A non-constant current low temperature static mass method calibration device and method thereof

Abstract

The present invention discloses a non-constant current low-temperature static mass method calibration device and a method thereof, wherein the non-constant current low-temperature static mass method calibration device comprises a low-temperature standard tank, an electronic balance, a cryogenic tank, a cryogenic storage tank, a recovery tank, a power source, a first pneumatic valve, a second pneumatic valve, a third pneumatic valve, a fourth pneumatic valve, a fifth pneumatic valve, a first quick-link valve group, a second quick-link valve group, and a meter to be tested. The non-constant current low-temperature static mass method calibration device provided by the present invention, in order to ensure the temperature of the recovered liquid, the recovered liquid first passes through a cryogenic tank for cooling, and then enters the cryogenic storage tank, thereby preventing the liquid from gasifying and also avoiding frosting of the pipeline and the outlet. In addition, the pipeline provided by the present invention adopts a vacuum pipeline, and other parts are subjected to insulation treatment to prevent liquid gas.

Description

Technical Field

[0001] The invention relates to the technical field of flow detection, and in particular to a non-constant current low-temperature static mass method calibration device and a method thereof. Background Art

[0002] The critical temperature of LNG (liquefied natural gas) under normal pressure is -162℃, which is easy to gasify, and pipelines and outlets are also easy to frost. Low temperature and large gas-liquid expansion ratio. In recent years, the problem of ecological environmental pollution has received more and more attention from the country and the public. As a clean, efficient and low-carbon energy, LNG has been identified as the first choice of low-carbon energy by the National Development and Reform Commission and the Ministry of Housing and Urban-Rural Development. Among all clean fuels, natural gas is regarded as the most suitable alternative fuel for automobiles by many countries and experts in the world for its mature application technology, safety and reliability, and economic feasibility. In particular, the application of LNG in automobiles is mainly urban public transportation, sanitation vehicles, taxis, intercity buses, heavy trucks, etc. LNG terminals, LNG plants and LNG filling stations are growing year by year, which involves trade measurement. Since LNG is a cryogenic liquid, the calibration tank for storing liquid in the existing normal temperature static mass method is non-closed. The traditional static mass method is that the weight value on the scale gradually increases, and the new low temperature static mass method is that the weight value on the scale gradually decreases. Summary of the invention

[0003] In order to solve the limitations and defects of the prior art, the present invention provides a non-constant current low-temperature static mass method calibration device, including a low-temperature standard tank, an electronic balance, a cryogenic tank, a low-temperature storage tank, a recovery tank, a power source, a first pneumatic valve, a second pneumatic valve, a third pneumatic valve, a fourth pneumatic valve, a fifth pneumatic valve, a first quick-link valve group, a second quick-link valve group, and a meter to be inspected;

[0004] The low-temperature standard tank is arranged on the electronic balance. The low-temperature standard tank is used to store the low-temperature medium used for calibration. The low-temperature standard tank is made of a vacuum tank. The electronic balance is used to weigh the weight change of the medium and provide a standard weight. One end of the low-temperature standard tank is connected to the low-temperature storage tank through the second quick-link valve group, and the other end of the low-temperature standard tank is connected to one end of the meter to be inspected through the first pneumatic valve. The other end of the meter to be inspected extends into the internal space of the recovery tank through the second pneumatic valve, and the other end of the meter to be inspected is connected to the power source through the first quick-link valve group;

[0005] The lower position of the recovery tank is connected to one end of the cryogenic tank, and the recovery tank is used to store the intermediate liquid used for calibration. The other end of the cryogenic tank is connected to the power source through the third pneumatic valve, and the cryogenic tank is used to cool the recovered liquid. The low-temperature storage tank is connected to the power source through the fourth pneumatic valve and the fifth pneumatic valve respectively, and the low-temperature storage tank is used to provide the low-temperature liquid required for calibration. The pneumatic valve is used to change the flow direction of the medium in the pipeline.

[0006] Optionally, the outer shell of the cryogenic tank is made using vacuum.

[0007] Optionally, the shell of the recovery tank is made using vacuum.

