagnetic switch valves EV are arranged on each of the two water transmission pipelines.

[0049] Preferably, the cold source of the constant temperature water tank is a water-cooled compression condensing unit, which uses electric heating to provide heat; the evaporating coil of the water-cooled compression condensing unit is immersed in the water of the constant temperature water tank, and forced convection heat exchange is achieved through an agitator; the water-cooled compression condensing unit is controlled by frequency conversion of a cooling water circulation pump.

[0050] Preferably, the air supply box is also provided with a dry-bulb temperature measuring point and a wet-bulb temperature measuring point.

[0051] The beneficial effects of the present invention are:

[0052] 1. High calculation accuracy.

[0053] The calculation method of the present invention is suitable for the research of high-precision cooling control strategies for high-temperature sensitive chips and corresponding photolithography temperature control occasions; when calculating, as long as a certain amount of basic temperature parameters are given, combined with conditions such as air specific volume, air enthalpy and air absolute humidity, then according to the calculation method of the present invention, the output percentage of the surface cooler inverter and the real-time output percentage of the electric heating device when the air-conditioning box is in a cooling state can be quickly determined, thereby realizing joint control and the calculation accuracy is accurate and efficient.

[0054] 2. Excellent adjustment performance.

[0055] The calculation method of the present invention, based on the processing characteristics of high-temperature sensitive chips, can be used independently, or it can be used on the basis of the existing onboard PID for coarse temperature control to quickly realize the calculation of the output percentage of the electric heating device and the output percentage of the cooler inverter, thereby achieving a rapid and accurate cooling effect of the chip processing environment; at the same time, the cooling state gradually changes with the influence of each temperature parameter in the calculation formula, and the adjustment trend becomes more obvious when approaching the set temperature, which is mainly manifested in that the output percentage of the cooler inverter also gradually stops participating in the regulation, so that the temperature control effect quickly approaches the ideal set temperature range, so as to achieve the optimal operating temperature control effect from the high temperature zone to the set temperature zone for the high-temperature sensitive chip, making up for the defects of the traditional PID coarse adjustment technology caused by the long adjustment time, relatively rough temperature control and the need for reciprocating temperature adjustment, and has the characteristics of excellent adjustment performance and high control accuracy.

[0056] 3. The design method is fast and concise.

[0057] The calculation method of the present invention can obtain the real-time output percentage of the electric heating device etc. in an algebraic manner by only inputting the design parameters. The calculation process is simple and fast, and the efficiency and practicality in engineering calculations are also guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the structure of the system of the present invention.

[0059] The actual correspondence between the reference numerals and component names of the present invention is as follows:

[0060] T cs1 , outlet wet bulb temperature measurement point; T cg1 , outlet dry bulb temperature measurement point; T hg1 , return air dry bulb temperature measurement point; V1, water regulating valve; EV, electromagnetic switch valve; T cg2 , Dry bulb temperature measurement point in the box: T cs2 , wet bulb temperature measuring point in the box;

[0061] a-static pressure chamber; b-temperature control chamber;

[0062] 11-temperature control box; 12-air supply box; 13-air supply channel; 14-return air channel;

[0063] 21-flow mixer; 22-high efficiency filter;

[0064] 31-electric heating device; 32-surface cooler; 33-surface cooling water pump;

[0065] 40- fan;

[0066] 50-primary filter;

[0067] 60- Constant temperature water tank;

[0068] 70-water-cooled compression condensing unit; 71-cooling water circulation pump. DETAILED DESCRIPTION

[0069] For ease of understanding, here we combine Figure 1 The specific structure and working mode of the present invention are further described as follows:

[0070] Volume of air supply box 12: 3±0.5m 3 . The temperature control box 11 for air supply is an integrated design. The temperature control box 11 contains components including: a primary filter 50, a surface cooler 32, an electric heating device 31, a fan 40, a mixer 21, a high-efficiency filter 22 and an air supply channel 13; the high-efficiency filter 22 and the top inner wall and side wall of the temperature control box 11 together enclose a static pressure chamber a; the space below the mixer 21 constitutes a temperature control chamber b. At the same time, it is possible to consider setting a surface cooler inlet temperature measuring point and a surface cooler outlet temperature measuring point; in addition, a return air dry-bulb temperature measuring point is set after the primary filter 50; and an outlet air dry-bulb temperature measuring point and an outlet air wet-bulb temperature measuring point are set in the air supply channel 13. Among them: the inlet water temperature of the surface cooler 32 needs to be precisely controlled and adjusted, so the system also integrates the water supply equipment of the surface cooler 32, that is, the constant temperature water tank 60. The cold source of the constant temperature water tank 60 is a water-cooled compression condensing unit 70, and the heat source is an electric heating method. When working, the evaporating coil of the water-cooled compression condensing unit 70 is immersed in the water of the constant temperature water tank 60, and the agitator is used to force convection heat exchange so as to transfer the coldness of the cold source to the water in the constant temperature water tank 60. Since the water temperature control accuracy of the constant temperature water tank 60 is very high, the coldness of the water-cooled compression condensing unit 70 is required to be able to achieve high-precision regulation with an accuracy of ten thousand levels, so the water-cooled compression condensing unit 70 adopts water cooling and is controlled by frequency conversion of the cooling water circulation pump 71. When in use, by monitoring and adjusting the cooling water inlet temperature and cooling water outlet temperature, controlling the inlet and outlet water temperature and temperature difference of the water-cooled compression condensing unit 70, and combining the frequency conversion to adjust the operating frequency of the water-cooled compression condensing unit 70, the coldness of the unit can be adjusted more accurately, until the regulation accuracy reaches ten thousand levels.

[0071] The water in the thermostatic water tank 60 is transported to the cooler 32 through the cooler pump 33 to meet the heat exchange requirements. The water regulating valve V1 on the water inlet transmission pipeline is used to accurately adjust the amount of water entering the cooler 32, thereby controlling the amount of cold entering, so that the cold amount of the entire air supply system can be accurately adjusted. The electromagnetic switch valve EV is used to quickly open and close the water circuit; because if a manual valve is used for cold water transmission, it will be more delayed than the electromagnetic valve, resulting in water entering the cooler 32 for a few seconds when cold water is not needed, which in turn causes excess coldness in the air supply system, causing the air supply temperature to rise or fall abnormally; the structure of the present invention can avoid the above problems.

[0072] The primary filter 50 and the high-efficiency filter 22 are used to filter the circulating air to ensure that the air supply reaches the required cleanliness. The above-mentioned mixed application of the present invention can greatly increase the airflow velocity, ensure the uniform temperature of the wind field, and even if the airflow passes through the mixer 21 at a very fast speed, the circulating airflow can be fully mixed and stirred to ensure the uniformity of the airflow when entering the high-efficiency filter 22, and make full use of the filtering effect of the high-efficiency filter 22 to the greatest extent. It can be seen from this that: through the above method, the present invention can solve the contradiction between wind speed, wind field uniformity and filtering effect, and is a perfect coupling of wind field uniformity and clean air supply products.

[0073] So far, the structural characteristics and control methods of the system formed by the above-mentioned components of the present invention have the following advantages:

[0074] ① The outlet dry-bulb temperature measurement point T of the system of the present invention cg1 And the wet bulb temperature measurement point T cs1 Set in the air supply channel 13, these two temperature points are used to measure and adjust the heat and cold input by the electric heating device 31 and the surface cooler 32. At the same time, the constant temperature control room is coupled to the clean room, and because it is close to the surface cooler 32 and the electric heater, the adjustment speed is fast and the measurement is accurate. Inside the air supply box 12, the processing area where the chip is placed, the dry bulb temperature measurement point T is set inside the box cg2 And the wet bulb temperature measurement point T in the box cs1 , used to control the temperature in the box, with an accuracy range of ±0.01℃; these two temperature points should be set as close as possible to the processing points in the processing area. cg1 , outlet wet bulb temperature measurement point T cs1 , Dry bulb temperature measurement point T in the box cg2 And the wet bulb temperature measurement point T in the box cs2 The separate settings can greatly improve the adjustment speed and accuracy. Return air dry bulb temperature measurement point T hg1Used to obtain real-time return air dry-bulb temperature; real-time outlet air dry-bulb temperature can be obtained through the air outlet temperature measuring point sensor of the air conditioning unit. This sensor is installed at the air outlet of the air conditioner and discharges air to the space in use. It will not be repeated here.

