Method for improving liquefied gas filling precision

Abstract

The invention relates to the technical field of liquefied gas filling, and discloses a method for improving liquefied gas filling precision, which comprises a liquefied gas pipeline and is characterized in that the surface of the liquefied gas pipeline is connected with a plurality of groups of liquefied gas rubber pipes, and the other ends of the liquefied gas rubber pipes are connected to one end of an electromagnetic valve arranged on a filling scale; the other end of the electromagnetic valve is connected with the other set of liquefied gas rubber pipes, the other ends of the liquefied gas rubber pipes are connected with inflation guns, the inflation guns are clamped on the surface of a steel cylinder angle valve, a mechanical arm is arranged on the side wall of the filling scale, a mechanical claw is arranged on one side of the mechanical arm and connected with a steel cylinder valve hand wheel, and a stepping motor is arranged at the top end of the mechanical claw. According to real-time weighing feedback and inflation feedback, the drift diameter of the angle valve of the steel cylinder is adjusted according to the weighing change rate or the filling rate of the steel cylinder, the opening degree of the angle valve of the steel cylinder is adjusted step by step through the mechanical claw, accurate filling is ensured, finally the set target weight is stopped, the liquefied gas filling precision is improved, the flow speed is gradually slowed down, and therefore the steel cylinder body is stabilized; the water hammer effect is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of liquefied gas filling, and in particular to a method for improving the liquefied gas filling accuracy. Background Art

[0002] As an efficient and clean energy source, liquefied gas is widely used. Every day, gas companies need to fill a large number of cylinders with electronic filling scales. At liquefied gas stations, multiple electronic filling scales are connected to the liquefied gas main pipeline through hoses. Usually, multiple electronic filling scales are used to inflate cylinders at the same time. When the liquefied gas filled by one of the electronic filling scales reaches the set weight, the solenoid valve of the electronic filling scale will automatically close, thereby cutting off the liquefied gas. When a solenoid valve is closed, the flow of the entire pipeline will suddenly decrease, which will cause a short-term flow or pressure fluctuation. This is called the "water hammer effect", which will affect the measurement accuracy of other electronic filling scales, especially for the automatic filling production line of the turntable that rotates and fills at the same time. In addition, when filling the cylinder with liquefied gas, due to the high pressure of the liquefied gas, the real-time weight of the cylinder measured by the electronic filling scale during filling includes the impact force of the liquefied gas on the cylinder, which will cause weighing errors; After searching, the Chinese patent with application number 202410487615.5 discloses a fluid tank parameter optimization control method and system, which maps valve control parameters in the total valve network, screens the total valve network performance based on a reasonable reference, and dynamically adjusts the screened total valve network performance to generate several test total valve network performances, and performs valve damage assessment, and screens the test total valve network performance based on the valve damage assessment, and updates it into the network performance library. The above technical solution of the present invention not only realizes the automatic adjustment of the opening of different valves, but also realizes the optimization of control parameters, ensuring the accuracy of valve control; The above technology has the following defects: when the existing liquefied gas electronic filling scale is filling the cylinder, it is necessary to set an early valve closing amount according to the set filling weight. However, due to the unstable flow rate of the liquefied gas, the pressure will change, and other filling scales will cause the pipeline water hammer effect when closing the solenoid valve, the filling accuracy is not high. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a method for improving the filling accuracy of liquefied gas, which solves the problems raised in the above-mentioned background technology.

[0004] To solve the above technical problems, according to one aspect of the present invention, more specifically, a method for improving the filling accuracy of liquefied gas comprises the following steps: S1. Place the steel cylinder on the filling scale, connect the liquefied gas pipeline through the liquefied gas hose, and deliver liquefied gas to the steel cylinder body; S2. Real-time monitoring of the weight of the steel cylinder by a filling scale. When the weight of the liquefied gas filled in the steel cylinder and the filling rate reach 96% of the preset filling weight or the filling rate of the steel cylinder reaches 96% of the preset filling value, the critical signal is transmitted to the angle calculation model; S3, the angle calculation model calculates the closing speed of the cylinder angle valve according to the weight data transmitted by the filling scale, and transmits the data to the instruction module; S4, the instruction module controls the stepper motor through the execution module, and drives the mechanical claw to rotate the cylinder valve handwheel through the stepper motor to gradually close the cylinder angle valve; S5. After the cylinder angle valve is closed, the solenoid valve is used to close the liquefied gas hose channel, and the cylinder is filled with liquefied gas.