[0008] Optionally, the power source is a cryogenic pump or a compressor.

[0009] Optionally, the low-temperature standard tank, the first pneumatic valve, the second pneumatic valve, the first quick-link valve group, the second quick-link valve group and the inspected meter are collectively arranged on the electronic balance.

[0010] The present invention also provides a non-constant current low temperature static mass method verification method, the non-constant current low temperature static mass method verification method uses the non-constant current low temperature static mass method verification device, the non-constant current low temperature static mass method verification method comprises:

[0011] The second pneumatic valve, the third pneumatic valve, and the fifth pneumatic valve are closed, and the first pneumatic valve, the fourth pneumatic valve, the first quick-link valve group, and the second quick-link valve group are opened, and the power source is started to allow the cryogenic liquid to flow from the cryogenic storage tank to the cryogenic standard tank until the cryogenic standard tank is filled;

[0012] Close the fourth pneumatic valve, the first quick-link valve group, the second quick-link valve group, the third pneumatic valve, and the fifth pneumatic valve, and open the first pneumatic valve and the second pneumatic valve, so that the cryogenic liquid flows from the cryogenic standard tank through the first pneumatic valve, through the meter under test, and then through the second pneumatic valve into the recovery tank, adjust the pressure of the second pneumatic valve and the calibration tank, and when the flow reaches the calibration flow point, record the weighing value Q1 of the electronic balance ij and count, the count being the number of pulses output by the meter under test. When the weight of the low-temperature standard tank drops to a preset value, the second pneumatic valve is closed and the weighing value Q2 of the electronic balance is recorded. ij and end count N ij ;

[0013] When the liquid level inside the recovery tank reaches a preset height, the third pneumatic valve and the fifth pneumatic valve are opened, the power source is started, and the recovered liquid enters the cryogenic tank for cooling. The cooled low-temperature liquid is recovered into the low-temperature storage tank.

[0014] Optionally, the calculation formula for the cumulative flow rate measured for the jth time at the i-th calibration point of the non-constant flow low-temperature static mass method calibration device is as follows:

[0015] (Q s ) ij =Q1 ij -Q2 ij

[0016] The calculation formula for the cumulative mass flow rate measured at the i-th inspection point of the inspected meter for the jth time is as follows:

[0017]

[0018] The error calculation formula for a single calibration is as follows:

[0019]

[0020] Among them, Q ij is the cumulative mass flow rate measured at the i-th inspection point of the inspected meter for the jth time, (Q s ) ij It is the cumulative flow rate measured for the jth time at the i-th calibration point of the non-constant flow low-temperature static mass method calibration device.

[0021] The present invention has the following beneficial effects:

[0022] The non-constant flow low-temperature static mass method calibration device provided by the present invention comprises a low-temperature standard tank, an electronic balance, a cryogenic tank, a cryogenic storage tank, a recovery tank, a power source, a first pneumatic valve, a second pneumatic valve, a third pneumatic valve, a fourth pneumatic valve, a fifth pneumatic valve, a first quick-link valve group, a second quick-link valve group, and a meter to be tested. In the non-constant flow low-temperature static mass method calibration device provided by the present invention, in order to ensure the temperature of the recovered liquid, the recovered liquid first passes through a cryogenic tank for cooling, and then enters the cryogenic storage tank, thereby preventing the liquid from gasifying and also avoiding frosting of the pipeline and the outlet. In addition, the pipeline provided by the present invention adopts a vacuum pipeline, and other parts are insulated to prevent liquid gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of a non-constant current low-temperature static mass method calibration device provided in Example 1 of the present invention.

[0024] Figure 2 A schematic diagram of a state of a non-constant current low-temperature static mass method calibration device provided in Example 1 of the present invention.

[0025] Figure 3 This is a schematic diagram of another state of the non-constant current low-temperature static mass method calibration device provided in Example 1 of the present invention.

[0026] Figure 4 This is a schematic diagram of the principle of the non-constant current low-temperature static mass method calibration device provided in Example 1 of the present invention.

