A mobile end steam flow calibration system and method based on high-temperature heat storage

Abstract

The application discloses a mobile end steam flow calibration system and method based on high-temperature heat storage, which comprises a heat network main pipeline, a user branch, a branch temperature sensor, a branch pressure sensor, a branch flowmeter, a branch stop valve, a plurality of heat users, a calibration bypass inlet, a bypass inlet stop valve, a bypass inlet connecting pipe, a mobile high-temperature heat storage calibration system, a bypass outlet connecting pipe, a bypass outlet stop valve and a calibration bypass outlet. The application uses a mobile heat storage steam generator to heat end steam, ensures that the heated steam is superheated steam, corrects the end steam flow by comparing the steam parameters before and after heating and combining the steam dryness, and ensures the accuracy of user-side steam metering.

Description

Technical Field

[0001] This invention belongs to the field of steam property measurement, specifically relating to a mobile terminal steam flow calibration system and method based on high-temperature thermal storage. Background Technology

[0002] Steam is widely used in industrial production and power industries. However, due to the presence of gas-liquid two-phase flow and frequent load fluctuations, it is difficult to accurately measure steam flow, which poses a great challenge to energy management control and equipment performance optimization.

[0003] Insufficient steam superheat and aging flow meters can both lead to inaccurate steam flow measurement at the terminal. To ensure flow measurement accuracy, regular maintenance and calibration of the steam flow measurement system are necessary. To address this issue, Chinese patent CN10526380A proposes connecting an internal cone flow meter and a vortex flow meter in series, calculating the wet steam flow rate using the steam pressure difference measured by the internal cone flow meter and the vortex generation frequency measured by the vortex flow meter. Chinese patent CN218822527U converts the measured steam flow rate into separate measurements of pressure, temperature, and liquid water flow rate. Both methods can solve the problem of insufficient steam superheat. However, with increasing service life, flow meter aging leading to decreased measurement accuracy remains unavoidable, and the fixed installation location of the measuring device limits flexibility. Therefore, how to accurately measure the steam flow rate with insufficient superheat at the terminal while improving the service life and flexibility of the measuring device becomes a problem that needs to be solved. Summary of the Invention

[0004] To overcome the above problems, the present invention provides a mobile terminal steam flow calibration system and method based on high-temperature thermal storage.

[0005] The specific technical solution adopted in this invention is as follows:

[0006] In a first aspect, the present invention provides a mobile terminal steam flow calibration system based on high-temperature thermal storage, which includes a main heating network pipeline, a user branch, a branch temperature sensor, a branch pressure sensor, a branch flow meter, a branch shut-off valve, a calibration bypass inlet, a bypass inlet shut-off valve, a bypass inlet connecting pipe, a mobile high-temperature thermal storage calibration system, a bypass outlet connecting pipe, a bypass outlet shut-off valve, and a calibration bypass outlet.

[0007] The main heating network pipeline is connected to several heat users through user branches. Each user branch is equipped with a branch shut-off valve near the user side. The user branch before the branch shut-off valve is equipped with a branch temperature sensor, a branch pressure sensor, and a branch flow meter. The user branch before the branch shut-off valve is equipped with a calibration bypass inlet for connecting to the bypass inlet connection pipe, and the user branch after the branch shut-off valve is equipped with a calibration bypass outlet for connecting to the bypass outlet connection pipe. The bypass inlet connection pipe and the bypass outlet connection pipe are respectively equipped with a bypass inlet shut-off valve and a bypass outlet shut-off valve.

[0008] The mobile high-temperature thermal storage calibration system includes a mobile vehicle-mounted device and a high-temperature thermal storage reheater, thermal storage temperature sensor, reheat steam temperature sensor, reheat steam pressure sensor, steam calibration flow meter, heating power interface and system controller, all mounted on the mobile vehicle-mounted device.

