Patent Application
20210237005
The disclosure relates to the field of electrical technology, in particular to the technical field of preparation for mixed insulating medium.
As an irreplaceable key power transmission and transformation equipment in modern power grids, the gas-insulated equipment has the advantages of compact structure, being less affected from environmental factors, and high operational safety and reliability. SF6 gas is currently the most widely used insulating medium in the power industry due to its excellent insulation and arc extinguishing performance.
However, SF6 gas has a strong greenhouse effect. In the “Kyoto Protocol” signed in 1997, SF6, CO2, CH4, N2O, PFC, and HFC are clearly listed as greenhouse gases that are restricted for emission. At this stage, there is still a huge demand for equipment using SF6 as insulation and arc extinguishing medium. In middle-high voltage field, the annual output of related equipment is still increasing by a double-digit percentage. To completely eliminate the impact of SF6 gas on the environment, the most effective way is to develop and use environment-friendly gas or its mixed gas to replace SF6.
Pipeline power transmission is an important way to solve the transmission bottleneck in special geographical environment. SF6 gas-insulated transmission pipelines (GIL) with a cumulative length of hundreds of kilometers have been laid in the world, with voltage levels covering 72 kV˜1200 kV. GIL uses a large amount of gas, and there is an urgent need to develop environmentally friendly transmission pipelines that do not contain SF6 gas. The 3M company has developed an environmentally friendly insulating gas C4F7N that does not contain SF6, and the GE company and ABB company have applied it to 420 kV GIL switchgear. The insulation performance of C4F7N is more than 2.2 times that of SF6 gas, and the greenhouse effect coefficient is only one-tenth of that of SF6 gas. While it is considered to be the most promising new insulating medium, the liquefaction temperature of C4F7N is relatively high (approximately −4.7° C. under one atmosphere), and it needs to be mixed with a certain proportion of buffer gas (such as CO2) when used.
Gas mixing ratio is a very important parameter for mixed insulating gas equipment. If the ratio is greater than the rated value, the mixed gas may liquefy under certain conditions; if the ratio is less than the rated value, the insulation strength of the mixed gas will be insufficient. At present, the national key research and development special plan “Environmental protection pipeline transmission key technology” has been jointly tackled by more than a dozen domestic top scientific research institutions, researching the scientific and technological issues in the application of the new mixed insulating gas C4F7N/CO2 in UHV GIL. The accurate preparation of C4F7N/CO2 mixed gas is a technical problem that must be solved before the scientific research and engineering application of C4F7N/CO2 mixed gas. On one hand, scientific research institutions need to accurately prepare a tiny amount of C4F7N/CO2 mixed gas for laboratory research; on the other hand, equipment manufacturers develop 1000 kV GIL, which has a large gas chamber volume and needs to use a large amount of C4F7N/CO2 mixed gas.
There are mainly two existing mixed gas preparation technologies. One is the dynamic gas preparation and inflation method, that is, the two gases are mixed first, and then the equipment is inflated. For example, Chinese patent application No. 2017109526872 discloses an eight-channel dynamic gas preparation method and system for sulfur hexafluoride. The method uses mass flow meters to control the flows of two gases, with high preparation accuracy and simple operation. However, the C4F7N vaporization speed is too slow, which limits the C4F7N/CO2 mixed gas preparation speed, and a large amount of mixed gas cannot be prepared quickly. Another method is partial pressure gas preparation using Dalton's law of partial pressure. First, the equipment is filled with C4F7N gas of a certain partial pressure, and then with CO2 gas of a certain partial pressure. In actual operation, the degree of automation is low and the gas preparation accuracy is poor, and it takes at least 24 hours for the two gases to be uniformly mixed in the equipment, which seriously affects the on-site construction period.
The disclosure aims to solve the technical problem that the C4F7N vaporization speed is too slow, which limits the preparation speed of the C4F7N/CO2 mixed gas and a large amount of mixed gas cannot be prepared quickly.
The present disclosure solves the above technical problems through the following technical means.
A multifunctional C4F7N/CO2 mixed gas preparation system, including a C4F7N input port, a CO2 input port, a C4F7N heat exchanger, a CO2 heat exchanger, a C4F7N/CO2 mixing pipeline structure, and a C4F7N/CO2 mixed gas output pipeline structure;
the C4F7N heat exchanger is used to heat and vaporize C4F7N input through the C4F7N input port; the CO2 heat exchanger is used to heat and vaporize CO2 input through the CO2 input port; the C4F7N/CO2 mixing pipeline structure is used to mix the vaporized C4F7N and CO2, and the C4F7N/CO2 mixed gas output pipeline structure is used to output the C4F7N/CO2 mixed gas;
the C4F7N/CO2 mixing pipeline structure includes a C4F7N/CO2 dynamic gas preparation pipeline structure and a C4F7N/CO2 partial pressure mixing pipeline structure;
the C4F7N/CO2 dynamic gas preparation pipeline structure and the C4F7N/CO2 partial pressure mixing pipeline structure are arranged in parallel; the C4F7N/CO2 dynamic gas preparation pipeline structure is used to quantitatively mix the vaporized CO2 and C4F7N; and the C4F7N/CO2 partial pressure mixing pipeline structure is used to mix the vaporized CO2 and C4F7N at certain pressures;
the C4F7N/CO2 partial pressure mixing pipeline structure includes partial pressure mixing tanks for mixing the CO2 and C4F7N of certain pressures; and a plurality of partial pressure mixing tanks are arranged in parallel.
The present disclosure first perform vacuum treatment to the gas preparation system; C4F7N input through the C4F7N input port is heated and vaporized through the C4F7N heat exchanger; CO2 input through the CO2 input port is heated and vaporized through the CO2 heat exchanger; the vaporized C4F7N and CO2 are mixed in the C4F7N/CO2 mixing pipeline structure; the vaporized C4F7N and CO2 are quantitatively mixed in the C4F7N/CO2 dynamic mixing pipeline structure; the vaporized C4F7N and CO2 are mixed at certain pressures through the C4F7N/CO2 partial pressure mixing pipeline structure; a plurality of the partial pressure mixing tanks are arranged in parallel and alternately perform gas preparation and output; and the C4F7N/CO2 mixed gas is output through the C4F7N/CO2 mixed gas output pipeline structure.
In the present disclosure, a C4F7N heat exchanger is installed at the C4F7N input port, and a CO2 heat exchanger is installed at the CO2 input port, so that the C4F7N and CO2 input are heated and vaporized respectively to ensure that the C4F7N and CO2 input to the subsequent pipelines are always in a stable gaseous state. In this way, the technical problems that the C4F7N vaporization speed is too slow and limit the C4F7N/CO2 mixed gas preparation speed, and that a large amount of mixed gas cannot be quickly prepared are effectively solved. By performing heat exchange and vaporization to C4F7N and CO2 at the input source, the stability of the state of the gas source input to the system is significantly ensured, and the gas preparation rate is improved.
Since the C4F7N/CO2 mixing pipeline structure of the present disclosure includes the C4F7N/CO2 dynamic gas preparation pipeline structure and the C4F7N/CO2 partial pressure mixing pipeline structure, it can realize two gas preparation modes: quantitative flow gas preparation and partial pressure gas preparation, realizing the versatility of the gas preparation of the present disclosure. According to different gas preparation purposes, different gas preparation pipeline structures can be switched: it can not only adopt the manner of quantitative flow gas preparation to meet the requirements of a tiny amount of C4F7N/CO2 mixed gas in the laboratory, but can also adopt the manner of partial pressure preparation to quickly prepare a large amount of C4F7N/CO2 mixed gas of different pressures. In addition, because the C4F7N heat exchanger is installed at the C4F7N input port and the CO2 heat exchanger is installed at the CO2 input port in the present disclosure, the CO2 and C4F7N input to the system are pre-vaporized, so that the quantitative flow gas preparation of the present disclosure also has application prospects for a large amount of C4F7N/CO2 mixed gas.
In the present disclosure, the two gas preparation pipeline structures of the C4F7N/CO2 dynamic gas preparation pipeline structure 51 and the C4F7N/CO2 partial pressure mixing pipeline structure 52 are integrated into an overall pipeline structure, so that the gas preparation system of the present disclosure has a high equipment integration rate, and can effectively reduce the cost of the system, simplify the complexity of the control and improve the flexibility of preparation.
