A large-flow hydrogen heat exchanger flow heat transfer and catalytic conversion testing device

Abstract

The application discloses a large-flow hydrogen heat exchanger flow heat transfer and catalytic conversion testing device, which is used for testing a heat exchange testing unit and comprises a hydrogen precooling and para-hydrogen measuring module, a low-temperature testing module and a low-temperature circulating module. The low-temperature circulating module adopts at least one low-temperature helium circulating module and / or at least one helium compression circulating module. The hydrogen precooling and para-hydrogen measuring module provides large-flow hydrogen for the low-temperature testing module through a connected pipeline and measures the para-hydrogen concentration of backflow. The low-temperature circulating module provides the low-temperature testing module with large-flow helium cold source required by the heat exchange testing unit through a connected pipeline. The heat exchange testing unit is arranged in a dewar of the low-temperature testing module through a VCR joint. The testing device can reach below the liquid nitrogen temperature zone and test the performance of a low-temperature hydrogen heat exchanger with a complete structure and multiple flow stocks under various working conditions, and obtain hydrogen heat exchange, flow and conversion data between the liquid nitrogen temperature zone and the liquid hydrogen temperature zone.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of low-temperature hydrogen heat exchangers in hydrogen liquefaction process, and particularly relates to a flow heat transfer and catalytic conversion testing device for a large-flow hydrogen heat exchanger. BACKGROUND

[0002] Hydrogen energy is one of the most promising energy carriers in the global decarbonization energy system. Liquid hydrogen is suitable for large-scale storage and application of hydrogen energy due to its high energy density, environmental friendliness, renewability, safety, and other advantages. The use of liquid hydrogen can reduce the dependence on limited resources such as traditional oil and natural gas, and reduce environmental pollution, which is an important direction for the development of future energy. Hydrogen liquefaction technology is one of the key technologies for the development of liquid hydrogen.

[0003] Hydrogen molecules can be divided into ortho-hydrogen and para-hydrogen according to the different spin states of hydrogen nuclei. At room temperature, hydrogen gas is composed of 75% ortho-hydrogen and 25% para-hydrogen. When the temperature decreases, the equilibrium proportion of para-hydrogen gradually increases, and at liquid nitrogen temperature, the equilibrium concentration of para-hydrogen is close to 50%, and until liquid hydrogen temperature, the equilibrium concentration of para-hydrogen is close to 100%. Due to the extremely slow spontaneous conversion rate of ortho-para hydrogen, normal hydrogen still contains a large amount of ortho-hydrogen after direct liquefaction. The heat release of ortho-para hydrogen conversion is higher than the latent heat of vaporization of liquid hydrogen, and if the ortho-hydrogen in liquid hydrogen spontaneously converts to para-hydrogen, it will cause liquid hydrogen evaporation loss. Therefore, in the hydrogen liquefaction process, high-efficiency ortho-para hydrogen conversion catalysts are needed to accelerate the increase of para-hydrogen content to more than 98% to reduce the evaporation loss of liquid hydrogen during storage.

[0004] The catalytic and heat exchange integrated low-temperature hydrogen heat exchanger is a key equipment for large-scale hydrogen liquefaction technology. Compared with the traditional separate arrangement scheme of catalytic converter and heat exchanger, its characteristics are: through the way of filling catalyst in the heat exchanger flow channel, the heat exchange flow process and the ortho-para hydrogen conversion process are combined into an integrated design, which is compact in structure, small in space occupation, low in installation and maintenance cost; it can cool and convert hydrogen at the same time, greatly improving the liquefaction efficiency, reducing energy loss and equipment cost, and compared with the separate setting of catalytic and heat exchange equipment, the hydrogen liquefaction energy consumption can be reduced by more than 15.3%.

[0005] In the actual production of liquid hydrogen, the structure of the integrated low-temperature hydrogen heat exchanger is more complex than that of the traditional heat exchanger, and at the same time, due to the numerous influencing factors, the internal heat exchange, flow, and catalytic process are more difficult to predict. The traditional heat exchanger flow heat transfer data and correlation are not applicable to the integrated heat exchanger. Therefore, the experimental data of continuous conversion are very limited, and the lack of relevant data also limits the application of continuous conversion low-temperature hydrogen heat exchanger in industry. Obtaining relevant data is crucial for the structural design and performance prediction of the integrated heat exchanger, and can provide reference for the ortho-para hydrogen conversion design in the hydrogen liquefaction process, and promote the application of continuous conversion in the hydrogen liquefaction industry.

[0006] Currently, the test of low-temperature plate-fin heat exchanger in the industry is usually limited to the heat transfer unit level, that is, the test of the heat transfer and flow characteristics of the fins. For the whole machine test, generally only the pressure-bearing and leakage rate tests are carried out before delivery, and the flow and heat transfer performance is not tested, but only evaluated after the overall flow process is assembled. This test method is obviously simple and rough, and cannot accurately evaluate the performance of the heat exchanger, so the heat transfer unit test cannot replace the whole machine test. Therefore, in the design of the heat exchanger, a larger design margin is usually provided, which leads to unnecessary increase in volume, weight and cost. As can be seen, due to the lack of a low-temperature test bench and data for the whole heat exchanger, the accuracy of the design cannot be accurately understood, and accurate data cannot be provided to the designers, which is not conducive to the technical progress of the entire industry. This is one of the pain points currently faced by the industry.