[0009] The high-temperature thermal reheater is connected between the bypass inlet connection pipe and the bypass outlet connection pipe. Through valve switching control, the steam from the main heating network pipeline to the user branch can be fed into the high-temperature thermal reheater through the bypass inlet connection pipe for heating, and then returned to the user branch on the heat user side from the bypass outlet connection pipe. The thermal reheat temperature sensor is used to detect the temperature of the thermal reheater. The reheat steam temperature sensor, reheat steam pressure sensor, and steam calibration flow meter are used to detect the steam temperature, steam pressure, and steam flow rate at the outlet of the high-temperature thermal reheater, respectively. All the sensors on the high-temperature thermal reheater are connected to the system controller to realize data acquisition and control.

[0010] As a preferred embodiment of the first aspect, the high-temperature heat storage reheater is a direct solid heat storage device, wherein the heat storage body is composed of solid heat storage material, the heat storage body is wrapped with an insulation layer, and the heat storage body is embedded with electric heating rods and heat exchange pipe assembly.

[0011] As a preferred embodiment of the first aspect mentioned above, the heat exchange pipeline group is a tubular structure or a plate structure, and the heat exchange pipeline group includes an inlet manifold, an outlet manifold, and several sets of series and parallel heat exchange tubes connected between the two.

[0012] As a preferred embodiment of the first aspect above, the solid heat storage material is a high-temperature solid heat storage material, including but not limited to one or a combination of graphite, concrete, cast iron, and magnesia bricks.

[0013] As a preferred embodiment of the first aspect, both the calibration bypass inlet and the calibration bypass outlet have flange structures for connection to external pipelines, and both the calibration bypass inlet and the calibration bypass outlet are normally closed when no bypass inlet connecting pipe and bypass outlet connecting pipe are connected.

[0014] Secondly, the present invention provides a calibration method for a mobile terminal steam flow calibration system according to the first aspect described above, which is as follows: After the high-temperature reheater in the mobile high-temperature thermal storage calibration system is charged, the entire mobile high-temperature thermal storage calibration system is moved to the location of the user branch to be tested using a mobile vehicle-mounted device, and connected to the user branch to be tested through the calibration bypass inlet and calibration bypass outlet; before using the mobile high-temperature thermal storage calibration system for measurement, the bypass inlet shut-off valve and bypass outlet shut-off valve on the user branch to be tested are opened, and the branch on the user branch to be tested is shut off. The shut-off valve allows steam from the user branch to flow completely through the calibration bypass inlet connection pipe, then through the high-temperature accumulator, and finally out through the bypass outlet connection pipe. In the mobile high-temperature thermal storage calibration system, the system controller continuously compares the data from the reheat steam temperature sensor and the reheat steam pressure sensor until the temperature measured by the reheat steam temperature sensor is greater than the saturated steam temperature corresponding to the pressure measured by the reheat steam pressure sensor. After the reading of the steam calibration flow meter stabilizes, the system records the flow rate data G1 measured by the branch flow meter, the flow rate data G2 measured by the steam calibration flow meter, and the temperature data T measured by the thermal storage temperature sensor. h Simultaneously, timing begins from the recording time as the reference point and stops when the reading of the heat storage temperature sensor changes. The entire timing process lasts for at least 15 seconds. Record the following data at the time of timing stop: temperature T1 measured by the branch temperature sensor, pressure P1 measured by the branch pressure sensor, temperature T2 measured by the reheat steam temperature sensor, pressure P2 measured by the reheat steam pressure sensor, and temperature T2 measured by the heat storage temperature sensor. l ;

[0015] After the measurement is completed, open the branch shut-off valve on the user branch to be tested, close the bypass inlet shut-off valve and bypass outlet shut-off valve on the user branch to be tested, and remove the mobile high-temperature heat storage calibration system.

[0016] Based on the measured data, the flow correction factor for the user's flow meter is calculated using the following method:

[0017] 1) Calculate the total flow correction factor c1 based on the recorded flow data G1 and flow data G2:

[0018]

[0019] 2) First, based on the recorded temperature data T h Temperature data T l And the duration t of the timing process, calculate

[0020] The average heat absorption rate q during the process of wet steam turning into superheated steam:

[0021]

[0022] Where c is the specific heat of the heat storage material in the high-temperature heat storage reheater, and m is the mass of the heat storage material in the high-temperature heat storage reheater.