Preferably, the C4F7N/CO2 dynamic gas preparation pipeline structure includes a first solenoid valve, a second solenoid valve, a first thermal mass flow meter, a second thermal mass flow meter, a buffer mixing tank, a first pipe, and a second pipe;
the buffer mixing tank is provided with a first gas inlet, a second gas inlet, and a first mixed gas outlet; and
the gas outlet of the CO2 heat exchanger is communicated with the first gas inlet through the first pipe, and the first solenoid valve and the first thermal mass flow meter are both arranged on the first pipe; the gas outlet of the C4F7N heat exchanger is communicated with the second gas inlet through the second pipe, and the second solenoid valve and the second thermal mass flow meter are both arranged on the second pipe; and the first mixed gas outlet is communicated with the inlet end of the C4F7N/CO2 mixed gas output pipeline structure.
Preferably, the C4F7N/CO2 partial pressure mixing pipeline structure further includes a third pipe, a fourth pipe, a fifth pipe, a third solenoid valve, a fourth solenoid valve, and a first proportional valve; the gas inlet of the third pipe is communicated with the CO2 input port, the gas inlet of the fourth pipe is communicated with the C4F7N input port, and the gas outlet of the third pipe and the gas outlet of the fourth pipe are both communicated with the gas inlet of the fifth pipe; the gas outlet of the fifth pipe is communicated with the gas inlets of the partial pressure mixing tanks; the third solenoid valve is arranged on the third pipe, the fourth solenoid valve is arranged on the fourth pipe, and the first proportional valve is arranged on the fifth pipe.
Preferably, the partial pressure mixing tank is further provided with a circulating mixing pipeline structure. The circulating mixing pipeline structure includes a fifth solenoid valve, a first air pump, a first one-way valve, a sixth solenoid valve, and a circulating pipe; the two ends of the partial pressure mixing tank are respectively provided with a circulating gas inlet and a circulating gas outlet; the two ends of the circulating pipe are respectively communicated with the circulating gas inlet and the circulating gas outlet; and the fifth solenoid valve, the first air pump, the first one-way valve and the sixth solenoid valve are sequentially arranged on the circulating pipe in the order in which the gas flows from the circulating gas outlet to the circulating gas inlet.
Preferably, the number of the partial pressure mixing tanks is two, namely the first partial pressure mixing tank and the second partial pressure mixing tank;
the circulating pipe includes a circulating gas inlet section, a circulating section, and a circulating gas outlet section that are communicated with each other end to end sequentially; the gas inlet of the circulating gas inlet section is communicated with the circulating gas outlet of the corresponding partial pressure mixing tank; the fifth solenoid valve is arranged on the corresponding circulating gas inlet section, and the gas outlets of the two circulating gas inlet sections are both communicated with the gas inlet of one circulating section; and
the first air pump and the first one-way valve are all provided on the circulating section; the gas outlet of the circulating section is communicated with the gas inlets of the two circulating gas outlet sections; the sixth solenoid valve is provided on the corresponding circulating gas outlet section, and the gas outlet of the circulating gas outlet section is communicated with the circulating gas inlet of the corresponding partial pressure mixing tank.
At the same time, the C4F7N/CO2 partial pressure mixing pipeline structure of the present disclosure includes a plurality of partial pressure mixing tanks, and the partial pressure mixing tanks are divided into two groups, so that when one group is in gas preparation, the other group is in the state of outputting mixed gas. Thus, the system is always in a state that the gas preparation and outputting of mixed gas are performed simultaneously, which saves gas preparation time and further improves gas preparation efficiency.
Preferably, the C4F7N/CO2 mixing pipeline structure further includes an output pipeline structure for extracting the C4F7N/CO2 mixed gas in the partial pressure mixing tank;
the output pipeline structure includes a seventh solenoid valve, a Fujiwara oil-free vacuum pump or a negative pressure pump, a second one-way valve, a third proportional valve, an eighth solenoid valve, a first output pipe, and a second output pipe;
the first output pipe and the second output pipe are arranged in parallel, the gas inlet of the first output pipe and the gas inlet of the second output pipe are both communicated with the gas outlet of the partial pressure mixing tank, and the gas outlet of the first output pipe and the gas outlet of the second output pipe are both communicated with the C4F7N/CO2 mixed gas output pipeline structure;
the seventh solenoid valve, the Fujiwara oil-free vacuum pump or the negative pressure pump, and the second one-way valve are sequentially arranged on the first output pipe along the gas conveying direction; and
the third proportional valve and the eighth solenoid valve are sequentially arranged on the second output pipe along the gas flow direction.
In order to fully output the C4F7N/CO2 mixed gas output from the partial pressure mixing tank, the present disclosure is equipped in the C4F7N/CO2 mixing pipeline structure with the output pipeline structure for extracting the C4F7N/CO2 mixed gas in the partial pressure mixing tank.
Preferably, the multifunctional C4F7N/CO2 mixed gas preparation system further includes a pressurizing pipeline structure, which is used to pressurize the C4F7N/CO2 mixed gas output from the C4F7N/CO2 mixing pipeline structure.
Preferably, the C4F7N/CO2 mixed gas output pipeline structure includes a tenth solenoid valve, a second buffer tank, and a mixed gas outlet pipe; the gas inlet of the mixed gas outlet pipe is communicated with the outlet end of the pressurizing pipeline structure; and the tenth solenoid valve and the second buffer tank are sequentially arranged on the mixed gas outlet pipe along the gas flow.
A C4F7N/CO2 mixed gas preparation method using the above multifunctional C4F7N/CO2 mixed gas preparation system to perform C4F7N/CO2 mixed gas preparation is further disclosed. The method includes the following steps:
S1, performing vacuum treatment to the gas preparation system;
S2, heating and vaporizing the C4F7N input through the C4F7N input port by the C4F7N heat exchanger; and heating and vaporizing the CO2 input through the CO2 input port by the CO2 heat exchanger;
S3, mixing the vaporized C4F7N and CO2 in the C4F7N/CO2 mixing pipeline structure;
the vaporized C4F7N and CO2 are quantitatively mixed in the C4F7N/CO2 dynamic mixing pipeline structure; the vaporized C4F7N and CO2 are mixed at certain pressures through the C4F7N/CO2 partial pressure mixing pipeline structure; a plurality of the partial pressure mixing tanks are arranged in parallel and alternately perform gas preparation and output; and
S4, outputting the C4F7N/CO2 mixed gas through the C4F7N/CO2 mixed gas output pipeline structure.
(1) In the present disclosure, a C4F7N heat exchanger is installed at the C4F7N input port, and a CO2 heat exchanger is installed at the CO2 input port, so that the C4F7N and CO2 input are heated and vaporized respectively to ensure that the C4F7N and CO2 input to the subsequent pipelines are always in a stable gaseous state. In this way, the technical problems that the C4F7N vaporization speed is too slow and limit the C4F7N/CO2 mixed gas preparation speed, and that a large amount of mixed gas cannot be quickly prepared are effectively solved. By performing heat exchange and vaporization treatment to C4F7N and CO2 at the input source, the stability of the state of the gas source input to the system is significantly ensured, and the gas preparation rate is improved.
(2) Since the C4F7N/CO2 mixing pipeline structure of the present disclosure includes the C4F7N/CO2 dynamic gas preparation pipeline structure and the C4F7N/CO2 partial pressure mixing pipeline structure, it can realize two gas preparation modes: quantitative flow gas preparation and partial pressure gas preparation, realizing the versatility of the gas preparation of the present disclosure. According to different gas preparation purposes, different gas preparation pipeline structures can be switched: it can not only adopt the manner of quantitative flow gas preparation to meet the requirements of a tiny amount of C4F7N/CO2 mixed gas in the laboratory, but can also adopt the manner of partial pressure preparation to quickly prepare a large amount of C4F7N/CO2 mixed gas of different pressures. In addition, because the C4F7N heat exchanger is installed at the C4F7N input port and the CO2 heat exchanger is installed at the CO2 input port in the present disclosure, the CO2 and C4F7N input to the system are pre-vaporized, so that the quantitative flow gas preparation of the present disclosure also has application prospects for a large amount of C4F7N/CO2 mixed gas.