[0027] Figure 5 This is a block diagram of a non-constant current low-temperature static mass method calibration device provided in Example 1 of the present invention.

[0028] Among them, the accompanying drawings are marked as: low-temperature standard tank-1, electronic balance-2, deep-cold tank-3, low-temperature storage tank-4, recovery tank-5, power source-6, first pneumatic valve-11, second pneumatic valve-12, third pneumatic valve-13, fourth pneumatic valve-14, fifth pneumatic valve-15, first quick-link valve group-16, second quick-link valve group-17, inspected table-20. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solution of the present invention, the non-constant current low-temperature static mass method calibration device and method provided by the present invention are described in detail below in conjunction with the accompanying drawings.

[0030] Embodiment 1

[0031] Figure 1 This is a schematic diagram of the structure of a non-constant current low-temperature static mass method calibration device provided in Example 1 of the present invention. Figure 2 A schematic diagram of a state of a non-constant current low-temperature static mass method calibration device provided in Example 1 of the present invention. Figure 3 This is another state schematic diagram of the non-constant current low temperature static mass method calibration device provided in the first embodiment of the present invention. Figure 1-3 As shown, the present embodiment provides a non-constant flow low-temperature static mass method calibration device, including a low-temperature standard tank 1, an electronic balance 2, a cryogenic tank 3, a cryogenic storage tank 4, a recovery tank 5, a power source 6, a first pneumatic valve 11, a second pneumatic valve 12, a third pneumatic valve 13, a fourth pneumatic valve 14, a fifth pneumatic valve 15, a first quick-link valve group 16, a second quick-link valve group 17, and a meter to be tested 20. The non-constant flow low-temperature static mass method calibration device provided in the present embodiment, in order to ensure the temperature of the recovered liquid, the recovered liquid first passes through a cryogenic tank for cooling, and then enters the cryogenic storage tank, thereby preventing the liquid from gasifying and also avoiding frost on the pipeline and outlet. In addition, the pipeline provided in the present embodiment adopts a vacuum pipeline, and other parts are insulated to prevent liquid gas.

[0032] In this embodiment, the low-temperature standard tank 1 is arranged on the electronic balance 2. The low-temperature standard tank 1 is used to store the low-temperature medium used for calibration. The low-temperature standard tank 1 is made of a vacuum tank. The electronic balance 2 is used to weigh the weight change of the medium and provide a standard weight. One end of the low-temperature standard tank 1 is connected to the low-temperature storage tank 4 through the second quick-link valve group 17, and the other end of the low-temperature standard tank 1 is connected to one end of the inspected meter 20 through the first pneumatic valve 11. The other end of the inspected meter 20 extends into the internal space of the recovery tank 5 through the second pneumatic valve 12, and the other end of the inspected meter 20 is connected to the power source 6 through the first quick-link valve group 16.

[0033] Figure 4 This is a schematic diagram of the principle of the non-constant current low-temperature static mass method calibration device provided in Example 1 of the present invention. Figure 5 This is a block diagram of a non-constant current low temperature static mass method calibration device provided in Embodiment 1 of the present invention. Figure 4 and Figure 5 As shown, the lower position of the recovery tank 5 is connected to one end of the cryogenic tank 3, and the recovery tank 5 is used to store the intermediate liquid used for calibration. The other end of the cryogenic tank 3 is connected to the power source 6 through the third pneumatic valve 13, and the cryogenic tank 3 is used to cool the recovered liquid. The low-temperature storage tank 4 is connected to the power source 6 through the fourth pneumatic valve 14 and the fifth pneumatic valve 15 respectively, and the low-temperature storage tank 4 is used to provide the low-temperature liquid required for calibration, and the pneumatic valve is used to change the flow direction of the medium in the pipeline.

[0034] In this embodiment, the outer shell of the cryogenic tank 3 is made of vacuum, the outer shell of the recovery tank 5 is made of vacuum, the power source 6 is a cryogenic pump or a compressor, and the cryogenic standard tank 1 and the first pneumatic valve 11, the second pneumatic valve 12, the first quick-link valve group 16, the second quick-link valve group 17 and the inspected meter 20 are collectively arranged on the electronic balance 2.

