Low-temperature pump regeneration heating system and regeneration heating method

Abstract

The invention belongs to the technical field of low-temperature pumps, and particularly relates to a low-temperature pump regeneration heating system and a regeneration heating method. The regeneration heating method comprises the steps that firstly, the state of a to-be-treated cold plate is evaluated according to the condensation layer area and the condensation layer temperature of the to-be-treated cold plate of the low-temperature pump, and when the to-be-treated cold plate is in an abnormal state, a cold plate temperature adjustment value Ct is obtained to adjust the temperature of the cold plate. The state of the cold plate can be judged according to the condensation layer area and the condensation layer temperature of the cold plate, the state of the cold plate, the environment temperature and the air exhaust speed of the low-temperature pump are analyzed, the temperature of the cold plate is accurately adjusted according to the analysis result, and therefore the accuracy of regeneration heating of the low-temperature pump is improved, and the regeneration efficiency of the low-temperature pump is improved. And the regeneration heating efficiency of the low-temperature pump is improved.

Description

Technical Field

[0001] This invention belongs to the field of cryogenic pump technology, specifically relating to a cryogenic pump regeneration heating system and regeneration heating method. Background Technology

[0002] A cryogenic pump is a vacuum-generating device that utilizes a low-temperature surface to condense, adsorb, and capture gases. It is widely used in semiconductor, integrated circuit, and space technology research fields. After a period of operation, the cold head of a cryogenic pump becomes covered with solidified gas, causing the surface temperature to rise and weakening or even stopping the gas adsorption. To restore the pump's pumping function, it needs to be heated to vaporize and expel the condensate adsorbed on the cold head; this process is called "regeneration."

[0003] In cryogenic pump systems, the pump regeneration process is a crucial step. Currently, the main regeneration heating methods for cryogenic pumps include natural heating, venting heating, and electric heating. Natural heating is slow and uneven; while venting heating and electric heating often use fixed power or simple heating methods, which makes temperature control imprecise, resulting in low regeneration efficiency and excessive temperature fluctuations or heat waste.

[0004] For some precision equipment or systems, especially applications involving cryogenic liquid transport, precise control of the cold plate temperature and improvement of regeneration efficiency are crucial. Therefore, it is necessary to provide a new cryogenic pump regeneration heating system and method. Summary of the Invention

[0005] To address the aforementioned problems, one objective of this invention is to provide a method for regenerating and heating a cryogenic pump.

[0006] The present invention adopts the following technical solution: A method for regenerating and heating a cryogenic pump involves assessing the condition of the cold plate to be treated based on the condensation layer area and temperature of the cold plate. When the cold plate is in an abnormal state, a temperature adjustment value for the cold plate is obtained. Adjust the temperature of the cold plate; Includes the following steps: S1. Obtain the condensation layer area and condensation layer temperature of the cold plate to be processed, and calculate the cold plate condition assessment value according to the following formula. The condition of the cold plate to be processed is assessed based on the calculated cold plate condition evaluation value: ; In the formula, The area factor of the condensation layer. For abnormal region factors, For temperature difference factor, , , The weighting coefficients and ; S2. Evaluate the condition of the cold plate. Compared with the cold plate condition assessment threshold, when the cold plate condition assessment value If the cold plate condition assessment threshold is exceeded, the cold plate to be processed is determined to be in an abnormal state and step S3 is performed; otherwise, it is in a normal state and the process returns to step S1. S3. Obtain the cold plate temperature adjustment value according to the following temperature adjustment model. And adjust the temperature of the cold plate: ; in, The current temperature of the cold plate to be processed. This is an assessment value for ambient temperature. This is an evaluation value for the pumping speed of the cryogenic pump. , These are all weighting coefficients, chosen based on experience, and .