(3) In the present disclosure, the two gas preparation pipeline structures of the C4F7N/CO2 dynamic gas preparation pipeline structure and the C4F7N/CO2 partial pressure mixing pipeline structure are integrated into an overall pipeline structure, so that the gas preparation system of the present disclosure has a high equipment integration rate, and can effectively reduce the cost of the system, simplify the complexity of the control and improve the flexibility of preparation.
(4) In addition, the C4F7N/CO2 dynamic gas preparation pipeline structure of the present disclosure can also meet the needs of gas supplementation, supplementing gas for leaking equipment, and accurately correcting the ratio of mixed gas in the equipment.
Furthermore, by installing the first thermal mass flow meter on the first pipe and the second thermal mass flow meter on the second pipe, the flow of CO2 into the first pipe and the flow of C4F7N into the second pipe are controlled in real time; in combination of the adjustment of the opening of the first solenoid valve and the opening of the second solenoid valve respectively, the flow of C4F7N and the flow of CO2 into the buffer mixing tank are ensured to be within the set value range, so as to further ensure that the ratio of the C4F7N/CO2 is always within a constant range and to ensure accurate gas preparation.
Furthermore, the C4F7N/CO2 partial pressure mixing pipeline structure of the present disclosure includes a plurality of partial pressure mixing tanks, and the partial pressure mixing tanks are divided into two groups, so that when one group is in gas preparation, the other group is in the state of outputting mixed gas. Thus, the system is always in a state that the gas preparation and outputting of mixed gas are performed simultaneously, which saves gas preparation time and further improves gas preparation efficiency.
Furthermore, compared with the prior art, which only relies on the free movement of gas molecules to achieve gas mixing, the present disclosure provides a circulating mixing pipeline structure to allow the C4F7N and CO2 to be mixed in a flowing state, which can further improve the mixing efficiency of C4F7N and CO2 and will ultimately improve the gas preparation efficiency.
Furthermore, the present disclosure only adopts one circulating section, by which the mixing of the gas in the two partial pressure mixing tanks can be realized, thereby simplifying the pipeline design and improving the integration effect of the pipelines.
Furthermore, by providing the second proportional valve, the flows of C4F7N and CO2 input into the circulating pipe can be adjusted. Thereby, the amount of C4F7N and CO2 to be mixed per unit time can be controlled according to the specific gas preparation requirements and the gas preparation environment, and the flexibility of mixing is improved.
Furthermore, by providing to weight sensors at the bottom of the partial pressure mixing tanks to monitor online the weight of the gas z in the partial pressure mixing tank, in combination of the online monitoring of the differential pressure sensor to achieve mutual feedback of quality value and pressure value, it is possible to monitor the accuracy of C4F7N and CO2 gas preparation more accurately.
In order to make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be described clearly and completely in conjunction with the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure.
It should be noted that when an element is referred to as being “fixed to” another element, it can be directly on the other element or an intermediate element may also be present. When an element is considered to be “connected” to another element, it can be directly connected to the other element or an intermediate element may be present at the same time.
As shown in
The C4F7N heat exchanger 3 is used to heat and vaporize the C4F7N input through the C4F7N input port 1. The CO2 heat exchanger 4 is used to heat and vaporize the CO2 input through the CO2 input port 2. The C4F7N/CO2 mixing pipeline structure 5 is used to mix the vaporized C4F7N and CO2, and the C4F7N/CO2 mixed gas output pipeline structure 7 is used to output the C4F7N/CO2 mixed gas.
The C4F7N/CO2 mixing pipeline structure 5 includes a C4F7N/CO2 dynamic gas preparation pipeline structure 51 and a C4F7N/CO2 partial pressure mixing pipeline structure 52.
The C4F7N/CO2 dynamic gas preparation pipeline structure 51 and the C4F7N/CO2 partial pressure mixing pipeline structure 52 are arranged in parallel. The C4F7N/CO2 dynamic gas preparation pipeline structure 51 is used to quantitatively mix the vaporized CO2 and C4F7N. The C4F7N/CO2 partial pressure mixing pipeline structure 52 is used to mix the vaporized CO2 and C4F7N at certain pressures.
The C4F7N/CO2 partial pressure mixing pipeline structure 52 includes a partial pressure mixing tank 521 for mixing CO2 and C4F7N of certain pressures. A plurality of partial pressure mixing tanks 521 are arranged in parallel and perform gas preparation and gas transmission alternately.
When the dynamic quantitative flow gas preparation for C4F7N/CO2 is required, the various pipes in the C4F7N/CO2 partial pressure mixing pipeline structure 52 are closed, and the pipes in the C4F7N/CO2 dynamic gas preparation pipeline structure 51 and the pipes in the C4F7N/CO2 mixed gas output pipeline structure 7 are opened, so that passages are formed among the C4F7N input port 1, the CO2 input port 2, the pipes in the C4F7N/CO2 dynamic gas preparation pipeline structure 51 and the pipes in the C4F7N/CO2 mixed gas output pipeline structure 7, and the pipelines are vacuumed. After the heat exchange of C4F7N through the C4F7N heat exchanger 3, the temperature rises to ensure that the C4F7N is stable in gaseous state. In the same way, after the heat exchange of CO2 through the heat exchanger 4, the temperature rises. The C4F7N and CO2 after heat exchange are input into the C4F7N/CO2 dynamic gas preparation pipeline structure 51, and by adjusting the flow of C4F7N and CO2, the quantitative mixing of C4F7N and CO2 is realized. Finally, the quantitatively mixed C4F7N and CO2 are output through the C4F7N/CO2 mixed gas output pipeline structure 7 to complete the C4F7N/CO2 dynamic quantitative flow gas preparation.
When the partial pressure preparation for C4F7N/CO2 is required, the pipes in the C4F7N/CO2 dynamic gas preparation pipeline structure 51 are closed, and the various pipes in the C4F7N/CO2 partial pressure mixing pipeline structure 52 and the pipes in the C4F7N/CO2 mixed gas output pipe structure 7 are opened, so that passages are formed among the C4F7N input port 1, the CO2 input port 2, the pipes in the C4F7N/CO2 partial pressure mixing pipeline structure 52 and the pipes in the C4F7N/CO2 mixed gas output pipeline structure 7, and the pipelines are vacuumed. After the heat exchange of C4F7N through the C4F7N heat exchanger 3, the temperature rises to ensure that the C4F7N is stable in gaseous state. In the same way, after the heat exchange of CO2 through the heat exchanger 4, the temperature rises. The C4F7N and CO2 after heat exchange are input into the C4F7N/CO2 partial pressure mixing pipeline structure 52, and by adjusting the partial pressure of C4F7N and the partial pressure of CO2, the pressure-adjusted C4F7N and CO2 are input into each partial pressure mixing tank 521, and mixed in the partial pressure mixing tank 521. In addition, while ensuring that some of the partial pressure mixing tanks 521 are in the mixing state, the other partial pressure mixing tanks 521 are in the state of inputting the C4F7N/CO2 mixed gas to the C4F7N/CO2 mixed gas output pipeline structure 7. Finally, the C4F7N and CO2 of quantitative pressures are output through the C4F7N/CO2 mixed gas output pipeline structure 7 to complete the C4F7N/CO2 partial pressure preparation.
The advantages of the present disclosure are as follows.
(1) In the present disclosure, a C4F7N heat exchanger 3 is installed at the C4F7N input port 1, and a CO2 heat exchanger 4 is installed at the CO2 input port 2, so that the C4F7N and CO2 input are heated and vaporized respectively to ensure that the C4F7N and CO2 input to the subsequent pipelines are always in a stable gaseous state. In this way, the technical problems that the C4F7N vaporization speed is too slow and limit the C4F7N/CO2 mixed gas preparation speed, and that a large amount of mixed gas cannot be quickly prepared are effectively solved. By heat exchange of C4F7N and CO2 at the input source, the stability of the state of the gas source input to the system is significantly ensured, and the gas preparation rate is improved.