[0007] Chinese patent with publication number CN 115343084 A discloses a multi-temperature zone test device and method for a packed plate-fin heat exchanger under low-temperature working conditions, mainly including a hydrogen source, a liquid nitrogen pre-cooler, a negative pressure liquid nitrogen pre-cooler, a GM refrigerator, a packed plate-fin heat exchanger with a cold-hot-cool three-layer structure, and a heat conduction analysis device. After the hydrogen passes through the liquid nitrogen pre-cooler, it is divided into two streams, the hot side is pre-cooled by the GM refrigerator and then enters the heat exchanger hot channel; the cold side is pre-cooled by the negative pressure liquid nitrogen pre-cooler and the GM refrigerator and then enters the heat exchanger cold channel.

[0008] However, the currently disclosed heat exchanger test device uses a GM refrigerator to provide a cold source. However, the current commercial single GM refrigerator can only provide a few tens of watts to hundreds of watts of refrigeration capacity in the range of 20-80K, and the corresponding hydrogen liquefaction device has a daily output of only a few tens of kilograms. However, in actual engineering, the daily output of a hydrogen liquefaction device is as high as 2-30 tons, and the heat exchange capacity of a low-temperature hydrogen heat exchanger is hundreds of kilowatts. Therefore, the currently disclosed low-temperature hydrogen heat exchanger test device based on the GM refrigerator cannot meet the large cold capacity demand of the industrial-level large-flow low-temperature hydrogen heat exchanger test. On the other hand, the hydrogen liquefaction process usually uses 2-5 stream hydrogen heat exchangers. The currently disclosed heat exchanger test device is only suitable for performance testing of small two-stream heat exchange modules, and does not consider the comprehensive influence of factors such as flow resistance and flow distribution uniformity on the performance of the heat exchanger, so it cannot be used for performance testing of multi-stream low-temperature hydrogen heat exchangers. Therefore, there is an urgent need for a large-flow low-temperature hydrogen heat exchanger performance test device to meet the key data acquisition and design improvement needs of the catalytic and heat exchange integrated low-temperature hydrogen heat exchanger of large-scale hydrogen liquefaction devices. SUMMARY

[0009] In order to realize the performance test of the large-flow integrated low-temperature hydrogen heat exchanger, the application provides a large-flow hydrogen heat exchanger flow heat transfer and catalytic conversion test device, which can test the performance of the catalytic and heat exchange integrated hydrogen heat exchanger for a large hydrogen liquefaction process, and obtain a series of basic data such as temperature distribution, pressure drop, catalyst consumption and normal and secondary hydrogen concentration under different working conditions.

[0010] A large-flow hydrogen heat exchanger flow heat transfer and catalytic conversion test device is used for testing a heat exchange test unit, comprising: a hydrogen precooling and secondary hydrogen measurement module, a low-temperature test module and a low-temperature circulation module; wherein the low-temperature circulation module adopts at least one low-temperature helium circulation module and / or at least one helium compression circulation module.

[0011] The hydrogen precooling and secondary hydrogen measurement module provides large-flow hydrogen for the low-temperature test module through the connected pipeline and measures the secondary hydrogen concentration of the backflow; the low-temperature helium circulation module and / or the helium compression circulation module provide the large-flow helium cold source required by the heat exchange test unit of the low-temperature test module through the connected pipeline; the heat exchange test unit in the low-temperature test module is placed in the low-temperature test module Dewar in a detachable manner through the VCR joint and is subjected to vacuum heat insulation treatment.

[0012] A temperature sensor is arranged near each VCR joint to measure the temperature of the inlet and outlet of the cold and hot fluids of the heat exchange test unit; at the same time, a branch is led out near each VCR joint to the outside of the low-temperature test module Dewar to connect a pressure sensor, which is used to measure the pressure of the inlet and outlet of the cold and hot fluids of the heat exchange test unit.

[0013] The heat exchange test unit is filled with normal and secondary hydrogen conversion catalyst in the flow channel on the hot fluid side, and the hydrogen flows in the flow channel with continuous catalytic conversion; the cold fluid side of the heat exchange test unit is connected with the low-temperature helium circulation module and / or the helium compression circulation module; temperature measuring points are arranged on the outer wall and the fluid wall of the heat exchange test unit for measuring the wall temperature so as to convert the fluid temperature distribution.

[0014] Further, the hydrogen precooling and secondary hydrogen measurement module comprises: a hydrogen precooling and secondary hydrogen measurement module Dewar, a high-pressure hydrogen cylinder, a hydrogen flow meter, a hydrogen flow adjusting valve, a hydrogen heater, a liquid nitrogen precooling tank, a liquid nitrogen coil, a temperature bypass adjusting valve, a nitrogen evacuation valve, a hydrogen evacuation valve, a measurement adjusting valve, a gas chromatograph and a measurement evacuation valve.

[0015] The high-pressure hydrogen cylinder is connected with the hydrogen flow meter and the hydrogen flow adjusting valve in sequence and is divided into two branches, one of which flows through the hot fluid side of the hydrogen heater and the liquid nitrogen coil in the liquid nitrogen precooling tank in sequence; the other branch flows through the temperature bypass adjusting valve and is combined with the hydrogen flowing out of the liquid nitrogen coil to adjust the temperature; and then flows into the hot fluid channel of the heat exchange test unit in the low-temperature test module.