[0023] Then, based on the recorded pressure data P1, the enthalpy of saturated water h is determined. f and saturated vapor enthalpy h g Based on the recorded pressure data P2 and temperature data T2, the enthalpy of the superheated steam at the outlet, h2, is determined, and the steam dryness fraction x is calculated as follows:

[0024]

[0025] Finally, the dry steam flow correction factor c2 is calculated as follows:

[0026]

[0027] Correction coefficients c1 and c2 are entered into the control system of the branch flow meter to correct the flow data recorded by the branch flow meter.

[0028] As a preferred embodiment of the second aspect mentioned above, in the control system of the branch flow meter, the total flow correction coefficient c1 is multiplied by the flow data recorded by the branch flow meter to obtain the corrected total steam flow.

[0029] As a preferred embodiment of the second aspect mentioned above, in the control system of the branch flow meter, the dry steam flow correction coefficient c2 is multiplied by the flow data recorded by the branch flow meter to obtain the corrected total dry steam flow.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] 1. The method of the present invention uses a mobile thermal regenerative steam generator to heat the terminal steam. The device can be moved to the measurement location when the flow rate needs to be checked, and can be disassembled at any time after the check is completed, which improves the service life and flexibility of the measurement system.

[0032] 2. The method of the present invention selects a solid heat storage body as a heat source to heat the terminal steam. Even when the steam subcooling degree is high and the steam flow rate is large, the terminal steam can still be heated to a superheated state quickly. Attached Figure Description

[0033] Figure 1 It is a mobile terminal steam flow calibration system based on high-temperature thermal storage;

[0034] Figure 2 This is a schematic diagram of a high-temperature heat storage reheater;

[0035] In the diagram: 1. Main heating network line; 2. User branch line; 3. Branch line temperature sensor; 4. Branch line pressure sensor; 5. Branch line flow meter; 6. Branch line shut-off valve; 7. Several heat users; 8. Calibration bypass inlet; 9. Bypass inlet shut-off valve; 10. Bypass inlet connecting pipe; 11. Mobile high-temperature heat storage calibration system; 12. Bypass outlet connecting pipe; 13. Bypass outlet shut-off valve; 14. Calibration bypass outlet; 15. High-temperature heat storage reheater; 16. Heat storage temperature sensor; 17. Reheat steam temperature sensor; 18. Reheat steam pressure sensor; 19. Steam calibration flow meter; 20. Heating power interface; 21. System controller; 22. Mobile vehicle-mounted device; 23. Solid heat storage material; 24. Insulation layer; 25. Electric heating rod and heat exchange pipe assembly; 26. Inlet manifold; 27. Outlet manifold; 28. Detailed Implementation

[0036] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] like Figure 1 As shown, this embodiment provides a terminal steam flow calibration system based on high-temperature thermal storage. This system is used to calibrate the steam flow measured on the user branch 2 connected to the heat user 7. The system consists of: a main heating network line 1, a user branch 2, a branch temperature sensor 3, a branch pressure sensor 4, a branch flow meter 5, a branch shut-off valve 6, a calibration bypass inlet 8, a bypass inlet shut-off valve 9, a bypass inlet connecting pipe 10, a bypass outlet connecting pipe 12, a bypass outlet shut-off valve 13, and a calibration bypass outlet 14. The mobile high-temperature thermal storage calibration system 11 includes a high-temperature thermal storage reheater 15, a thermal storage temperature sensor 16, a reheat steam temperature sensor 17, a reheat steam pressure sensor 18, a steam calibration flow meter 19, a heating power interface 20, a system controller 21, and a mobile vehicle-mounted device 22.