[0007] Preferably, the cold plate to be processed is divided into several detection areas with equal area. The sum of the areas of the cold plate in all detection areas is the total detection area, and the sum of the areas of the condensation layer on the cold plate in all detection areas is the total condensation layer area. Then: Condensation layer area factor ; The temperature difference between the condensation layer and the cold plate in each detection area is processed to obtain a temperature difference value. This temperature difference value is compared with a preset temperature difference range. If the temperature difference value is within the preset range, the detection area is marked as a normal area; otherwise, it is marked as an abnormal area. Abnormal region factor ; The temperature difference value in the abnormal region is compared with two endpoints of a preset temperature difference range. The endpoint value m closest to the temperature difference value is selected and the difference is processed with the temperature difference value to obtain the temperature difference deviation value. Then: Temperature difference factor .

[0008] Preferably, the current ambient temperature of the cryogenic pump is obtained, and the current ambient temperature is compared with two endpoints of the standard temperature range. The endpoint value n closest to the current ambient temperature is selected and the difference is calculated with the current ambient temperature to obtain the ambient temperature difference. Then: Ambient temperature assessment value .

[0009] Preferably, the current pumping speed of the cryogenic pump is obtained, and the current pumping speed is compared with two endpoints of the standard pumping speed range. The endpoint value 'o' closest to the current pumping speed is selected, and the difference between this endpoint and the current pumping speed is calculated to obtain the pumping speed difference. Then: Cryogenic pump pumping speed evaluation value .

[0010] Preferably, when multiple abnormal areas exist, the temperature difference factor is calculated using the largest temperature difference deviation value. .

[0011] In this method, the aforementioned cold plate condition assessment threshold, temperature difference preset range, standard temperature range, and standard air extraction speed range are all empirical values, set according to actual needs.

[0012] The second objective of this invention is to provide a cryogenic pump regeneration heating system for performing the cryogenic pump regeneration heating method described above.

[0013] A third objective of this invention is to provide a chip that stores a program for performing the cryogenic pump regeneration heating method described above.

[0014] The beneficial effects of this application are as follows: This invention can determine the state of a cold plate in real time by measuring the area and temperature of its condensation layer, providing timely feedback on the cold plate's status. Furthermore, it can analyze the cold plate's state, ambient temperature, and cryogenic pump's pumping speed, and precisely adjust the cold plate's temperature based on the analysis results. This keeps the condensation layer of the cold plate within a standard range, maintaining the cold plate's adsorption capacity, thereby improving the accuracy and efficiency of cryogenic pump regeneration heating. Detailed Implementation

[0015] The technical solution of the present invention will be described in more detail below with reference to the embodiments.

[0016] Example 1 A method for regenerating and heating a cryogenic pump involves assessing the condition of the cold plate to be treated based on the condensation layer area and temperature of the cold plate. When the cold plate is in an abnormal state, a temperature adjustment value for the cold plate is obtained. Adjust the temperature of the cold plate.

[0017] Includes the following steps: S1. Divide the cold plate to be processed into several detection areas based on average area. The sum of the areas of the cold plate in all detection areas is the total detection area, and the sum of the areas of the condensation layer on the cold plate in all detection areas is the total condensation layer area. Calculate the condensation layer area factor. : ; The temperature difference between the condensation layer and the cold plate in each detection area is processed to obtain a temperature difference value. This temperature difference value is compared with a preset temperature difference range. If the temperature difference value is within the preset range, the detection area is marked as a normal area; otherwise, it is marked as an abnormal area. An abnormal area factor is calculated. : ; The temperature difference value in the abnormal region is compared with two endpoints of a preset temperature difference range. The endpoint value m closest to the actual temperature difference value is selected and its difference is processed to obtain the temperature difference deviation value. The temperature difference factor is then calculated. : ; When multiple abnormal regions exist, the temperature difference factor mentioned above is calculated using the largest temperature difference deviation value. .

