Mobile terminal steam flow calibration system and method based on high-temperature heat storage

Abstract

The invention discloses a mobile terminal steam flow calibration system and method based on high-temperature heat storage. The system comprises a heat supply 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 movable high-temperature heat storage calibration system, a bypass outlet connecting pipe, a bypass outlet stop valve and a calibration bypass outlet. The movable heat storage steam generator is used for heating the tail end steam, it is guaranteed that the heated steam is superheated steam, by comparing the steam parameters before and after heating and combining the steam dryness, correction of the tail end steam flow is achieved, and it is guaranteed that the user side steam is accurately metered.

Description

Technical Field

[0001] The present invention belongs to the field of steam property measurement, and in particular relates to a mobile terminal steam flow calibration system and method based on high-temperature heat storage. Background Art

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

[0003] Insufficient steam superheat and aging of the flowmeter will lead to inaccurate measurement of the terminal steam flow. In order to ensure the accuracy of flow measurement, the steam flow measurement system needs to be regularly maintained and calibrated. To solve this kind of problem, Chinese patent CN10526380A proposes to connect the inner cone flowmeter and the vortex flowmeter in series, and calculate the wet steam flow by the steam pressure difference measured by the inner cone flowmeter and the vortex frequency measured by the vortex flowmeter; Chinese patent CN218822527U converts the measured steam flow into pressure, temperature and liquid water flow for separate measurement. The above two methods can solve the problem of insufficient steam superheat. However, with the increase of service life, the decrease in measurement accuracy caused by the aging of the flowmeter is still unavoidable, and the installation position of the measuring device is fixed and the flexibility is limited. How to accurately measure the steam flow with insufficient terminal superheat while improving the service life and flexibility of the measuring device has become a problem that needs to be solved. Summary of the invention

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

[0005] The technical solutions specifically adopted in the present invention are as follows:

[0006] In a first aspect, the present invention provides a mobile terminal steam flow calibration system based on high-temperature heat storage, which includes a heat network main line, a user branch, a branch temperature sensor, a branch pressure sensor, a branch flow meter, a branch stop valve, 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;

[0007] The main pipeline of the heat network is connected to several heat users through user branches. A branch stop valve is provided on each user branch near the user side. A branch temperature sensor, a branch pressure sensor and a branch flow meter are installed on the user branch before the branch stop valve. A calibration bypass inlet for connecting to a bypass inlet connecting pipe is provided on the user branch before the branch stop valve. A calibration bypass outlet for connecting to a bypass outlet connecting pipe is provided on the user branch after the branch stop valve. A bypass inlet connecting pipe and a bypass outlet connecting pipe are provided with a bypass inlet stop valve and a bypass outlet stop valve respectively.

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

[0009] The high-temperature heat storage reheater is connected between the bypass inlet connecting pipe and the bypass outlet connecting pipe. Through valve switching control, the steam input into the user branch from the heat network main line can be input into the high-temperature heat storage reheater through the bypass inlet connecting pipe for heating, and then return to the user branch on the heat user side from the bypass outlet connecting pipe; the heat storage temperature sensor is used to detect the temperature of the heat storage body in the high-temperature heat storage reheater, the reheat steam temperature sensor, the reheat steam pressure sensor, and the steam calibration flowmeter are respectively used to detect the steam temperature, steam pressure, and steam flow at the output port of the high-temperature heat storage reheater. The various sensors on the high-temperature heat storage reheater are connected to the system controller to realize data acquisition and control.

[0010] As a preferred embodiment of the first aspect above, the high-temperature heat storage reheater is a direct solid heat storage device, in which the heat storage body is composed of solid heat storage material, the outside of the heat storage body is wrapped with an insulation layer, and the inside of the heat storage body is embedded with an electric heating rod and a heat exchange pipe group.

[0011] As a preferred embodiment of the first aspect, the heat exchange pipe group is a tubular structure or a plate structure, and the heat exchange pipe group includes an inlet header, an outlet header, and a plurality of groups of series-parallel heat exchange pipes connected therebetween.