(2) Since the C4F7N/CO2 mixing pipeline structure 5 of the present disclosure includes the C4F7N/CO2 dynamic gas preparation pipeline structure 51 and the C4F7N/CO2 partial pressure mixing pipeline structure 52, it can realize two gas preparation modes: quantitative flow gas preparation and partial pressure gas preparation, realizing the versatility of the gas preparation of the present disclosure. According to different gas preparation purposes, different gas preparation pipeline structures can be switched. The present disclosure can not only adopt the method of quantitative flow gas preparation to meet the requirements of a tiny amount of C4F7N/CO2 mixed gas in the laboratory, but also adopt the method of partial pressure preparation to quickly prepare a large amount of C4F7N/CO2 mixed gas of different pressures and different proportions. In addition, because the C4F7N heat exchanger 3 is installed at the C4F7N input port 1 and the CO2 heat exchanger 4 is installed at the CO2 input port 2 in the present disclosure, the CO2 and C4F7N input to the system are preheated and vaporized, so that the quantitative flow gas preparation of the present disclosure also has application prospects for a large amount of C4F7N/CO2 mixed gas.
(3) In the present disclosure, the two gas preparation pipeline structures of the C4F7N/CO2 dynamic gas preparation pipeline structure 51 and the C4F7N/CO2 partial pressure mixing pipeline structure 52 are integrated into an overall pipeline structure, so that the gas preparation system of the present disclosure has a high equipment integration rate, and can effectively reduce the cost of the system, simplify the complexity of the control and improve the flexibility of preparation.
(4) In addition, the C4F7N/CO2 dynamic gas preparation pipeline structure 51 of the present disclosure can also meet the needs of gas supplementation, supplementing gas for leaking equipment, and accurately correcting the ratio of mixed gas in the equipment.
As shown in
The C4F7N/CO2 dynamic gas preparation pipeline structure 51 includes a first solenoid valve 511, a second solenoid valve 512, a first thermal mass flow meter 513, a second thermal mass flow meter 514, a buffer mixing tank 515, a first pipe 516, and a second pipe 517.
The buffer mixing tank 515 is provided with a first gas inlet, a second gas inlet, and a first mixed gas outlet.
The gas outlet of the CO2 heat exchanger 4 is communicated with the first gas inlet through the first pipe 516, and the first solenoid valve 511 and the first thermal mass flow meter 513 are both arranged on the first pipe 516. The gas outlet of the C4F7N heat exchanger 3 is communicated with the second gas inlet through the second pipe 517, and the second solenoid valve 512 and the second thermal mass flow meter 514 are both arranged on the second pipe 517. The first mixed gas outlet is in communicated with the gas intake end of the C4F7N/CO2 mixed gas output pipeline structure 7.
When dynamic quantitative flow preparation for C4F7N/CO2 is required, the first solenoid valve 511 and the second solenoid valve 512 are respectively opened to control the flow of the heated CO2 passing through the first pipe 516 per unit time and the flow of the heated C4F7N passing through the second pipe 517 per unit time, and the flows of CO2 and C4F7N are effectively monitored through the first thermal mass flow meter 513 and the second thermal mass flow meter 514. If the flow is abnormal, that is, the flow is not within the set value range, the corresponding thermal mass flow meter sends an abnormal signal to the control center. After analyzing the signal, the control center sends instructions to drive the corresponding solenoid valve to work, and performs online flow adjustment by adjusting the magnitude of the opening by the solenoid valve. The CO2 and C4F7N monitored by the first thermal mass flow meter 513 and the second thermal mass flow meter 514 are mixed in the buffer mixing tank 515, and are output through the C4F7N/CO2 mixed gas output pipeline structure 7 after being mixed.
In the present disclosure, by installing the first thermal mass flow meter 513 on the first pipe 516 and the second thermal mass flow meter 514 on the second pipe 517, the flow of CO2 into the first pipe 516 and the flow of C4F7N into the second pipe are controlled in real time; in combination of the adjustment of the opening of the first solenoid valve 511 and the opening of the second solenoid valve 512, the flow of C4F7N and the flow of CO2 into the buffer mixing tank 515 are ensured to be within the set value range, so as to further ensure that the mass ratio of the mixed C4F7N/CO2 is always within a constant range and to ensure accurate gas preparation.
As shown in
As shown in
In this embodiment, the C4F7N/CO2 partial pressure mixing pipeline structure 52 is disclosed with the number of the partial pressure mixing tanks 521 being two, which are the first partial pressure mixing tank 5211 and the second partial pressure mixing tank 5212 respectively. Of course, other numbers of partial pressure mixing tanks 521 should also fall within the protection scope of the present disclosure.
The gas inlet of the third pipe 522 is communicated with the CO2 input port 2, the gas inlet of the fourth pipe 523 is communicated with the C4F7N input port 1, and the gas outlet of the third pipe 522 and the gas outlet of the fourth pipe 523 are both communicated with the gas inlet of the fifth pipe 524. The gas outlet of the fifth pipe 524 is communicated with the gas inlet of the first partial pressure mixing tank 5211 and the gas inlet of the second partial pressure mixing tank 5212 respectively. The third solenoid valve 525 is provided on the third pipe 522, the fourth solenoid valve 526 is provided on the fourth pipe 523, the first proportional valve 527 is provided on the fifth pipe 524, and the gas inlet solenoid valve 528 is provided on the corresponding partial pressure mixing tank 521 at the gas inlet. The gas inlet of the first partial pressure mixing tank 5211 is equipped with a first gas inlet solenoid valve 5281, and the gas inlet of the second partial pressure mixing tank 5212 is equipped with a second gas inlet solenoid valve 5282.
When partial pressure preparation for C4F7N/CO2 is required, in the present disclosure, the third solenoid valve 525 and the fourth solenoid valve 526 are respectively opened to control the CO2 flow passing through the first pipe 516 per unit time and control the C4F7N flow passing through the second pipe 517.
In actual operation, the third solenoid valve 525 and the fourth solenoid valve 526 are not opened at the same time, that is, the C4F7N and CO2 of certain pressures are sequentially input into the corresponding partial pressure mixing tank 521. Introduction herein is conducted in the manner of first conveying C4F7N to the partial pressure mixing tank 521 and then CO2 to the partial pressure mixing tank 521, and the manner of first conveying CO2 to the partial pressure mixing tank 521 and then C4F7N to the partial pressure mixing tank 521 should be also within the protection scope of the present disclosure.
The specific partial pressure preparation steps are as follows.
S1, open the third solenoid valve 525, the fourth solenoid valve 526, the first proportional valve 527 and the first gas inlet solenoid valve 5281, close the second gas inlet solenoid valve 5282, and adjust the opening of the first proportional valve 527; the heated and vaporized C4F7N passes through the fourth pipe 523 and the fifth pipe 524 sequentially, and after flow adjustment, the C4F7N output from the first proportional valve 527 reaches the set pressure and is input to the first partial pressure mixing tank 5211; the heated CO2 passes through the third pipe 522 and the fifth pipe 524 sequentially, and after flow adjustment, the CO2 output from the first proportional valve 527 reaches the set pressure and is input to the first partial pressure mixing tank 5211; the C4F7N and CO2 are mixed in the first partial pressure mixing tank 5211.
S2, upon completing the mixing in the first partial pressure mixing tank 5211, close the first gas inlet solenoid valve 5281 and open the second gas inlet solenoid valve 5282; the heated and vaporized C4F7N passes through the fourth pipe 523 and the fifth pipe 524 sequentially, and after flow adjustment, the C4F7N output from the first proportional valve 527 reaches the set pressure and is input to the second partial pressure mixing tank 5212; the heated CO2 passes through the third pipe 522 and the fifth pipe 524 sequentially, and after flow adjustment, the CO2 output from the first proportional valve 527 reaches the set pressure and is input to the second partial pressure mixing tank 5212; the C4F7N and CO2 are mixed in the second partial pressure mixing tank 5212.
S3, the C4F7N/CO2 mixed gas mixed in the first partial pressure mixing tank 5211 is output through the C4F7N/CO2 mixed gas output pipeline structure 7; the C4F7N/CO2 mixed gas mixed in the second partial pressure mixing tank 5212 is output through C4F7N/CO2 mixed gas output pipeline structure 7.
S4, the above steps S1 and S2 are performed alternately, and gas preparation and conveying is alternatively conducted for the first partial pressure mixing tank 5211 and the second partial pressure mixing tank 5212.
The C4F7N/CO2 partial pressure mixing pipeline structure 52 of the present disclosure includes a plurality of partial pressure mixing tanks 521, and the plurality of partial pressure mixing tanks 521 are divided into two groups, so that when one group is in gas preparation, the other group is in the state of outputting mixed gas. Thus, the system is always in a state that the gas preparation and outputting of mixed gas are performed simultaneously, which saves gas preparation time and further improves gas preparation efficiency.