[0018] Then, calculate the cold plate condition assessment value according to the following formula. The condition of the cold plate to be processed is assessed based on the calculated cold plate condition evaluation value: ; In the formula, The area factor of the condensation layer. For abnormal region factors, For temperature difference factor, , , The weighting coefficients and ; S2. Evaluate the condition of the cold plate. Compared with the cold plate condition assessment threshold, when the cold plate condition assessment value If the cold plate condition assessment threshold is exceeded, the cold plate to be processed is determined to be in an abnormal state and step S3 is performed; otherwise, it is in a normal state and the process returns to step S1. S3. Obtain the current ambient temperature of the cryogenic pump, compare the current ambient temperature with two endpoints of the standard temperature range, select the endpoint value n closest to the current ambient temperature, perform difference processing with the current ambient temperature to obtain the ambient temperature difference, and calculate the ambient temperature assessment value. : ; Obtain the current pumping speed of the cryogenic pump, compare the current pumping speed with two endpoints of the standard pumping speed range, select the endpoint value closest to the current pumping speed (o), and calculate the difference between this endpoint and the current pumping speed to obtain the pumping speed difference. Then, calculate the cryogenic pumping speed evaluation value. : ; Then, based on the following temperature adjustment model, obtain the cold plate temperature adjustment value. And adjust the temperature of the cold plate: ; in, The current temperature of the cold plate to be processed. , These are all weighting coefficients, chosen based on experience, and .

[0019] In the above method, the cold plate acts as a cooling component, maintaining a low temperature using liquid helium. When gas molecules collide with the surface of the cold plate, they are cooled and condense into solids or liquids, forming a condensate layer. At this point, the temperature of the condensate layer should be close to the temperature of the cold plate. However, if the condensate layer gradually thickens, there will be some thermal resistance, causing the surface temperature of the condensate layer to be slightly higher than the temperature of the cold plate. If the temperature difference between the condensate layer and the cold plate is too large, it may cause the temperature of the condensate layer to rise, increasing the vapor pressure of the gas molecules and causing some of the condensate to re-evaporate. This would reduce the pumping efficiency of the cryogenic pump and even disrupt the vacuum environment. Therefore, it is necessary to maintain the temperature difference between the cold plate and the condensate layer within a certain range to ensure the stable existence of the condensate and to continuously capture gas molecules. Therefore, this method introduces a temperature difference value and calculates anomaly region factors. and temperature difference factor This is to correct for errors caused by the thickness of the condensation layer.

[0020] Example 2 A cryogenic pump regeneration heating system is provided for performing the cryogenic pump regeneration heating method in Example 1. The regeneration heating system includes a data acquisition module, an analysis module, and an adjustment module. The analysis module is electrically connected to the data acquisition module and the adjustment module, respectively. The data acquisition module includes a temperature measuring device installed on the cold plate. The adjustment module is used to adjust the cryogenic pump. The analysis module processes the information acquired from the data acquisition module and outputs the cold plate temperature adjustment value Ct to the adjustment module.

[0021] Specifically, the data acquisition module may include: The cold plate detection module is used to divide the cold plate into several detection areas on an even scale and obtain the status data of the cold plate within the detection area; the status data includes the area of ​​the condensation layer and the temperature of the condensation layer. The environmental monitoring module is used to detect the current ambient temperature.

[0022] The analysis module should include at least the following functions: The cold plate condition analysis module is used to generate cold plate condition assessment values ​​based on the area and temperature of the condensation layer. Furthermore, the cold plate condition analysis module also includes: The area analysis submodule is used to generate the condensation layer area factor based on the condensation layer temperature. The anomaly region analysis submodule is used to generate anomaly region factors based on the condensation layer temperature. The temperature difference analysis submodule is used to generate a temperature difference factor based on the temperature difference value; the temperature difference value refers to the difference between the temperature of the condensation layer and the temperature of the cold plate. The cold plate status determination module is used to determine whether the cold plate is in an abnormal state based on the cold plate status evaluation value; further, the cold plate status determination module may also include: The cold plate condition assessment value generation submodule is used to generate cold plate condition assessment values ​​based on the condensation layer area factor, abnormal area factor, and temperature difference factor. The cold plate temperature adjustment value generation module generates a cold plate temperature adjustment value based on the cold plate condition assessment value, ambient temperature assessment value, and air extraction speed assessment value when the cold plate condition is abnormal. Furthermore, the cold plate temperature adjustment value generation module also includes: The ambient temperature assessment submodule is used to generate an ambient temperature assessment value based on the ambient temperature. The pumping speed evaluation submodule is used to generate a pumping speed evaluation value based on the pumping speed. The data output submodule is used to establish an adjustment model. It substitutes the cold plate condition assessment value, ambient temperature assessment value, and air extraction speed assessment value into the adjustment model to generate the cold plate temperature adjustment value.

