A test system for adiabatic specific heat capacity of flowing high-temperature molten salt fluid

Abstract

The present invention discloses a flow high temperature molten salt fluid adiabatic specific heat capacity test system, which includes an experimental test subsystem, a bridge test subsystem, and an information acquisition and control subsystem; the experimental test subsystem includes an insulated kettle, a calorimeter located in the insulated kettle, and a conveying channel for the sample to be tested, and a corresponding heating device is provided on the conveying channel for the sample to be tested; the bridge test subsystem includes two Wheatstone bridges sharing two resistors, and the resistance of the sample to be tested can be obtained by measuring the resistance value of a known resistor; the information acquisition and control subsystem is used to collect all voltage, pressure and pressure signals of the system, and calculate the specific heat capacity of the sample to be tested. The present invention broadens the measurement range of temperature and pressure, and provides a certain theoretical basis for engineering design and calculation.

Description

Technical Field

[0001] The invention belongs to the field of thermal property testing of energy storage high-temperature molten salt, and in particular relates to a system for testing the adiabatic specific heat capacity of a flowing high-temperature molten salt fluid. Background Art

[0002] Specific heat capacity is one of the main thermophysical properties of matter. It is not only the basic data for scientific research and engineering practice, but also an important parameter for testing state equations and other relationships in thermophysical research. At present, the thermophysical research on high-temperature molten salt fluids focuses on the direct measurement of thermal conductivity, specific heat capacity and thermal diffusivity, as well as the microstructure observation of the solid phase after solidification. Most of the flow calorimeters at home and abroad are aimed at studying the specific heat capacity of gases, and the research on the specific heat capacity of liquids, especially the specific heat capacity of liquids under high temperature and high pressure, is relatively small.

[0003] The measurement methods of specific heat capacity can be divided into two categories: cooling method and heating method according to the different heat exchange methods of the calorimeter; the heating method is relatively easy to implement in engineering practice and experimental measurement, so it is widely used. The heating method can be divided into two types: flow type and non-flow type. Among them, the non-flow type has the highest measurement accuracy with the adiabatic method, and the method is simple and direct with fast measurement speed. The non-flow adiabatic method can be divided into two types according to the different heating methods; one is the constant heat heating method; the other is the continuous heating method, also known as the quasi-steady-state method.

[0004] The precise value of specific heat capacity mainly comes from experimental measurement. There are many methods for measuring the specific heat capacity of liquids, such as mixing method, comparison method, cooling method, etc., but these methods are only applicable to measurements at low temperatures. The more mature high-temperature specific heat capacity measurement methods mainly include differential scanning calorimeter (DSC), flow calorimeter, adiabatic calorimeter, etc. The adiabatic method is a type of electric heating method. Its basic measurement principle is similar to that of the flow calorimeter, that is, by measuring the absorbed heat and temperature rise, the specific heat capacity is calculated. The measurement accuracy of the adiabatic method for measuring specific heat capacity mainly depends on the thermal insulation performance of the device, that is, by achieving good thermal insulation to reduce heat loss. However, the adiabatic method has a relatively high accuracy at low temperatures to about 500°C, but when the temperature is higher than 500°C, the accuracy decreases, mainly because with the increase in temperature, thermal insulation control becomes more and more difficult, resulting in an increase in radiation heat loss.

[0005] The existing methods for testing the specific heat of high-temperature liquids are mainly divided into two types: heating method and cooling method. The heating method is easier to implement in engineering practice and experimental measurement. The flow calorimeter method and adiabatic calorimetry method in the heating method are simpler, easier to operate and more accurate. However, most of the test devices based on this principle cannot meet the temperature test requirements of high-temperature molten salt fluids (>300°C); and high-temperature molten salt fluids are corrosive and conductive, which cannot be met by existing devices. Summary of the invention

[0006] In view of the shortcomings of the existing high-temperature molten salt fluid specific heat capacity test, the present invention proposes a flowing high-temperature molten salt fluid adiabatic specific heat capacity test system, and the specific technical scheme is as follows:

[0007] A flowing high-temperature molten salt fluid adiabatic specific heat capacity testing system, comprising an experimental testing subsystem, a bridge testing subsystem, and an information acquisition and control subsystem;