[0039] The aforementioned main heating network pipeline 1 is connected to several heat users 7 via different user branches 2. Each user branch 2 is equipped with a branch shut-off valve 6 near the user side. A branch temperature sensor 3, a branch pressure sensor 4, and a branch flow meter 5 are installed on the user branch 2 before the branch shut-off valve 6. These sensors are used to detect the steam temperature, steam pressure, and steam flow rate on the user branch 2, respectively. A calibration bypass inlet 8 is provided on the user branch 2 before the branch shut-off valve 6 for connecting to the bypass inlet connection pipe 10. Steam from the user branch 2 can flow into the bypass inlet connection pipe 10 by connecting the inlet end of the bypass inlet connection pipe 10. A calibration bypass outlet 14 is provided on the user branch 2 after the branch shut-off valve 6 for connecting to the bypass outlet connection pipe 12. Steam from the user branch 2 can flow into the bypass outlet connection pipe 12 by connecting the inlet end of the bypass outlet connection pipe 12. In addition, bypass inlet connecting pipe 10 and bypass outlet connecting pipe 12 are respectively equipped with bypass inlet shut-off valve 9 and bypass outlet shut-off valve 13, which can control the opening and closing of their respective pipelines. Branch shut-off valve 6, bypass inlet shut-off valve 9 and bypass outlet shut-off valve 13 can cooperate to switch the steam flow path. When branch shut-off valve 6 is open and bypass inlet shut-off valve 9 and bypass outlet shut-off valve 13 are closed, the steam entering user branch 2 in the main heating network pipeline 1 will be directly supplied to heat user 7 through user branch 2; while when branch shut-off valve 6 is closed and bypass inlet shut-off valve 9 and bypass outlet shut-off valve 13 are open, the steam entering user branch 2 in the main heating network pipeline 1 will bypass branch shut-off valve 6, pass through bypass inlet connecting pipe 10, mobile high-temperature heat storage calibration system 11, bypass outlet connecting pipe 12 and then be supplied to heat user 7 through user branch 2.

[0040] The mobile high-temperature thermal storage calibration system 11 heats the terminal steam in the user branch 2, raising it to a superheated state, thereby determining the steam flow correction coefficient. The mobile high-temperature thermal storage calibration system 11 includes a mobile vehicle-mounted device 22, and mounted on the mobile vehicle-mounted device 22 are a high-temperature thermal storage reheater 15, a thermal storage temperature sensor 16, a reheat steam temperature sensor 17, a reheat steam pressure sensor 18, a steam calibration flow meter 19, a heating power interface 20, and a system controller 21.

[0041] The aforementioned mobile vehicle-mounted device 22 can be any vehicle with the capability to carry the equipment. Therefore, the entire mobile high-temperature heat storage calibration system 11 can be flexibly moved to different locations to test user branch lines 2.

[0042] The high-temperature thermal reheater 15 is connected between the bypass inlet connection pipe 10 and the bypass outlet connection pipe 12. Through valve switching control, steam from the main heating network line 1 to the user branch 2 can be fed into the high-temperature thermal reheater 15 via the bypass inlet connection pipe 10 for heating, and then returned to the user branch 2 on the heat user 7 side from the bypass outlet connection pipe 12. A thermal storage temperature sensor 16 is installed on the high-temperature thermal reheater 15 to detect the temperature of the thermal storage medium inside the high-temperature thermal reheater 15. A reheat steam temperature sensor 17, a reheat steam pressure sensor 18, and a steam calibration flow meter 19 are respectively installed on the bypass outlet connection pipe 12 connected to the outlet end of the high-temperature thermal reheater 15 to detect the steam temperature, steam pressure, and steam flow rate at the outlet of the high-temperature thermal reheater 15. The system controller 21 serves as the central control and data processing device for the entire mobile high-temperature thermal storage calibration system 11. All sensors on the high-temperature thermal reheater 15 are connected to the system controller 21 for data acquisition and control.

[0043] See Figure 2 As shown, in this embodiment, the high-temperature heat storage reheater 15 is a direct-type solid heat storage device, whose components include solid heat storage material 23, insulation layer 24, electric heating rod 25, and heat exchange pipe assembly 26. The heat storage body is composed of solid heat storage material 23, and is wrapped with insulation layer 24. Electric heating rod 25 and heat exchange pipe assembly 26 are embedded inside the heat storage body. The heat exchange pipe assembly 26 can be either a tubular structure or a plate structure. (See also...) Figure 2 As shown, the heat exchange pipe group 26 includes an inlet manifold 27, an outlet manifold 28, and several sets of series and parallel heat exchange pipes connected between the two. The inlet ends of these series and parallel heat exchange pipes are all uniformly connected to the inlet manifold 27, and the outlet ends are all uniformly connected to the outlet manifold 28.