[0023] The adjustment module includes a temperature control module, which is used to adjust the temperature of the cold plate according to the cold plate temperature adjustment value, for example by controlling the power of the refrigeration unit in the cryogenic pump or adjusting the liquid nitrogen flow rate.

[0024] Example 3 A cryogenic pump uses the cryogenic pump regeneration heating method provided in this application during operation. The method is as follows: 1. Initial parameter settings The cryogenic pump cooling plate was divided into 16 equal-area detection regions (4×4 grid); the weighting coefficients in the temperature adjustment model were set empirically. =0.6, =0.4 ( + =1); Based on experience, the preset range for the temperature difference value is set to [0.5K, 2.0K]; Based on experience, the threshold for evaluating the cold plate condition is set to 0.6, that is, when the cold plate condition evaluation value Pb ≥ 0.6, the cold plate is determined to be in an abnormal state; Based on experience, the weighting coefficients ai are set as follows: =0.5, =0.3, =0.2(∑ =1); Based on experience, the standard temperature range of the environment is set as [290K, 300K], and the standard pumping speed range is [1000 L / s, 1200 L / s].

[0025] Measure the current temperature of the cold plate It is 60K.

[0026] 2. Evaluate and adjust according to the following steps: S1. Calculate the cold plate condition assessment value Pb In this embodiment, the total detection area is divided into 16 regions, and the total area of ​​the condensation layer occupies 10 regions. Therefore: Condensation layer area factor =0.625; In this embodiment, the temperature difference detection results for each region show that 12 regions have temperature differences ∈ [0.5K, 2.0K], which are considered normal. Four regions have temperature differences exceeding the limit, with values ​​of 2.3K, 2.5K, 0.3K, and 0.2K respectively. Therefore: Abnormal region factor ; The temperature difference values ​​of 2.3K, 2.5K, 0.3K, and 0.2K in the abnormal region are compared with the two endpoints of the preset temperature difference range, 0.5K and 2.0K. The endpoint value m closest to the temperature difference value is selected and the difference value is processed to obtain temperature difference deviation values ​​of 0.3K, 0.5K, 0.2K, and 0.3K, respectively. Therefore, the temperature difference factor is calculated based on the maximum temperature difference deviation value of 0.5K. ,but: Temperature difference factor ; Calculated , , Substituting the cold plate condition assessment value Pb, we obtain: ; S2. State Determination because The cold plate is determined to be in normal condition and no temperature adjustment is required. Return to step S1 to continue testing.

[0027] Abnormal scenario simulation

[0028] Assuming changes occur during monitoring, three new abnormal areas are added, and the most severe temperature difference rises to 3.0K. At this point, the total number of abnormal areas is 7, and the condensation layer area factor... If it remains unchanged, then: Abnormal region factor ; Temperature difference factor ; ; at this time If the cold plate is determined to be in normal condition and no temperature adjustment is needed, return to step S1 to continue testing.

[0029] Until a certain period, the number of abnormal areas increased to 10, with the most severe temperature difference reaching 3.2K, and the condensation layer area factor... If it remains unchanged, then: Abnormal region factor ; Temperature difference factor ; ; at this time If the cold plate is determined to be in an abnormal state, proceed to step S3 to adjust the temperature.