[0075] ②Due to the dry bulb temperature measurement point T cg2 And the wet bulb temperature measurement point T in the box cs2 The high precision and intensive collection time of this temperature usually generate a large amount of data, which has high requirements for the configuration of the collector and the computer software configuration, and requires a very large hard disk, so there are certain requirements for construction. When the traditional equipment is supplied, after the air supply box 12 is installed separately to the use position, on-site construction is required to connect the temperature control box 11 for air supply and even the water-cooled compression condensing unit 70 and the constant temperature water tank 60 as the cold source. The air supply channel 13 and the return air channel 14 are usually constructed, installed and connected after the air supply box 12 is in place at a later stage, which requires a high-precision equipment manufacturing process, but obviously, when the construction quality is difficult to guarantee, it will also cause problems such as air leakage and cold leakage, affecting the air supply accuracy. Since the present invention integrates all the above-mentioned components into one, forming an overall modular product, after ensuring the accuracy and standards of production and processing, it only needs to be in place as a whole when it is shipped to the client, and the high-precision air supply box 12 can be used, and the actual measured effect is remarkable.

[0076] On the basis of the above hardware structure, taking a specific high temperature sensitive chip as the object and a processing temperature requirement of 23°C ± 0.3°C as an example, the actual control process of the present invention is described in the following embodiment.

[0077] Example:

[0078] The actual control process of the present invention is divided into a coarse adjustment logic and a precise temperature control adjustment step given by the calculation method of the present invention. The idea is that when the coarse adjustment cannot achieve the result or the time is too slow, the system will cut into the precise temperature control adjustment step to assist the adjustment; the details are as follows:

[0079] 1. Coarse adjustment logic:

[0080] After the machine is turned on and running for 30 seconds, the real-time heat Q is calculated based on the real-time outlet dry-bulb temperature, real-time return air dry-bulb temperature and air supply volume. q ;in:

[0081] Air supply volume maintained at 750m 3 / h, it is necessary to open the setting window of this air volume parameter so that different air volume values ​​can be entered. The real-time outlet dry bulb temperature and the real-time return air dry bulb temperature are taken from the installed high-precision platinum resistor. The water volume of the surface cooling water pump 33 is 0.7m when it is turned on 100% by default. 3 / h; the inlet and outlet temperatures of the surface cooler 32 are taken from the self-contained temperature of the water-cooled compression condensing unit 70. The input cooling capacity of the surface cooler 32 is obtained by the water volume and the inlet and outlet water temperature difference; the maximum cooling capacity of the surface cooler 32 is Q C In this embodiment, Q C =1.2kw.

[0082] In actual operation, the air supply volume is 750m 3 / h; Air conditioning box's own electric heating Q Z= 1.5kW, maximum cooling capacity of the surface cooler Q C= 1.2kW, all three values ​​can be entered dynamically. In addition, the real-time heat Q is calculated q Since all heat is sensible, the formula used is Q=Cm△T, where m is calculated by multiplying the air volume by the density of the air. Taking this embodiment as an example, it is specifically:

[0083] According to the real-time air outlet dry bulb temperature t out , Real-time return air dry bulb temperature t in and air supply volume, calculate real-time heat Q q ,like:

[0084] Known t out =21℃; t in =24℃; Q m =750m 3 / h=0.208 m 3 / s; the specific heat of air at constant pressure is 1.005kJ / (kg×K); the air density is 1.29kg / m 3 ,but:

[0085] Q q =(t in -t out )×Q m ×1.005×1.29=0.81kw=810w.