[0044] It should be noted that the aforementioned solid heat storage material 23 is a high-temperature solid heat storage material, and the specific material form includes, but is not limited to, one of graphite, concrete, cast iron, magnesia bricks, and combinations thereof.

[0045] In addition, for ease of connection, both the calibration bypass inlet 8 and the calibration bypass outlet 14 have flange structures for connection to external pipelines. The external pipelines can be tightly connected to the flange structures on the calibration bypass inlet 8 and the calibration bypass outlet 14 through the flanges at their ends. To prevent leakage, the calibration bypass inlet 8 and the calibration bypass outlet 14 are normally closed when not connected to the bypass inlet connecting pipe 10 and the bypass outlet connecting pipe 12.

[0046] Example 2

[0047] Based on Example 1, this example provides a method for calibrating the terminal steam flow rate using this terminal steam flow rate calibration system, the specific steps of which are as follows:

[0048] The high-temperature reheater 15 in the mobile high-temperature thermal storage calibration system 11 needs to be preheated. After the high-temperature reheater 15 in the mobile high-temperature thermal storage calibration system 11 is preheated, the entire mobile high-temperature thermal storage calibration system 11 is moved to the location of the user branch 2 to be tested using the mobile vehicle-mounted device 22. It is then connected to the user branch 2 to be tested through the calibration bypass inlet 8 and the calibration bypass outlet 14. Before using the mobile high-temperature thermal storage calibration system 11 for measurement, the bypass inlet shut-off valve 9 and the bypass outlet shut-off valve 13 on the user branch 2 to be tested are opened, and the branch shut-off valve 6 on the user branch 2 to be tested is closed, so that the steam in the user branch 2 flows completely through the calibration bypass inlet connecting pipe 10, flows through the high-temperature accumulator 11, and then flows out from the bypass outlet connecting pipe 12. Then, the system controller 21 in the mobile high-temperature thermal storage calibration system 11 continuously compares the data from the reheat steam temperature sensor 17 and the reheat steam pressure sensor 18 until the temperature measured by the reheat steam temperature sensor 17 is greater than the saturated steam temperature corresponding to the pressure measured by the reheat steam pressure sensor 18, and after the reading of the steam calibration flow meter 19 has basically stabilized, the flow data G1 measured by the branch flow meter 5, the flow data G2 measured by the steam calibration flow meter 19, and the temperature data T measured by the thermal storage temperature sensor 16 are recorded. h Simultaneously, timing begins from the recording time as the reference point and stops when the reading of the heat storage temperature sensor 16 changes. It is important to note that to ensure measurement accuracy, timing should be stopped only after a significant change in the reading, and the entire timing process, t, should not be less than 15 seconds. Furthermore, at the moment timing stops, the following data should be recorded: temperature T1 measured by branch temperature sensor 3, pressure P1 measured by branch pressure sensor 4, temperature T2 measured by reheat steam temperature sensor 17, pressure P2 measured by reheat steam pressure sensor 18, and temperature T1 measured by heat storage temperature sensor 16. l , used to calculate the flow correction coefficient for the current user branch 2 under test.

[0049] After the measurement is completed, open the branch shut-off valve 6 on the user branch 2 under test, close the bypass inlet shut-off valve 9 and the bypass outlet shut-off valve 13 on the user branch 2 under test, and remove the mobile high-temperature heat storage calibration system 11. The mobile high-temperature heat storage calibration system 11 can be further moved to the next user branch 2 to continue the measurement.