[0030] S3. Adjust temperature The current ambient temperature of the cryogenic pump is 303K. This is compared to the two endpoints of the standard temperature range, 209K and 300K. The endpoint closest to the current ambient temperature (n=300K) is selected, and the difference is calculated between this endpoint and the current ambient temperature, resulting in an ambient temperature difference of 3K. Therefore: Ambient temperature assessment value ; The current pumping speed is 950 L / s. This is compared to the two endpoints of the standard pumping speed range, 1000 L / s and 1200 L / s. The endpoint closest to the current pumping speed is selected, and the difference is calculated between this endpoint and the current pumping speed. The resulting pumping speed difference is 50 L / s. Therefore: Cryogenic pump pumping speed evaluation value ; Cold plate temperature adjustment value : ; By controlling the power of the cryogenic pump or adjusting the liquid nitrogen flow rate, the temperature of the cold plate was reduced from the current temperature to 38.52K, and this was continuously monitored until... It has returned to normal.

[0031] As can be seen from the above embodiments, the regenerative heating method provided in this application has good feasibility in adjusting the cryogenic pump.

[0032] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for regenerating and heating a cryogenic pump, characterized in that, Based on the condensation layer area and condensation layer temperature of the cold plate to be treated by the cryogenic pump, the condition of the cold plate is assessed. When the cold plate is in an abnormal state, the cold plate temperature adjustment value is obtained. Adjust the temperature of the cold plate; Includes the following steps: S1. Obtain the condensation layer area and condensation layer temperature of the cold plate to be processed, and calculate the cold plate condition assessment value according to the following formula. The condition of the cold plate to be processed is assessed based on the calculated cold plate condition evaluation value: ； In the formula, The area factor of the condensation layer. For abnormal region factors, For temperature difference factor, , , The weighting coefficients and ; S2. Evaluate the condition of the cold plate. Compared with the cold plate condition assessment threshold, when the cold plate condition assessment value If the cold plate condition assessment threshold is exceeded, the cold plate to be processed is determined to be in an abnormal state and step S3 is performed; otherwise, it is in a normal state and the process returns to step S1. S3. Obtain the cold plate temperature adjustment value according to the following temperature adjustment model. And adjust the temperature of the cold plate: ； in, The current temperature of the cold plate to be processed. This is an assessment value for ambient temperature. This is an evaluation value for the pumping speed of the cryogenic pump. , These are all weighting coefficients, chosen based on experience, and .

2. The cryogenic pump regeneration heating method as described in claim 1, characterized in that, The cold plate to be processed is divided into several testing areas based on its average area. The sum of the areas of the cold plate in all testing areas is the total testing area, and the sum of the areas of the condensation layer on the cold plate in all testing areas is the total condensation layer area. Then: Condensation layer area factor ; The temperature difference between the condensation layer and the cold plate in each detection area is processed to obtain a temperature difference value. This temperature difference value is compared with a preset temperature difference range. If the temperature difference value is within the preset range, the detection area is marked as a normal area; otherwise, it is marked as an abnormal area. Abnormal region factor ; The temperature difference value in the abnormal region is compared with two endpoints of a preset temperature difference range. The endpoint value m closest to the temperature difference value is selected and the difference is processed with the temperature difference value to obtain the temperature difference deviation value. Then: Temperature difference factor .

3. The cryogenic pump regeneration heating method as described in claim 1, characterized in that, Obtain the current ambient temperature of the cryogenic pump, compare the current ambient temperature with two endpoints of the standard temperature range, select the endpoint value n closest to the current ambient temperature, and perform difference processing on the difference to obtain the ambient temperature difference. Then: Ambient temperature assessment value .

4. The cryogenic pump regeneration heating method as described in claim 1, characterized in that, Obtain the current pumping speed of the cryogenic pump, compare the current pumping speed with the two endpoints of the standard pumping speed range, select the endpoint value 'o' closest to the current pumping speed, and perform difference processing with the current pumping speed to obtain the pumping speed difference. Then: Cryogenic pump pumping speed evaluation value .

5. The cryogenic pump regeneration heating method as described in claim 2, characterized in that, When multiple abnormal regions exist, the temperature difference factor is calculated using the largest temperature difference deviation. .

6. A cryogenic pump regeneration heating system for performing the cryogenic pump regeneration heating method as described in any one of claims 1-5.

7. A chip storing a program for performing the cryogenic pump regeneration heating method as described in any one of claims 1-5.

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