Performance failure test method and test device for LNG air temperature type gasifier

Abstract

A performance failure test method and test device for LNG air temperature vaporizer, comprising the following steps: ①test air temperature vaporizer sample installation; ②air temperature vaporizer test internal medium connection supply; ③air temperature vaporizer external environment record; ④air temperature vaporizer sample initial temperature change and corresponding time test; ⑤minimum temperature stress, strain and working frequency change cycle test; ⑥medium temperature stress, strain and working frequency change cycle test; ⑦greater temperature stress, strain and working frequency change cycle test; ⑧quantitative stress, strain and working frequency curve; the method and device can ensure that the LNG air temperature vaporizer is determined and quantitatively evaluated under the premise of normal work. The working condition environment of low temperature and accelerated running frequency is provided, the engineering working condition is redesigned, the process is scientific, the test time is short, the test sequence before and after is reasonable, the test medium is saved, and the test is safe and reliable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure vessel detection, in particular to a performance failure test method and test device for an LNG air-cooled vaporizer. BACKGROUND

[0002] As a clean energy, liquefied natural gas (LNG) is natural gas compressed and cooled to a temperature below its boiling point (-161.5℃) to become a liquid, its main component is methane, and it is transported by special ship or oil tank truck, and gasified when used.

[0003] With the increasing development of China's economy and technology, and the increasing environmental protection awareness, natural gas as a clean energy has been widely used, and LNG point supply facilities have been widely promoted. At present, there is no clear performance evaluation and failure test method for the long-term quality reliability problem of the air-cooled vaporizer in the LNG point supply facility. The technical method and experimental device for measuring and evaluating the ability and performance change of the air-cooled vaporizer under long-term low-temperature operating conditions are still in the blank stage.

[0004] Through patent retrieval, the following comparison files are found:

[0005] The LNG ship storage tank insulation layer cold detection test device and method (CN201810680036.7) discloses a LNG ship storage tank insulation layer cold detection test device and method. The LNG ship storage tank insulation layer cold detection test device comprises: a low-temperature medium container for storing low-temperature medium, the boiling point of the low-temperature medium being ≤163℃; a first branch, the inlet end of which is in communication with the low-temperature medium container, and the outlet end thereof being used for communication with the LNG storage tank; a gasifier and a first regulating valve are arranged on the first branch; the gasifier is used for gasifying the liquid-phase low-temperature medium into gas-phase low-temperature medium; the first regulating valve is in communication with the output end of the gasifier, and is used for controlling the transmission of the gas-phase low-temperature medium circulating in the first branch; a second branch, the inlet end of which is in communication with the low-temperature medium container, and the outlet end thereof being used for communication with the LNG storage tank, so as to transmit the liquid-phase low-temperature medium to the LNG storage tank; a second regulating valve is arranged on the second branch, and is used for controlling the transmission of the liquid-phase low-temperature medium circulating in the second branch. It is beneficial for the technical personnel to effectively detect the insulation layer of the LNG storage tank.

[0006] After analysis, the LNG storage tank in the above-mentioned published patent belongs to a ship equipment, which is quite different from the LNG air-cooled vaporizer in the present application, and the detection content, detection method and detection equipment are all different, so the above-mentioned patent does not affect the novelty of the present application. SUMMARY

[0007] The present application aims to overcome the deficiencies of the prior art, and provides a performance failure test method and test device for an LNG air temperature vaporizer, which can ensure the determination and quantitative evaluation of the applicable performance of the LNG air temperature vaporizer under normal working conditions. The working conditions are redesigned to provide low-temperature and accelerated running frequency conditions, so as to achieve scientific process, short test time, reasonable test sequence, saving of test medium, and safe and reliable purposes.

[0008] A performance failure test method for an LNG air temperature vaporizer, comprising the following steps:

[0009] ① Test air temperature vaporizer sample installation: one or more groups of air temperature vaporizers to be tested are placed on the test stations of the test device, the test stations are placed in the protective isolation box, the air inlets of the air temperature vaporizers to be tested are connected to the corresponding air inlets, and the air outlets are in the form of a diffuser outlet;

[0010] ② Internal medium connection and supply for air temperature vaporizer test: connect the gas supply system to simulate the actual running state, and use liquid nitrogen as the internal medium for testing the device;

[0011] ③ Air temperature vaporizer external environment recording: record the external environmental conditions at the beginning of the experiment, including air pressure, temperature, humidity and other parameters;

[0012] ④ Air temperature vaporizer sample initial temperature change and corresponding time test: at the beginning of the test, first open the electromagnetic valve, observe the diffused liquid nitrogen of the device, and correspond to the surface temperature of the test sample collected by the temperature sensor, digital-to-analog conversion module, control host, data / signal transmission line, to obtain a series of test point temperature and time changes;