[0050] For any user branch 2, the flow correction factor of the user flow meter can be calculated based on the data measured from user branch 2. The flow correction factor is divided into two types: total flow correction factor and dry steam flow correction factor. The calculation methods for each are as follows:

[0051] 1) The total flow correction factor is calculated as follows:

[0052] Based on the recorded traffic data G1 and traffic data G2, calculate the total traffic correction factor c1:

[0053]

[0054] 2) The calculation process for the dry steam flow correction factor is as follows:

[0055] First, based on the temperature changes of the thermal storage system, the recorded temperature data T... h Temperature data T l Given the duration t of the timing process, calculate the average heat absorption rate q of the process from wet steam to superheated steam:

[0056]

[0057] Where c is the specific heat of the heat storage material in the high-temperature heat storage reheater 15, and m is the mass of the heat storage material in the high-temperature heat storage reheater 15.

[0058] Then, based on the recorded pressure data P1, the enthalpy of saturated water h is determined. f and saturated vapor enthalpy h g Based on the recorded pressure data P2 and temperature data T2, the enthalpy of the superheated steam at the outlet, h2, is determined, and the steam dryness fraction x is calculated as follows:

[0059]

[0060] Finally, based on the data measured by steam calibration flow meter 19, the data of branch flow meter 5 is corrected, and the dry steam flow correction factor c2 is calculated as follows:

[0061]

[0062] Once the correction coefficients c1 and c2 are obtained, they can be entered into the control system of the branch flow meter 5 to correct the flow data recorded by the branch flow meter 5.

[0063] The control system of branch flowmeter 5 can be a local control system or a remote control system, without restriction. In the control system of branch flowmeter 5, the specific choice between the total flow correction factor c1 and the dry steam flow correction factor c2 can be made according to the actual flow calibration requirements. Specifically: multiplying the total flow correction factor c1 by the flow data recorded by branch flowmeter 5 yields the corrected total steam flow rate; while multiplying the dry steam flow correction factor c2 by the flow data recorded by branch flowmeter 5 yields the corrected total dry steam flow rate.

[0064] This embodiment further demonstrates the usage of the above-mentioned terminal steam flow calibration system and method based on high-temperature thermal storage using a specific case.

[0065] In a typical steam heating network system, the mobile high-temperature thermal storage calibration system in Example 1 is connected to a user branch. The thermal parameters of the thermal storage body and the steam at both ends of the inlet and outlet of the thermal storage system are obtained through the system controller, as shown in the table below.

[0066] <![CDATA[Inlet steam temperature T1 [°C]]]> <![CDATA[Import steam pressure P1 [MPa]]]> <![CDATA[Branch flow rate G1 [kg / s]]]> 196.43 1.58 82.58 <![CDATA[Outlet steam temperature T2 [°C]]]> <![CDATA[Outlet steam pressure P2 [MPa]]]> <![CDATA[Calibration flow rate G2 [kg / s]]]> 212.48 1.63 89.23 <![CDATA[Initial temperature T of the regenerator h [℃]]]> <![CDATA[Final temperature T of the heat storage body l [℃]]]> Heating process duration t[s] 450.06 448.96 130.4

[0067] Based on the steam flow calibration method provided in Example 2, the coefficients are calculated as follows:

[0068] ①The total flow correction factor c1 is:

[0069]

[0070] ② Dry steam flow rate correction factor c2. Given that the specific heat of the thermal storage material c is 1050 J / (kg·K) and the mass of the thermal storage material m is 3617.8 kg, the average heat absorption rate q during the process of wet steam turning into superheated steam can be obtained:

[0071]

[0072] The corresponding saturated water enthalpy h is obtained based on the steam inlet pressure P1. f The enthalpy of the inlet saturated steam is 855.73 kJ / kg. g The enthalpy of the superheated steam at the outlet is 2792.46 kJ / kg. Based on the outlet steam pressure P2 and outlet temperature T2, the enthalpy h2 of the superheated steam at the outlet is 2822.76 kJ / kg. Therefore, the steam dryness fraction x is:

[0073]

[0074] The calorific value and flow rate correction factor c2 is:

[0075]

[0076] In summary, for this user branch, correction coefficients c1 and c2 are entered into the control system of the branch flow meter. Depending on the requirements, c1 or c2 is selected and multiplied by the data of the branch flow meter to obtain the corrected flow record. When c1 is selected, the corrected flow rate is the total steam flow rate, while when c2 is selected, the corrected flow rate is the dry steam flow rate.

