CN104390679A

CN104390679A - Device for calibrating quality flow exceeding allowable temperature of reference flowmeter and method adopting device

Info

Publication number: CN104390679A
Application number: CN201410584523.5A
Authority: CN
Inventors: 程迪; 孟令瑾; 范学军
Original assignee: Institute of Mechanics of CAS
Current assignee: Institute of Mechanics of CAS
Priority date: 2014-10-27
Filing date: 2014-10-27
Publication date: 2015-03-04
Anticipated expiration: 2034-10-27
Also published as: CN104390679B

Abstract

The invention discloses a mass flow calibrating device which exceeds the allowable temperature of a reference flowmeter. The high-temperature working fluid provided and the cooling working fluid provided by the cooling working fluid supply and measuring unit are mutually dissolved in the mixer to reach the medium-temperature working medium measuring unit. The high-temperature working fluid supply unit includes the first pressure gauge, the first temperature gauge, the mass to be calibrated For the flow meter, the cooling working fluid supply measurement unit includes a second pressure gauge, a second temperature gauge, and a first standard mass flowmeter, and the medium temperature working fluid measurement unit includes a third pressure gauge, a third temperature gauge, and a second standard mass flowmeter. Methods of using the device are also provided.

Description

A mass flow calibration device and method exceeding the allowable temperature of a reference flowmeter

技术领域technical field

本发明属于自动化装置与设备的技术领域，具体地涉及一种超出参考流量计许用温度的质量流量标定装置，以及采用该装置的方法。The invention belongs to the technical field of automation devices and equipment, and in particular relates to a mass flow calibration device whose temperature exceeds the allowable temperature of a reference flow meter, and a method using the device.

背景技术Background technique

在航空航天和石油化工领域中，经常需要对高温条件下的质量流量进行测量，而传统的M-t法，其测量精度严重依赖于t的精确测量，而在进行高温大流量质量流量计标定时，由于标准流量源工作时间有限以及高温阀门关闭时间测量精度有限，给标定带来严重困难。In aerospace and petrochemical fields, it is often necessary to measure the mass flow rate under high temperature conditions, while the measurement accuracy of the traditional M-t method depends heavily on the accurate measurement of t. Due to the limited working time of the standard flow source and the limited measurement accuracy of the closing time of the high-temperature valve, it brings serious difficulties to the calibration.

而在进行传递标定时，特别是超过现有的标准质量流量计的工作温度范围时，需要在两个流量计间对工质进行加热或者冷却，在大流量时需要较大的换热功率和较大的换热器内容积，前者会增加标定成本，后者会提高对流量源的稳定性要求和对标定总时间(即总流量)的要求。When performing transfer calibration, especially when the working temperature range of the existing standard mass flowmeter is exceeded, it is necessary to heat or cool the working medium between the two flowmeters, and a large heat exchange power and The larger the internal volume of the heat exchanger, the former will increase the calibration cost, and the latter will increase the stability requirements of the flow source and the total calibration time (ie the total flow).

发明内容Contents of the invention

本发明的技术解决问题是：克服现有技术的不足，提供一种超出参考流量计许用温度的质量流量标定装置,其操作简单、效率高和成本低。The technical problem of the present invention is: to overcome the deficiencies of the prior art, to provide a mass flow calibration device with a temperature exceeding the allowable temperature of the reference flow meter, which is simple in operation, high in efficiency and low in cost.

本发明的技术解决方案是：这种超出参考流量计许用温度的质量流量标定装置，该装置包括高温工质供应单元、冷却工质供应测量单元、混合器、中温工质测量单元，由高温工质供应单元提供的高温工质与由冷却工质供应测量单元提供的冷却工质在混合器中互溶后达到中温工质测量单元，高温工质供应单元包括第一压力表、第一温度表、待标定质量流量计，冷却工质供应测量单元包括第二压力表、第二温度表、第一标准质量流量计，中温工质测量单元包括第三压力表、第三温度表、第二标准质量流量计。The technical solution of the present invention is: the mass flow calibration device that exceeds the allowable temperature of the reference flowmeter, the device includes a high-temperature working fluid supply unit, a cooling working fluid supply measurement unit, a mixer, and a medium-temperature working fluid measurement unit. The high-temperature working fluid provided by the working fluid supply unit and the cooling working fluid provided by the cooling working fluid supply and measuring unit are mixed in the mixer to reach the medium-temperature working medium measuring unit. The high-temperature working fluid supply unit includes the first pressure gauge and the first temperature gauge. , The mass flowmeter to be calibrated, the cooling working medium supply measurement unit includes the second pressure gauge, the second temperature gauge, the first standard mass flowmeter, the medium temperature working fluid measurement unit includes the third pressure gauge, the third temperature gauge, the second standard Mass flowmeter.

