CN113280986A - Method for detecting leakage rate of furnace tube vacuum pump - Google Patents

Abstract

The invention belongs to the field of photovoltaic crystalline silicon batteries. A method for detecting the leakage rate of a furnace tube vacuum pump comprises the steps that for the same furnace tube, firstly, the furnace tube is vacuumized by the intact vacuum pump, when the pressure in the furnace tube is 300mTorr, the furnace tube is ventilated, the pressure in the furnace tube is kept unchanged, the corresponding relation between the ventilation flow S and the opening gamma of a butterfly valve of the vacuum pump is measured every other minute, and a straight line with the slope beta is obtained through fitting; installing a vacuum pump to be tested on a furnace tube, starting the vacuum pump to be tested to pump vacuum, when the pressure in the furnace tube is 300mTorr, ventilating the furnace tube, keeping the pressure in the furnace tube unchanged, observing the butterfly valve opening gamma of the vacuum pump to be tested, and obtaining the butterfly valve opening gamma of the vacuum pump after the butterfly valve opening gamma is stable₀Vacuum pump leak rate Q to be measured_{Leakage net}=P_stp*(β/γ₀) If Q is_{Leakage net}If the leakage rate is more than or equal to 800PaL/S, the leakage rate Q of the vacuum pump to be tested is obtained_{Leakage net}The real leakage rate of the vacuum pump to be measured is obtained.

Description

Method for detecting leakage rate of furnace tube vacuum pump

Technical Field

The invention relates to the field of solar cell production.

Background

In the production process of the industrial photovoltaic cell, the integrity of equipment can ensure the stability of the process, the problem of the leakage rate of a vacuum pump of coating process equipment is directly related to the quality of a coating film, and the professional side leakage equipment is high in price and complex in operation, so that the equipment is not beneficial to application in the production process.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: how to provide a method for rapidly detecting the leak rate of a furnace tube vacuum pump.

The technical scheme adopted by the invention is as follows: a method for detecting the leakage rate of a furnace tube vacuum pump is carried out according to the following steps

Step one, installing a vacuum pump to be tested on a furnace tube, starting the vacuum pump to be tested to vacuumize, detecting whether the internal pressure of the furnace tube can be lower than 50mTorr, and if not, indicating that the leakage rate of the vacuum pump is greater than or equal to 2000 PaL/S;

secondly, for the same furnace tube, firstly, vacuumizing the furnace tube by using a finished vacuum pump, ventilating the furnace tube when the pressure in the furnace tube is 300mTorr, keeping the pressure in the furnace tube unchanged, measuring the corresponding relation between the ventilation flow S and the opening gamma of a butterfly valve of the vacuum pump every minute, establishing a direct coordinate system by taking gamma as a horizontal coordinate and S as a vertical coordinate, and fitting to obtain a straight line with the slope beta;

step three, installing the vacuum pump to be tested on the furnace tube, starting the vacuum pump to be tested to pump vacuum, and when the pressure in the furnace tube is300mTorr, ventilating the furnace tube, keeping the pressure in the furnace tube unchanged, observing the opening gamma of the butterfly valve of the vacuum pump to be detected, and obtaining the opening gamma of the butterfly valve of the vacuum pump after the opening gamma is stable₀Vacuum pump leak rate Q to be measured_{Leakage net}=P_stp*(β/γ₀) Wherein P is_stpIs the pressure difference between the inside and outside of the furnace tube, P_stpTaking the atmospheric pressure, if Q_{Leakage net}If the leakage rate is more than or equal to 800PaL/S, the leakage rate Q of the vacuum pump to be tested is obtained_{Leakage net}The real leakage rate of the vacuum pump to be measured is obtained, otherwise, the step four is carried out;