[0016] The hydrogen gas flowing out of the heat transfer test unit of the low-temperature test module enters the hydrogen pre-cooling and para-hydrogen measuring module, flows through the cold fluid side of the hydrogen gas reheater, and is safely discharged through the hydrogen gas evacuation valve; a branch is introduced before the hydrogen gas evacuation valve, and a measuring and adjusting valve, a gas chromatograph, and a measuring evacuation valve are connected in sequence before a safe evacuation.

[0017] Further, the hydrogen gas reheater, the liquid nitrogen pre-cooling tank, the liquid nitrogen coil, and the temperature bypass adjusting valve are placed in the hydrogen pre-cooling and para-hydrogen measuring module Dewar and are subjected to vacuum heat insulation treatment.

[0018] The liquid nitrogen pre-cooling tank is multi-layer insulated and discharges nitrogen gas generated by evaporation through the nitrogen gas evacuation valve.

[0019] Further, the low-temperature helium circulation module comprises a low-temperature helium circulation module Dewar, a high-pressure helium tank, a helium tank air supply valve, a circulating filling valve, a pre-cooling tank, a liquid nitrogen coil, a temperature bypass adjusting valve, a low-temperature fan, and a nitrogen gas evacuation valve.

[0020] The high-flow helium gas flowing out of the cold fluid channel of the heat transfer test unit of the low-temperature test module enters the low-temperature helium circulation module, sequentially flows through the liquid nitrogen coil in the pre-cooling tank and the low-temperature fan, and then flows into the cold fluid channel of the heat transfer test unit of the low-temperature test module to form a circulation loop.

[0021] The helium tank air supply valve, the high-pressure helium tank, and the circulating filling valve are connected in sequence and connected to the helium circulation loop before the helium gas enters the pre-cooling tank; a branch is introduced before the helium gas enters the pre-cooling tank, and the helium gas flowing out of the liquid nitrogen coil is combined after flowing through the temperature bypass adjusting valve to perform temperature adjustment.

[0022] Further, the pre-cooling tank, the liquid nitrogen coil, the temperature bypass adjusting valve, and the low-temperature fan are placed in the low-temperature helium circulation module Dewar and are subjected to vacuum heat insulation treatment.

[0023] The pre-cooling tank is multi-layer insulated and discharges nitrogen gas generated by evaporation through the nitrogen gas evacuation valve.

[0024] Alternatively, the pre-cooling tank is a liquid nitrogen pre-cooling tank, a liquid hydrogen pre-cooling tank, or a combination of the two.

[0025] Further, the helium gas compression circulation module comprises a helium gas compression circulation module Dewar, a helium gas secondary reheater, a helium gas primary reheater, a compressor, a high-pressure helium tank, a pressure reducing valve, a helium tank air supply valve, a helium pressure stabilizing tank, a liquid nitrogen pre-cooling tank, a liquid nitrogen coil, a temperature bypass adjusting valve, a liquid hydrogen pre-cooling tank, a liquid hydrogen coil, a liquid hydrogen loop valve, a hydrogen gas evacuation valve, and a nitrogen gas evacuation valve.

[0026] The high-flow helium gas flowing out from the cold fluid passage of the heat exchange test unit in the low-temperature test module enters the helium gas compression circulation module; the high-flow helium gas flows through the helium gas secondary heat exchanger cold fluid passage, the helium gas primary heat exchanger cold fluid passage, the compressor, the helium gas pressure stabilizing tank, the helium gas primary heat exchanger hot fluid passage, the liquid nitrogen coil in the liquid nitrogen precooling tank, the helium gas secondary heat exchanger hot fluid passage, the liquid hydrogen coil in the liquid hydrogen precooling tank, and then flows into the cold fluid passage of the heat exchange test unit in the low-temperature test module after the liquid hydrogen loop valve, to form a circulation loop;

[0027] The helium tank air supply valve, the high-pressure helium tank, the pressure reducing valve and the helium pressure stabilizing tank are connected in sequence to maintain the circulating helium pressure; another branch is introduced after the helium gas leaves the liquid nitrogen coil in the liquid nitrogen precooling tank, and is connected to the pipeline after the liquid hydrogen loop valve through the temperature bypass regulating valve to perform temperature regulation.

[0028] Further, the helium gas secondary heat exchanger, the helium gas primary heat exchanger, the liquid nitrogen precooling tank, the liquid nitrogen coil, the temperature bypass regulating valve, the liquid hydrogen precooling tank, the liquid hydrogen coil and the liquid hydrogen loop valve are all placed in the helium gas compression circulation module Dewar and are subjected to vacuum heat insulation treatment.

[0029] The liquid nitrogen precooling tank adopts multi-layer insulation and discharges the nitrogen gas generated by evaporation through the nitrogen gas exhaust valve; the liquid hydrogen precooling tank adopts multi-layer insulation and discharges the nitrogen gas generated by evaporation through the hydrogen gas exhaust valve.

[0030] When the heat exchange test unit in the low-temperature test module is a normal parahydrogen conversion low-temperature heat exchanger in the form of multiple streams, multiple low-temperature helium circulation modules, multiple helium gas compression circulation modules or a combination of low-temperature helium circulation modules and helium gas compression circulation modules are used to provide helium gas for the low-temperature test module.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] 1. The present application is based on low-temperature helium circulation and uses liquid nitrogen or liquid hydrogen as a cold source, and can perform flow heat transfer and catalytic conversion testing under large flow for a low-temperature hydrogen heat exchanger closer to the actual large-scale hydrogen liquefaction scale. At the same time, a helium refrigeration unit is used to obtain a low-temperature cold source while avoiding a hydrogen cold source, reducing the amount of hydrogen used and improving the safety of the system.