还提供了采用以上超出参考流量计许用温度的质量流量标定装置的方法，包括以下步骤：Also provided is a method of employing the above mass flow calibration device above the allowable temperature of the reference flowmeter, comprising the steps of:

(1)关闭高温工质供应测量单元，打开冷却工质供应测量单元和中温工质测量单元，对第一、二标准质量流量计进行调零；(1) Turn off the high-temperature working fluid supply measurement unit, open the cooling working fluid supply measurement unit and the medium-temperature working fluid measurement unit, and zero-adjust the first and second standard mass flowmeters;

(2)根据预期的高温工质流量，选择合适的冷却工质流量，保证标定的高温工质流量具有最小相对误差，同时确保第二压力表数值和第三压力表数值均低于第一压力表数值；(2) According to the expected high-temperature working fluid flow, select the appropriate cooling working medium flow rate to ensure that the calibrated high-temperature working medium flow rate has the minimum relative error, and at the same time ensure that the values of the second pressure gauge and the third pressure gauge are lower than the first pressure table value;

(3)打开高温工质供应测量单元，监视第三温度表数值以保证第二标准质量流量计不被损坏，若第三温度表数值超过指定限值则切断高温工质供应测量单元；若未超过则待达到稳态，记录下第一压力表数值、第一温度表数值和第一、二标准质量流量计的读数；(3) Turn on the high-temperature working fluid supply measurement unit, monitor the value of the third thermometer to ensure that the second standard mass flowmeter is not damaged, if the third thermometer value exceeds the specified limit, cut off the high-temperature working fluid supply measurement unit; if not If it exceeds, it will reach a steady state, and record the first pressure gauge value, the first temperature gauge value and the readings of the first and second standard mass flowmeters;

(4)关闭高温工质供应测量单元，间隔指定时间后，关闭冷却工质供应测量单元和中温工质测量单元；(4) Turn off the high-temperature working fluid supply measurement unit, and after a specified time interval, turn off the cooling working fluid supply measurement unit and the medium-temperature working fluid measurement unit;

(5)通过第二标准质量流量计的读数减去第一标准质量流量计的读数，得到待标定质量流量计的数值。(5) The value of the mass flowmeter to be calibrated is obtained by subtracting the reading of the first standard mass flowmeter from the reading of the second standard mass flowmeter.

根据能量守恒原理，利用低温可互溶的流体与待标定高温流体掺混得到可直接测量质量流量的中温流体，其中T₁＞T_limit＞T₃＞T₂，其中T₁为高温工质的温度，T_limit为待标定质量流量计的额定温度，T₃为中温工质的温度，T₂为冷却工质的温度。所以本发明的中温工质的温度不会超过待标定质量流量计的额定温度，这样就保证本发明能够实现。通过本发明将冷却工质与高温工质相混合，得到中温工质，再采用标准质量流量计测量冷却工质、中温工质的流量，相减后就得到待测的高温工质的流量，相对于现有装置和方法操作更简单、效率更高和成本更低。According to the principle of energy conservation, the medium-temperature fluid that can directly measure the mass flow rate is obtained by mixing the low-temperature miscible fluid with the high-temperature fluid to be calibrated, where T ₁ >T _limit >T ₃ >T ₂ , where T ₁ is the temperature of the high-temperature working fluid , T _limit is the rated temperature of the mass flowmeter to be calibrated, T ₃ is the temperature of the medium-temperature working fluid, and T ₂ is the temperature of the cooling working fluid. Therefore, the temperature of the medium-temperature working medium in the present invention will not exceed the rated temperature of the mass flowmeter to be calibrated, thus ensuring that the present invention can be realized. Through the present invention, the cooling working fluid and the high-temperature working fluid are mixed to obtain the medium-temperature working medium, and then the flow rate of the cooling working medium and the medium-temperature working medium is measured by using a standard mass flowmeter, and the flow rate of the high-temperature working medium to be measured is obtained after subtraction. Compared with the existing devices and methods, the operation is simpler, the efficiency is higher and the cost is lower.