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

[0013] As a preferred embodiment of the above-mentioned first aspect, the calibration bypass inlet and the calibration bypass outlet both have a flange structure connected to an external pipeline, and the calibration bypass inlet and the calibration bypass outlet are both in a normally closed state when the bypass inlet connecting pipe and the bypass outlet connecting pipe are not connected.

[0014] In a second aspect, the present invention provides a calibration method for a mobile terminal steam flow calibration system according to the first aspect, which is specifically as follows: after the high-temperature heat storage reheater in the mobile high-temperature heat storage calibration system is charged, the mobile high-temperature heat storage calibration system is moved as a whole to the position of the user branch to be tested using a mobile vehicle-mounted device, and connected to the user branch to be tested through a calibration bypass inlet and a calibration bypass outlet; before using the mobile high-temperature heat storage calibration system for measurement, open the bypass inlet stop valve and the bypass outlet stop valve on the user branch to be tested, and shut off the branch on the user branch to be tested. The stop valve allows the steam of the user branch to completely pass through the calibration bypass inlet connecting pipe, flow through the high-temperature heat accumulator, and then flow out from the bypass outlet connecting pipe; the system controller in the mobile high-temperature heat storage calibration system continuously compares the data of 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, and after the indication of the steam calibration flowmeter is stable, the flow data G1 measured by the branch flowmeter, the flow data G2 measured by the steam calibration flowmeter and the temperature data T measured by the heat storage temperature sensor are recorded. h At the same time, start timing with the recording time as the reference point, and stop timing after the heat storage temperature sensor reading changes. The duration t of the entire timing process is not less than 15s. Record the temperature data T1 measured by the branch temperature sensor, the pressure data P1 measured by the branch pressure sensor, the temperature data T2 measured by the reheat steam temperature sensor, the pressure data P2 measured by the reheat steam pressure sensor, and the temperature data T measured by the heat storage temperature sensor at the time of stopping timing. l ;

[0015] After the measurement is completed, the branch stop valve on the user branch to be measured is opened, the bypass inlet stop valve and the bypass outlet stop valve on the user branch to be measured are closed, and the mobile high-temperature thermal storage calibration system is removed;

[0016] Based on the measured data, the flow correction coefficient of the user flow meter is calculated as follows:

[0017] 1) Calculate the total flow correction coefficient 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 of the process of wet steam becoming superheated steam is:

[0021]

[0022] Wherein, 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 determine the saturated water enthalpy value h based on the recorded pressure data P1 f and saturated steam enthalpy h g , according to the recorded pressure data P2 and temperature data T2, the outlet superheated steam enthalpy h2 is determined, and the steam dryness x is calculated as:

[0024]

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

[0026]

[0027] The 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, in the control system of the branch flowmeter, the total flow correction coefficient c1 is multiplied by the flow data recorded by the branch flowmeter to obtain the corrected total steam flow.

[0029] As a preferred embodiment of the above second aspect, in the control system of the branch flowmeter, the dry steam flow correction coefficient c2 is multiplied by the flow data recorded by the branch flowmeter 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 adopts a mobile thermal storage steam generator to heat the terminal steam. The device can be moved to the position to be measured when the flow needs to be calibrated, and can be disassembled at any time after the calibration is completed, thereby improving 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 supercooling degree is high and the steam flow rate is large, the terminal steam can still be quickly heated to a superheated state. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0035] In the figure: heat network main line 1, user branch 2, branch temperature sensor 3, branch pressure sensor 4, branch flowmeter 5, branch stop valve 6, several heat users 7, calibration bypass inlet 8, bypass inlet stop valve 9, bypass inlet connecting pipe 10, mobile high-temperature thermal storage calibration system 11, bypass outlet connecting pipe 12, bypass outlet stop valve 13, calibration bypass outlet 14, high-temperature thermal storage reheater 15, thermal storage temperature sensor 16, reheat steam temperature sensor 17, reheat steam pressure sensor 18, steam calibration flowmeter 19, heating power supply interface 20, system controller 21, mobile vehicle-mounted device 22, solid thermal storage material 23, insulation layer 24, electric heating rod 25 and heat exchange pipeline group 26, inlet header 27, outlet header 28. DETAILED DESCRIPTION

[0036] The present invention will be further described and illustrated below in conjunction with the accompanying drawings and specific implementation methods.