and step four, for the same furnace tube, firstly, vacuumizing the furnace tube by using a finished vacuum pump, when the pressure in the furnace tube is lower than 50mTorr, closing the vacuum pump, ventilating the furnace tube, gradually increasing the ventilation flow to be 500sccm at the maximum, recording the ventilation flow of the furnace tube once when the ventilation flow is increased by 50sccm, and simultaneously calculating the pressure increase rate omega of the furnace tube_ΔPTo increase the rate omega of the furnace pressure_ΔPThe abscissa and the furnace tube ventilation flow are used as the ordinate, and a straight line with the slope of alpha is obtained by establishing direct coordinate system fitting;

step five, installing a vacuum pump to be tested on the furnace tube, starting the vacuum pump to be tested to pump vacuum, when the pressure in the furnace tube is lower than 50mTorr, closing the vacuum pump, recording the pressure increase value of the furnace tube per minute, and taking the average value as the pressure increase rate omega of the furnace tube_ΔPTrue leakage rate Q of vacuum pump to be measured_{Leak repairing}=P_stp*(ω_ΔP/α)，P_stpIs the pressure difference between the inside and outside of the furnace tube, P_stpTaking the atmospheric pressure, Q_{Leak repairing}Less than 800 PaL/S.

The invention has the beneficial effects that: the invention provides a method for detecting the leak rate of a furnace tube vacuum pump, which can be used according to different leak rates, has low cost and simple operation and is beneficial to popularization and application in industrial production.

Detailed Description

A method for detecting the leakage rate of a furnace tube vacuum pump comprises the following steps

Step one, installing a vacuum pump to be tested on a furnace tube, starting the vacuum pump to be tested to vacuumize, detecting whether the internal pressure of the furnace tube can be lower than 50mTorr, and if not, indicating that the leakage rate of the vacuum pump is greater than or equal to 2000 PaL/S; when the leakage rate of the vacuum pump is more than or equal to 2000PaL/S, the leakage rate can be directly observed manually without testing and detecting.

Secondly, for the same furnace tube, firstly, vacuumizing the furnace tube by using a finished vacuum pump, ventilating the furnace tube when the pressure in the furnace tube is 300mTorr, keeping the pressure in the furnace tube unchanged, measuring the corresponding relation between the ventilation flow S and the opening gamma of a butterfly valve of the vacuum pump every minute, establishing a direct coordinate system by taking gamma as a horizontal coordinate and S as a vertical coordinate, and fitting to obtain a straight line with the slope beta; the ventilation flow rate S and the opening gamma of the butterfly valve of the vacuum pump are in a linear relation.

Step three, installing the vacuum pump to be tested on the furnace tube, starting the vacuum pump to be tested to pump vacuum, when the pressure in the furnace tube is 300mTorr, ventilating the furnace tube, keeping the pressure in the furnace tube unchanged, observing the opening gamma of the butterfly valve of the vacuum pump to be tested, and obtaining the opening gamma of the butterfly valve of the vacuum pump after the opening gamma is stabilized₀Vacuum pump leak rate Q to be measured_{Leakage net}=P_stp*(β/γ₀) Wherein P is_stpThe pressure difference between the inside and the outside of the furnace tube (the pressure in the furnace tube is 300mTorr and is very small relative to the atmospheric pressure of the outside), P is calculated_stpTaking the atmospheric pressure, if Q_{Leakage net}If the leakage rate is more than or equal to 800PaL/S, the leakage rate Q of the vacuum pump to be tested is obtained_{Leakage net}The real leakage rate of the vacuum pump to be measured is obtained, otherwise, the step four is carried out;

and step four, for the same furnace tube, firstly, vacuumizing the furnace tube by using a finished vacuum pump, when the pressure in the furnace tube is equal to 30mTorr, closing the vacuum pump, ventilating the furnace tube, gradually increasing the ventilation flow to be 500sccm at the maximum, recording the ventilation flow of the furnace tube once when the ventilation flow is increased by 50sccm, and simultaneously calculating the pressure increase rate omega of the furnace tube_ΔPTo increase the rate omega of the furnace pressure_ΔPThe abscissa and the furnace tube ventilation flow are used as the ordinate, and a straight line with the slope of alpha is obtained by establishing direct coordinate system fitting;