附图说明Description of drawings

图1示出了根据本发明的超出参考流量计许用温度的质量流量标定装置的结构示意图；Fig. 1 shows a schematic structural view of a mass flow calibration device exceeding the allowable temperature of a reference flowmeter according to the present invention;

图2是冷却工质流量的最小相对误差线；Fig. 2 is the minimum relative error line of the cooling working fluid flow rate;

图3示出了根据本发明的超出参考流量计许用温度的质量流量标定方法的原理图；Fig. 3 shows the schematic diagram of the mass flow calibration method exceeding the allowable temperature of the reference flowmeter according to the present invention;

图4示出了根据本发明的超出参考流量计许用温度的质量流量标定装置一个优选实施例的结构示意图。Fig. 4 shows a schematic structural diagram of a preferred embodiment of a mass flow calibration device for exceeding the allowable temperature of the reference flowmeter according to the present invention.

具体实施方式Detailed ways

图1示出了根据本发明的超出参考流量计许用温度的质量流量标定装置的结构示意图。从图1中可以看出，这种超出参考流量计许用温度的质量流量标定装置，该装置包括高温工质供应单元、冷却工质供应测量单元、混合器、中温工质测量单元，由高温工质供应单元提供的高温工质与由冷却工质供应测量单元提供的冷却工质在混合器中互溶后达到中温工质测量单元，高温工质供应单元包括第一压力表P1、第一温度表T1、待标定质量流量计，冷却工质供应测量单元包括第二压力表P2、第二温度表T2、第一标准质量流量计，中温工质测量单元包括第三压力表P3、第三温度表T3、第二标准质量流量计。Fig. 1 shows a schematic structural diagram of a mass flow calibration device for exceeding the allowable temperature of a reference flowmeter according to the present invention. It can be seen from Figure 1 that this mass flow calibration device that exceeds the allowable temperature of the reference flowmeter includes a high-temperature working fluid supply unit, a cooling working fluid supply measurement unit, a mixer, and a medium-temperature working fluid measurement unit. The high-temperature working fluid provided by the working fluid supply unit and the cooling working fluid provided by the cooling working fluid supply and measurement unit are mutually dissolved in the mixer and reach the medium-temperature working fluid measurement unit. The high-temperature working fluid supply unit includes the first pressure gauge P1, the first temperature Table T1, the mass flowmeter to be calibrated, the cooling working fluid supply measurement unit includes the second pressure gauge P2, the second temperature gauge T2, the first standard mass flowmeter, the medium temperature working fluid measurement unit includes the third pressure gauge P3, the third temperature Table T3, the second standard mass flow meter.

另外，为了使冷却工质能够更好地与高温工质在标定比例下互溶，高温工质和冷却工质是同一物质。In addition, in order to make the cooling working fluid and the high temperature working fluid better miscible at the calibrated ratio, the high temperature working fluid and the cooling working fluid are the same substance.

另外，混合器包括一个三通，三通的第一、二、三管口分别连接高温工质供应单元、冷却工质供应测量单元、中温工质测量单元；第二管口的管径小，以便使进入三通内的冷却工质保持在湍流状态。In addition, the mixer includes a tee, and the first, second, and third nozzles of the tee are respectively connected to the high-temperature working fluid supply unit, the cooling working fluid supply measurement unit, and the medium-temperature working fluid measurement unit; the diameter of the second nozzle is small, In order to keep the cooling fluid entering the tee in a turbulent state.

另外，冷却工质供应测量单元通过一个直管连接到所述第二管口，直管的长度是直管的管径的10倍。这样能够保证进入三通内的冷却工质在湍流状态。In addition, the cooling working medium supply measuring unit is connected to the second nozzle through a straight pipe, and the length of the straight pipe is 10 times the diameter of the straight pipe. This can ensure that the cooling medium entering the tee is in a turbulent state.

另外，该装置还包括工质收集单元，其与中温工质测量单元连接。这样冷却之后的混合物如果满足要求可以再作为低温工质使用，能够节约成本，而且绿色环保。In addition, the device also includes a working fluid collection unit, which is connected with the medium temperature working fluid measurement unit. In this way, if the cooled mixture meets the requirements, it can be used as a low-temperature working fluid again, which can save costs and is environmentally friendly.