[0033] 2. Compared with directly using liquid coolant as a circulating working medium, the present application avoids the potential influence of the instability of gas-liquid phase change in the cold fluid passage on the performance testing of the heat exchanger; in addition, the specific heat capacity of helium is higher than that of nitrogen, which is more than twice that of nitrogen. The mass flow of the circulating working medium can be effectively reduced, thereby reducing the input power of the circulation.

[0034] 3. This invention enables wide-range adjustment of temperature and flow rate. The inlet state of the hot hydrogen fluid in the heat exchange test unit can be adjusted via a hydrogen flow regulating valve and a temperature bypass regulating valve, thus decoupling the temperature and flow rate operating parameters. The cooling capacity provided by the cold fluid at different temperatures can be adjusted via the flow rate and temperature bypass regulating valve of the helium circulation, thereby obtaining basic data on heat exchange flow and catalytic conversion of the cryogenic hydrogen heat exchanger under different operating conditions that more closely approximate actual large-scale hydrogen liquefaction processes.

[0035] 4. The heat exchange test unit of the present invention is connected to the pipeline through the VCR interface, which allows for sample replacement, including multi-flow heat exchangers, to test heat exchange units of different structures and types, thereby obtaining a wider range of relevant basic data.

[0036] 5. This invention can be used for performance testing of multi-stream cryogenic hydrogen heat exchangers. Currently disclosed heat exchanger testing devices are only suitable for performance testing of small two-stream heat exchange modules and do not consider the comprehensive impact of factors such as end cap flow resistance and stream distribution uniformity on heat exchanger performance. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall structure of the high-flow-rate hydrogen heat exchanger flow heat transfer and catalytic conversion test device using a low-temperature helium circulation module according to the present invention.

[0038] Figure 2 This is a schematic diagram of the overall structure of the high-flow-rate hydrogen heat exchanger flow heat transfer and catalytic conversion test device using a helium compression circulation module according to the present invention.

[0039] In the figure: 100-hydrogen pre-cooling and para-hydrogen measurement module Dewar, 101-high pressure hydrogen cylinder, 102-hydrogen flow meter, 103-hydrogen flow regulating valve, 104-hydrogen heat exchanger, 105-liquid nitrogen pre-cooling tank, 106-liquid nitrogen coil, 107-temperature bypass regulating valve, 108-nitrogen evacuation valve, 109-hydrogen evacuation valve, 110-measurement regulating valve, 111-gas chromatograph, 112-measurement evacuation valve, 200-low temperature test module Dewar, 201-heat exchange test unit, 202-VCR joint, 300-low temperature helium circulation module Dewar, 301-high pressure helium tank, 302-helium tank air charging valve, 303-circulation charging valve, 304-pre-cooling tank, 305-liquid nitrogen coil, 306-temperature bypass regulating valve, 307-low temperature fan, 308-nitrogen evacuation valve, 400-helium compression circulation module Dewar, 401-helium secondary heat exchanger, 402-helium primary heat exchanger, 403-compressor, 404-high pressure helium tank, 405-reducing valve, 406-helium tank air charging valve, 407-helium pressure stabilizing tank, 408-liquid nitrogen pre-cooling tank, 409-liquid nitrogen coil, 410-temperature bypass regulating valve, 411-liquid hydrogen pre-cooling tank, 412-liquid hydrogen coil, 413-liquid hydrogen loop valve, 414-hydrogen evacuation valve, 415-nitrogen evacuation valve. DETAILED DESCRIPTION

[0040] The application will be described in further detail below in connection with the drawings and examples, it should be noted that the following examples are intended to facilitate the understanding of the application and do not limit the application in any way.

[0041] The application is to achieve the experimental conditions in the liquid hydrogen temperature range to the liquid nitrogen temperature range and higher, to obtain the related data of the flow heat exchange and catalytic conversion performance of hydrogen at low temperature, and to provide a reference for the industrial design of low-temperature hydrogen heat exchanger. A large-flow hydrogen heat exchanger flow heat transfer and catalytic conversion test device is designed, which can realize comprehensive testing of various forms of low-temperature hydrogen heat exchanger under different fluid temperature, pressure, flow and other working condition parameters. Through the test platform, a series of basic data such as temperature distribution, pressure drop, catalyst dosage, normal and para-hydrogen concentration under different working conditions can be obtained, and the comprehensive influence of factors such as end flow resistance and flow distribution uniformity on the performance of the heat exchanger is explored.

[0042] Example 1

[0043] As Figure 1As shown, the large-flow hydrogen heat exchanger flow heat transfer and catalytic conversion test device using a low-temperature helium circulation module is used to test the heat exchange test unit 201, which includes: a hydrogen precooling and para-hydrogen measurement module 1, a low-temperature test module 2, and a low-temperature helium circulation module 3. Among them, the hydrogen precooling and para-hydrogen measurement module 1 provides large-flow hydrogen for the low-temperature test module 2 through the connected pipeline and measures the para-hydrogen concentration of the backflow; the low-temperature helium circulation module 3 provides the large-flow helium cold source required by the heat exchange test unit 201 through the connected pipeline; in the low-temperature test module 2, the heat exchange test unit 201 is placed in the low-temperature test module Dewar 200 in a detachable manner through the VCR joint 202 and is subjected to vacuum insulation treatment. Temperature sensors are arranged near each VCR joint 202 to measure the temperature of the inlet and outlet of the cold and hot fluids of the heat exchange test unit 201. A branch is led out near each VCR joint 202 to the outside of the low-temperature test module Dewar 200 to connect a pressure sensor for measuring the pressure of the inlet and outlet of the cold and hot fluids of the heat exchange test unit 201.