[0008] The experimental test subsystem includes an insulated kettle, and a sample container, a horizontal flow pump, a back pressure valve, a cooler, a vacuum pump located outside the insulated kettle, and an electric heater, an inlet temperature detector, a calorimeter, an outlet temperature detector, an external heating belt, an internal heating belt, a first thermocouple, a second thermocouple, and a pressure gauge located inside the insulated kettle;

[0009] The sample container, the horizontal flow pump, the electric heater, the calorimeter, and the cooler are connected in sequence through stainless steel pipes; the back pressure valve is installed on the stainless steel pipe between the horizontal flow pump and the electric heater, the inlet temperature detector is installed on the stainless steel pipe between the electric heater and the calorimeter, and the outlet temperature detector is installed on the stainless steel pipe between the calorimeter and the cooler; the external heating belt and the internal heating belt are respectively arranged on the upper and lower sides of the calorimeter, and each heating belt is arranged with a second thermocouple for detecting temperature changes on the detection belt; the first thermocouple and the pressure gauge are installed on the side wall of the insulated kettle, respectively used to measure the ambient temperature and pressure inside the insulated kettle;

[0010] The bridge test subsystem includes a DC regulated power supply, a bridge switch, a first resistance box, a first resistor, a second resistor, a second resistance box, a third resistance box, a first voltmeter, and a second voltmeter;

[0011] The first resistor, the second resistor, the second resistor box and the inlet temperature detector are connected to form a quadrilateral to form four bridge arms of the Wheatstone bridge; the first resistor, the second resistor, the third resistor box and the outlet temperature detector are connected to form a quadrilateral to form four bridge arms of the Wheatstone bridge; both Wheatstone bridges are connected to the two ends of the DC regulated power supply, the bridge switch and the first resistor box which are connected in series in sequence;

[0012] The information acquisition and control subsystem includes a computer and a data acquisition card which are electrically connected in sequence, and the data acquisition card is electrically connected to the first voltmeter, the second voltmeter, the first thermocouple, the second thermocouple, the electric heater, the inlet temperature detector, the outlet temperature detector, and the pressure gauge through wires, and is used to collect corresponding pressure signals and temperature signals, and transmit the input to the computer equipped with thermal analysis software and temperature and pressure control software;

[0013] The computer is used for real-time display of the voltage, pressure and temperature data collected by the data acquisition card, calculating the specific heat capacity of the molten salt to be measured based on these data, and conveying temperature instructions to the external heating belt, the internal heating belt and the electric heater.

[0014] Furthermore, the calorimeter is designed as a sleeve type and is supported at the center of the insulated kettle by a support frame; the internal channel of the calorimeter is annular and is welded with stainless steel pipes of different diameters, namely an outer pipe, a middle pipe and an inner pipe; a calorimeter inlet is opened on one side of the outer pipe, a calorimeter outlet is opened at the bottom of the outer pipe, and a mixer is also installed in the calorimeter outlet; the middle pipe is nested in the outer pipe, and there is a gap between it and the top surface of the outer pipe, and the inner pipe is nested in the middle pipe, and there is a gap between it and the bottom of the middle pipe; a heating wire made of a high-strength chromium-nickel alloy double helix is ​​placed inside the inner pipe, and the gap between the heating wire and the inner pipe is filled with high-temperature resistant magnesium oxide powder, and the top is sealed with epoxy glue; a radiation screen is provided on the outer wall of the calorimeter to keep the wall temperature of the outer heating zone and the inner heating zone consistent with the outer wall of the calorimeter, and the radiation screen maintains a smooth surface to minimize heat loss caused by thermal radiation.

[0015] Furthermore, the inlet temperature detector and the outlet temperature detector are both thermistor structures.

[0016] Furthermore, an insulating isolation plate is installed at the upper part of the interior of the insulating kettle, and the experimental test subsystem is located on the insulating isolation plate. The insulating isolation plate is used to separate the experimental test subsystem from the bridge test subsystem.

[0017] Furthermore, the outer heating belt and the inner heating belt are wound in a double helix manner.

[0018] Furthermore, a lead inlet and outlet are provided on the side wall of the insulation kettle, which are outlets for all leads of the experimental test subsystem and the bridge test subsystem in the insulation kettle.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) The traditional method of measuring specific heat capacity generally uses temperature sensors such as platinum resistance thermometers and thermocouples to measure temperature, which has the problems of large temperature reading errors, inconvenient reading, and a high possibility of introducing random errors in a single measurement. The present invention transforms the traditional Wheatstone bridge, which adopts a dual parallel system to convert thermal signals into electrical signals, calculates specific heat capacity using voltage ratios, and collects and processes data through computers, which is more intelligent and accurate.