(2)根据预期的高温工质流量，选择合适的冷却工质流量(可以根据图2来选择)，保证标定的高温工质流量具有最小相对误差，同时确保第二压力表数值和第三压力表数值均低于第一压力表数值；(2) According to the expected high-temperature working fluid flow, select the appropriate cooling working fluid flow (can be selected according to Figure 2), to ensure that the calibrated high-temperature working fluid flow has the minimum relative error, and at the same time ensure that the second pressure gauge value and the third pressure The gauge values are all lower than the first pressure gauge value;

(5)根据质量守恒原理，通过第二标准质量流量计的读数减去第一标准质量流量计的读数，得到待标定质量流量计的数值。(5) According to the principle of mass conservation, the value of the mass flowmeter to be calibrated is obtained by subtracting the reading of the first standard mass flowmeter from the reading of the second standard mass flowmeter.

另外，按照图2的最小相对误差线来选择冷却工质流量，可以使标定流量的相对误差最小化，在步骤(2)中，选择合适的冷却工质流量，以便最小化根据公式(1)计算出的待标定质量流量的相对误差，In addition, selecting the flow rate of the cooling medium according to the minimum relative error line in Figure 2 can minimize the relative error of the calibration flow rate. In step (2), select the appropriate flow rate of the cooling medium so as to minimize The calculated relative error of the mass flow rate to be calibrated,

${e e}_{11} = = \frac{Δ Δ {\overset{\cdot &Center Dot;}{m m}}_{11}}{{\overset{\cdot &Center Dot;}{m m}}_{11}} = = \frac{\sqrt{{e e}_{22}^{22} {\overset{\cdot &Center Dot;}{m m}}_{22}^{22} + + {e e}_{33}^{22} {(({\overset{\cdot &Center Dot;}{m m}}_{11} + + {\overset{\cdot \cdot}{m m}}_{22}))}^{22}}}{{\overset{\cdot &Center Dot;}{m m}}_{11}} - - - - - - ((11))$

其中e表示相对误差，表示质量流量，表示质量流量的测量偏差，下标1、2、3分别代表高温介质、低温介质和混合后的中温介质，而最进行小化时所需满足的约束为公式(2)：where e represents the relative error, represents the mass flow rate, Indicates the measurement deviation of the mass flow rate, and the subscripts 1, 2, and 3 represent the high-temperature medium, low-temperature medium, and mixed medium-temperature medium, respectively, and the constraints that need to be satisfied when minimizing are formula (2):

$\{\begin{matrix} {\overset{\cdot &Center Dot;}{m m}}_{33} = = {\overset{\cdot &Center Dot;}{m m}}_{11} + + {\overset{\cdot &Center Dot;}{m m}}_{22} \\ Δ Δ {\overset{\cdot &Center Dot;}{m m}}_{11} = = \sqrt{Δ Δ {\overset{\cdot \cdot}{m m}}_{22}^{22} + + Δ Δ {\overset{\cdot \cdot}{m m}}_{33}^{22}} \\ Δ Δ {\overset{\cdot \cdot}{m m}}_{22} = = {e e}_{22} {\overset{\cdot \cdot}{m m}}_{22} \\ Δ Δ {\overset{\cdot \cdot}{m m}}_{33} = = {e e}_{33} {\overset{\cdot \cdot}{m m}}_{33} \\ {\overset{\cdot \cdot}{m m}}_{11} {h h}_{11} + + {\overset{\cdot &Center Dot;}{m m}}_{22} {h h}_{22} = = {\overset{\cdot &Center Dot;}{m m}}_{33} {h h}_{33} (({T T}_{33})) \\ {\overset{\cdot &Center Dot;}{m m}}_{11} > > 00 \\ {\overset{\cdot &Center Dot;}{m m}}_{22,, min min} < < {\overset{\cdot &Center Dot;}{m m}}_{22} < < {\overset{\cdot &Center Dot;}{m m}}_{22,, max max} \\ {\overset{\cdot &Center Dot;}{m m}}_{33,, min min} < < {\overset{\cdot &Center Dot;}{m m}}_{33} < < {\overset{\cdot &Center Dot;}{m m}}_{33,, max max} \\ {T T}_{33} < < {T T}_{33,, max max} \end{matrix} - - - - - - ((22))$