[0086] Then, through Q q , Q Z and Q C The relationship between the output of each device is dynamically adjusted to t out =23℃ as an example, specifically including:

[0087] Z1. Current real-time outlet dry bulb temperature t out When t sd >t out ,and

[0088] Q q When -1.5<0, the output percentage of the electric heating device is: [(Q Z -Q q) / 1.5]×100%, the inverter output percentage of the surface cooler 32 is 0%;

[0089] Q q When -1.5>0, the output percentage of the electric heating device is 0%, and the output percentage of the inverter of the surface cooler 32 is:

[0090] [(Q Z -Q q ) / 1.2]×100%;

[0091] Q q When -1.5=0, the output percentage of the electric heating device is 40%, the purpose is to neutralize the cooling capacity of the surface cooler 32; the output percentage of the inverter of the surface cooler 32 is 50%, the purpose is to open the surface cooling water pump 33 to exhaust.

[0092] Z2. When the real-time outlet dry-bulb temperature is greater than 23°C, that is, t sd <t out ,and

[0093] Q q When -1.5<0, the output percentage of the electric heating device is 0%, and the output percentage of the inverter of the surface cooler 32 is:

[0094] [(Q C -Q q ) / 1.2]×100%;

[0095] Q q When -1.5>0, the output percentage of the electric heating device is 0%, and the output percentage of the inverter of the surface cooler 32 is 100%;

[0096] Q q When -1.5=0, the output percentage of the electric heating device is 0%, and the output percentage of the inverter of the surface cooler 32 is 100%;

[0097] Z3. When the real-time air outlet dry bulb temperature = 23℃, that is, t sd =t out ,and

[0098] Q q When -1.5>0, the output percentage of the electric heating device is 0%, and the output percentage of the inverter of the surface cooler 32 is 100%;

[0099] Q q When -1.5<0, the output percentage of the electric heating device is 0%, and the output percentage of the inverter of the surface cooler 32 is 100%;

[0100] Q qWhen -1.5=0, the output percentage of the electric heating device is 40%, the purpose is to neutralize the cooling capacity of the surface cooler 32; the output percentage of the inverter of the surface cooler 32 is 50%, the purpose is to open the surface cooling water pump 33 to exhaust.

[0101] Z4. Within a certain period after the previous operation, such as 60 seconds, the real-time outlet dry-bulb temperature and the real-time return dry-bulb temperature can be read again to calculate Q again. q When the real-time air outlet dry-bulb temperature is less than 23°C, or when the real-time air outlet dry-bulb temperature is greater than 23°C, proceed according to step Z1 or Z2 until t sd =t out Or the difference between the two is within the tolerance range of ±0.3℃, and the built-in PID adjustment is always used by default.

[0102] 2. Precision temperature control steps:

[0103] Under the above coarse adjustment logic, if the difference between two consecutive readings (i.e. within 120 seconds) is out of the tolerance zone, and the real-time outlet dry-bulb temperature is greater than 23°C, it indicates that the chip operating environment has a tendency to overheat for a long time, and PID active accelerated cooling and real-time accelerated temperature control are required. At this time, enter step Z5, i.e. the precise temperature control step; specifically, it includes:

[0104] Z5.T sd = 23℃ as an example, first, we need to determine The relationship with R is as follows:

[0105] Z51. Current real-time outlet dry bulb temperature t out =25℃, real-time return air dry-bulb temperature t in =27℃:

[0106] From the physical property table, we can see that h tin = 67.19 kJ / kg;h tout =60.563 kJ / kg;

[0107] According to the real-time air outlet dry bulb temperature t out The query shows that Vssout = 0.864m 3 / kg;Xssout=0.013913kg / kg;

[0108] Q m =750m 3 / h;