[0077] In summary, this invention utilizes a mobile thermal regenerative steam generator to heat the terminal steam, ensuring that the heated steam is superheated. By comparing the steam parameters before and after heating and combining the steam dryness, the terminal steam flow rate is corrected, ensuring accurate steam metering on the user side.

[0078] The embodiments described above are merely some preferred implementations of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all technical solutions obtained through equivalent substitution or transformation fall within the protection scope of the present invention.

Claims

1. A mobile terminal steam flow calibration system based on high-temperature thermal storage, characterized in that... It includes the main heating network pipeline (1), user branch pipeline (2), branch temperature sensor (3), branch pressure sensor (4), branch flow meter (5), branch shut-off valve (6), calibration bypass inlet (8), bypass inlet shut-off valve (9), bypass inlet connecting pipe (10), mobile high temperature heat storage calibration system (11), bypass outlet connecting pipe (12), bypass outlet shut-off valve (13), and calibration bypass outlet (14); The main heating network pipeline (1) is connected to several heat users (7) through user branches (2). Each user branch (2) is equipped with a branch shut-off valve (6) near the user side. The user branch (2) before the branch shut-off valve (6) is equipped with a branch temperature sensor (3), a branch pressure sensor (4), and a branch flow meter (5). The user branch (2) before the branch shut-off valve (6) is equipped with a calibration bypass inlet (8) for connecting to the bypass inlet connection pipe (10). The user branch (2) after the branch shut-off valve (6) is equipped with a calibration bypass outlet (14) for connecting to the bypass outlet connection pipe (12). The bypass inlet connection pipe (10) and the bypass outlet connection pipe (12) are respectively equipped with a bypass inlet shut-off valve (9) and a bypass outlet shut-off valve (13). The mobile high-temperature heat storage calibration system (11) includes a mobile vehicle-mounted device (22) and a high-temperature heat storage reheater (15), a heat storage temperature sensor (16), a reheat steam temperature sensor (17), a reheat steam pressure sensor (18), a steam calibration flow meter (19), a heating power interface (20), and a system controller (21) mounted on the mobile vehicle-mounted device (22). The high-temperature heat storage reheater (15) is connected between the bypass inlet connection pipe (10) and the bypass outlet connection pipe (12). Through valve switching control, the steam input from the main heating network pipeline (1) to the user branch (2) can be input into the high-temperature heat storage reheater (15) through the bypass inlet connection pipe (10) for heating, and then return to the user branch (2) on the side of the heat user (7) from the bypass outlet connection pipe (12). The heat storage temperature sensor (16) is used to detect the temperature of the heat storage body in the high-temperature heat storage reheater (15). The reheat steam temperature sensor (17), the reheat steam pressure sensor (18), and the steam calibration flow meter (19) are used to detect the steam temperature, steam pressure, and steam flow at the outlet of the high-temperature heat storage reheater (15), respectively. The various sensors on the high-temperature heat storage reheater (15) are connected to the system controller (21) to realize data acquisition and control. The high-temperature heat storage reheater (15) is a direct solid heat storage device, wherein the heat storage body is composed of solid heat storage material (23), the heat storage body is wrapped with an insulation layer (24), and the heat storage body is embedded with an electric heating rod (25) and a heat exchange pipe assembly (26).

2. The mobile terminal steam flow calibration system based on high-temperature thermal storage according to claim 1, characterized in that... The heat exchange piping group (26) is a tubular or plate structure. The heat exchange piping group (26) includes an inlet manifold (27), an outlet manifold (28), and several sets of series and parallel heat exchange pipes connected between the two.

3. The mobile terminal steam flow calibration system based on high-temperature thermal storage according to claim 1, characterized in that... The solid heat storage material (23) is a high-temperature solid heat storage material, including but not limited to one of graphite, concrete, cast iron, magnesium bricks and combinations thereof.