[0035] The cryogenic standard tank provided in this embodiment is used to store the cryogenic medium for calibration, and the cryogenic standard tank is made of a vacuum tank. The electronic balance is used to weigh the weight change of the medium and provide the standard weight. The cryogenic tank is used to cool the recovered liquid, and the outer shell of the cryogenic tank is made of vacuum. The cryogenic storage tank is used to provide the cryogenic liquid required for calibration, and the recovery tank is used to store the intermediate liquid for calibration, and the outer shell of the recovery tank is made of vacuum. The power source is a cryogenic pump or a compressor. The pneumatic valve provided in this embodiment changes the flow direction of the medium in the pipeline as needed.

[0036] The non-constant flow low-temperature static mass method calibration device provided in the present embodiment includes a low-temperature standard tank, an electronic balance, a cryogenic tank, a cryogenic storage tank, a recovery tank, a power source, a first pneumatic valve, a second pneumatic valve, a third pneumatic valve, a fourth pneumatic valve, a fifth pneumatic valve, a first quick-link valve group, a second quick-link valve group, and a meter to be tested. In the non-constant flow low-temperature static mass method calibration device provided in the present embodiment, in order to ensure the temperature of the recovered liquid, the recovered liquid first passes through a cryogenic tank for cooling, and then enters the cryogenic storage tank, thereby preventing the liquid from gasifying and also avoiding frosting of the pipeline and the outlet. In addition, the pipeline provided in the present embodiment adopts a vacuum pipeline, and the other parts are insulated to prevent liquid gas.

[0037] Embodiment 2

[0038] This embodiment provides a non-constant current low-temperature static mass method calibration method, which uses the non-constant current low-temperature static mass method calibration device provided in Example 1. The specific content can be referred to the description of the above Example 1, which will not be repeated here.

[0039] See also Figure 2 In this embodiment, the second pneumatic valve 12, the third pneumatic valve 13, and the fifth pneumatic valve 15 are closed, and the first pneumatic valve 11, the fourth pneumatic valve 14, the first quick-link valve group 16, and the second quick-link valve group 17 are opened, and the power source 6 is started, so that the cryogenic liquid flows from the cryogenic storage tank 4 to the cryogenic standard tank 1 until the cryogenic standard tank 1 is filled. In the non-constant flow low-temperature static mass method calibration device provided in this embodiment, in order to ensure the temperature of the recovered liquid, the recovered liquid first passes through a cryogenic tank for cooling, and then enters the cryogenic storage tank, thereby preventing the liquid from gasifying and also avoiding frosting of the pipeline and the outlet. In addition, the pipeline provided in this embodiment adopts a vacuum pipeline, and other parts are insulated to prevent liquid gas.

[0040] See also Figure 3 In this embodiment, the fourth pneumatic valve 14, the first quick-link valve group 16, the second quick-link valve group 17, the third pneumatic valve 13, and the fifth pneumatic valve 15 are closed, and the first pneumatic valve 11 and the second pneumatic valve 12 are opened, so that the cryogenic liquid flows from the cryogenic standard tank 1 through the first pneumatic valve 11, through the meter under test 20, and then through the second pneumatic valve 12, into the recovery tank 5, and the pressure of the second pneumatic valve 12 and the calibration tank is adjusted. When the flow rate reaches the calibration flow point, the weighing value Q1 of the electronic balance 2 is recorded. ij and count, the count being the number of pulses output by the meter under test 20. When the weight of the low temperature standard tank 1 drops to a preset value, the second pneumatic valve 12 is closed and the weighing value Q2 of the electronic balance 2 is recorded. ijand end count N ij .