[0109] R is the lowest load node value of the electric heating device, and R=360;

[0110] Substitute the calculation into the following:

[0111] , it can be seen that >360;

[0112] At this time, the real-time inverter output percentage of the surface cooler is calculated by the following formula: outc The real-time output percentage of the electric heating device in the cooling state out :

[0113] ,

[0114] ;

[0115] Where:

[0116] =10%;

[0117] t cout =12℃; t cin =7℃

[0118] F cm100% =0.35m 3 / h;

[0119] r =1.165;

[0120] Q 出风电加热100% Enter the value on the touch screen, that is, the set value 1500W.

[0121] Substitute the calculation into the following:

[0122] ,

[0123] ;

[0124] Z52. Current real-time outlet dry-bulb temperature t out =23.5℃, real-time return air dry-bulb temperature t in =23.7℃:

[0125] From the physical property table, we can see that h tin = 56.512 kJ / kg;h tout =55.904 kJ / kg;

[0126] According to the real-time air outlet dry bulb temperature t out The query shows that Vssout = 0.858m 3 / kg;Xssout=0.012689kg / kg;

[0127] Q m =750m 3 / h; R=360;

[0128] Substitute the calculation into the following:

[0129] ;

[0130] At this time, maintain the real-time inverter output percentage of the surface cooler outc =0%, and the output percentage of the real-time electric heating device in the cooling state is calculated separately by the following formula out :

[0131] ;

[0132] After that, every 60 seconds, the operation of step Z4 is repeated, and at t sd <t out When the temperature is lowered rapidly and accurately, the high temperature sensitive chip is prevented from being in the high temperature zone for a long time, and the high temperature sensitive chip can be processed under temperature control within the set temperature range.

[0133] Of course, for those skilled in the art, the present invention is not limited to the details of the above exemplary embodiments, but also includes the same or similar methods that can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is limited by the appended claims rather than the above description.

[0134] The technical parts not described in detail in the present invention are all well-known technologies.

Claims

1. A method for calculating the heat balance of an electric heating device under cooling conditions, characterized in that: when >R, The real-time inverter output percentage of the surface cooler is calculated by the following formula: outc The real-time output percentage of the electric heating device in the cooling state out : outc = ， and out = ; when ≤R, Pick outc =0%, and the output percentage of the real-time electric heating device in the cooling state is calculated by the following formula out : out = ； Where: h tin is the air enthalpy value corresponding to the real-time return air dry-bulb temperature, unit: kJ / kg; h tout It is the air enthalpy value corresponding to the real-time outlet dry-bulb temperature, unit: kJ / kg; Q m is the air supply volume of the air conditioning box, unit: m 3 / h; Vssout It is the specific volume of air at the real-time outlet dry-bulb temperature, unit: m 3 / kg; Xssout It is the absolute humidity of air at the real-time outlet dry-bulb temperature, unit: kg / kg; CT is the cooling capacity overflow of the surface cooler, unit: %; R is the lowest load node value of the electric heating device; t cout The real-time outlet temperature of chilled water, unit: °C; t cin The real-time inlet temperature of chilled water, unit: °C; F cm100% The chilled water flow rate of the inverter of the surface cooler at 100% output, unit: m 3 / h; r is the calculation constant; Q 出风电加热100% It is the heating capacity of the electric heating device of the air conditioner at 100% output, unit: W.

2. The adjustment method is characterized in that The following steps are involved: S1. t sd To set the outlet dry bulb temperature, t out It is the real-time outlet dry bulb temperature; when t sd > t out When the air conditioner is in heating state; when t sd < t out When the air conditioner is in cooling state, the system PLC uses the built-in PID to adjust the real-time dry-bulb temperature of the air outlet by default until t sd = t out Or the difference between the two is within the tolerance range; S2. When the air-conditioning box is found to be in cooling state after two consecutive monitorings during the set time period, and the difference exceeds the tolerance zone, the real-time inverter output percentage of the surface cooler and the real-time output percentage of the electric heating device are calculated according to the heat balance calculation method of the electric heating device in cooling state as described in claim 1 to achieve the purpose of active temperature control and regulation, and then repeat step S1.