4. A mobile terminal steam flow calibration system based on high-temperature thermal storage according to claim 1, characterized in that... Both the calibration bypass inlet (8) and the calibration bypass outlet (14) have flange structures for connecting to external pipelines, and both the calibration bypass inlet (8) and the calibration bypass outlet (14) are normally closed when not connected to the bypass inlet connecting pipe (10) and the bypass outlet connecting pipe (12).

5. A calibration method for a mobile terminal steam flow calibration system according to claim 1, characterized in that: After the high-temperature heat storage reheater (15) in the mobile high-temperature heat storage calibration system (11) is charged, the mobile high-temperature heat storage calibration system (11) is moved to the user branch (2) to be tested using a mobile vehicle-mounted device (22). It is then connected to the user branch (2) to be tested through the calibration bypass inlet (8) and the calibration bypass outlet (14). Before using the mobile high-temperature heat storage calibration system (11) for measurement, the bypass inlet shut-off valve (9) and bypass outlet shut-off valve (13) on the user branch (2) to be tested are opened, and the branch shut-off valve (6) on the user branch (2) to be tested is closed, so that the steam in the user branch (2) is completely connected through the calibration bypass inlet. The pipe (10) flows through the high-temperature accumulator (11) and then flows out from the bypass outlet pipe (12). The system controller (21) in the mobile high-temperature accumulator calibration system (11) continuously compares the data of the reheat steam temperature sensor (17) and the reheat steam pressure sensor (18) until the temperature measured by the reheat steam temperature sensor (17) is greater than the saturated steam temperature corresponding to the pressure measured by the reheat steam pressure sensor (18). After the reading of the steam calibration flow meter (19) stabilizes, the flow data G1 measured by the branch flow meter (5), the flow data G2 measured by the steam calibration flow meter (19), and the temperature data T measured by the accumulator temperature sensor (16) are recorded. h Simultaneously, timing begins from the recording time as the reference point, and stops when the reading of the heat storage temperature sensor (16) changes. The duration of the entire timing process is not less than 15 seconds. The temperature data T1 measured by the branch temperature sensor (3), the pressure data P1 measured by the branch pressure sensor (4), the temperature data T2 measured by the reheat steam temperature sensor (17), the pressure data P2 measured by the reheat steam pressure sensor (18), and the temperature data T1 measured by the heat storage temperature sensor (16) are recorded at the time the timing stops. l ; After the measurement is completed, open the branch shut-off valve (6) on the user branch (2) to be tested, close the bypass inlet shut-off valve (9) and bypass outlet shut-off valve (13) on the user branch (2) to be tested, and remove the mobile high temperature heat storage calibration system (11). Based on the measured data, the flow correction factor for the user's flow meter is calculated using the following method: 1) Calculate the total flow correction factor c1 based on the recorded flow data G1 and flow data G2: 2) First, based on the recorded temperature data T h Temperature data T l Given the duration t of the timing process, calculate the average heat absorption rate q of the process from wet steam to superheated steam: Where c is the specific heat of the heat storage material in the high-temperature heat storage reheater (15), and m is the mass of the heat storage material in the high-temperature heat storage reheater (15). Then, based on the recorded pressure data P1, the enthalpy of saturated water h is determined. f and saturated vapor enthalpy h g Based on the recorded pressure data P2 and temperature data T2, the enthalpy of the superheated steam at the outlet, h2, is determined, and the steam dryness fraction x is calculated as follows: Finally, the dry steam flow correction factor c2 is calculated as follows: The correction coefficients c1 and c2 are entered into the control system of the branch flow meter (5) to correct the flow data recorded by the branch flow meter (5).

6. The calibration method according to claim 5, characterized in that: In the control system of the branch flow meter (5), the total flow correction coefficient c1 is multiplied by the flow data recorded by the branch flow meter (5) to obtain the corrected total steam flow.

7. The calibration method according to claim 5, characterized in that: In the control system of the branch flow meter (5), the dry steam flow correction coefficient c2 is multiplied by the flow data recorded by the branch flow meter (5) to obtain the corrected total dry steam flow.

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