[0041] See also Figure 4 When the liquid level inside the recovery tank 5 reaches a preset height, the third pneumatic valve 13 and the fifth pneumatic valve 15 are opened, the power source 6 is started, and the recovered liquid enters the cryogenic tank 3 for cooling. The low-temperature liquid after cooling is recovered into the low-temperature storage tank 4. The calculation formula for the cumulative flow measured at the i-th calibration point of the non-constant flow low-temperature static mass method calibration device for the j-th time is as follows:

[0042] (Q s ) ij =Q1 ij -Q2 ij

[0043] The calculation formula for the cumulative mass flow rate measured at the i-th inspection point of the inspected meter 20 for the jth time is as follows:

[0044]

[0045] The error calculation formula for a single calibration is as follows:

[0046]

[0047] Among them, Q ij is the cumulative mass flow rate measured at the jth time at the i-th inspection point of the inspected meter 20, (Q s ) ij It is the cumulative flow rate measured for the jth time at the i-th calibration point of the non-constant flow low-temperature static mass method calibration device.

[0048] The steps of the standard tank liquid filling process and flow meter precooling provided in this embodiment are as follows:

[0049] Close the second pneumatic valve, the third pneumatic valve, and the fifth pneumatic valve, open the first pneumatic valve, the fourth pneumatic valve, the first quick-link valve group, and the second quick-link valve group, start the power source, and allow the cryogenic liquid to flow from the cryogenic storage tank to the standard tank and fill it up. In this process, the flow meter is precooled.

[0050] The steps of flow meter calibration provided in this embodiment are as follows:

[0051] Close the fourth pneumatic valve, the first quick-link valve group, the second quick-link valve group, the third pneumatic valve, and the fifth pneumatic valve, and open the first pneumatic valve and the second pneumatic valve. The cryogenic liquid flows from the standard tank through the meter to be tested, and then through the second pneumatic valve into the recovery tank, through the second pneumatic valve and the pressure of the calibration tank. When the flow reaches the calibration flow point, the control system simultaneously records the current weighing value Q1 ijAnd count (count the output pulse number of the meter under test), when the weight of the standard tank drops to the preset value, close the second pneumatic valve and record the weighing value Q2 ij and end count N ij . The calibration is completed once. When the liquid level in the recovery tank reaches a certain height, open the third pneumatic valve and the fifth pneumatic valve, start the power source, and recover the low-temperature liquid to the storage tank. To ensure the temperature of the recovered liquid, the recovered liquid enters the storage tank after cooling in the deep cold tank.

[0052] See also Figure 4 , the cumulative flow rate (kg) measured by the jth calibration device at the i-th calibration point is:

[0053] (Q s )ij=Q1 ij -Q2 ij

[0054] The cumulative mass flow rate (kg) measured by the flowmeter at the i-th calibration point for the jth time is:

[0055]

[0056] The error of a single test is:

[0057]

[0058] The low temperature standard tank provided in this embodiment is installed on the electronic balance together with the first pneumatic valve, the second pneumatic valve, the first quick-connect valve group, the second quick-connect valve group and the meter under test. The pipeline adopts a vacuum pipeline, and the other parts are insulated to prevent liquid gas. Since the Coriolis mass flowmeter has no requirements for the front and rear straight pipe sections, the used pipeline is also as short as possible.

[0059] In the non-constant flow low-temperature static mass method calibration method provided in the present embodiment, the non-constant flow low-temperature static mass method calibration device includes a low-temperature standard tank, an electronic balance, a cryogenic tank, a cryogenic storage tank, a recovery tank, a power source, a first pneumatic valve, a second pneumatic valve, a third pneumatic valve, a fourth pneumatic valve, a fifth pneumatic valve, a first quick-link valve group, a second quick-link valve group, and a meter to be tested. In the non-constant flow low-temperature static mass method calibration device provided in the present embodiment, in order to ensure the temperature of the recovered liquid, the recovered liquid first passes through a cryogenic tank for cooling, and then enters the cryogenic storage tank, thereby preventing the liquid from gasifying and also avoiding frosting of the pipeline and the outlet. In addition, the pipeline provided in the present embodiment adopts a vacuum pipeline, and other parts are insulated to prevent liquid gas.