In some embodiments, a second differential pressure sensor 5210 is further provided on the fifth pipe 524, and the second differential pressure sensor 5210 is close to the gas outlet of the first proportional valve 527. By providing the second differential pressure sensor 5210 at the gas outlet of the first proportional valve 527, the pressure value of C4F7N or CO2 input to the partial pressure mixing tank 521 can be effectively detected online. Of course, if the pressure value of C4F7N or CO2 deviates from the set range, the second differential pressure sensor 5210 will send a signal to the control center, and the control center will drive the first proportional valve 527 to adjust the corresponding opening.
As shown in
The two ends of the partial pressure mixing tank 521 are respectively provided with a circulating gas inlet and a circulating gas outlet. The two ends of the circulating pipe 5295 are respectively communicated with the circulating gas inlet and the circulating gas outlet. The fifth solenoid valve 5291, the first air pump 5292, the first one-way valve 5293 and the sixth solenoid valve 5294 are sequentially arranged on the circulating pipe 5295 in the order in which the gas flows from the circulating gas outlet to the circulating gas inlet.
In this embodiment, the circulating mixing of the first partial pressure mixing tank 5211 is taken as an example to illustrate the working principle. The circulating mixing principle of the second partial pressure mixing tank 5212 refers to the first partial pressure mixing tank 5211.
In operation, the fifth solenoid valve 5291, the first air pump 5292, the first one-way valve 5293, the sixth solenoid valve 5294 and the first gas inlet solenoid valve 5281 are opened; the second gas inlet solenoid valve 5282 is closed, and the C4F7N and CO2 in the partial pressure mixing tank 521 are output from the circulating gas inlet of the partial pressure mixing tank 521, and after passing through the circulating pipe 5295, are then input from the circulating gas outlet of the partial pressure mixing tank 521 into the partial pressure mixing tank 521, and so on.
Compared with the prior art, which only relies on the free movement of gas molecules to achieve gas mixing, the present disclosure provides a circulating mixing pipeline structure 529 to allow the C4F7N and CO2 to be mixed in a flowing state, which can further improve the mixing efficiency of C4F7N and CO2 and will ultimately improve the gas preparation efficiency.
As shown in
The circulating pipe 5295 includes a circulating gas inlet section 52951, a circulating section 52952, and a circulating gas outlet section 52593 that are communicated with each other end to end sequentially. The gas inlet of the circulating gas inlet section 52951 is communicated with the circulating gas outlet of the corresponding partial pressure mixing tank 521. The fifth solenoid valve 5291 is arranged on the corresponding circulating gas inlet section 52951. The gas outlets of the two circulating gas inlet sections 52951 are both communicated with the gas inlet of one circulating section 52952.
The first air pump 5292 and the first one-way valve 5293 are all provided on the circulating section 52952. The gas outlet of the circulating section 52952 is communicated with the gas inlets of the two circulating gas outlet sections 52591. The sixth solenoid valve 5294 is provided on the corresponding circulating gas outlet section 52593, and the gas outlet of the circulating gas outlet section 52593 is communicated with the circulating gas inlet of the corresponding partial pressure mixing tank 521.
When the C4F7N and CO2 gases in the first partial pressure mixing tank 5211 are mixed, the first gas inlet solenoid valve 5281, the first air pump 5292, the first one-way valve 5293, and the six solenoid valve 5294 and the fifth solenoid valve 5291 close to the first partial pressure mixing tank 5211 are opened, and the second gas inlet solenoid valve 5282, the sixth solenoid valve 5294 and the fifth solenoid valve 5291 close to the second partial pressure mixing tank 5212 are closed; then the C4F7N and CO2 of the first partial pressure mixing tank 5211 can be mixed in the circulating mixing pipeline structure 529. When the C4F7N and CO2 gases in the second partial pressure mixing tank 5212 are mixed, the second gas inlet solenoid valve 5282, the first air pump 5292, the first one-way valve 5293, the sixth solenoid valve 5294 and the fifth solenoid valve 5291 close to the second partial pressure mixing tank 5212 are opened, and the first gas inlet solenoid valve 5281, the sixth solenoid valve 5294 and the fifth solenoid valve 5291 close to the first partial pressure mixing tank 5211 are closed; then the C4F7N and CO2 in the first partial pressure mixing tank 5212 can be mixed in the circulating mixing pipeline structure 529.
Since the present disclosure only adopts one circulating section 52952, the mixing of the gas in the two partial pressure mixing tanks 5211 can be realized, thereby simplifying the pipeline design and improving the integration effect of the pipelines.
In some embodiments, a second proportional valve 5296 is also provided at the beginning of the circulating section 52952, and the second proportional valve 5296 is close to the gas inlet of the first air pump 5292.
By providing the second proportional valve 5296, the flows of C4F7N and CO2 input into the circulating pipe 5295 can be adjusted. Thereby, the amount of C4F7N and CO2 to be mixed per unit time can be controlled according to the specific gas preparation requirements and the gas preparation environment, and the flexibility of mixing is improved.
As shown in
In some embodiments, a fourth differential pressure sensor 52013 is further provided on the partial pressure mixing tank 521.
By providing quality sensors at the inlet and outlet of the partial pressure mixing tank 521 respectively to perform online monitoring of the gas quality in the partial pressure mixing tank 521, in combination of the online monitoring of the differential pressure sensor to achieve mutual feedback of quality value and pressure value, it is possible to monitor the accuracy of C4F7N and CO2 gas preparation more accurately.
As shown in
The output pipeline structure 53 includes a seventh solenoid valve 531, a Fujiwara oil-free vacuum pump 532 or a negative pressure pump, a second one-way valve 533, a third proportional valve 534, an eighth solenoid valve 535, a first output pipe 536, and a second output pipe 537.
The first output pipe 536 and the second output pipe 537 are arranged in parallel, the gas inlet of the first output pipe 536 and the gas inlet of the second output pipe 537 are both communicated with the gas outlet of the partial pressure mixing tank, and the gas outlet of the first output pipe 536 and the gas outlet of the second output pipe 537 are both communicated with the C4F7N/CO2 mixed gas output pipeline structure.
The seventh solenoid valve 531, the Fujiwara oil-free vacuum pump 532 or the negative pressure pump, and the second one-way valve 533 are sequentially arranged on the first output pipe 536 along the gas conveying direction.
The third proportional valve 534 and the eighth solenoid valve 535 are sequentially arranged on the second output pipe 537 along the gas flow direction.
In order to fully output the C4F7N/CO2 mixed gas output from the partial pressure mixing tank 521, the present disclosure is equipped in the C4F7N/CO2 mixing pipeline structure 5 with the output pipeline structure 53 for extracting the C4F7N/CO2 mixed gas in the partial pressure mixing tank 521.
The output pipeline structure 53 realizes the output of C4F7N/CO2 mixed gas by the following steps. The C4F7N/CO2 mixed gas prepared through the partial pressure mixing tank has a relatively high pressure at the beginning of its output. At this time, by closing the seventh solenoid valve 531 and opening the third proportional valve 534 and the eighth solenoid valve 535, the C4F7N/CO2 mixed gas is input to the subsequent pipes through the second output pipe 537, and then output from the C4F7N/CO2 mixed gas output pipeline structure. When the pressure of the C4F7N/CO2 mixed gas in the partial pressure mixing tank 521 is lower than the set value (130 kPa), at this time, it is difficult to output the remaining C4F7N/CO2 mixed gas in the partial pressure mixing tank through only the C4F7N/CO2 mixed gas output pipeline structure in combination with the second output pipeline 537. At this time, by closing the third proportional valve 534 and the eighth solenoid valve 535, and opening the seventh solenoid valve 531, the Fujiwara oil-free vacuum pump 532 or negative pressure pump, the C4F7N/CO2 mixed gas is input to the subsequent pipes from the first output pipe 536 under the suction effect of the Fujiwara oil-free vacuum pump 532 or the negative pressure pump, until the pressure of the C4F7N/CO2 mixed gas in the partial pressure mixing tank 521 is reduced to 5 kPa.
