阅读说明：本技术 一种用于冷镜法极低露点快速测量的气路系统 (Gas circuit system for quickly measuring extremely low dew point by cold mirror method ) 是由 宋巍巍 顾正华 盖文 刘向波 韩杰 梁文清 张文清 顾光武 曾星 于 2019-11-28 设计创作，主要内容包括：本发明公开了一种用于冷镜法极低露点快速测量的气路系统,该方案包括有进气口、不锈钢进气管道、测量腔、镜面、制冷机、质量流量控制器MFC、不锈钢出气管道和出气口；镜面设置在测量腔内；镜面通过制冷管路与设置在测量腔外的制冷机连接；不锈钢进气管道一端与进气口连接,另一端与测量腔连通；不锈钢出气管道一端与出气口连接,另一端与测量腔连通；质量流量控制器MFC串联安装在出气管道上。该方案可以避免由于MFC内部容易存水导致内表面材料缓慢释放水分,影响测量速度和精度。同时通过电伴热升温,减少气路管道内壁材料吸附水份的含量,提高露点测量速度。(The invention discloses a gas path system for quick measurement of an extremely low dew point by a cold mirror method, which comprises a gas inlet, a stainless steel gas inlet pipeline, a measurement cavity, a mirror surface, a refrigerator, a mass flow controller MFC, a stainless steel gas outlet pipeline and a gas outlet; the mirror surface is arranged in the measuring cavity; the mirror surface is connected with a refrigerator arranged outside the measuring cavity through a refrigeration pipeline; one end of the stainless steel air inlet pipeline is connected with the air inlet, and the other end of the stainless steel air inlet pipeline is communicated with the measuring cavity; one end of the stainless steel gas outlet pipeline is connected with the gas outlet, and the other end of the stainless steel gas outlet pipeline is communicated with the measuring cavity; the mass flow controller MFC is installed in series on the outlet pipe. The scheme can avoid the influence on the measurement speed and precision due to the fact that water is easy to be stored in the MFC, and the moisture is slowly released from the inner surface material. Meanwhile, the content of water adsorbed by the inner wall material of the gas path pipeline is reduced by electric tracing temperature rise, and the dew point measurement speed is increased.)

1. The utility model provides a gas circuit system that is used for extremely low dew point rapid survey of cold mirror method, characterized by: comprises an air inlet, a stainless steel air inlet pipeline, a measuring cavity, a mirror surface, a refrigerator, a mass flow controller MFC, a stainless steel air outlet pipeline and an air outlet; the mirror surface is arranged in the measuring cavity; the mirror surface is connected with a refrigerator arranged outside the measuring cavity through a refrigeration pipeline; one end of the stainless steel air inlet pipeline is connected with the air inlet, and the other end of the stainless steel air inlet pipeline is communicated with the measuring cavity; one end of the stainless steel gas outlet pipeline is connected with the gas outlet, and the other end of the stainless steel gas outlet pipeline is communicated with the measuring cavity; the mass flow controller MFC is installed on the gas outlet pipeline in series.

2. The gas circuit system for the quick measurement of the extremely low dew point by the cold mirror method as claimed in claim 1, which is characterized in that: and the outer part of the tail end of one side of the stainless steel air inlet pipeline, which is close to the measuring cavity, is provided with a high-efficiency radiator.

3. The gas circuit system for the quick measurement of the extremely low dew point by the cold mirror method as claimed in claim 1, which is characterized in that: an electric tracing band is arranged outside the stainless steel air inlet pipeline and is connected with a temperature controller.

4. The gas circuit system for the quick measurement of the extremely low dew point by the cold mirror method as claimed in claim 1, which is characterized in that: and a bypass branch is arranged on the stainless steel air inlet pipeline and is communicated with the safety relief valve.

5. The gas circuit system for the quick measurement of the extremely low dew point by the cold mirror method as claimed in claim 1, which is characterized in that: a circular hole is formed in the center of the bottom of the measuring cavity; the mirror surface can extend into the measuring cavity through the circular hole; and the round hole is provided with a sealing ring which can form a sealing structure with the refrigeration pipeline.

Technical Field

The invention relates to the field of gas dew point detection by a cold mirror method, in particular to a gas path system for quickly measuring an extremely low dew point by the cold mirror method.

Background

The dew point temperature of a gas is the temperature at which the gas cools to saturation without changing both the moisture content and the gas pressure. In the existing dew point detection technology, a common self-adjusting gas path device mainly uses an MFC (gas mass flow meter) to automatically control the flow of various clean and dry gases, a mass flow controller consists of a flow sensor, a flow divider channel, a flow regulating valve, an amplification controller and the like, can conveniently and accurately monitor various gases flowing in a pipeline, is convenient to use, and the conventional metering system is arranged in a dew point detection system.

Moisture adsorbed by the internal surface materials of the gas path pipes and accessories (joints, valves, etc.) is gradually released as the gas flow passes through, and the measurement of the true dew point of the gas may be affected. The measurement work of the metering mechanism is generally carried out in a constant-temperature and constant-humidity laboratory, under the working condition, the air source with the dew point temperature of about minus 80 ℃ is detected, and a common metering system requires that the air channel pipeline is blown off for more than 24 hours, so that the speed and the accuracy of dew point detection are prevented from being influenced due to the release of water adsorbed by the inner surface material of the metering mechanism.

In actual industrial conditions, the dew point of the measured gas may fluctuate within a certain range, and the measuring equipment and the gas circuit accessories are required to be capable of quickly responding, and the measurement of the extremely low dew point below-80 ℃ can be completed within 30 minutes or even shorter. The application data of the MFC in the field of dew point detection is inquired, and the research of the influence of the MFC application on the low-temperature dew point measurement speed is not clearly related. In practical research and development, the gas circuit device is found to be difficult to meet the requirement of rapid measurement in the process of extremely low temperature dew point measurement due to the reasons that the MFC has a complex internal structure and is easy to store water, and the moisture adsorbed on the inner surfaces of the gas circuit pipeline and the accessories is difficult to blow completely in a short time.