[0013] ⑤ Perform minimum temperature stress, strain and working frequency change cycle test: according to the temperature and time law obtained from the above test, select the temperature difference between the environment and the surface of the test sample not greater than 100℃, and the corresponding electromagnetic valve opening time as the running working time; when the working time is exceeded, the electromagnetic valve is closed by the control host, and the fan is started to adjust to the maximum wind speed, and after the gasification of the medium in the pipe is completed, the temperature of the test point is restored, and the above steps are repeated;

[0014] ⑥ Perform medium temperature stress, strain and working frequency change cycle test: according to the temperature and time law obtained from the above test, select the temperature difference between the environment and the surface of the test sample in the range of 100℃-120℃, and the corresponding electromagnetic valve opening time as the running working time; when the working time is exceeded, the electromagnetic valve is closed by the control host, and the fan is started to adjust to the maximum wind speed, and after the gasification of the medium in the pipe is completed, the temperature of the test point is restored, and the above steps are repeated;

[0015] ⑦Carrying out stress, strain and working frequency change cycle test of larger temperature: according to the temperature and time rule obtained in the above test, when the temperature difference between the ambient temperature and the surface temperature of the test sample is greater than 120 DEG C, the corresponding electromagnetic valve opening time is selected as the running working time; when the working time is exceeded, the electromagnetic valve is closed by using the control host, and the fan is started and adjusted to the maximum wind speed; after the gasification of the medium in the pipe is completed and the temperature of the test point is restored, the above steps are repeated.

[0016] ⑧Obtaining the quantized stress, strain and working frequency curve: drawing the curve with stress, strain and gasification frequency as the coordinate axis, evaluating the failure performance change, and comprehensively evaluating the LNG air temperature type gasifier capacity under the operating condition of low temperature fuel gas;

[0017] Moreover, the test device comprises a medium gas source supply system, a test station, an accelerated gasification system and a protection isolation box.

[0018] Moreover, the medium gas source supply system is composed of a raw material gas supply main pipe and a distribution pipe, a pipeline manual valve, an electromagnetic valve, a branch distribution pipe and a branch collecting pipe, and is sequentially connected to the raw material gas supply device, the pipeline manual valve and then converged to the raw material gas supply main pipe; after the electromagnetic valve distribution pipe, the branch distribution pipe is connected to the branch collecting pipe and the air temperature type gasifier test piece; wherein: the stress / strain sensor and the temperature sensor need to be installed at the connection between the branch distribution pipe and the branch collecting pipe and the elbow of the air temperature type gasifier test piece; the stress / strain sensor and the temperature sensor are connected to the digital-to-analog conversion module of the control host through the data / signal transmission line, for bidirectional / one-way transmission of the voltage or current signals and control instructions of the stress, strain and temperature of the test piece part, and for completion of the control of the opening and closing time of the electromagnetic valve, and for control of the flow and frequency of the supplied medium when simulating the working condition of the air temperature type gasifier test piece.

[0019] Moreover, the test station is composed of a branch collecting pipe and a distribution pipe, an air temperature type gasifier test piece, a stress / strain sensor, a temperature sensor, a digital-to-analog conversion module, a control host and a data / signal transmission line, which are comprehensively composed of a key parameter test system for performance failure of the air temperature type gasifier; the stress / strain sensor and the temperature sensor are installed at the connection between the branch distribution pipe and the branch collecting pipe, for testing the stress and strain degradation of different pipe diameters in the air temperature type gasifier test piece under low temperature variable load; the stress / strain sensor and the temperature sensor are installed at the elbow of the air temperature type gasifier, for testing the stress and strain degradation of the non-straight pipe section in the air temperature type gasifier test piece under low temperature variable load; both are connected to the digital-to-analog conversion module of the control host through the data / signal transmission line, for transmission of the signals and control instructions.

[0020] Moreover, the acceleration gasification system comprises a digital-analog conversion module, a control host, a data / signal transmission line and a fan, which are connected with the digital-analog conversion module of the control host through the data / signal transmission line, and the rotation speed of the fan is controlled, and different air flow rates are carried out at the test station to realize medium gasification acceleration.

[0021] Moreover, the raw material supply main pipe and the distribution pipe and the branch pipe are pipelines composed of metal pipes with a diameter of not less than 50 mm, and the branch distribution pipe is a pipeline composed of metal pipes with a diameter of not more than 25 mm.