[0021] (2) The temperature measuring device adopts dual-channel testing, one for voltage signal and the other for thermocouple sensor signal, so as to largely eliminate experimental errors.

[0022] (3) By improving the flow calorimeter and designing the internal and external insulation screens and electric heating system, the measurement range of temperature and pressure was broadened, providing a certain theoretical basis for engineering design and calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of a system for testing adiabatic specific heat capacity of a flowing high-temperature molten salt fluid according to an embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of an experimental test subsystem 101;

[0025] Figure 3 is a schematic diagram of a calorimeter 101-8;

[0026] Figure 4 is a schematic diagram of the bridge test subsystem 102;

[0027] Figure 5 It is a schematic diagram of the information collection and control subsystem 103.

[0028] In the figure, the experimental test subsystem 101, the bridge test subsystem 102, the information collection and control subsystem 103, the sample container 101-1, the horizontal flow pump 101-2, the stainless steel pipe 101-3, the back pressure valve 101-4, the insulated kettle 101-5, the electric heater 101-6, the inlet temperature detector 101-7, the calorimeter 101-8, the outlet temperature detector 101-9, the cooler 101-10, the support frame 101-11, the insulated isolation plate 101-12, the external heating belt 101-13, the internal heating belt 101-14, the lead inlet and outlet 101-15, the vacuum pump 101-16, the first thermocouple 101-17, the second thermocouple 101-18, the pressure Table 101-19, calorimeter inlet 101-8-1, middle tube 101-8-3, inner tube 101-8-4, heating wire 101-8-5, high temperature resistant magnesium oxide powder 101-8-6, radiation screen 101-8-7, mixer 101-8-8, calorimeter inlet 101-8-9, DC regulated power supply 102-1, bridge switch 102-2, first precision resistance box 102-3, first precision resistor 102-4, second precision resistor 102-5, second precision resistor box 102-6, third precision resistor box 102-7, first precision voltmeter 102-8, second precision voltmeter 102-9, computer 103-1, data acquisition card 103-2. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments, and the purpose and effects of the present invention will become more clear. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] like Figure 1 As shown, the adiabatic specific heat capacity testing system of flowing high-temperature molten salt fluid of the present invention includes an experimental testing subsystem 101, an electric bridge testing subsystem 102, and an information collection and control subsystem 103.

[0031] Among them, Figure 2 As shown, the experimental test subsystem 101 includes an insulated kettle 101-5, and a sample container 101-1, a horizontal flow pump 101-2, a back pressure valve 101-4, a cooler 101-10, a vacuum pump 101-16 located outside the insulated kettle 101-5, and an electric heater 101-6, an inlet temperature detector 101-7, a calorimeter 101-8, an outlet temperature detector 101-9, a support frame 101-11, an insulating isolation plate 101-12, an external heating belt 101-13, an internal heating belt 101-14, a first thermocouple 101-17, a second thermocouple 101-18, and a pressure gauge 101-19 located inside the insulated kettle 101-5.

[0032] The sample container 101-1, the horizontal flow pump 101-2, the electric heater 101-6, the calorimeter 101-8, and the cooler 101-10 are connected in sequence through the stainless steel pipe 101-3. The back pressure valve 101-4 is installed on the stainless steel pipe 101-3 between the horizontal flow pump 101-2 and the electric heater 101-6, the inlet temperature detector 101-7 is installed on the stainless steel pipe 101-3 between the electric heater 101-6 and the calorimeter 101-8, and the outlet temperature detector 101-9 is installed on the stainless steel pipe 101-3 between the calorimeter 101-8 and the cooler 101-10.

[0033] The sample container 101-1 is a container for holding the molten salt to be tested, and the horizontal flow pump 101-2 pumps the molten salt to be tested in the sample container 101-1 at a uniform speed. The back pressure valve 101-4 is used to adjust the pressure inside the insulated kettle 101-5. The insulated kettle 101-5 is cylindrical in shape, and both ends are insulated and sealed to provide insulation conditions for the test environment. After the molten salt to be tested is heated to the set temperature by the electric heater 101-6, it is transported to the inlet temperature detector 101-7, and its temperature data is accurately measured by the molten salt inlet temperature detector 101-7. After the temperature of the molten salt to be tested is measured, it is added to the calorimeter 101-8 from the calorimeter inlet 101-8-1.