The output pipeline structure 53 of the present disclosure provides two sets of gas transmission branch pipelines. When the pressure of the mixed gas is high, the opening of the second output pipe 537 can be used to complete the output of the C4F7N/CO2 mixed gas. The setting of the third proportional valve 534 in the present disclosure is to control the output pressure of the mixed gas, and adjust accordingly with the output of the C4F7N/CO2 mixed gas, so as to ensure the stability of the gas output. When the pressure of the mixed gas is relatively small, through the first output pipeline 536 and with the effect of the Fujiwara oil-free vacuum pump 532 or the negative pressure pump, it is possible to ensure that the mixed gas in the partial pressure mixing tank 521 is output as much as possible, and prevent cross contamination from occurring when preparing mixed gas of different proportions and different pressures next time. In addition, the vacuum-pumping difference between the Fujiwara oil-free vacuum pump and the ordinary pipeline is that the ordinary vacuum pump has lubricating oil. During the preparation of the mixed gas, if the ordinary vacuum pump is used, the gas may be polluted.
In some embodiments, the gas outlet of each partial pressure mixing tank 521 is respectively communicated with the inlet end of an output pipeline structure 53 through a transition pipe 54, and a ninth solenoid valve 541 is arranged on the transition pipe 54.
By opening and closing the corresponding ninth solenoid valve 541, the mixed gas of different partial pressure mixing tanks 521 can be selectively input into the output pipeline structure 53 according to actual needs.
As shown in
The pressurizing pipeline structure 6 includes a first buffer tank 61, a third air pump 62, a third one-way valve 63, a first pressurizing pipe 64, a second pressurizing pipe 65, a fourth proportional valve 66, and a third pressurizing pipe 67.
Both ends of the first pressurizing pipe 64 are respectively communicated with the outlet end of the C4F7N/CO2 dynamic gas preparation pipeline structure 51 and the first gas inlet of the first buffer tank 61.
Both ends of the second pressurizing pipe 65 are respectively communicated with the outlet end of the C4F7N/CO2 partial pressure mixing pipeline structure 52 and the second inlet of the first buffer tank 61.
Both ends of the third pressurizing pipe 67 are respectively communicated with the gas outlet of the first buffer tank 61 and the inlet end of the C4F7N/CO2 mixed gas output pipeline structure 7.
The fourth proportional valve 66 is arranged on the first pressurizing pipe 64, and the third air pump 62 and the third one-way valve 63 are sequentially arranged on the third pressurizing pipe 67 along the gas flow direction. The third air pump 62 of the present disclosure is preferably a compressor, and other air pumps in the prior art should also fall within the protection scope of the present disclosure.
Due to the fact that in actual operation, especially for equipment manufacturers to develop 1000 kV GIL and the equipment gas chamber is large, it is difficult for the C4F7N/CO2 mixed gas prepared through C4F7N/CO2 mixing pipeline structure 5 to be directly input to the C4F7N/CO2 mixed gas output pipeline structure 7. Therefore, the present disclosure is provided with a pressurizing pipeline structure 6.
When outputting the quantitative C4F7N/CO2 mixed gas prepared through the C4F7N/CO2 dynamic gas preparation pipeline structure 51, in the present disclosure, by opening the third gas pump 62 and the third one-way valve 63, adjusting the opening of the fourth proportional valve 66, and closing the output pipeline structure 53, it is possible to allow quantitative C4F7N/CO2 mixed gas to be input through the first pressurizing pipe 64 to the first buffer tank 61 for buffering, and then output to the C4F7N/CO2 mixed gas output pipeline structure 7 through the third pressurizing pipe 67.
When outputting the C4F7N/CO2 mixed gas of certain pressure prepared through the C4F7N/CO2 partial pressure mixing pipeline structure 52, by opening the third air pump 62, the third one-way valve 63 and the output pipeline structure 53, and closing the fourth proportional valve 66 is closed, it is possible to allow the C4F7N/CO2 mixed gas of certain pressure to be input through the second pressurizing pipe 65 to the first buffer tank 61 for buffering, and is output to the C4F7N/CO2 mixed gas output pipeline structure 7 through the third pressurizing pipe 67.
In some embodiments, a sixth differential pressure sensor 68 is further arranged on the third pressurizing pipe 67, and the sixth differential pressure sensor 68 is close to the gas outlet of the third air pump 62. The pressure of the mixed gas input into the third pressurizing pipe 67 is monitored online by the sixth differential pressure sensor 68.
As shown in
The C4F7N/CO2 mixed gas output pipeline structure 7 includes a tenth solenoid valve 71, a second buffer tank 72, and a mixed gas outlet pipe 73. The gas inlet of the mixed gas outlet pipe 73 is connected to the outlet end of the C4F7N/CO2 mixing pipeline structure 5. The tenth solenoid valve 71 and the second buffer tank 72 are sequentially arranged on the mixed gas outlet pipe 73 along the gas flow.
In operation, by opening the tenth solenoid valve 71, the C4F7N/CO2 mixed gas is input through the mixed gas outlet pipe 73 to the second buffer tank 72 for buffering, and is output to external equipment through the second buffer tank 72.
In some embodiments, a third differential pressure sensor 721 is arranged on the second buffer tank 72. The pressure of the mixed gas in the second buffer tank 72 is monitored online by the third differential pressure sensor 721.
As shown in
In order to further ensure the accuracy and purity of the mixed preparation of the C4F7N/CO2 mixed gas output to the equipment, a sampling branch structure 74 is arranged in the C4F7N/CO2 mixed gas output pipeline structure 7. By opening the pressure reducing and stabilizing valve 742 and adjusting the fifth proportional valve 743, a small amount of C4F7N/CO2 mixed gas is output from the sampling branch pipe 741, and sampling is performed at the end of the sampling branch pipe 741. The sample is analyzed to ensure the purity and accuracy of the C4F7N/CO2 mixed gas.
As shown in
The first vacuum branch pipe 88 and the second vacuum branch pipe 89 are arranged in parallel. The gas outlet of the first vacuum branch pipe 88 and the gas outlet of the second vacuum branch pipe are both communicated with the gas inlet of the main vacuum pipe 87, the gas inlet of the first vacuum branch pipe 88 is communicated with the outlet end of the C4F7N/CO2 dynamic gas preparation pipeline structure 51, and the gas inlet of the second vacuum branch pipe 89 is communicated with the gas outlet of the first proportional valve 527.
The fourth air pump 81, the sixth proportional valve 82, the third buffer tank 83, and the eleventh solenoid valve 84 are sequentially arranged on the main vacuum pipe 87 along the gas flow direction.
The twelfth solenoid valve 85 is arranged on the first vacuum branch pipe 88.
The thirteenth solenoid valve 86 is arranged on the second vacuum branch pipe 89.
In order to eliminate other impurities such as air in the pipeline and prevent the presence of impurities from affecting the accuracy of the prepared mixed gas, it is also necessary to vacuumize the current gas preparation system using the vacuum pipeline structure 8 of the present disclosure before gas preparation.
By opening the fourth air pump 81, the sixth proportional valve 82, the eleventh solenoid valve 84, the twelfth solenoid valve 85, the first solenoid valve 511, and the second solenoid valve 512, the vacuum treatment to the C4F7N/CO2 dynamic gas preparation pipeline structure 51 is performed.
By opening the fourth air pump 81, the sixth proportional valve 82, the twelfth solenoid valve 85, the eleventh solenoid valve 84, the third gas pump 62, and the tenth solenoid valve 71, the vacuum treatment to the C4F7N/CO2 mixed gas output pipeline structure is performed.
By opening the fourth air pump 81, the sixth proportional valve 82, the thirteenth solenoid valve 86, the third solenoid valve 525, the fourth solenoid valve 526, the first proportional valve 527, the first gas inlet solenoid valve 5281, the second gas inlet solenoid valve 5282, the ninth solenoid valve 541, the third proportional valve 534, the eighth solenoid valve 535, the twelfth solenoid valve 85, the third air pump 62, and the tenth solenoid valve 71, the vacuum treatment to the C4F7N/CO2 partial pressure mixing pipeline structure is performed.
In some embodiments, a fifth differential pressure sensor 831 is further arranged on the third buffer tank 83. The fifth differential pressure sensor 831 is used to monitor the pressure of the gas in the third buffer tank 83 online to determine the degree of vacuum.
In some embodiments, a pressure control switch 810 is further arranged on the main vacuum pipe 87, and the pressure control switch 810 is close to the gas outlet of the eleventh solenoid valve 84. The degree of vacuum is controlled by the pressure control switch 810, and the vacuum of the present disclosure is controlled at 0.08 MPa.