其中h表示流体的比焓，T表示流体的温度，下标_min,max分别表示下限和上限。其可行域如图2所示，而对e₁求导数可得：Where h represents the specific enthalpy of the fluid, T represents the temperature of the fluid, and the subscripts _{min and max} represent the lower limit and upper limit, respectively. Its feasible region is shown in Figure 2, and the derivative of e ₁ can be obtained:

$\frac{&PartialD; &PartialD; {e e}_{11}}{&PartialD; &PartialD; {\overset{\cdot &Center Dot;}{m m}}_{11}} = = - - \frac{{\overset{\cdot &Center Dot;}{m m}}_{22} (({e e}_{22}^{22} {\overset{\cdot &Center Dot;}{m m}}_{22} + + {e e}_{33}^{22} (({\overset{\cdot &Center Dot;}{m m}}_{11} + + {\overset{\cdot &Center Dot;}{m m}}_{22}))))}{{\overset{\cdot &Center Dot;}{m m}}_{11}^{22} \sqrt{{e e}_{22}^{22} {\overset{\cdot &Center Dot;}{m m}}_{22}^{22} + + {e e}_{33}^{22} {(({\overset{\cdot &Center Dot;}{m m}}_{11} + + {\overset{\cdot &Center Dot;}{m m}}_{22}))}^{22}}} < < 00$

$\frac{&PartialD; &PartialD; {e e}_{11}}{&PartialD; &PartialD; {\overset{\cdot &Center Dot;}{m m}}_{22}} = = \frac{{e e}_{22}^{22} {\overset{\cdot \cdot}{m m}}_{22} + + {e e}_{33}^{22} (({\overset{\cdot &Center Dot;}{m m}}_{11} + + {\overset{\cdot &Center Dot;}{m m}}_{22}))}{{\overset{\cdot &Center Dot;}{m m}}_{11} \sqrt{{e e}_{22}^{22} {\overset{\cdot &Center Dot;}{m m}}_{22}^{22} + + {e e}_{33}^{22} {(({\overset{\cdot \cdot}{m m}}_{11} + + {\overset{\cdot &Center Dot;}{m m}}_{22}))}^{22}}} > > 00$

所以在在高温介质流量一定时，与其混合的低温介质流量越小，此种方法的标定的相对误差越小，在考虑公式(2)中的不等式约束，可以得到图2中的最小相对误差线。Therefore, when the high-temperature medium flow rate is constant, the smaller the low-temperature medium flow rate mixed with it, the smaller the relative error of calibration by this method. Considering the inequality constraints in formula (2), the minimum relative error line in Figure 2 can be obtained .

根据能量守恒原理，利用低温可互溶的流体与待标定高温流体掺混得到可直接测量质量流量的中温流体，其中T₁＞T_limit＞T₃＞T₂，其中T₁为高温工质的温度，T_limit为待标定质量流量计的额定温度，T₃为中温工质的温度，T₂为冷却工质的温度。所以本发明的中温工质的温度不会超过待标定质量流量计的额定温度，这样就保证本发明能够实现。图3示出了根据本发明的超出质量流量计温度范围的质量流量标定方法的原理图。通过本发明将冷却工质混合到高温工质，得到中温工质，再采用标准质量流量计测量冷却工质、中温工质的流量，相减后就得到待测的高温工质的流量，相对于现有装置和方法操作更简单、效率更高和成本更低。According to the principle of energy conservation, the medium-temperature fluid that can directly measure the mass flow rate is obtained by mixing the low-temperature miscible fluid with the high-temperature fluid to be calibrated, where T ₁ >T _limit >T ₃ >T ₂ , where T ₁ is the temperature of the high-temperature working fluid , T _limit is the rated temperature of the mass flowmeter to be calibrated, T ₃ is the temperature of the medium-temperature working fluid, and T ₂ is the temperature of the cooling working fluid. Therefore, the temperature of the medium-temperature working medium in the present invention will not exceed the rated temperature of the mass flowmeter to be calibrated, thus ensuring that the present invention can be realized. Fig. 3 shows a schematic diagram of a mass flow calibration method beyond the temperature range of a mass flow meter according to the present invention. Through the present invention, the cooling working fluid is mixed with the high-temperature working fluid to obtain the medium-temperature working medium, and then the flow rate of the cooling working medium and the medium-temperature working medium is measured by using a standard mass flowmeter, and the flow rate of the high-temperature working medium to be measured is obtained after subtraction. Compared with existing devices and methods, the operation is simpler, the efficiency is higher and the cost is lower.

