[0026] See figure 1 , 2 , A performance failure test device for cryogenic valves for LNG, including a medium gas supply system, a closed box and a cryogenic valve test station.
[0027] The cryogenic valve test station is located in a closed box, and a drive mechanism and the cryogenic valve to be tested connected to the cryogenic valve test station are installed. The drive mechanism is composed of a torque and displacement sensor and a servo motor connected to it. No less than three sets of nitrogen concentration sensors and temperature sensors are installed on the upper, middle and bottom of one side wall of the enclosed box, and an air outlet pipe is installed on the other side wall.
[0028] The medium gas source supply system includes a liquid nitrogen storage tank, a liquid nitrogen supply main pipe and a multi-branch distribution pipe, wherein the inlet of the liquid nitrogen supply main pipe is connected to the liquid nitrogen storage tank and a manual valve is installed on it, The outlet of the liquid nitrogen supply main pipe is connected to a multi-branch distribution pipe, each branch distribution pipe is equipped with a valve and a solenoid valve, and the outlet of the solenoid valve is connected to the cryogenic valve to be tested through an air inlet pipe. The raw material gas supply main pipe and the multi-branch distribution pipe are pipes composed of metal pipes with a diameter of less than or equal to 200 mm. The inlet pipe connected to the outlet of the solenoid valve is a pipe composed of a metal pipe with a diameter of ≤150 mm.
[0029] The solenoid valve on each branch distribution pipe, the nitrogen concentration sensor and temperature sensor on the closed box, and the drive mechanism on the cryogenic valve test station are all connected to the control host PLC through a data/signal transmission line, and the solenoid valve passes the data / The signal transmission line is connected with the control host PLC to control the opening and closing time of the solenoid valve, and achieve the purpose of controlling the flow and working time of the supply medium.
[0030] The above-mentioned test method for the performance failure test device of the cryogenic valve for LNG includes the following steps:
[0031] ①Install the cryogenic valve to be tested, the nitrogen concentration sensor and the temperature sensor: place one or more cryogenic valves to be tested on the cryogenic valve test station, put the test position of the cryogenic valve in the closed box, and place the cryogenic valve to be tested The air inlet is connected to the corresponding LNG gas supply pipe, the air outlet is connected to the corresponding outlet pipe on the side wall of the closed box, and a nitrogen concentration sensor and a temperature sensor are installed on the upper, middle and lower parts of one side wall of the closed box respectively;
[0032] ②Start the medium gas source gas supply system to supply the internal medium liquid nitrogen to the cryogenic valve to be tested to simulate the actual operating state;
[0033] ③Initial temperature change and corresponding time test: At the beginning of the test, first turn on the solenoid valve, observe the release of liquid nitrogen in the closed box, and correspond with the outer surface temperature of the closed box collected by the temperature sensor and transmitted to the control host PLC to obtain a The series of temperature sensors collect the temperature and time changes of the points, and determine the time when the external temperature of the cryogenic valve under test is stable under the state of maximum flow, nominal flow and 5-30% of the nominal flow;
[0034] ④ Carry out the maximum flow performance, air tightness and torque change test:
[0035] According to the corresponding relationship between flow, temperature and time obtained in step ③, the maximum flow Q 1 As an example, determine the corresponding solenoid valve opening time t 1 , And use this as the operating time for cyclic testing. First, set the solenoid valve opening time to t through the control host PLC 1 , Working frequency n 1 , Initial torque performance k 11 , Initial nitrogen concentration k 12 , When the opening time reaches the utilization t 1 After that, the control host PLC closes the solenoid valve, the drive mechanism in the low-temperature valve test station moves, executes the valve opening and closing actions, records the operating frequency once, torque performance, and calculates and analyzes the arithmetic average of the 3 groups of nitrogen concentrations. Repeat the above steps, when the working frequency is n 1 If it reaches 10,000 times or the performance of stress and torque changes by 10% or the nitrogen concentration changes by 5%, the test ends;
[0036] ⑤Test the working performance, air tightness and torque change of the nominal flow:
[0037] According to the corresponding relationship between flow, temperature and time obtained in step ③, use the nominal flow Q 2 As an example, determine the corresponding solenoid valve opening time t 2 , And use this as the operating time for cyclic testing. First, set the solenoid valve opening time to t through the control host PLC 2 , Working frequency n 2 , Initial torque performance k 21 , Initial nitrogen concentration k 22 , When the opening time reaches the utilization t 1 After that, the control host PLC closes the solenoid valve, the drive mechanism in the low-temperature valve test station moves, executes the valve opening and closing actions, records the operating frequency once, torque performance, and calculates and analyzes the arithmetic average of the 3 groups of nitrogen concentrations. Repeat the above steps, when the working frequency is n 2 If it reaches 10,000 times or the performance of stress and torque changes by 10% or the nitrogen concentration changes by 5%, the test ends;
[0038] ⑥Test performance, air tightness and torque change at 20% of the nominal flow rate:
[0039] According to the corresponding relationship between flow, temperature and time obtained in step ③, use 20% of nominal flow Q 3 As an example, determine the corresponding solenoid valve opening time t 3 , And use this as the operating time for cyclic testing. First, set the solenoid valve opening time to t through the control host PLC 3 , Working frequency n 3 , Initial torque performance k 31 , Initial nitrogen concentration k 32 , When the opening time reaches the utilization t 3 After that, the control host PLC closes the solenoid valve, the drive mechanism in the low-temperature valve test station moves, executes the valve opening and closing actions, records the operating frequency once, torque performance, and calculates and analyzes the arithmetic average of the 3 groups of nitrogen concentrations. Repeat the above steps, when the working frequency is n 3 If it reaches 10,000 times or the performance of stress and torque changes by 10% or the nitrogen concentration changes by 5%, the test ends;
[0040] ⑦Get quantified adaptability and its performance change curve:
[0041] Taking the number of operations under the air-tight performance condition as the probability density, the life reliability of the cryogenic valve is evaluated, and the curve of different flow and torque changes is established to comprehensively evaluate the performance failure trend of the cryogenic valve.
[0042] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. And variations, the scope of the present invention is defined by the appended claims and their equivalents.