[0037] Example 1

[0038] like Figure 1 As shown, in this embodiment, a terminal steam flow calibration system based on high temperature heat storage is provided, which is used to calibrate the steam flow measured on the user branch 2 connected to the heat user 7. The system comprises: a heat network main line 1, a user branch 2, a branch temperature sensor 3, a branch pressure sensor 4, a branch flow meter 5, a branch stop valve 6, a calibration bypass inlet 8, a bypass inlet stop valve 9, a bypass inlet connecting pipe 10, a bypass outlet connecting pipe 12, a bypass outlet stop valve 13, and a calibration bypass outlet 14. The mobile high temperature heat storage calibration system 11 comprises 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, a system controller 21 and a mobile vehicle-mounted device 22.

[0039] The main pipeline 1 of the heat network is connected to a number of heat users 7 through different user branches 2. A branch stop valve 6 is provided on each user branch 2 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 stop valve 6. The branch temperature sensor 3, the branch pressure sensor 4 and the branch flow meter 5 are used to detect the steam temperature, steam pressure and steam flow on the user branch 2 respectively. A calibration bypass inlet 8 for connecting to a bypass inlet connecting pipe 10 is provided on the user branch 2 before the branch stop valve 6. The inlet end of the bypass inlet connecting pipe 10 can be connected to the calibration bypass inlet 8 so that the steam in the user branch 2 flows into the bypass inlet connecting pipe 10. A calibration bypass outlet 14 for connecting to a bypass outlet connecting pipe 12 is provided on the user branch 2 after the branch stop valve 6. The inlet end of the bypass outlet connecting pipe 12 can be connected to the calibration bypass outlet 14 so that the steam in the user branch 2 flows into the bypass outlet connecting pipe 12. In addition, the bypass inlet connecting pipe 10 and the bypass outlet connecting pipe 12 are respectively provided with a bypass inlet stop valve 9 and a bypass outlet stop valve 13, which can respectively control the opening and closing of the respective pipelines. The branch stop valve 6, the bypass inlet stop valve 9 and the bypass outlet stop valve 13 can cooperate to switch the flow path of the steam. When the branch stop valve 6 is turned on, the bypass inlet stop valve 9 and the bypass outlet stop valve 13 are turned off, the steam input into the user branch 2 in the main pipeline 1 of the heat network will be directly supplied to the heat user 7 through the user branch 2; and when the branch stop valve 6 is turned off, the bypass inlet stop valve 9 and the bypass outlet stop valve 13 are turned on, the steam input into the user branch 2 in the main pipeline 1 of the heat network will bypass the branch stop valve 6, pass through the bypass inlet connecting pipe 10, the mobile high-temperature thermal storage calibration system 11, and the bypass outlet connecting pipe 12, and then be supplied to the heat user 7 through the user branch 2.

[0040] The function of the mobile high-temperature thermal storage calibration system 11 is to heat the terminal steam in the user branch 2 so that the terminal steam is heated to a superheated state, thereby realizing the determination of the steam flow correction coefficient. The mobile high-temperature thermal storage calibration system 11 includes a mobile vehicle-mounted device 22 and 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 flowmeter 19, a heating power interface 20 and a system controller 21 which are integrally mounted on the mobile vehicle-mounted device 22.

[0041] The above-mentioned mobile vehicle-mounted device 22 can be any vehicle with equipment carrying capacity, so the entire mobile high-temperature thermal storage calibration system 11 can be flexibly moved to detect user branches 2 at different locations.

[0042] The high temperature heat storage reheater 15 is connected between the bypass inlet connecting pipe 10 and the bypass outlet connecting pipe 12. Through valve switching control, the steam input from the heat network main line 1 to the user branch 2 can be input to the high temperature heat storage reheater 15 through the bypass inlet connecting pipe 10 for heating, and then return to the user branch 2 on the side of the heat user 7 from the bypass outlet connecting pipe 12. The heat storage temperature sensor 16 is installed on the high temperature heat storage reheater 15 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 flowmeter 19 are respectively installed on the bypass outlet connecting pipe 12 connected to the outlet end of the high temperature heat storage reheater 15 to detect the steam temperature, steam pressure, and steam flow at the outlet of the high temperature heat storage reheater 15. The system controller 21 serves as the central control and data processing equipment of the entire mobile high temperature heat storage calibration system 11. Each sensor on the high temperature heat storage reheater 15 is connected to the system controller 21 to realize data acquisition and control.