The difference between this embodiment and the foregoing embodiment is that C4F7N is input to the C4F7N input port 1 through the C4F7N gas tank, and CO2 is input to the CO2 input port 2 through the CO2 gas tank. A heating and vaporizing device of the prior art is installed on the periphery of the C4F7N gas tank and the periphery of the CO2 gas tank. For example, a heating pipe can be wound around the gas tank, and hot water or other high-temperature medium can be filled in the heating pipe.
As shown in
The C4F7N heat exchanger 3 is used to heat and vaporize the C4F7N input through the C4F7N input port 1. The CO2 heat exchanger 4 is used to heat and vaporize the CO2 input through the CO2 input port 2. The C4F7N/CO2 mixing pipeline structure 5 is used to mix the heated C4F7N and CO2, and the C4F7N/CO2 mixed gas output pipeline structure 7 is used to output the C4F7N/CO2 mixed gas.
The C4F7N/CO2 mixing pipeline structure 5 includes a C4F7N/CO2 dynamic gas preparation pipeline structure 51 and a C4F7N/CO2 partial pressure mixing pipeline structure 52.
The C4F7N/CO2 dynamic gas preparation pipeline structure 51 and the C4F7N/CO2 partial pressure mixing pipeline structure 52 are arranged in parallel. The C4F7N/CO2 dynamic gas preparation pipeline structure 51 is used to quantitatively mix the heated CO2 and C4F7N. The C4F7N/CO2 partial pressure mixing pipeline structure 52 is used to mix the heated CO2 and C4F7N at certain pressures.
The C4F7N/CO2 partial pressure mixing pipeline structure 52 includes a partial pressure mixing tank 521, and the partial pressure mixing tank 521 is used to mix CO2 and C4F7N of certain pressures. A plurality of partial pressure mixing tanks 521 are arranged in parallel and perform gas preparation and gas transmission alternately.
The C4F7N/CO2 dynamic gas preparation pipeline structure 51 includes a first solenoid valve 511, a second solenoid valve 512, a first thermal mass flow meter 513, a second thermal mass flow meter 514, a buffer mixing tank 515, a first pipe 516, and a second pipe 517.
The buffer mixing tank 515 is provided with a first gas inlet, a second gas inlet, and a first mixed gas outlet.
The gas outlet of the CO2 heat exchanger 4 is communicated with the first gas inlet through the first pipe 516, and the first solenoid valve 511 and the first thermal mass flow meter 513 are both arranged on the first pipe 516. The gas outlet of the C4F7N heat exchanger 3 is communicated with the second gas inlet through the second pipe 517, and the second solenoid valve 512 and the second thermal mass flow meter 514 are both arranged on the second pipe 517. The first mixed gas outlet is communicated with the inlet end of the C4F7N/CO2 mixed gas output pipeline structure 7.
A first differential pressure sensor 518 is arranged on the buffer mixing tank 515. By arranging the first differential pressure sensor 518 on the buffer mixing tank 515, the pressure of the C4F7N/CO2 mixed gas is tested, and the accuracy of the mixed gas preparation is further monitored. Of course, if the pressure value of the C4F7N/CO2 mixed gas deviates from the set range, the first differential pressure sensor 518 also sends a signal to the control center, and the control center will drive the first solenoid valve 511 and the second solenoid valve 512 to adjust the corresponding opening.
The C4F7N/CO2 partial pressure mixing pipeline structure 52 includes a partial pressure mixing tank 521, a third pipe 522, a fourth pipe 523, a fifth pipe 524, a third solenoid valve 525, a fourth solenoid valve 526, a first proportional valve 527, and a gas inlet solenoid valve 528.
In this embodiment, the C4F7N/CO2 partial pressure mixing pipeline structure 52 is disclosed with the number of the partial pressure mixing tanks 521 being two, which are the first partial pressure mixing tank 5211 and the second partial pressure mixing tank 5212 respectively. Of course, other numbers of partial pressure mixing tanks 521 should also fall within the protection scope of the present disclosure.
The gas inlet of the third pipe 522 is communicated with the CO2 input port 2, the gas inlet of the fourth pipe 523 is communicated with the C4F7N input port 1, and the gas outlet of the third pipe 522 and the gas outlet of the fourth pipe 523 are both communicated with the gas inlet of the fifth pipe 524. The gas outlet of the fifth pipe 524 is communicated with the gas inlet of the first partial pressure mixing tank 5211 and the gas inlet of the second partial pressure mixing tank 5212 respectively. The third solenoid valve 525 is arranged on the third pipe 522, the fourth solenoid valve 526 is arranged on the fourth pipe 523, the first proportional valve 527 is arranged on the fifth pipe 524, and the gas inlet solenoid valve 528 is arranged at the gas inlet of the corresponding partial pressure mixing tank 521. The gas inlet of the first partial pressure mixing tank 5211 is equipped with a first gas inlet solenoid valve 5281, and the gas inlet of the second partial pressure mixing tank 5212 is equipped with a second gas inlet solenoid valve 5282.
A second differential pressure sensor 5210 is further arranged on the fifth pipe 524, and the second differential pressure sensor 5210 is close to the gas outlet of the first proportional valve 527. By providing the second differential pressure sensor 5210 at the gas outlet of the first proportional valve 527, the pressure of the output mixed gas is monitored.
The partial pressure mixing tank 521 is also equipped with a circulating mixing pipeline structure 529. The circulating mixing pipeline structure 529 includes a fifth solenoid valve 5291, a first air pump 5292, a first one-way valve 5293, a sixth solenoid valve 5294, and a circulating pipe 5295.
The two ends of the partial pressure mixing tank 521 are respectively provided with a circulating gas inlet and a circulating gas outlet. The two ends of the circulating pipe 5295 are respectively communicated with the circulating gas inlet and the circulating gas outlet. The fifth solenoid valve 5291, the first air pump 5292, the first one-way valve 5293 and the sixth solenoid valve 5294 are sequentially arranged on the circulating pipe 5295 in the order in which the gas flows from the circulating gas outlet to the circulating gas inlet.
The circulating pipe 5295 includes a circulating gas inlet section 52951, a circulating section 52952, and a circulating gas outlet section 52593 that are communicated with each other end to end sequentially. The gas inlet of the circulating gas inlet section 52951 is communicated with the circulating gas outlet of the corresponding partial pressure mixing tank 521. The fifth solenoid valve 5291 is arranged on the corresponding circulating gas inlet section 52951. The gas outlets of the two circulating gas inlet sections 52951 are both communicated with the gas inlet of one circulating section 52952.
The first air pump 5292 and the first one-way valve 5293 are all arranged on the circulating section 52952, and the gas outlet of the circulating section 52952 is communicated with the gas inlets of both the two circulating gas outlet sections 52591. The sixth solenoid valve 5294 is arranged on the corresponding circulating gas outlet section 52593, and the gas outlet of the circulating gas outlet section 52593 is communicated with the circulating gas inlet of the corresponding partial pressure mixing tank 521.
A second proportional valve 5296 is also arranged at the beginning of the circulating section 52952, and the second proportional valve 5296 is close to the gas inlet of the first air pump 5292.
A first mass sensor 52011 is provided at the gas inlet of the partial pressure mixing tank 521, and a second mass sensor 52012 is provided at the gas outlet of the partial pressure mixing tank 521.
A fourth differential pressure sensor 52013 is also provided on the partial pressure mixing tank 521.
The C4F7N/CO2 mixing pipeline structure 5 further includes an output pipeline structure 53 for extracting the C4F7N/CO2 mixed gas in the partial pressure mixing tank 521.
The output pipeline structure 53 includes a seventh solenoid valve 531, a Fujiwara oil-free vacuum pump 532 or a negative pressure pump, a second one-way valve 533, a third proportional valve 534, an eighth solenoid valve 535, a first output pipe 536, and a second output pipe 537.
The first output pipe 536 and the second output pipe 537 are arranged in parallel, the gas inlet of the first output pipe 536 and the gas inlet of the second output pipe 537 are both communicated with the gas outlet of the partial pressure mixing tank 521, and the gas outlet of the first output pipe 536 and the gas outlet of the second output pipe 537 are both communicated with the C4F7N/CO2 mixed gas output pipeline structure 7.