[0044] The heat exchange test unit 201 is filled with normal-para hydrogen conversion catalyst in the flow channel on the hot fluid side, and the hydrogen gas undergoes a flow heat exchange process accompanied by continuous catalytic conversion in the flow channel; the cold fluid side of the heat exchange test unit 201 is connected to the low-temperature helium circulation module 3; and temperature measurement sites are provided on the outer wall and the fluid wall of the heat exchange test unit 201 for measuring the wall temperature to convert the fluid temperature distribution.

[0045] The hydrogen precooling and para-hydrogen measurement module 1 includes: a hydrogen precooling and para-hydrogen measurement module Dewar 100, a high-pressure hydrogen cylinder 101, a hydrogen flowmeter 102, a hydrogen flow regulating valve 103, a hydrogen heater 104, a liquid nitrogen precooling tank 105, a liquid nitrogen coil 106, a temperature bypass regulating valve 107, a nitrogen evacuation valve 108, a hydrogen evacuation valve 109, a measurement regulating valve 110, a gas chromatograph 111, and a measurement evacuation valve 112.

[0046] Among them, the high-pressure hydrogen cylinder 101 is sequentially connected to the hydrogen flowmeter 102 and the hydrogen flow regulating valve 103 and then divided into two branches, one of which sequentially flows through the hot fluid side of the hydrogen heater 104 and the liquid nitrogen coil 106 in the liquid nitrogen precooling tank 105; the other branch flows through the temperature bypass regulating valve 107 and merges with the hydrogen flowing out of the liquid nitrogen coil 106 for temperature regulation; and then flows into the hot fluid channel of the heat exchange test unit 201 in the low-temperature test module 2. The hydrogen flow and pressure of the hydrogen hot fluid entering the heat exchange test unit 201 from the high-pressure hydrogen cylinder 101 as a gas source are adjusted and controlled through the hydrogen flowmeter 102 and the hydrogen flow regulating valve 103. When the temperature bypass regulating valve 107 is fully closed, the temperature of the hydrogen entering the heat exchange test unit 201 is about 78K. The temperature of the hydrogen entering the heat exchange test unit 201 is adjusted by adjusting the opening of the temperature bypass regulating valve 107 to meet the test conditions of greater than 78K.

[0047] The hydrogen gas flowing out of the heat transfer test unit 201 of the low-temperature test module 2 enters the hydrogen pre-cooling and para-hydrogen measuring module 1; after flowing through the cold fluid side of the hydrogen gas reheater 104, the hydrogen gas is safely discharged through the hydrogen gas evacuation valve 109; a branch is introduced before the hydrogen gas evacuation valve 109, and the measuring and adjusting valve 110, the gas chromatograph 111 and the measuring evacuation valve 112 are sequentially connected in series, and then the hydrogen gas is safely discharged.

[0048] The gas chromatograph 111 uses standard hydrogen in the high-pressure hydrogen cylinder 101 as a carrier gas to measure the normal and para-hydrogen concentrations of the hydrogen gas flowing out of the low-temperature test module 2 and entering the gas chromatograph 111.

[0049] The hydrogen gas reheater 104, the liquid nitrogen pre-cooling tank 105, the liquid nitrogen coil 106 and the temperature bypass adjusting valve 107 in the hydrogen pre-cooling and para-hydrogen measuring module 1 are placed in the hydrogen pre-cooling and para-hydrogen measuring module Dewar 100 and are subjected to vacuum heat insulation treatment. The liquid nitrogen pre-cooling tank 105 adopts multi-layer insulation and discharges nitrogen gas generated by evaporation through the nitrogen gas evacuation valve 108.

[0050] The low-temperature helium circulation module 3 comprises a low-temperature helium circulation module Dewar 300, a high-pressure helium tank 301, a helium tank air charging valve 302, a circulation charging valve 303, a liquid nitrogen pre-cooling tank 304, a liquid nitrogen coil 305, a temperature bypass adjusting valve 306, a low-temperature fan 307 and a nitrogen gas evacuation valve 308.

[0051] The large-flow helium gas flowing out of the cold fluid channel of the heat transfer test unit 201 of the low-temperature test module 2 enters the low-temperature helium circulation module 3; the large-flow helium gas flows into the cold fluid channel of the heat transfer test unit 201 of the low-temperature test module 2 after sequentially flowing through the liquid nitrogen coil 305 in the liquid nitrogen pre-cooling tank 304 and the low-temperature fan 307, thereby forming a circulation loop. The flow rate of the helium circulation loop is indirectly controlled by adjusting the rotation speed of the low-temperature fan 307.

[0052] The helium tank air charging valve 302, the high-pressure helium tank 301 and the circulation charging valve 303 are sequentially connected and then connected to the helium circulation loop before the helium gas flows into the liquid nitrogen pre-cooling tank 304. The helium tank air charging valve 302 is used to charge the high-pressure helium tank 301, so that the high-pressure helium tank 301 can maintain a high-pressure state; and the high-pressure helium tank 301 is charged with high-pressure helium gas at the working pressure of the heat transfer test unit 201 through the circulation charging valve 303 before the system is operated.