step five, installing a vacuum pump to be tested on the furnace tube, starting the vacuum pump to be tested to pump vacuum, when the pressure in the furnace tube is lower than 50mTorr, closing the vacuum pump, recording the pressure increase value of the furnace tube per minute, and taking the average value as the pressure increase rate omega of the furnace tube_ΔPTrue leakage rate Q of vacuum pump to be measured_{Leak repairing}=P_stp*(ω_ΔP/α)，P_stpThe pressure difference between the inside and the outside of the furnace tube (the pressure in the furnace tube is very small relative to the atmospheric pressure of the outside), P_stpTaking the atmospheric pressure, Q_{Leak repairing}Less than 800 PaL/S.

Claims (1)

1. A method for detecting the leak rate of a furnace tube vacuum pump is characterized by comprising the following steps: the following steps are carried out

Step one, installing a vacuum pump to be tested on a furnace tube, starting the vacuum pump to be tested to vacuumize, detecting whether the internal pressure of the furnace tube can be lower than 50mTorr, and if not, indicating that the leakage rate of the vacuum pump is greater than or equal to 2000 PaL/S;

secondly, for the same furnace tube, firstly, vacuumizing the furnace tube by using a finished vacuum pump, ventilating the furnace tube when the pressure in the furnace tube is 300mTorr, keeping the pressure in the furnace tube unchanged, measuring the corresponding relation between the ventilation flow S and the opening gamma of a butterfly valve of the vacuum pump every minute, establishing a direct coordinate system by taking gamma as a horizontal coordinate and S as a vertical coordinate, and fitting to obtain a straight line with the slope beta;

step three, installing the vacuum pump to be tested on the furnace tube, starting the vacuum pump to be tested to pump vacuum, when the pressure in the furnace tube is 300mTorr, ventilating the furnace tube, keeping the pressure in the furnace tube unchanged, observing the opening gamma of the butterfly valve of the vacuum pump to be tested, and obtaining the opening gamma of the butterfly valve of the vacuum pump after the opening gamma is stabilized₀Vacuum pump leak rate Q to be measured_{Leakage net}=P_stp*(β/γ₀) Wherein P is_stpIs the pressure difference between the inside and outside of the furnace tube, P_stpTaking the atmospheric pressure, if Q_{Leakage net}If the leakage rate is more than or equal to 800PaL/S, the leakage rate Q of the vacuum pump to be tested is obtained_{Leakage net}The real leakage rate of the vacuum pump to be measured is obtained, otherwise, the step four is carried out;

and step four, for the same furnace tube, firstly, vacuumizing the furnace tube by using a finished vacuum pump, when the pressure in the furnace tube is lower than 50mTorr, closing the vacuum pump, ventilating the furnace tube, gradually increasing the ventilation flow to be 500sccm at the maximum, recording the ventilation flow of the furnace tube once when the ventilation flow is increased by 50sccm, and simultaneously calculating the pressure increase rate omega of the furnace tube_ΔPTo increase the rate omega of the furnace pressure_ΔPThe abscissa and the furnace tube ventilation flow are used as the ordinate, and a straight line with the slope of alpha is obtained by establishing direct coordinate system fitting;

step five, installing a vacuum pump to be tested on the furnace tube, starting the vacuum pump to be tested to pump vacuum, when the pressure in the furnace tube is lower than 50mTorr, closing the vacuum pump, recording the pressure increase value of the furnace tube per minute, and taking the average value as the pressure increase rate omega of the furnace tube_ΔPTrue leakage rate Q of vacuum pump to be measured_{Leak repairing}=P_stp*(ω_ΔP/α)，P_stpIs the pressure difference between the inside and outside of the furnace tube, P_stpTaking the atmospheric pressure, Q_{Leak repairing}Less than 800 PaL/S.