[0043] See also Figure 2 As shown, in this embodiment, the high-temperature heat storage reheater 15 is a direct solid heat storage, and its components include solid heat storage material 23, insulation layer 24, electric heating rod 25 and heat exchange pipe group 26. The heat storage body is composed of solid heat storage material 23, the heat storage body is wrapped with insulation layer 24, and the heat storage body is embedded with electric heating rod 25 and heat exchange pipe group 26. The heat exchange pipe group 26 can adopt two types of tubular structure or plate structure. Figure 2 As shown, the heat exchange pipe group 26 includes an inlet header 27, an outlet header 28 and several groups of series-parallel heat exchange tubes connected therebetween. The inlet ends of these series-parallel heat exchange tubes are all connected to the inlet header 27, and the outlet ends are all connected to the outlet header 28.

[0044] It should be noted that the above-mentioned 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 brick and a combination thereof.

[0045] In addition, for the convenience of connection, the calibration bypass inlet 8 and the calibration bypass outlet 14 are provided with flange structures connected to the external pipeline, and the external pipeline can be closely connected with the flange structures on the calibration bypass inlet 8 and the calibration bypass outlet 14 through the flange at the end. In order to avoid leakage, the calibration bypass inlet 8 and the calibration bypass outlet 14 are both in a normally closed state when the bypass inlet connecting pipe 10 and the bypass outlet connecting pipe 12 are not connected.

[0046] Example 2

[0047] On the basis of Example 1, this embodiment provides a terminal steam flow calibration method based on the terminal steam flow calibration system, and the specific steps are as follows:

[0048] The high-temperature heat storage reheater 15 in the mobile high-temperature heat storage calibration system 11 needs to be pre-charged. After the high-temperature heat storage reheater 15 in the mobile high-temperature heat storage calibration system 11 is fully charged, the mobile high-temperature heat storage calibration system 11 is moved as a whole to the position of the user branch 2 to be tested using the mobile vehicle-mounted device 22, and 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, open the bypass inlet stop valve 9 and the bypass outlet stop valve 13 on the user branch 2 to be tested, and close the branch stop valve 6 on the user branch 2 to be tested, so that the steam of the user branch 2 completely passes through the calibration bypass inlet connecting pipe 10, flows through the high-temperature heat 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 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, and after the indication of the steam calibration flowmeter 19 is basically stable, the flow data G1 measured by the branch flowmeter 5, the flow data G2 measured by the steam calibration flowmeter 19 and the temperature data T measured by the thermal storage temperature sensor 16 are recorded. h , and start timing with the recording time as the reference point, and stop timing after the reading of the heat storage temperature sensor 16 changes. It should be noted that in order to ensure the accuracy of the measurement, the timing should be stopped after the reading changes significantly, and the duration t of the entire timing process should not be less than 15s. Moreover, at the moment of stopping the timing, 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 T measured by the heat storage temperature sensor 16 should also be recorded at that moment. l , used to calculate the flow correction coefficient of the user branch 2 currently to be tested.

[0049] After the measurement is completed, the branch stop valve 6 on the user branch 2 to be measured is opened, the bypass inlet stop valve 9 and the bypass outlet stop valve 13 on the user branch 2 to be measured are closed, and the mobile high-temperature thermal storage calibration system 11 is removed. The mobile high-temperature thermal 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 coefficient of the user flow meter can be calculated based on the data measured from the user branch 2, where the flow correction coefficient is divided into two types: total flow correction coefficient and dry steam flow correction coefficient. The calculation methods of each are as follows:

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

[0052] According to the recorded flow data G1 and G2, calculate the total flow correction coefficient c1:

[0053]

[0054] 2) The calculation process of dry steam flow correction coefficient is as follows:

[0055] First, according to the temperature change of the heat storage system, the recorded temperature data T h , Temperature data T l And the duration t of the timing process, calculate the average heat absorption rate q of the process of wet steam becoming superheated steam:

[0056]

[0057] Wherein, 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 determine the saturated water enthalpy value h based on the recorded pressure data P1 f and saturated steam enthalpy h g , according to the recorded pressure data P2 and temperature data T2, the outlet superheated steam enthalpy h2 is determined, and the steam dryness x is calculated as:

[0059]

[0060] Finally, the data of the branch flowmeter 5 is corrected according to the data measured by the steam calibration flowmeter 19, and the dry steam flow correction coefficient c2 is calculated as:

[0061]

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

[0063] The control system of the branch flowmeter 5 can be a local control system of the flowmeter or a remote control system, and there is no restriction on this. In the control system of the branch flowmeter 5, the specific selection of the total flow correction coefficient c1 or the dry steam flow correction coefficient c2 can be selected according to the actual flow calibration requirements. Among them: the total flow correction coefficient c1 is multiplied by the flow data recorded by the branch flowmeter 5 to obtain the corrected total steam flow; and the dry steam flow correction coefficient c2 is multiplied by the flow data recorded by the branch flowmeter 5 to obtain the corrected total dry steam flow.

[0064] This embodiment further demonstrates the use of the above-mentioned terminal steam flow calibration system and method based on high-temperature heat storage based on 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, and the thermal parameters of the thermal storage body and the steam at both ends of the thermal storage system inlet and outlet are obtained through the system controller as shown in the following table.

[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 [℃]]]> <![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 heat storage body h [℃]]]> <![CDATA[Final temperature T of the heat storage body l [℃]]]> Heating process duration t[s] 450.06 448.96 130.4

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

[0068] ①Total flow correction coefficient c1 is:

[0069]

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

[0071]

[0072] According to the steam inlet pressure P1, the corresponding saturated water enthalpy value h is obtained. f is 855.73 kJ / kg, and the inlet saturated steam enthalpy is h g It is 2792.46 kJ / kg. According to the outlet steam pressure P2 and outlet temperature T2, the outlet superheated steam enthalpy h2 is 2822.76 kJ / kg. The steam dryness x is:

[0073]

[0074] The calorific value flow correction coefficient c2 is:

[0075]

[0076] In summary, for this user branch, the correction coefficients c1 and c2 are entered into the control system of the branch flowmeter, and c1 or c2 is selected according to demand to multiply the data of the branch flowmeter as the corrected flow record, where when c1 is selected, the corrected result is the total steam flow, and when c2 is selected, the corrected result is the dry steam flow.

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

[0078] The above-described embodiments are only some preferred implementations of the present invention, but are not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A mobile terminal steam flow calibration system based on high temperature heat storage, characterized in that It comprises a heat network main line (1), a user branch line (2), a branch temperature sensor (3), a branch pressure sensor (4), a branch flow meter (5), a branch stop valve (6), a calibration bypass inlet (8), a bypass inlet stop valve (9), a bypass inlet connecting pipe (10), a mobile high-temperature heat storage calibration system (11), a bypass outlet connecting pipe (12), a bypass outlet stop valve (13) and a calibration bypass outlet (14); A heat network main line (1) is connected to a plurality of heat users (7) through a user branch line (2); a branch stop valve (6) is provided on each user branch line (2) 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 line (2) before the branch stop valve (6); a calibration bypass inlet (8) for connecting to a bypass inlet connecting pipe (10) is provided on the user branch line (2) before the branch stop valve (6); a calibration bypass outlet (14) for connecting to a bypass outlet connecting pipe (12) is provided on the user branch line (2) after the branch stop valve (6); a bypass inlet stop valve (9) and a bypass outlet stop valve (13) are provided on the bypass inlet connecting pipe (10) and the bypass outlet connecting pipe (12), respectively; The mobile high-temperature thermal storage calibration system (11) comprises a mobile vehicle-mounted device (22) and a high-temperature thermal storage reheater (15) integrally mounted on the mobile vehicle-mounted device (22), 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 supply interface (20) and a system controller (21); The high-temperature heat storage reheater (15) is connected between the bypass inlet connecting pipe (10) and the bypass outlet connecting pipe (12). Through valve switching control, the steam input from the heat network main line (1) to the user branch (2) can be input into the high-temperature heat storage reheater (15) through the bypass inlet connecting pipe (10) for heating, and then return to the user branch (2) on the heat user (7) side from the bypass outlet connecting 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 flowmeter (19) are respectively used to detect the steam temperature, steam pressure, and steam flow at the output port of the high-temperature heat storage reheater (15); and the various sensors on the high-temperature heat storage reheater (15) are connected to the system controller (21) to realize data collection and control.