[0022] Moreover, the length of the gasification finned tube of the air temperature type gasifier test piece is not less than 300 mm.

[0023] The advantages and technical effects of the present application are:

[0024] 1. The test method provided by the present application adjusts the operating condition of the to-be-tested air temperature type gasifier test piece, tests the mechanical properties of the key parts of the valve under high temperature difference, medium temperature difference and low temperature difference, analyzes a series of normal working states corresponding to the limit conditions, quantitatively evaluates the failure performance change, comprehensively evaluates the ability of the LNG air temperature type gasifier to adapt to the low-temperature gas operating condition, and measures the adaptability of the to-be-tested air temperature type gasifier test piece to different operating conditions and the performance change trend.

[0025] 2. The test method provided by the present application takes the opening time of the electromagnetic valve as a state option, constitutes a process of the test, and finally completes the information collection and statistics of specific numerical values of process stress and strain, temperature and test times through the control host.

[0026] 3. The test device provided by the present application can realize the output of different operating frequency conditions under different test conditions, measure the performance and failure state under various operating gasification frequency conditions according to the test requirements or actual working environment, and quantitatively measure the performance change curve of the air temperature type gasifier. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram of the performance failure test device of the LNG air temperature type gasifier.

[0028] 1-control host; 2-pipeline manual valve; 3-electromagnetic valve; 4-branch distribution pipe; 5-temperature sensor, stress and strain sensor; 6-fan; 7-protection isolation box; 8-test piece; 9-diffusion outlet. DETAILED DESCRIPTION

[0029] In order to further understand the content, characteristics and effects of the present application, the following examples are given below, and the details are described below with reference to the drawings. It should be noted that the present examples are descriptive, not limiting, and the protection scope of the present application cannot be limited thereby.

[0030] A performance failure test method of an LNG air temperature type vaporizer is performed according to the following steps:

[0031] ① Test air temperature type vaporizer sample installation

[0032] One or more groups of to-be-tested air temperature type vaporizers are placed on the test station, the test station is positioned in the protection isolation box 7, the gas inlet of the to-be-tested air temperature type vaporizer is connected to the corresponding gas inlet pipe, and the gas outlet is a diffusion outlet 9 in a diffusion shape.

[0033] ② Internal medium connection supply for air temperature type vaporizer test

[0034] The gas source gas supply system is connected, the actual running state is simulated, and liquid nitrogen is used as the internal medium for testing of the device.

[0035] ③ Air temperature type vaporizer external environment recording

[0036] The external environmental conditions at the beginning of the experiment are recorded, including parameters such as air pressure, temperature, humidity, etc.

[0037] ④ Open the electromagnetic valve 3, observe the device diffusion liquid nitrogen situation, test the initial temperature change and corresponding time of the air temperature type vaporizer sample

[0038] At the beginning of the test, the electromagnetic valve is first opened, the device diffusion liquid nitrogen situation is observed, the outer surface temperature of the test sample is collected through the temperature sensor, the digital-to-analog conversion module, the control host 1, and the data / signal transmission line, and a series of test point temperature and time changes are obtained.

[0039] ⑤ Perform minimum temperature stress, strain and working frequency change cycle test

[0040] According to the temperature and time law obtained in the above experiment, combined with the ambient temperature, the corresponding internal and external environmental temperature difference is calculated, and according to the temperature and time corresponding relationship obtained in step 4, taking the temperature difference T1 as an example, the corresponding electromagnetic valve opening time t1 is determined, and this is used as the running working time to perform a cycle test. First, set the electromagnetic valve opening time to t1, the working frequency number n1, the stress initial performance k1, and the strain initial performance k2 through the control host, when the opening time reaches t1, the control host closes the electromagnetic valve, and starts the fan 6, adjusts to the maximum wind speed, waits for the gasification of the medium in the pipe to be completed, and records the working frequency 1 time after the temperature difference of the test point returns to T1, and repeats the above steps. When the working frequency number n1 reaches 100000 times or the stress and strain performance changes by 10% or the test sample fails, the test is ended.

[0041] ⑥Perform stress, strain and working frequency change cycle test at medium temperature

[0042] According to the temperature and time law obtained in the above experiment, combined with the ambient temperature, the corresponding internal and external environmental temperature difference is calculated, and according to the temperature and time corresponding relationship obtained in step 4, taking the temperature difference T1 as an example, the corresponding electromagnetic valve opening time t1 is determined, and this is used as the running working time to perform a cycle test. First, set the electromagnetic valve opening time to t1, the working frequency number n1, the stress initial performance k1, and the strain initial performance k2 through the control host, when the opening time reaches t1, the control host closes the electromagnetic valve, and starts the fan 6, adjusts to the maximum wind speed, waits for the gasification of the medium in the pipe to be completed, and records the working frequency 1 time after the temperature difference of the test point returns to T1, and repeats the above steps. When the working frequency number n1 reaches 100000 times or the stress and strain performance changes by 10% or the test sample fails, the test is ended.