[0053] A branch line is drawn before the helium enters the liquid nitrogen precooling tank 304. This branch line flows through the temperature bypass regulating valve 306 and merges with the helium exiting the liquid nitrogen coil 305 for temperature regulation. With the temperature bypass regulating valve 306 fully closed, the temperature of the helium entering the cold channel of the heat exchange test unit 201 is approximately 78K, which is within the liquid nitrogen temperature range. The temperature entering the heat exchange test unit 201 is adjusted by regulating the opening of the temperature bypass regulating valve 306 to meet the test conditions greater than 78K.

[0054] The liquid nitrogen precooling tank 304, liquid nitrogen coil 305, temperature bypass regulating valve 306, and cryogenic fan 307 in the cryogenic helium circulation module 3 are all placed inside the cryogenic helium circulation module Dewar 300 and are subjected to vacuum insulation treatment. The liquid nitrogen precooling tank 304 adopts multi-layer insulation and discharges the nitrogen generated by evaporation through the nitrogen vent valve 308.

[0055] As an improvement, the liquid nitrogen precooling tank 304 in the cryogenic helium circulation module 3 can be replaced with a liquid hydrogen precooling tank, allowing the cryogenic helium circulation module 3 to provide cryogenic helium in a lower temperature range. Alternatively, a liquid hydrogen precooling tank can be connected in series after the liquid nitrogen precooling tank 304, enabling the cryogenic helium circulation module 3 to provide cryogenic helium in a lower temperature range. By adjusting the temperature bypass regulating valve 306, the temperature of the helium entering the cold channel of the heat exchange test unit 201 can be maintained in the range of 20-80K.

[0056] The hydrogen regenerator 104 in the hydrogen precooling and secondary hydrogen measurement module 1 adopts a spiral sleeve heat exchanger. The inside of the tube is hot fluid, and the outside of the tube is cold fluid.

[0057] The heat exchange test unit 201 inside the low-temperature test module 2 can be replaced with various types of low-temperature heat exchangers for the conversion of n- and para-hydrogen.

[0058] Example 2

[0059] like Figure 2 The image shows a high-flow-rate hydrogen heat exchanger flow heat transfer and catalytic conversion test device using a helium compression circulation module. In this embodiment, the difference from Embodiment 1 is that the cryogenic helium circulation module 3 is replaced by a helium compression circulation module 4. The configuration and operation of other components are the same as in Embodiment 1, and will not be repeated here.

[0060] The helium compression cycle module 4 includes: a helium compression cycle module Dewar 400, a helium secondary regenerator 401, a helium primary regenerator 402, a compressor 403, a high-pressure helium tank 404, a pressure reducing valve 405, a helium tank replenishment valve 406, a helium pressure stabilizing tank 407, a liquid nitrogen precooling tank 408, a liquid nitrogen coil 409, a temperature bypass regulating valve 410, a liquid hydrogen precooling tank 411, a liquid hydrogen coil 412, a liquid hydrogen loop valve 413, a hydrogen vent valve 414, and a nitrogen vent valve 415.

[0061] In this process, a large flow of helium gas flowing out of the cold fluid channel of the heat exchange test unit 201 in the cryogenic test module 2 enters the helium compression circulation module 4. The large flow of helium gas flows sequentially through the cold fluid channel of the helium secondary regenerator 401, the cold fluid channel of the helium primary regenerator 402, the compressor 403, the helium pressure stabilizing tank 407, the hot fluid channel of the helium primary regenerator 402, the liquid nitrogen coil 409 in the liquid nitrogen precooling tank 408, the hot fluid channel of the helium secondary regenerator 401, the liquid hydrogen coil 412 in the liquid hydrogen precooling tank 411, and the liquid hydrogen loop valve 413 before flowing into the cold fluid channel of the heat exchange test unit 201 in the cryogenic test module 2, forming a circulation loop.

[0062] The helium tank replenishment valve 406, high-pressure helium tank 404, pressure reducing valve 405, and helium pressure stabilizing tank 407 are sequentially connected to maintain the helium pressure measured by the heat exchange test unit 201 under the specified operating conditions. Helium replenishment valve 406 replenishes the high-pressure helium tank 301.

[0063] In this system, after the helium gas leaves the liquid nitrogen coil 409 in the liquid nitrogen precooling tank 408, another branch is led out and connected to the pipeline after the liquid hydrogen circuit valve 413 via the temperature bypass regulating valve 410 for temperature regulation. In the helium compression circulation module 4, closing the temperature bypass regulating valve 410 and opening the liquid hydrogen circuit valve 413 allows the helium gas circulation to reach the liquid hydrogen temperature range of 20K; closing the liquid hydrogen circuit valve 413 and opening the temperature bypass regulating valve 410 allows the helium gas circulation to reach the liquid nitrogen temperature range of 80K; by adjusting the temperature bypass regulating valve 410 and the liquid hydrogen circuit valve 413, the helium gas circulation can be adjusted between the liquid nitrogen and liquid hydrogen temperature ranges of 80-20K.

[0064] The helium secondary regenerator 401, helium primary regenerator 402, liquid nitrogen precooling tank 408, liquid nitrogen coil 409, temperature bypass regulating valve 410, liquid hydrogen precooling tank 411, liquid hydrogen coil 412, and liquid hydrogen loop valve 413 in the helium compression cycle module 4 are all housed within the helium compression cycle module Dewar 400 and are subjected to vacuum insulation. The liquid nitrogen precooling tank 408 employs multi-layer insulation and discharges the nitrogen produced by evaporation through the nitrogen vent valve 415. The liquid hydrogen precooling tank 411 also employs multi-layer insulation and discharges the nitrogen produced by evaporation through the hydrogen vent valve 414.