2. A mobile terminal steam flow calibration system based on high temperature heat storage according to claim 1, characterized in that The high-temperature heat storage reheater (15) is a direct solid heat storage device, wherein the heat storage body is composed of a solid heat storage material (23), the outside of the heat storage body is wrapped with a heat insulation layer (24), and the inside of the heat storage body is embedded with an electric heating rod (25) and a heat exchange pipe group (26).

3. A mobile terminal steam flow calibration system based on high temperature heat storage according to claim 2, characterized in that The heat exchange pipe group (26) is a tubular structure or a plate structure, and comprises an inlet header (27), an outlet header (28), and a plurality of groups of series-parallel heat exchange pipes connected therebetween.

4. A mobile terminal steam flow calibration system based on high temperature heat storage according to claim 2, 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, magnesia brick and a combination thereof.

5. The mobile terminal steam flow calibration system based on high temperature heat storage according to claim 1 is characterized in that The calibration bypass inlet (8) and the calibration bypass outlet (14) both have flange structures connected to external pipelines, and the calibration bypass inlet (8) and the calibration bypass outlet (14) are both in a normally closed state when the bypass inlet connecting pipe (10) and the bypass outlet connecting pipe (12) are not connected.

6. 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 fully charged, the mobile high-temperature heat storage calibration system (11) is moved as a whole to the position of the user branch (2) to be tested using a mobile vehicle-mounted device (22), and connected to the user branch (2) to be tested via a calibration bypass inlet (8) and a calibration bypass outlet (14); before using the mobile high-temperature heat storage calibration system (11) for measurement, the bypass inlet stop valve (9) and the bypass outlet stop valve (13) on the user branch (2) to be tested are opened, and the branch stop valve (6) on the user branch (2) to be tested is closed, so that the steam of the user branch (2) is completely discharged through the calibration bypass inlet connection (8). The steam flows through the pipe (10), passes through the high-temperature heat storage device (11), and then flows out from the bypass outlet connecting pipe (12); the system controller (21) in the mobile high-temperature heat storage 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), and after the indication of the steam calibration flowmeter (19) is stable, the flow data G1 measured by the branch flowmeter (5), the flow data G2 measured by the steam calibration flowmeter (19), and the temperature data T measured by the heat storage temperature sensor (16) are recorded. h At the same time, the timing is started with the recording time as the reference point, and the timing is stopped after the reading of the heat storage temperature sensor (16) changes. The duration t 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 T measured by the heat storage temperature sensor (16) at the time of stopping the timing are recorded. l ; After the measurement is completed, the branch stop valve (6) on the user branch (2) to be measured is opened, the bypass inlet stop valve (9) and the bypass outlet stop valve (13) on the user branch (2) to be measured are closed, and the mobile high-temperature thermal storage calibration system (11) is removed; Based on the measured data, the flow correction coefficient of the user flow meter is calculated as follows: 1) Calculate the total flow correction coefficient 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 And the duration t of the timing process, calculate the average heat absorption rate q of the process of wet steam becoming superheated steam: Wherein, 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 determine the saturated water enthalpy value h based on the recorded pressure data P1 f and saturated steam enthalpy h g , according to the recorded pressure data P2 and temperature data T2, the outlet superheated steam enthalpy h2 is determined, and the steam dryness x is calculated as: Finally, the dry steam flow correction coefficient c2 is calculated as: 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).

7. The calibration method according to claim 6, 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.

8. The calibration method according to claim 6, characterized in that: In the control system of the branch flowmeter (5), the dry steam flow correction coefficient c2 is multiplied by the flow data recorded by the branch flowmeter (5) to obtain the corrected total dry steam flow.

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