[0043] ⑦Perform stress, strain and working frequency change cycle test at medium temperature

[0044] According to the temperature and time law obtained in the above experiment, combined with the ambient temperature, the corresponding internal and external environmental temperature difference is calculated, and according to the temperature and time corresponding relationship obtained in step 4, taking the temperature difference T1 as an example, the corresponding electromagnetic valve opening time t1 is determined, and this is used as the running working time to perform a cycle test. First, set the electromagnetic valve opening time to t1, the working frequency number n1, the stress initial performance k1, and the strain initial performance k2 through the control host, when the opening time reaches t1, the control host closes the electromagnetic valve, and starts the fan 6, adjusts to the maximum wind speed, waits for the gasification of the medium in the pipe to be completed, and records the working frequency 1 time after the temperature difference of the test point returns to T1, and repeats the above steps. When the working frequency number n1 reaches 100000 times or the stress and strain performance changes by 10% or the test sample fails, the test is ended.

[0045] ⑧ Get the stress, strain and working frequency curve

[0046] Draw the curve with stress, strain and gasification frequency as the coordinate axis, evaluate the failure performance change, and comprehensively evaluate the capacity of the LNG air temperature type gasifier under the operating condition of low temperature gas.

[0047] Referring to the accompanying drawings Figure 1 : The test device used in the performance failure test method of the LNG air temperature type gasifier, comprising a medium gas source supply system, a test station, an accelerated gasification system and a protection isolation box;

[0048] The medium gas source supply system is composed of a raw material gas supply main pipe and a distribution pipe, a pipeline manual valve 2, an electromagnetic valve, a branch distribution pipe 4 and a branch collecting pipe, which are sequentially connected to the raw material gas supply device, the pipeline manual valve and then merged into the raw material gas supply main pipe; after the electromagnetic valve and the distribution pipe, the branch distribution pipe is connected to the branch collecting pipe and the air temperature type gasifier test piece 8; wherein: stress and strain sensors and temperature sensors 5 need to be installed at the connection between the branch distribution pipe and the branch collecting pipe and the elbow of the air temperature type gasifier test piece, which are connected to the digital-to-analog conversion module of the control host through the data / signal transmission line, realizing the bidirectional / one-way transmission of voltage or current signals and control instructions of the test piece part, completing the control of the opening and closing time of the electromagnetic valve, simulating the working conditions of the air temperature type gasifier test piece, and achieving the purpose of controlling the flow and frequency of the supplied medium.

[0049] The test station is a key parameter test system for the performance failure of the air temperature type gasifier, which is composed of a branch collecting pipe and a distribution pipe, an air temperature type gasifier test piece, stress and strain sensors, temperature sensors, a digital-to-analog conversion module, a control host and a data / signal transmission line, stress and strain sensors and temperature sensors are installed at the connection between the branch distribution pipe and the branch collecting pipe, which are used to test the stress and strain degradation of different pipe diameters in the air temperature type gasifier test piece under low temperature variable load; stress and strain sensors and temperature sensors are installed at the elbow of the air temperature type gasifier, which are used to test the stress and strain degradation of the non-straight pipe section in the air temperature type gasifier test piece under low temperature variable load, which are connected to the digital-to-analog conversion module of the control host through the data / signal transmission line, realizing the transmission of signals and control instructions.

[0050] The accelerated gasification system includes a digital-to-analog conversion module, a control host, a data / signal transmission line and a fan, which are connected to the digital-to-analog conversion module of the control host through the data / signal transmission line, realizing the regulation and control of the fan speed, achieving different airflow speeds at the test station and thus realizing the purpose of medium gasification acceleration.

[0051] The above-mentioned raw material gas supply main pipe and distribution pipe, as well as the branch collecting pipe, are composed of metal pipes with a diameter not less than 50mm, and the branch distribution pipe is composed of metal pipes with a diameter not greater than 25mm.

[0052] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since various modifications can be made by those skilled in the art, without departing from the spirit and scope of the application, which are defined by the appended claims and their equivalents.

[0053] It is to be understood that all the improvements and changes which come within the spirit of the application are protected by the following claims.