Therefore, it is desirable to provide a gas circuit system for fast measurement of extremely low dew point, which can automatically adjust the gas flow rate in real time through an MFC (gas mass flow meter), and avoid affecting the speed and accuracy of dew point measurement due to slow release of water and the like from the water stored inside the MFC, the material of the inner surface of the gas circuit pipeline and the accessories.

Disclosure of Invention

The invention aims to overcome the defects that the precision and the speed of low-temperature dew point measurement are influenced by the reasons that the MFC has a complex internal structure and is easy to store water, and the materials on the inner surfaces of pipelines and accessories absorb water and slowly release the water, and the like, and provides a gas circuit system for quickly measuring the extremely low dew point by a cold mirror method.

The technical scheme provided by the invention is as follows:

a gas path system for quick measurement of extremely low dew point by a cold mirror method comprises a gas inlet, a stainless steel gas inlet pipeline, a measurement cavity, a mirror surface, a refrigerator, a mass flow controller MFC, a stainless steel gas outlet pipeline and a gas outlet; the mirror surface is arranged in the measuring cavity; the mirror surface is connected with a refrigerator arranged outside the measuring cavity through a refrigeration pipeline; one end of the stainless steel air inlet pipeline is connected with the air inlet, and the other end of the stainless steel air inlet pipeline is communicated with the measuring cavity; one end of the stainless steel gas outlet pipeline is connected with the gas outlet, and the other end of the stainless steel gas outlet pipeline is communicated with the measuring cavity; the mass flow controller MFC is installed in series on the outlet pipe.

The scheme is preferably as follows: the end of the stainless steel air inlet pipeline close to one side of the measuring cavity is externally provided with an efficient radiator.

The scheme is preferably as follows: an electric tracing band is arranged outside the stainless steel air inlet pipeline and is connected with a temperature controller.

The scheme is preferably as follows: the stainless steel air inlet pipeline is provided with a bypass branch which is communicated with the safety relief valve.

The scheme is preferably as follows: a circular hole is formed in the center of the bottom of the measuring cavity; the mirror surface can extend into the measuring cavity through the round hole; the round hole is provided with a sealing ring which can form a sealing structure with the refrigeration pipeline.

Due to the adoption of the technical scheme, the invention has the beneficial effects that: by arranging and installing the MCF at the downstream of the measuring cavity, the phenomenon that water stored in the MFC flows through the measuring cavity along with the detected gas to influence dew point measurement during dew point measurement is avoided. Meanwhile, in order to avoid the increase of the pressure at the upstream of the gas circuit, the pressure in the measuring cavity is increased and the measurement is influenced due to the fact that the opening degree of the gate is reduced through MFC adjustment, a branch bypass safety relief valve is arranged at the upstream of the measuring cavity and on the stainless steel gas inlet pipeline, and the influence of the pressure fluctuation of the gas circuit on the measurement is avoided.

The stainless steel air inlet pipeline is provided with the electric tracing band and the temperature controller, the saturated vapor pressure of water on the inner surface of the air path pipeline is improved through temperature rise, so that the air path pipeline can be quickly dehydrated and dehumidified when air flow passes through the air path pipeline, and the phenomenon that the measurement speed is influenced by slow release of water adsorbed by the inner wall materials of the pipeline and the accessories is avoided.

The round hole is formed in the center of the bottom of the measuring cavity, the mirror surface extends into the measuring cavity from the round hole, a sealing structure is formed between the refrigerating pipeline and the round hole through a sealing ring, air is prevented from entering the measuring cavity to affect measurement, in addition, the mirror surface and the refrigerating machine are integrated into a whole to improve the heat conduction efficiency, the refrigerating machine is guaranteed to be capable of rapidly reducing the temperature of the mirror surface from the ambient temperature to below-100 ℃, and the extremely-low dew point measuring speed is accelerated.

The high-efficiency radiator is arranged outside the stainless steel gas inlet pipeline close to the tail end of the measurement cavity, so that high-temperature gas is quickly cooled to be close to the ambient temperature through the high-efficiency radiator before the detected gas enters the measurement cavity, and the high-temperature gas is prevented from influencing refrigeration of the refrigerator and causing the extremely-low dew point measurement speed to fall.

In conclusion, the MFC is arranged at the downstream of the measuring cavity, so that the gas flow can be automatically adjusted in real time through the MFC, and the influence on the measuring speed and the measuring precision due to the fact that water is easily stored in the MFC and the moisture is slowly released by the inner surface material can be avoided. Meanwhile, the content of water adsorbed by the inner wall material of the gas path pipeline is reduced by electric tracing temperature rise, and the dew point measurement speed is increased. Compared with the prior art, the scheme has prominent substantive features and remarkable progress, and the beneficial effects of the implementation are also obvious.

Drawings

FIG. 1 is a schematic diagram of a gas path system for rapid measurement of an extremely low dew point by a cold mirror method.

In the figure, 1 is an air inlet, 2 is a temperature controller, 3 is a safety pressure relief valve, 4 is a stainless steel air inlet pipeline, 5 is an electric tracing band, 6 is a high-efficiency radiator, 7 is a measuring cavity, 8 is a mirror surface, 9 is a refrigerator, 10 is a mass flow controller MFC, 11 is a stainless steel air outlet pipeline, 12 is an air outlet, and 13 is a refrigerating pipeline.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Any feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.