[0005] Furthermore, the calculation formula for the diameter of the cylinder angle valve in the angle calculation model is: ; In the formula, The diameter required to be adjusted for the cylinder angle valve; The weight of liquefied gas monitored by the filling scale; is the preset filling weight; It is the critical value of the liquefied gas weight, and the critical value is 96% of the preset weight; when When it reaches 96% of the preset weight, is 100%; At 100% of the preset weight, 0%, that is, the cylinder angle valve is completely closed.

[0006] Furthermore, the calculation formula for the filling rate of the liquefied gas in the cylinder is: ; Where, L is the filling rate inside the cylinder; V is the effective volume inside the cylinder; is the gas phase space inside the cylinder; d is the density of the saturated liquid inside the cylinder; P is the filling pressure of the liquefied gas, which is 0.8~1.2MPa; It is the inflation pressure after the liquefied gas bus is automatically switched, and the value is 1.1MPa; is the standard atmospheric pressure, which is 0.1MPa; It is the volume inside the cylinder.

[0007] Furthermore, when the cylinder angle valve is adjusted, if the weight of the liquefied gas monitored by the filling scale reaches 99% of the preset filling weight, the reduction ratio of the cylinder angle valve is reduced to 50% to avoid closing the angle valve prematurely.

[0008] Furthermore, the accuracy of each step of rotation of the stepper motor is set to 0.9°, ensuring that the accuracy of the diameter adjustment of the cylinder angle valve is consistent with the filling accuracy. When the liquefied gas weight monitored by the filling scale is equal to the preset filling weight, the stepper motor immediately closes the cylinder angle valve and stops filling.

[0009] Furthermore, the surface of the liquefied gas pipeline is connected to multiple groups of liquefied gas hoses, the other end of the liquefied gas hose is connected to one end of the solenoid valve provided on the filling scale, the other end of the solenoid valve is connected to another group of liquefied gas hoses, the other end of the liquefied gas hose is connected to an inflation gun, and the inflation gun is clamped on the surface of the cylinder angle valve. A manipulator is provided on the side wall of the filling scale, a mechanical claw is provided on one side of the manipulator, and the mechanical claw is connected to the handwheel of the cylinder valve, and a stepping motor is provided on the top of the mechanical claw.

[0010] The beneficial effects of the method for improving the filling accuracy of liquefied gas of the present invention are as follows: 1. When the cylinder body is conveying liquefied gas, the present invention monitors the weight of the cylinder body or the filling rate of the cylinder in real time through a filling scale during liquefied gas conveyance, calculates the diameter of the cylinder angle valve that needs to be reduced through an angle calculation model, and controls the stepper motor through an instruction module and an execution module. The stepper motor drives the mechanical claw to drive the cylinder valve handwheel to rotate, gradually reducing the diameter of the cylinder angle valve until the angle valve diameter is closed, and the cylinder liquefied gas filling is completed. The present invention adjusts the angle valve diameter through the weighing change rate based on real-time weighing feedback to ensure that the flow rate is gradually slowed down and the water hammer effect is reduced.

[0011] 2. The present invention gradually adjusts the opening of the cylinder angle valve through mechanical claws to ensure accurate filling, and finally stops at the set target weight, thereby increasing the accuracy of liquefied gas filling. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0013] Figure 1 It is a structural schematic diagram of the present invention.

[0014] Figure 2 It is a schematic structural diagram of the liquefied gas filling device of the present invention.