[0065] Both the helium primary regenerator 402 and the helium secondary regenerator 401 in the helium compression cycle module 4 adopt spiral sleeve heat exchangers. The inside of the tube is hot fluid, and the outside of the tube is cold fluid.

[0066] Example 3

[0067] The difference between the above-mentioned embodiments 1 and 2 is that, in this embodiment, a plurality of low-temperature helium circulation modules 3, a plurality of helium compression circulation modules 4, or a combination of the low-temperature helium circulation module 3 and the helium compression circulation module 4 are used to jointly provide helium for the low-temperature test module 2 to meet the test requirements of the multi-stream heat exchanger. The heat exchange test unit 201 in the low-temperature test module 2 can be replaced by various forms of primary and secondary hydrogen conversion low-temperature heat exchangers, including multi-stream heat exchangers. The configurations of other components and the operation modes are consistent with those of the above-mentioned embodiments 1 and 2, and will not be described here.

[0068] The above-mentioned embodiments have described the technical solutions and beneficial effects of the present application in detail. It should be understood that the above-mentioned embodiments are only specific embodiments of the present application and are not used to limit the present application. Any modification, supplement and equivalent replacement made within the principle range of the present application should be included in the protection range of the present application.

Claims

1. A high flow hydrogen heat exchanger flow heat transfer and catalytic conversion test apparatus for testing a heat exchanger test unit (201), characterized by, The application relates to a hydrogen precooling and para-hydrogen measurement module (1), a low-temperature test module (2) and a low-temperature circulation module; wherein the low-temperature circulation module adopts at least one low-temperature helium circulation module (3) and / or at least one helium compression circulation module (4). The hydrogen precooling and para-hydrogen measurement module (1) provides high-flow hydrogen for the low-temperature test module (2) through a connecting pipeline and measures the para-hydrogen concentration of backflow; the low-temperature helium circulation module (3) and / or the helium compression circulation module (4) provide the low-temperature test module (2) with high-flow helium cold sources required by a heat exchange test unit (201) through a connecting pipeline; the heat exchange test unit (201) is detachably arranged in a low-temperature test module Dewar (200) through a VCR joint (202) and is subjected to vacuum heat insulation treatment in the low-temperature test module Dewar (200); A temperature sensor is arranged near each VCR joint (202) to measure the temperature of the cold and hot fluid inlets and outlets of the heat exchange test unit (201); meanwhile, a branch is led out near each VCR joint (202) to connect a pressure sensor outside the low-temperature test module Dewar (200) to measure the pressure of the cold and hot fluid inlets and outlets of the heat exchange test unit (201); The heat exchange test unit (201) is filled with normal-para hydrogen conversion catalyst in the flow channel of the hot fluid side, and the hydrogen gas is subjected to a continuous catalytic conversion flow heat exchange process in the flow channel; the cold fluid side of the heat exchange test unit (201) is connected with the low-temperature helium circulation module (3) and / or the helium compression circulation module (4); temperature measuring points are arranged on the outer wall and the fluid wall of the heat exchange test unit (201) to measure the wall temperature and thus to calculate the fluid temperature distribution. The hydrogen precooling and para-hydrogen measurement module (1) comprises a hydrogen precooling and para-hydrogen measurement module Dewar (100), a high-pressure hydrogen cylinder (101), a hydrogen flowmeter (102), a hydrogen flow regulating valve (103), a hydrogen heater (104), a liquid nitrogen precooling tank (105), a liquid nitrogen coil (106), a temperature bypass regulating valve (107), a nitrogen evacuation valve (108), a hydrogen evacuation valve (109), a measurement regulating valve (110), a gas chromatograph (111) and a measurement evacuation valve (112); 2. The high flow hydrogen heat exchanger flow heat transfer and catalytic conversion test apparatus of claim 1, wherein, The high-pressure hydrogen cylinder (101) is sequentially connected with the hydrogen flowmeter (102) and the hydrogen flow regulating valve (103) and is divided into two branches, one of which sequentially flows through the hot fluid side of the hydrogen heater (104) and the liquid nitrogen coil (106) in the liquid nitrogen precooling tank (105); the other branch flows through the temperature bypass regulating valve (107) and is combined with the hydrogen flowing out of the liquid nitrogen coil (106) to perform temperature regulation; and then the hydrogen flows into the hot fluid channel of the heat exchange test unit (201) in the low-temperature test module (2). ​ The hydrogen gas flowing out of the heat transfer test unit (201) of the low-temperature test module (2) enters the hydrogen gas precooling and para-hydrogen measurement module (1), flows through the cold fluid side of the hydrogen gas reheater (104), and is safely discharged through the hydrogen gas evacuation valve (109); a branch is introduced before the hydrogen gas evacuation valve (109) and is sequentially connected with the measurement and adjustment valve (110), the gas chromatograph (111), and the measurement evacuation valve (112) and is safely discharged.

3. The high flow hydrogen heat exchanger flow heat transfer and catalytic conversion test apparatus of claim 2, wherein, The hydrogen gas reheater (104), the liquid nitrogen precooling tank (105), the liquid nitrogen coil (106), and the temperature bypass adjustment valve (107) are all placed in the hydrogen gas precooling and para-hydrogen measurement module Dewar (100) and are subjected to vacuum heat insulation treatment. The liquid nitrogen precooling tank (105) is multi-layer insulated and discharges nitrogen gas generated by evaporation through the nitrogen gas evacuation valve (108).