[0034] like Figure 3As shown, the calorimeter 101-8 is designed as a sleeve type and is supported at the center of the insulated kettle 101-5 by a support frame 101-11. The internal channel of the calorimeter 101-8 is annular and is welded with stainless steel pipes of different diameters, namely an outer pipe 101-8-2, a middle pipe 101-8-3 and an inner pipe 101-8-4. A calorimeter inlet 101-8-1 is provided on one side of the outer pipe 101-8-2, and a calorimeter outlet 101-8-9 is provided at the bottom of the outer pipe 101-8-2. A mixer 101-8-8 is also installed in the calorimeter outlet 101-8-9. The middle tube 101-8-3 is nested in the outer tube 101-8-2, and there is a gap between the middle tube 101-8-3 and the top surface of the outer tube 101-8-2. The inner tube 101-8-4 is nested in the middle tube 101-8-3, and there is a gap between the middle tube 101-8-3 and the bottom. A heating wire 101-8-5 made of a high-strength chromium-nickel alloy double spiral is placed inside the inner tube 101-8-4, and the gap between the heating wire 101-8-5 and the inner tube 101-8-4 is filled with high-temperature resistant magnesium oxide powder 101-8-6, and the top is sealed with epoxy glue. The outer wall of the calorimeter 101-8 is provided with a radiation screen 101-8-7, so that the wall temperature of the outer heating belt 101-13 and the inner heating belt 101-14 is consistent with the outer wall of the calorimeter 101-8. The radiation screen 101-8-7 maintains a smooth surface to minimize the heat loss caused by thermal radiation.

[0035] The molten salt to be tested enters the calorimeter from the inlet 101-8-1, passes through the cavities of the outer tube 101-8-2 and the middle tube 101-8-3, and then flows into the cavities of the middle tube 101-8-3 and the inner tube 101-8-4 for heating. After the molten salt to be tested is heated, it finally stays for a while at the mixer 101-8-8 at the bottom for sufficient heat exchange before leaving.

[0036] The outlet temperature detector 101-9 measures the outlet temperature in the same manner as the inlet temperature detector 101-7, and is then transported to the cooler 101-10 located outside the insulated kettle 101-5, where the molten salt to be tested is cooled and collected for processing. The first thermocouple 101-17 is installed on the side wall of the insulated kettle 101-5 to measure the ambient temperature inside the insulated kettle 101-5. The pressure gauge 101-19 is installed on the side wall of the insulated kettle 101-5 to measure the ambient pressure inside the insulated kettle 101-5.

[0037] The insulating isolation plate 101-12 is located at the upper part of the insulating kettle 101-5, and is used to separate the experimental test subsystem 101 and the bridge test subsystem 102. The external heating belt 101-13 and the internal heating belt 101-14 are respectively arranged on the upper and lower sides of the calorimeter 101-8, and the external heating belt 101-13 and the internal heating belt 101-14 are wound in a double helix manner, and a second thermocouple 101-18 is arranged thereon to detect temperature changes on the detection belt. The information acquisition and control subsystem 103 controls the temperature together with the external heating belt 101-13, the internal heating belt 101-14 and the second thermocouple 101-18 to ensure that the temperature of the inner and outer cavities is basically consistent with the temperature of the calorimeter 101-8 in the experimental test subsystem 101, so as to prevent heat loss due to a certain temperature gradient formed by the calorimeter 101-8, the external heating belt 101-13 and the internal heating belt 101-14 when measuring the specific heat capacity at high temperature.

[0038] A lead inlet and outlet 101-15 is provided on the side wall of the insulated kettle 101-5, which is the outlet of all leads of the experimental test subsystem 101 and the bridge test subsystem 102 in the insulated kettle 101-5. The vacuum pump 101-16 and the back pressure valve 101-4 jointly provide a vacuum environment inside the insulated kettle 101-5 to ensure that the calorimeter 101-8 is in a vacuum state to prevent heat loss.

[0039] like Figure 4 As shown, the bridge test subsystem 102 includes a DC regulated power supply 102-1, a bridge switch 102-2, a first resistance box 102-3, a first resistor 102-4, a second resistor 102-5, a second resistance box 102-6, a third precision resistance box 102-7, a first precision voltmeter 102-8, and a second precision voltmeter 102-9.