[0015] The accompanying drawings are marked as follows: 1. liquefied gas pipeline; 2. liquefied gas hose; 3. filling scale; 4. manipulator; 5. stepper motor; 6. mechanical claw; 7. cylinder angle valve. DETAILED DESCRIPTION

[0016] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0017] like Figure 1 According to one aspect of the present invention, a method for improving liquefied gas filling accuracy is provided, comprising the following steps: S1, place the steel cylinder on the weighing platform of the filling scale 3, connect the liquefied gas pipeline 1 through the liquefied gas hose 2, and transport the liquefied gas to the steel cylinder body; S2, monitoring the weight of the steel cylinder in real time through the filling scale 3, when the weight of the liquefied gas filled in the steel cylinder and the filling rate reach 96% of the preset filling weight or the filling rate of the steel cylinder reaches 96% of the preset filling value, starting to transmit the critical signal to the angle calculation model; S3, the angle calculation model calculates the closing speed of the cylinder angle valve 7 according to the weight data transmitted by the filling scale 3, and transmits the data to the instruction module; S4, the instruction module controls the stepper motor 5 through the execution module, and the stepper motor 5 drives the mechanical claw 6 to rotate the cylinder valve handwheel, gradually closing the cylinder angle valve 7; S5. After the cylinder angle valve 7 is closed, the solenoid valve is used to close the liquefied gas hose 2 channel, and the cylinder is filled with liquefied gas.

[0018] In this embodiment, the calculation formula of the diameter of the cylinder angle valve 7 in the angle calculation model is: ; In the formula, The diameter required to be adjusted for the cylinder angle valve 7; The weight of liquefied gas monitored by the filling scale 3; is the preset filling weight; It is the critical value of the liquefied gas weight, and the critical value is 96% of the preset weight; when When it reaches 96% of the preset weight, is 100%; At 100% of the preset weight, 0%, that is, the cylinder angle valve 7 is completely closed.

[0019] In this embodiment, the calculation formula for the filling rate of the liquefied gas in the steel cylinder is: ;

[0020] Where, L is the filling rate inside the cylinder; V is the effective volume inside the cylinder; is the gas phase space inside the cylinder (when inputting liquefied gas, the flow meter is used to monitor the amount of liquefied gas passing through the cross-sectional area in real time within a certain period of time, thereby measuring the liquefied gas flow rate and estimating the remaining amount or real-time flow rate of liquefied gas in the cylinder, so as to measure the gas phase space inside the cylinder); d is the density of the saturated liquid inside the cylinder; P is the inflation pressure of the liquefied gas, which is 0.8~1.2MPa; It is the inflation pressure after the liquefied gas bus is automatically switched, and the value is 1.1MPa; is the standard atmospheric pressure, which is 0.1MPa; is the volume inside the cylinder; When the filling rate of liquefied gas in the cylinder is at 96%, the critical signal is again transmitted to the angle calculation model, making the filling accuracy of this application more accurate.

[0021] In this embodiment, when the cylinder angle valve 7 is adjusted, if the liquefied gas weight monitored by the filling scale 3 reaches 99% of the preset filling weight, the reduction angle valve ratio of the cylinder angle valve 7 is reduced to 50% to avoid premature closing of the angle valve.

[0022] In this embodiment, the accuracy of each step of rotation of the stepper motor 5 is set to 0.9°, ensuring that the accuracy of the diameter adjustment of the cylinder angle valve 7 is consistent with the filling accuracy. When the liquefied gas weight monitored by the filling scale 3 is equal to the preset filling weight, the stepper motor 5 immediately closes the cylinder angle valve 7 and stops filling.

[0023] In this embodiment, a plurality of groups of liquefied gas hoses 2 are connected to the surface of the liquefied gas pipeline 1, the other end of the liquefied gas hose 2 is connected to one end of the solenoid valve provided on the filling scale 3, the other end of the solenoid valve is connected to another group of liquefied gas hoses 2, the other end of the liquefied gas hose 2 is connected to an inflation gun, and the inflation gun is clamped on the surface of the cylinder angle valve 7, a manipulator 4 is provided on the side wall of the filling scale 3, a mechanical claw 6 is provided on one side of the manipulator 4, and the mechanical claw 6 is connected to the handwheel of the cylinder valve, and a stepping motor 5 is provided on the top of the mechanical claw 6.