The seventh solenoid valve 531, the Fujiwara oil-free vacuum pump 532 or the negative pressure pump, and the second one-way valve 533 are sequentially arranged on the first output pipe 536 along the gas conveying direction.
The third proportional valve 534 and the eighth solenoid valve 535 are sequentially arranged on the second output pipe 537 along the gas flow direction.
The gas outlet of each partial pressure mixing tank 521 is respectively communicated with the inlet end of an output pipeline structure 53 through a transition pipe 54, and a ninth solenoid valve 541 is arranged on the transition pipe 54.
The multifunctional C4F7N/CO2 mixed gas preparation system further includes a pressurizing pipeline structure 6, which is used to pressurize the C4F7N/CO2 mixed gas output from the C4F7N/CO2 mixing pipeline structure 5.
The pressurizing pipeline structure 6 includes a first buffer tank 61, a third air pump 62, a third one-way valve 63, a first pressurizing pipe 64, a second pressurizing pipe 65, a fourth proportional valve 66, and a third pressurizing pipe 67.
Both ends of the first pressurizing pipe 64 are respectively communicated with the outlet end of the C4F7N/CO2 dynamic gas preparation pipeline structure 51 and the first gas inlet of the first buffer tank 61.
Both ends of the second pressurizing pipe 65 are respectively communicated with the outlet end of the C4F7N/CO2 partial pressure mixing pipeline structure 52 and the second inlet of the first buffer tank 61.
Both ends of the third pressurizing pipe 67 are respectively communicated with the gas outlet of the first buffer tank 61 and the inlet end of the C4F7N/CO2 mixed gas output pipeline structure 7.
The fourth proportional valve 66 is provided on the first pressurizing pipe 64, and the third air pump 62 and the third one-way valve 63 are sequentially arranged on the third pressurizing pipe 67 along the gas flow direction.
A sixth differential pressure sensor 68 is further provided on the third pressurizing pipe 67, and the sixth differential pressure sensor 68 is close to the gas outlet of the third air pump 62.
The C4F7N/CO2 mixed gas output pipeline structure 7 includes a tenth solenoid valve 71, a second buffer tank 72, and a mixed gas outlet pipe 73. The gas inlet of the mixed gas outlet pipe 73 is communicated with the outlet end of the C4F7N/CO2 mixing pipeline structure 5. The tenth solenoid valve 71 and the second buffer tank 72 are sequentially arranged on the mixed gas outlet pipe 73 along the gas flow.
A third differential pressure sensor 721 is provided on the second buffer tank 72.
The C4F7N/CO2 mixed gas output pipeline structure 7 further includes a sampling branch structure 74. The sampling branch structure 74 includes a sampling branch pipe 741, a pressure reducing and stabilizing valve 742 and a fifth proportional valve 743. The gas inlet of the sampling branch pipe 741 is communicated with the gas outlet of the second buffer tank 72. The pressure reducing and stabilizing valve 742 and the fifth proportional valve 743 are sequentially arranged on the sampling branch pipe 741 along the gas flow.
The multifunctional C4F7N/CO2 mixed gas preparation system further includes a vacuum pipeline structure 8. This embodiment provides a specific vacuum pipeline structure 8, including a fourth air pump 81, a sixth proportional valve 82, a third buffer tank 83, an eleventh solenoid valve 84, a twelfth solenoid valve 85, a thirteenth solenoid valve 86, a main vacuum pipe 87, a first vacuum branch pipe 88, and second vacuum branch pipe 89.
The first vacuum branch pipe 88 and the second vacuum branch pipe 89 are arranged in parallel. The outlet of the first vacuum branch pipe 88 and the outlet of the second vacuum branch pipe are both communicated to the gas inlet of the main vacuum pipe 87, the gas inlet of the first vacuum branch pipe 88 is communicated with the outlet end of the C4F7N/CO2 dynamic gas preparation pipeline structure 51, and the gas inlet of the second vacuum branch pipe 89 is communicated with the gas outlet of the first proportional valve 527.
The fourth air pump 81, the sixth proportional valve 82, the third buffer tank 83, and the eleventh solenoid valve 84 are sequentially arranged on the main vacuum pipe 87 along the gas flow direction.
The twelfth solenoid valve 85 is arranged on the first vacuum branch pipe 88.
The thirteenth solenoid valve 86 is arranged on the second vacuum branch pipe 89.
A fifth differential pressure sensor 831 is further arranged on the third buffer tank 83.
A pressure control switch 810 is further provided on the main vacuum pipe 87, and the pressure control switch 810 is close to the gas outlet of the eleventh solenoid valve 84.
For a GIL gas chamber with a length of 18 m and an inner diameter of 1 m, it is necessary to prepare C4F7N/CO2 mixed gas of 10% of 0.5 MPa (the volume ratio of C4F7N to CO2 is 1:9). The different gas preparation methods and their effects are as follows.
The qualities of C4F7N and CO2 required:
GIL pipe volume: V1=πr2d=3.14×0.25×18=14 m3
Required Mixed gas volume: V2=6V1=8.4 m3
Required C4F7N volume: V(C4F7N)=84×10%=8.4 m3
Required C4F7N quality: mC4=ρ×VC4=7.9×8.4=66 kg
Required CO2 volume: V(CO2)=84×90% =75.6 m3
Required CO2 quality: mCO
The partial pressures of C4F7N and CO2 required:
Partial pressure of C4F7N: P1=0.06 MPa
Partial pressure of CO2: P2=0.54 MPa
Traditional dynamic gas preparation method
The traditional dynamic gas preparation method uses mass flow meters to control the flow of C4F7N and CO2. The maximum gas preparation speed can reach 6 m3/h. It takes at least 14 h to prepare 84 m3 of C4F7N/CO2 mixed gas.
Traditional Partial Pressure Method
Fill the equipment first with C4F7N of 0.06 MPa, and then with CO2 gas of 0.54 MPa. Due to the low accuracy of the pressure gauge used, there is a relatively great error. Generally, the proportion error of the gases in the mixed gas reaches 2%-3%; it takes a relatively short time to inflate the equipment, but it takes at least 24 h for the gas to be evenly mixed in the equipment.
Multifunctional Gas Preparation Method of the Present Disclosure
Since the flow through the solenoid valve is not limited by the gas type, the gas preparation speed of this method can reach 60 m3/h, and the gas preparation work of the GIL gas chamber can be completed in less than 2 h. Since the mass/pressure dual measurement methods are adopted, the sensitivity is 1%, which can meet the requirements of accurately monitoring the partial pressures of the two gases. Thus, the method has fast gas preparation speed and high precision.
In summary, the present disclosure greatly guarantees the stability of the state of the gas source input to the system and improves the gas preparation speed. That is to say, it can realize the two gas preparation modes of quantitative flow gas preparation and partial pressure gas preparation, and realize the versatility of the gas preparation of the present disclosure. According to different gas preparation purposes, different gas preparation pipeline structures can be switched. It can not only use the method of quantitative flow gas preparation to meet the needs of a tiny amount of C4F7N/CO2 mixed gas in the laboratory, but also use the method of partial pressure preparation to quickly prepare a large amount of C4F7N/CO2 mixed gas at different pressures. The present disclosure integrates two gas preparation pipeline structures into one overall pipeline structure, so that the gas preparation system of the present disclosure has a high equipment integration rate, and can effectively reduce the cost of the system, simplify the complexity of the control and improve the flexibility of preparation. The present disclosure can also meet the needs of gas supplementing, such as supplementing gas for leaking equipment, and accurately correcting the proportion of mixed gas in the equipment.
It should be noted that if there are relationship terms such as “first” and “second”, etc., they are only used to distinguish one entity or operation from another, and do not necessarily require or imply that there are any such actual relationships or orders between these entities or operations. Moreover, the terms “include”, “comprise” or any other variants thereof are intended to cover the meaning of non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but further includes other elements that are not explicitly listed, or include elements inherent to this process, method, article or device. If there are no more restrictions, the elements defined by the sentence “including a . . . ” do not exclude the existence of other identical elements in the process, method, article or equipment that includes the elements.
The foregoing embodiments are only used to illustrate the technical solution of the present disclosure, but not to limit it. Although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or equivalently replace some of the technical features. These modifications or replacements, however, do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201910726123.6 | Aug 2019 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/105713 | 7/30/2020 | WO | 00 |