[0040] Among them, the DC regulated power supply 102-1 provides a DC regulated voltage for the line, and the bridge switch 102-2 controls the entire bridge line switch. The first resistor box 102-3 is an adjustable precision resistor box, which is mainly used to protect the circuit system and avoid short circuit. The first resistor 102-4 and the second resistor 102-5 are both 50Ω precision resistors, and the inlet temperature detector 101-7 and the outlet temperature detector 101-9 are both thermistor structures, and the testable temperature range is 100-800℃. The first resistor 102-4, the second resistor 102-5, the second resistor box 102-6 and the inlet temperature detector 101-7 are connected to form a quadrilateral to form the four bridge arms of the Wheatstone bridge. The first resistor 102-4, the second resistor 102-5, the third resistor box 102-7 and the outlet temperature detector 101-9 are connected to form a quadrilateral to form the four bridge arms of the Wheatstone bridge. The two bridge systems share the first resistor 102-4 and the second resistor 102-5, but do not interfere with each other's test. The first voltmeter 102-8 and the second voltmeter 102-9 are connected in series on the diagonal (A and B; A and C), and the voltage data of the first voltmeter 102-8 and the second voltmeter 102-9 are connected to the data acquisition card 103-2.

[0041] In order to make full use of the accuracy of the measuring equipment and ensure that the linear section can be maintained for at least 3-5 seconds, a 1V DC voltage is selected for heating. The bridge voltage difference is generally 10-20mV, the corresponding temperature rise of the hot wire is 1-2K, and the repeatability of the data is within 1%.

[0042] The first resistor box 102-3 is R0, the first resistor 102-4 is R1, the second resistor 102-5 is R2, the first resistor 102-4 is R3, the second resistor 102-5 is R4, and the inlet temperature detector 101-7 is R x1 , the outlet temperature detector 101-9 is R x2 , turn on the power supply. When the bridge is not balanced, current flows through the galvanometer on the "bridge", and the galvanometer deflects. By adjusting the resistance of each arm, the potential between points A and B and between points A and C can be equal. There is no current on the "bridge", and the bridge is said to be in a balanced state. When the bridge is in a balanced state, R3R2=R1R x1 And R4R2=R1R x1 , this formula is the balance condition of the bridge, that is, the product of the resistances of the two arms of the bridge is equal. According to the balance condition of the bridge, if the resistance of any three arms is known, the resistance of another arm can be calculated. Therefore, the calculation formula for the bridge resistance is R x1 =R2 / R1·R3=KR3 and R x2 =R2 / R1·R4=KR4, the resistance is the ratio arm of the bridge, R1=R2 is often used in experiments, R x1 and R x2The arm to be tested is R3 and R4 as standard resistors for comparison. The thermistors before and after the molten salt inlet are set as the arm to be tested, that is, the arm to be tested R x1 and R x2 After power is turned on, the corresponding hot wire resistance R is calculated based on the measured bridge voltage difference. x1 and R x2 , and based on the relationship between thermistor and temperature, the temperature change of the molten salt is obtained.

[0043] like Figure 5 As shown, the information acquisition and control subsystem 103 includes a computer 103-1 and a data acquisition card 103-2. The data acquisition card 103-2 and the first voltmeter 102-8, the second voltmeter 102-9, the first thermocouple 101-17, the second thermocouple 101-18, the electric heater 101-6, the inlet temperature detector 101-7, the outlet temperature detector 101-9, and the pressure gauge 101-19 are electrically connected through wires to collect corresponding pressure signals and temperature signals, and transmit the input to the computer 103-1 equipped with thermal analysis software and temperature and pressure control software. The computer 103-1 has three main functions, one is to collect and display the voltage and temperature data collected by the data acquisition card 103-2 in real time, the second is to convey temperature instructions to the external heating belt 101-13, the internal heating belt 101-14 and the electric heater 101-6, and the third is to process the obtained data and calculate the specific heat capacity of the molten salt to be measured.