Claims

1. A performance failure test method for an LNG ambient temperature vaporizer, characterized in that, Includes the following steps: ① Installation of test air-temperature vaporizer samples: Place one or more sets of air-temperature vaporizers to be tested on the test station of the test device, place the test station in the protective isolation box, connect the air inlet of the air-temperature vaporizer to the corresponding air inlet pipe, and let the air outlet be in a venting state. ② Internal medium connection and supply for ambient temperature vaporizer test: Connect to the gas supply system to simulate actual operating conditions, and use liquid nitrogen as the internal medium for this device test. ③ Record the external environment of the ambient air vaporizer: Record the external environmental conditions at the beginning of the experiment, including air pressure, temperature and humidity parameters; ④ Initial temperature change and corresponding time test of ambient temperature vaporizer sample: At the beginning of the test, the solenoid valve was opened first to observe the release of liquid nitrogen by the device, and the temperature of the outer surface of the test sample was compared with the temperature sensor, digital-to-analog converter module, control host and data signal transmission line to obtain the temperature and time changes of a series of test points. ⑤ Conduct cyclic tests on stress, strain, and operating frequency changes at the lowest temperature: Based on the temperature and time patterns obtained from the above tests, select the solenoid valve opening time when the temperature difference between the ambient temperature and the surface temperature of the test sample is no more than 100℃ as the operating time; after the operating time is exceeded, use the control host to close the solenoid valve and start the fan, adjust it to the maximum wind speed, wait for the vaporization of the medium in the pipe to be completed, and wait for the temperature at the measuring point to recover, then repeat the above steps. ⑥ Conduct cyclic tests of stress, strain, and operating frequency changes at moderate temperatures: Based on the temperature and time patterns obtained from the above tests, select the solenoid valve opening time when the temperature difference between the ambient temperature and the surface temperature of the test sample is 100℃~120℃ as the operating time; after the operating time is exceeded, use the control host to close the solenoid valve and start the fan, adjust it to the maximum wind speed, wait for the vaporization of the medium in the pipe to be completed, and wait for the temperature at the measuring point to recover, then repeat the above steps; ⑦ Conduct cyclic tests on stress, strain, and operating frequency changes at large temperatures: Based on the temperature and time patterns obtained from the above tests, select the solenoid valve opening time when the temperature difference between the ambient temperature and the surface temperature of the test sample is greater than 120℃ as the operating time; after the operating time is exceeded, use the control host to close the solenoid valve and start the fan, adjust it to the maximum wind speed, wait for the vaporization of the medium in the pipe to be completed, and wait for the temperature at the measuring point to recover, then repeat the above steps; ⑧ Obtain quantified stress, strain, and operating frequency curves: Plot curves with stress, strain, and vaporization frequency as coordinate axes, evaluate the changes in failure performance, and comprehensively evaluate the ability of the LNG ambient temperature vaporizer to adapt to low-temperature gas operation conditions. The testing apparatus used in the above-mentioned LNG ambient temperature vaporizer performance failure test method includes a medium gas supply system, a test station, an accelerated vaporization system, and a protective isolation box; The medium gas supply system consists of a raw material gas supply main pipe and distribution pipe, manual valves, solenoid valves, branch distribution pipes and branch manifolds. These are sequentially connected to the raw material gas supply device and the manual valves before converging and connecting to the raw material gas supply main pipe. After passing through the solenoid valves and distribution pipes, the branch distribution pipes connect to the branch manifolds and the ambient air vaporizer test piece. Stress, strain, and temperature sensors are installed at the connections between the branch distribution pipes and the branch manifolds, and at the bends of the ambient air vaporizer test piece. These sensors are connected to the analog-to-digital converter module of the control host via data signal transmission lines. The bidirectional or unidirectional transmission of voltage or current signals of stress, strain, and temperature at the test piece location, along with control commands, controls the opening and closing times of the solenoid valves, simulating the working conditions of the ambient air vaporizer test piece and achieving the goal of controlling the flow rate and frequency of the supplied medium. The testing station is a key parameter testing system for the performance failure of an ambient air vaporizer, consisting of branch manifolds and distribution pipes, ambient air vaporizer test pieces, stress and strain sensors, temperature sensors, a digital-to-analog converter module, a control host, and data signal transmission lines. Stress, strain, and temperature sensors are installed at the connection between the branch distribution pipes and the branch manifolds to test the stress and strain degradation of different pipe diameters in the ambient air vaporizer test pieces under low-temperature variable loads. Stress, strain, and temperature sensors are installed on the bends of the ambient air vaporizer to test the stress and strain degradation of non-straight pipe sections in the ambient air vaporizer test pieces under low-temperature variable loads. All of these are connected to the digital-to-analog converter module of the control host via data signal transmission lines to realize the transmission of signals and control commands.

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