图4示出了根据本发明的超出质量流量计温度范围的质量流量标定装置一个优选实施例(超临界煤油音速喷管流量计的标定装置)的结构示意图。该装置由高温工质供应单元、冷却工质供应测量单元、混合器、中温工质测量单元、工质收集单元组成。Fig. 4 shows a schematic structural diagram of a preferred embodiment of a mass flow calibration device (calibration device for a supercritical kerosene sonic nozzle flowmeter) that exceeds the temperature range of the mass flow meter according to the present invention. The device is composed of a high temperature working fluid supply unit, a cooling working fluid supply measuring unit, a mixer, a medium temperature working fluid measuring unit and a working fluid collecting unit.

具体操作步骤如下：The specific operation steps are as follows:

1.关闭高温油阀门V1，打开冷油阀门V2和混合油阀门V3，打开冷油柱塞泵，先将管道中灌满冷油，再关闭冷油柱塞泵，并将V2和V3关闭，对质量流量计MF2和MF3进行调零；1. Close the high temperature oil valve V1, open the cold oil valve V2 and the mixed oil valve V3, turn on the cold oil plunger pump, first fill the pipeline with cold oil, then close the cold oil plunger pump, and close V2 and V3, Zero-adjust the mass flow meters MF2 and MF3;

2.然后打开V2、V3，打开冷油柱塞泵，根据预期的热油流量，按照图2选择合适的冷油流量，保证标定具有最小相对误差，同时确保P2和P3低于P1；2. Then turn on V2 and V3, and turn on the cold oil plunger pump. According to the expected hot oil flow, select the appropriate cold oil flow according to Figure 2 to ensure that the calibration has the smallest relative error, and at the same time ensure that P2 and P3 are lower than P1;

3.从热油入口通入热油，打开V1，通入热油，监视T3保证MF3不被损坏，若T3超限立即切断V1，待达到稳态，记录下P1、T1和MF3，MF2读数；3. Feed hot oil from the hot oil inlet, open V1, feed hot oil, monitor T3 to ensure that MF3 is not damaged, if T3 exceeds the limit, immediately cut off V1, and when it reaches a steady state, record the readings of P1, T1, MF3, and MF2 ;

4.关闭V1，待冷油带走管道中的热量，关闭冷油柱塞泵，关闭V2，V3；4. Turn off V1, wait for the cold oil to take away the heat in the pipeline, turn off the cold oil plunger pump, turn off V2, V3;

5.重复上述过程，得到不同P1、T1情况下的超临界煤油音速喷管流量计流量MF1＝MF3-MF2。5. Repeat the above process to obtain the flow rate of the supercritical kerosene sonic nozzle flowmeter MF1=MF3-MF2 under different conditions of P1 and T1.

以上所述，仅是本发明的较佳实施例，并非对本发明作任何形式上的限制，凡是依据本发明的技术实质对以上实施例所作的任何简单修改、等同变化与修饰，均仍属本发明技术方案的保护范围。The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are still within the scope of this invention. The protection scope of the technical solution of the invention.

Claims

1. one kind exceeds the mass rate caliberating device of reference stream gauge allowable temperature, it is characterized in that: this device comprises high temperature refrigerant feeding unit, cooling working medium supply measuring unit, mixer, middle temperature working medium measuring unit, middle temperature working medium measuring unit is reached after the high temperature refrigerant provided by high temperature refrigerant feeding unit and the cooling working medium supplied measuring unit provided by cooling working medium dissolve each other in a mixer, high temperature refrigerant feeding unit comprises the first tensimeter, first thermometer, mass flowmeter to be calibrated, cooling working medium supply measuring unit comprises the second tensimeter, second thermometer, first standard mass flow meter, middle temperature working medium measuring unit comprises the 3rd tensimeter, 3rd thermometer, second standard mass flow meter.

2. the mass rate caliberating device exceeding reference stream gauge allowable temperature according to claim 1, is characterized in that: described high temperature refrigerant and described cooling working medium are the materials that can dissolve each other completely.