4. The high flow hydrogen heat exchanger flow heat transfer and catalytic conversion test apparatus of claim 1, wherein, The low-temperature helium circulation module (3) comprises a low-temperature helium circulation module Dewar (300), a high-pressure helium tank (301), a helium tank air supply valve (302), a circulation filling valve (303), a precooling tank, a liquid nitrogen coil (305), a temperature bypass adjustment valve (306), a low-temperature fan (307), and a nitrogen gas evacuation valve (308). The high-flow helium flowing out of the cold fluid channel of the heat transfer test unit (201) of the low-temperature test module (2) enters the low-temperature helium circulation module (3), sequentially flows through the liquid nitrogen coil (305) in the precooling tank and the low-temperature fan (307), and then flows into the cold fluid channel of the heat transfer test unit (201) of the low-temperature test module (2) to form a circulation loop. The helium tank air supply valve (302), the high-pressure helium tank (301), and the circulation filling valve (303) are sequentially connected and then connected to the helium circulation loop before helium flows into the precooling tank; a branch is introduced before helium enters the precooling tank, flows through the temperature bypass adjustment valve (306), and then merges with the helium flowing out of the liquid nitrogen coil (305) to adjust the temperature.

5. The high flow hydrogen heat exchanger flow heat transfer and catalytic conversion test apparatus of claim 4, wherein, The precooling tank, the liquid nitrogen coil (305), the temperature bypass adjustment valve (306), and the low-temperature fan (307) are all placed in the low-temperature helium circulation module Dewar (300) and are subjected to vacuum heat insulation treatment. The precooling tank is multi-layer insulated and discharges nitrogen gas generated by evaporation through the nitrogen gas evacuation valve (308).

6. The large-flow hydrogen heat exchanger flow heat transfer and catalytic conversion test device according to claim 5, wherein the precooling tank is a liquid nitrogen precooling tank (304), a liquid hydrogen precooling tank, or a combination of the two.

7. The high flow hydrogen heat exchanger flow heat transfer and catalytic conversion test apparatus according to claim 1, wherein, The helium gas compression circulation module (4) comprises a helium gas compression circulation module Dewar (400), a helium gas secondary reheater (401), a helium gas primary reheater (402), a compressor (403), a high-pressure helium tank (404), a pressure reducing valve (405), a helium tank air supply valve (406), a helium pressure stabilizing tank (407), a liquid nitrogen precooling tank (408), a liquid nitrogen coil (409), a temperature bypass adjustment valve (410), a liquid hydrogen precooling tank (411), a liquid hydrogen coil (412), a liquid hydrogen loop valve (413), a hydrogen gas evacuation valve (414), and a nitrogen gas evacuation valve (415). The high-flow helium gas flowing out of the cold fluid passage of the heat exchange test unit (201) in the low-temperature test module (2) enters the helium gas compression circulation module (4); the high-flow helium gas flows through the cold fluid passage of the helium secondary heat regenerator (401), the cold fluid passage of the helium primary heat regenerator (402), the compressor (403), the helium pressure stabilizing tank (407), the hot fluid passage of the helium primary heat regenerator (402), the liquid nitrogen coil (409) in the liquid nitrogen precooling tank (408), the hot fluid passage of the helium secondary heat regenerator (401), the liquid hydrogen coil (412) in the liquid hydrogen precooling tank (411), and the liquid hydrogen circuit valve (413) in sequence, and then flows into the cold fluid passage of the heat exchange test unit (201) in the low-temperature test module (2), thereby forming a circulation loop. The helium tank air supply valve (406), the high-pressure helium tank (404), the pressure reducing valve (405), and the helium pressure stabilizing tank (407) are connected in sequence to maintain the circulation helium pressure; another branch is introduced after the helium gas leaves the liquid nitrogen coil (409) in the liquid nitrogen precooling tank (408), and is connected to the liquid hydrogen circuit valve (413) through the temperature bypass adjusting valve (410), thereby performing temperature adjustment.

8. The high flow hydrogen heat exchanger flow heat transfer and catalytic conversion test apparatus of claim 7, wherein, The helium secondary heat regenerator (401), the helium primary heat regenerator (402), the liquid nitrogen precooling tank (408), the liquid nitrogen coil (409), the temperature bypass adjusting valve (410), the liquid hydrogen precooling tank (411), the liquid hydrogen coil (412), and the liquid hydrogen circuit valve (413) are all placed in the helium gas compression circulation module Dewar (400) and are subjected to vacuum heat insulation treatment. The liquid nitrogen precooling tank (408) is provided with multilayer insulation and is provided with a nitrogen exhaust valve (415) to exhaust the nitrogen gas generated by evaporation; the liquid hydrogen precooling tank (411) is provided with multilayer insulation and is provided with a hydrogen exhaust valve (414) to exhaust the nitrogen gas generated by evaporation.

9. The high flow hydrogen heat exchanger flow heat transfer and catalytic conversion test apparatus of claim 1, wherein, When the heat exchange test unit (201) in the low-temperature test module (2) is a multiple-flow primary-tertiary hydrogen conversion low-temperature heat exchanger, multiple low-temperature helium circulation modules (3), multiple helium gas compression circulation modules (4), or a combination of the low-temperature helium circulation module (3) and the helium gas compression circulation module (4) are used to provide helium gas for the low-temperature test module (2).

Images