[0044] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. A system for testing the adiabatic specific heat capacity of a flowing high-temperature molten salt fluid, characterized in that: Including experimental test subsystem, bridge test subsystem, information acquisition and control subsystem; The experimental test subsystem includes an insulated kettle, and a sample container, a horizontal flow pump, a back pressure valve, a cooler, a vacuum pump located outside the insulated kettle, and an electric heater, an inlet temperature detector, a calorimeter, an outlet temperature detector, an external heating belt, an internal heating belt, a first thermocouple, a second thermocouple, and a pressure gauge located inside the insulated kettle; The sample container, the horizontal flow pump, the electric heater, the calorimeter, and the cooler are connected in sequence through stainless steel pipes; the back pressure valve is installed on the stainless steel pipe between the horizontal flow pump and the electric heater, the inlet temperature detector is installed on the stainless steel pipe between the electric heater and the calorimeter, and the outlet temperature detector is installed on the stainless steel pipe between the calorimeter and the cooler; the external heating belt and the internal heating belt are respectively arranged on the upper and lower sides of the calorimeter, and each heating belt is arranged with a second thermocouple for detecting temperature changes on the detection belt; the first thermocouple and the pressure gauge are installed on the side wall of the insulated kettle, respectively used to measure the ambient temperature and pressure inside the insulated kettle; The bridge test subsystem includes a DC regulated power supply, a bridge switch, a first resistance box, a first resistor, a second resistor, a second resistance box, a third resistance box, a first voltmeter, and a second voltmeter; The first resistor, the second resistor, the second resistor box and the inlet temperature detector are connected to form a quadrilateral to form four bridge arms of the Wheatstone bridge; the first resistor, the second resistor, the third resistor box and the outlet temperature detector are connected to form a quadrilateral to form four bridge arms of the Wheatstone bridge; both Wheatstone bridges are connected to the two ends of the DC regulated power supply, the bridge switch and the first resistor box which are connected in series in sequence; The information acquisition and control subsystem includes a computer and a data acquisition card which are electrically connected in sequence, and the data acquisition card is electrically connected to the first voltmeter, the second voltmeter, the first thermocouple, the second thermocouple, the electric heater, the inlet temperature detector, the outlet temperature detector, and the pressure gauge through wires, and is used to collect corresponding pressure signals and temperature signals, and transmit the input to the computer equipped with thermal analysis software and temperature and pressure control software; The computer is used for real-time display of the voltage, pressure and temperature data collected by the data acquisition card, calculating the specific heat capacity of the molten salt to be measured based on these data, and conveying temperature instructions to the external heating belt, the internal heating belt and the electric heater.

2. The adiabatic specific heat capacity testing system for flowing high-temperature molten salt fluid according to claim 1 is characterized in that: The calorimeter is designed as a sleeve type and is supported at the center of the insulated kettle by a support frame; the internal channel of the calorimeter is annular and is welded by stainless steel pipes of different diameters, namely an outer pipe, a middle pipe and an inner pipe; a calorimeter inlet is opened on one side of the outer pipe, a calorimeter outlet is opened at the bottom of the outer pipe, and a mixer is also installed in the calorimeter outlet; the middle pipe is nested in the outer pipe, and there is a gap between it and the top surface of the outer pipe, and the inner pipe is nested in the middle pipe, and there is a gap between it and the bottom of the middle pipe; a heating wire made of high-strength chromium-nickel alloy double helix is ​​placed inside the inner pipe, and the gap between the heating wire and the inner pipe is filled with high-temperature resistant magnesium oxide powder, and the top is sealed with epoxy glue; a radiation screen is arranged on the outer wall of the calorimeter to keep the wall temperature of the outer heating belt and the inner heating belt consistent with the outer wall of the calorimeter, and the radiation screen maintains a smooth surface to minimize heat loss caused by thermal radiation.

3. The adiabatic specific heat capacity testing system for flowing high-temperature molten salt fluid according to claim 1 is characterized in that: The inlet temperature detector and the outlet temperature detector are both thermistor structures.

4. The adiabatic specific heat capacity testing system for flowing high-temperature molten salt fluid according to claim 1 is characterized in that: An insulating isolation plate is installed at the upper part of the interior of the insulating kettle, and the experimental test subsystem is located on the insulating isolation plate. The insulating isolation plate is used to separate the experimental test subsystem from the bridge test subsystem.

5. The adiabatic specific heat capacity testing system for flowing high-temperature molten salt fluid according to claim 1 is characterized in that: The outer heating belt and the inner heating belt are wound in a double helix manner.

6. The adiabatic specific heat capacity testing system for flowing high-temperature molten salt fluid according to claim 1 is characterized in that: The side wall of the thermal insulation kettle is provided with a lead inlet and outlet, which is the outlet of all the leads of the experimental test subsystem and the bridge test subsystem in the thermal insulation kettle.

Images