3. the mass rate caliberating device exceeding reference stream gauge allowable temperature according to claim 2, it is characterized in that: described mixer comprises a threeway, first, second and third mouth of pipe of threeway connects high temperature refrigerant feeding unit, cooling working medium supply measuring unit, middle temperature working medium measuring unit respectively; The caliber of second mouth of pipe is little, to make the cooling working medium entered in threeway remain on turbulence state.

4. the mass rate caliberating device exceeding reference stream gauge allowable temperature according to claim 3, is characterized in that: cooling working medium supply measuring unit is connected to described second mouth of pipe by a straight tube, and the length of straight tube is 10 times of the caliber of straight tube.

5. the mass rate caliberating device exceeding reference stream gauge allowable temperature according to claim 1, is characterized in that: this device also comprises working medium collector unit, and it is connected with middle temperature working medium measuring unit.

6. adopt the method exceeding the mass rate caliberating device of reference stream gauge allowable temperature according to claim 1, it is characterized in that: comprise the following steps:

(1) close high temperature refrigerant supply measuring unit, open cooling working medium supply measuring unit and middle temperature working medium measuring unit, first and second standard mass flow meter is returned to zero;

(2) according to the high temperature refrigerant flow of expection, select suitable cooling working medium flow, ensure that the high temperature refrigerant flow demarcated has minimum relative error, guarantee that the second tensimeter numerical value and the 3rd tensimeter numerical value are all lower than the first tensimeter numerical value simultaneously;

(3) open high temperature refrigerant supply measuring unit, monitor that the 3rd thermometer numerical value is to ensure that the second standard mass flow is not damaged, if the 3rd thermometer numerical value exceedes specify limit value, cut off high temperature refrigerant supply measuring unit; If do not exceed, stable state to be achieved, records the reading of the first tensimeter numerical value, the first thermometer numerical value and first and second standard mass flow meter;

(4) close high temperature refrigerant supply measuring unit, after the fixed time of interval, close cooling working medium supply measuring unit and middle temperature working medium measuring unit;

(5) deducted the reading of the first standard mass flow meter by the reading of the second standard mass flow meter, obtain the numerical value of mass flowmeter to be calibrated.

7. method according to claim 6, is characterized in that: in step (2), selects suitable cooling working medium flow, to minimize the relative error of the mass rate to be calibrated calculated according to formula (1),

e_{1} = \frac{Δ {\overset{\cdot}{m}}_{1}}{{\overset{\cdot}{m}}_{1}} = \frac{\sqrt{e_{2}^{2} {\overset{\cdot}{m}}_{2}^{2} + e_{3}^{2} {({\overset{\cdot}{m}}_{1} + {\overset{\cdot}{m}}_{2})}^{2}}}{{\overset{\cdot}{m}}_{1}} - - - (1)

Wherein e represents relative error, represent mass rate, represent the measured deviation of mass rate, subscript 1,2,3 represents high-temperature medium, cryogenic media and mixed middle temperature medium respectively, and requiredly when carrying out littleization most satisfied is constrained to formula (2):

\{\begin{matrix} {\overset{\cdot}{m}}_{3} = {\overset{\cdot}{m}}_{1} + {\overset{\cdot}{m}}_{2} \\ Δ {\overset{\cdot}{m}}_{1} = \sqrt{Δ {\overset{\cdot}{m}}_{2}^{2} + Δ {\overset{\cdot}{m}}_{3}^{2}} \\ Δ {\overset{\cdot}{m}}_{2} = e_{2} {\overset{\cdot}{m}}_{2} \\ Δ {\overset{\cdot}{m}}_{3} = e_{3} {\overset{\cdot}{m}}_{3} \\ {\overset{\cdot}{m}}_{1} h_{1} + {\overset{\cdot}{m}}_{2} h_{2} = {\overset{\cdot}{m}}_{3} h_{3} (T_{3}) \\ {\overset{\cdot}{m}}_{1} > 0 \\ {\overset{\cdot}{m}}_{2, \min} < {\overset{\cdot}{m}}_{2} < {\overset{\cdot}{m}}_{2, \max} \\ {\overset{\cdot}{m}}_{3, \min} < {\overset{\cdot}{m}}_{3} < {\overset{\cdot}{m}}_{3, \max} \\ T_{3} < T_{3, \max} \end{matrix} - - - (2)

Wherein h represents the specific enthalpy of fluid, and T represents the temperature of fluid, subscript _{min, max}represent lower limit and the upper limit respectively.