[0024] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention also fall within the protection scope of the present invention.

Claims

1. A method for improving the filling accuracy of liquefied gas, characterized by: The following steps are involved: S1. Place the steel cylinder on the weighing platform of the filling scale (3), connect the liquefied gas pipeline (1) via the liquefied gas hose (2), and deliver liquefied gas to the steel cylinder body; S2, monitoring the weight of the cylinder in real time through the filling scale (3), and when the weight of the liquefied gas filled in the cylinder and the filling rate reach 96% of the preset filling weight or the filling rate of the cylinder reaches 96% of the preset filling value, starting to transmit the critical signal to the angle calculation model; S3, the angle calculation model calculates the closing speed of the cylinder angle valve (7) according to the weight data transmitted by the filling scale (3), and transmits the data to the instruction module; S4, the command module controls the stepper motor (5) through the execution module, and the stepper motor (5) drives the mechanical claw (6) to rotate the cylinder valve handwheel, gradually closing the cylinder angle valve (7); S5. After the cylinder angle valve (7) is closed, the solenoid valve is used to close the liquefied gas hose (2) channel, and the cylinder is filled with liquefied gas.

2. A method for improving liquefied gas filling accuracy according to claim 1, characterized in that: The calculation formula for the diameter of the cylinder angle valve (7) in the angle calculation model is: ; In the formula, The diameter required to be adjusted for the cylinder angle valve (7); The weight of liquefied gas monitored by the filling scale (3); is the preset filling weight; It is the critical value of the liquefied gas weight, and the critical value is 96% of the preset weight; when When it reaches 96% of the preset weight, is 100%; At 100% of the preset weight, 0%, that is, the cylinder angle valve (7) is completely closed.

3. A method for improving liquefied gas filling accuracy according to claim 1, characterized in that: The calculation formula for the filling rate of the liquefied gas in the cylinder is: ； Where, L is the filling rate inside the cylinder; V is the effective volume inside the cylinder; is the gas phase space inside the cylinder; d is the density of the saturated liquid inside the cylinder; P is the filling pressure of the liquefied gas, which is 0.8~1.2MPa; It is the inflation pressure after the liquefied gas bus is automatically switched, and the value is 1.1MPa; is the standard atmospheric pressure, which is 0.1MPa; It is the volume inside the cylinder.

4. A method for improving liquefied gas filling accuracy according to claim 1, characterized in that: When the cylinder angle valve (7) is adjusted, if the weight of the liquefied gas monitored by the filling scale (3) reaches 99% of the preset filling weight, the reduction angle valve ratio of the cylinder angle valve (7) is reduced to 50% to avoid premature closing of the angle valve.

5. A method for improving liquefied gas filling accuracy according to claim 1, characterized in that: The stepper motor (5) has a rotation accuracy of 0.9° per step, ensuring that the diameter adjustment accuracy of the cylinder angle valve (7) is consistent with the filling accuracy. When the liquefied gas weight monitored by the filling scale (3) is equal to the preset filling weight, the stepper motor (5) immediately closes the cylinder angle valve (7) to stop filling.

6. A method for improving liquefied gas filling accuracy according to claim 1, characterized in that: The surface of the liquefied gas pipeline (1) is connected to a plurality of groups of liquefied gas hoses (2), the other end of the liquefied gas hoses (2) is connected to one end of a solenoid valve provided on a filling scale (3), the other end of the solenoid valve is connected to another group of liquefied gas hoses (2), the other end of the liquefied gas hoses (2) is connected to an air charging gun, and the air charging gun is clamped on the surface of a steel cylinder angle valve (7), the side wall of the filling scale (3) is provided with a manipulator (4), one side of the manipulator (4) is provided with a mechanical claw (6), and the mechanical claw (6) is connected to a hand wheel of the steel cylinder valve, and a stepping motor (5) is provided at the top of the mechanical claw (6).

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