3. The adjustment method according to claim 2, characterized in that: Tolerance range = ±0.3℃.

4. The adjustment method according to claim 2 or 3, characterized in that: when t sd > t out When , the temperature control logic of PID is: A1. Calculate the real-time heat according to the real-time outlet dry-bulb temperature, real-time return air dry-bulb temperature and air supply volume Q q ; A2. The electric heating capacity of the electric heating device of the air conditioner is Q Z , the maximum cooling capacity of the surface cooler is Q C ,but: Q q - Q Z When <0, the output percentage of the electric heating device is: [( Q Z - Q q ) / Q C ]*100%, the inverter output percentage of the cooler is 0%; Q q - Q Z >0, the output percentage of the electric heating device is 0%, and the inverter output percentage of the surface cooler is: [( Q Z - Q q ) / Q C ]*100%; Q q - Q Z =0, the output percentage of the electric heating device is 40%, and the output percentage of the inverter of the surface cooler is 50%.

5. The adjustment method according to claim 4, characterized in that: when t sd < t out When , the temperature control logic of PID is: Q q -Q Z When <0, the output percentage of the electric heating device is 0%, and the output percentage of the inverter of the surface cooler is: [(Q C -Q q ) / Q C ]*100%; Q q -Q Z >0, the output percentage of the electric heating device is 0%, and the inverter output percentage of the surface cooler is 100%; Q q - Q Z =0, the output percentage of the electric heating device is 0%, and the inverter output percentage of the surface cooler is 100%.

6. A system, which uses the heat balance calculation method of the electric heating device under cooling state as claimed in claim 1, characterized in that: The invention comprises a temperature control box (11) and an air supply box (12) constituting an air conditioner. A circulating air path is formed between the temperature control box (11) and the air supply box (12) through an air supply channel (13) and a return air channel (14). A mixer (21) and a high-efficiency filter (22) are arranged in sequence at the top of the temperature control box (11) along the air flow direction. The high-efficiency filter (22) and the inner wall and side wall of the top of the temperature control box (11) are enclosed together to form a static pressure chamber (a). The space below the mixer (21) forms a temperature control chamber (b). An electric heating device (31) and a surface cooler (32) are arranged adjacent to each other from top to bottom in the temperature control chamber (b). A fan (40) for blowing air to the mixer (21) is arranged above the electric heating device (31). A primary filter (50) is arranged in the return air channel (14). A wet bulb temperature measuring point (T cs1 ) and outlet dry bulb temperature measurement point (T cg1 ), a return air dry-bulb temperature measuring point (T hg1 ).

7. The system according to claim 6, characterized in that: The water in the thermostatic water tank (60) is transported to the surface cooler (32) via the surface cooling water pump (33) located on the water inlet transmission pipeline, and flows back to the thermostatic water tank (60) via the water outlet transmission pipeline to meet the heat exchange requirements; a water regulating valve (V1) for accurately regulating the amount of water entering the surface cooler (32) is also arranged on the water inlet transmission pipeline; and a group of electromagnetic switch valves (EV) are respectively arranged on the two water transmission pipelines.

8. The system according to claim 7, characterized in that: The cold source of the constant temperature water tank (60) is a water-cooled compression condensing unit (70), which uses electric heating to provide heat; the evaporating coil of the water-cooled compression condensing unit (70) is immersed in the water of the constant temperature water tank (60), and forced convection heat exchange is performed through an agitator; the water-cooled compression condensing unit (70) is frequency-controlled by a cooling water circulation pump (71).

9. The system according to claim 7 or 8, characterized in that: The air supply box (12) is also provided with a dry-bulb temperature measuring point (T cg2 ) and the wet bulb temperature measurement point in the box (T cs2 ).

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