[0060] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A non-constant current low temperature static mass method calibration device, characterized in that: Including low temperature standard tank, electronic balance, cryogenic tank, low temperature storage tank, recovery tank, power source, first pneumatic valve, second pneumatic valve, third pneumatic valve, fourth pneumatic valve, fifth pneumatic valve, first quick link valve group, second quick link valve group, and table under inspection; The low-temperature standard tank is arranged on the electronic balance. The low-temperature standard tank is used to store the low-temperature medium used for calibration. The low-temperature standard tank is made of a vacuum tank. The electronic balance is used to weigh the weight change of the medium and provide a standard weight. One end of the low-temperature standard tank is connected to the low-temperature storage tank through the second quick-link valve group, and the other end of the low-temperature standard tank is connected to one end of the meter to be inspected through the first pneumatic valve. The other end of the meter to be inspected extends into the internal space of the recovery tank through the second pneumatic valve, and the other end of the meter to be inspected is connected to the power source through the first quick-link valve group; The lower part of the recovery tank is connected to one end of the cryogenic tank, the recovery tank is used to store the intermediate liquid used for calibration, the other end of the cryogenic tank is connected to the power source through the third pneumatic valve, the cryogenic tank is used to cool the recovered liquid, the low-temperature storage tank is connected to the power source through the fourth pneumatic valve and the fifth pneumatic valve respectively, the low-temperature storage tank is used to provide the low-temperature liquid required for calibration, and the pneumatic valve is used to change the flow direction of the medium in the pipeline; The power source is a cryogenic pump or a compressor; The low-temperature standard tank, the first pneumatic valve, the second pneumatic valve, the first quick-link valve group, the second quick-link valve group and the inspected meter are arranged on the electronic balance.

2. The non-constant current low temperature static mass method calibration device according to claim 1, characterized in that: The outer shell of the cryogenic tank is made using vacuum.

3. The non-constant current low temperature static mass method calibration device according to claim 1, characterized in that: The outer shell of the recovery tank is made using vacuum.

4. A non-constant current low temperature static mass method verification method, characterized in that: The non-constant current low temperature static mass method verification method uses the non-constant current low temperature static mass method verification device according to any one of claims 1 to 3, and the non-constant current low temperature static mass method verification method comprises: The second pneumatic valve, the third pneumatic valve, and the fifth pneumatic valve are closed, and the first pneumatic valve, the fourth pneumatic valve, the first quick-link valve group, and the second quick-link valve group are opened, and the power source is started to allow the cryogenic liquid to flow from the cryogenic storage tank to the cryogenic standard tank until the cryogenic standard tank is filled; Close the fourth pneumatic valve, the first quick-link valve group, the second quick-link valve group, the third pneumatic valve, and the fifth pneumatic valve, and open the first pneumatic valve and the second pneumatic valve, so that the cryogenic liquid flows from the cryogenic standard tank through the first pneumatic valve, through the meter under test, and then through the second pneumatic valve into the recovery tank, adjust the pressure of the second pneumatic valve and the calibration tank, and when the flow reaches the calibration flow point, record the weighing value Q1 of the electronic balance ij and count, the count being the number of pulses output by the meter under test. When the weight of the low-temperature standard tank drops to a preset value, the second pneumatic valve is closed and the weighing value Q2 of the electronic balance is recorded. ij and end count N ij ; When the liquid level inside the recovery tank reaches a preset height, the third pneumatic valve and the fifth pneumatic valve are opened, the power source is started, and the recovered liquid enters the cryogenic tank for cooling. The cooled low-temperature liquid is recovered into the low-temperature storage tank.

5. The non-constant current low temperature static mass method verification method according to claim 4 is characterized in that: The calculation formula for the cumulative flow rate measured at the jth time at the i-th calibration point of the non-constant flow low-temperature static mass method calibration device is as follows: (Q s ) ij =Q1 ij -Q2 ij The calculation formula for the cumulative mass flow rate measured at the i-th inspection point of the inspected meter for the jth time is as follows: The error calculation formula for a single calibration is as follows: Among them, Q ij is the cumulative mass flow rate measured at the i-th inspection point of the inspected meter for the jth time, (Q s ) ij It is the cumulative flow rate measured for the jth time at the i-th calibration point of the non-constant flow low-temperature static mass method calibration device.

Images