Ultralow-pressure gas constant-pressure source device

Abstract

The utility model discloses an ultra-low pressure gas constant pressure source device which comprises a manual pressure regulating valve close to a gas inlet, and the output end of the manual pressure regulating valve is sequentially provided with a high-speed electric proportional valve, an overflow valve and a buffer tank in the gas conveying direction. Two branches are arranged on the pipeline at the output end of the buffer tank, and the tail ends of the branches are respectively connected with a pipeline starting point pressure transmitter and a pipeline terminal point pressure transmitter. The device has the beneficial effects that the device which is stable and adjustable in pressure and can reliably run for a long time is provided for measurement and production equipment of the ultra-low pressure ejector, and is used as an ancillary facility of the measurement and production equipment; according to the system, the pressure of the inlet of the ejector is automatically constant under different input pressures and different flows, and a guarantee is provided for testing and continuous production of the ultra-low-pressure gas ejector.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of gas delivery, specifically relates to a kind of ultra-low pressure gas constant voltage source device. BACKGROUND

[0002] In domestic gas / natural gas generator, the conventional pressure reducing valve reduces the gas or natural gas from pipeline pressure (usually low pressure, after the gas of pressure reduction) to 2-5KPa low pressure state for engine use. Due to this low pressure range, the pressure loss in pipeline is large, causing the fluctuation and instability of gas flow. In practical application, the engine controller adjusts the injection pulse width of injector (i.e. the length of time of each injection) to keep the engine speed constant. This compensation method can adapt to pressure fluctuation, and ensure the stable operation of engine.

[0003] However, in the development, testing and production process of injector, the inlet pressure of injector must be kept constant to ensure the accuracy and consistency of test results. But after the gas is reduced to 2-5KPa low pressure by the pressure reducing valve, due to the pressure loss in pipeline, the gas pressure will fluctuate. This fluctuation will cause the instability of gas flow of injector, affect the performance of engine, and may cause speed fluctuation, even the phenomenon of difficult start or unstable operation. And when the gas flow is large, the pressure loss is more significant, which will cause the inconsistency of gas flow input to injector, so that the engine controller is difficult to accurately maintain constant speed when adjusting injection pulse width. Therefore, a special device is needed to provide stable pressure source. SUMMARY

[0004] The purpose of the utility model is to solve the above problems and provide a kind of ultra-low pressure gas constant voltage source device, see the elaboration below.

[0005] To achieve the above object, the utility model provides the following technical scheme:

[0006] The utility model provides a kind of ultra-low pressure gas constant voltage source device, including the manual pressure regulating valve close to gas inlet, the output of manual pressure regulating valve is sequentially provided with high-speed electric proportional valve, overflow valve, buffer tank along gas delivery direction;

[0007] The pipeline of the output of buffer tank is provided with two branches, the branch end is connected with pipeline starting point pressure transmitter and pipeline terminal point pressure transmitter respectively, wherein the pipeline starting point pressure transmitter is close to the buffer tank outlet and is provided, and the pipeline terminal point pressure transmitter is close to the injector inlet and is provided;It also includes controller, the high-speed electric proportional valve, the pipeline starting point pressure transmitter and the pipeline terminal point pressure transmitter are electrically connected with the controller.

[0008] Further, the buffer tank is provided with a buffer tank pressure transmitter, which is electrically connected with the controller, for detecting the gas pressure in the buffer tank.

[0009] Further, the pressure at the outlet of the manual pressure regulating valve is 0.06-0.2 MPa.

[0010] Further, the pipeline starting point pressure transmitter and the pipeline ending point pressure transmitter are both provided with an ejector pulse signal electrically connected with the controller, for high-speed sampling of the pipeline pressure at the pipeline starting point pressure transmitter position and the pipeline ending point pressure transmitter position.

[0011] Further, the overflow valve is connected with a recovery tank.

[0012] Further, the buffer tank is provided with a safety valve.

[0013] Further, the outlet of the buffer tank is provided with a one-way valve.

[0014] Beneficial effects are that:

[0015] The device can realize 1-10 KPa gas pressure supply, and is used as an auxiliary facility of measuring and production equipment.

[0016] The system realizes the practicability of the super-low pressure gas injector measuring and production equipment, and can independently produce and match various single equipment and automatic production lines. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0018] Figure 1 is a pipeline principle diagram of the present application.

[0019] The reference signs are explained as follows:

[0020] 1, manual pressure regulating valve; 2, high-speed electric proportional valve; 3, overflow valve; 4, buffer tank; 5, buffer tank pressure transmitter; 6, pipeline starting point pressure transmitter; 7, pipeline ending point pressure transmitter; 8, controller; 9, ejector pulse signal. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the utility model more clear, the technical scheme of the utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without making creative efforts belong to the scope protected by the utility model.

[0022] First embodiment:

[0023] Referring to Figure 1 The utility model provides a kind of ultra-low pressure gas constant voltage source device, including the manual pressure regulating valve 1 close to gas entrance, the output of manual pressure regulating valve 1 is sequentially provided with high-speed electrical proportional valve 2, overflow valve 3, buffer tank 4 along gas delivery direction, overflow valve 3 ensures that the pressure in system does not exceed safety limit, avoid system failure by overflow;Overflow valve 3 end is connected with recovery tank;Further, the outlet of buffer tank 4 is equipped with check valve, and its tank body high end is equipped with safety valve, the pipeline on the output of buffer tank 4 is equipped with two branches, the branch end is connected with pipeline starting point pressure transmitter 6 and pipeline terminal point pressure transmitter 7 respectively, wherein pipeline starting point pressure transmitter 6 is close to buffer tank 4 outlet setting, pipeline terminal point pressure transmitter 7 is close to injector inlet setting;

[0024] It further includes controller 8, high-speed electrical proportional valve 2, pipeline starting point pressure transmitter 6 and pipeline terminal point pressure transmitter 7 are electrically connected with controller 8, and the electric control equipment on system is accurately controlled by controller 8;

[0025] The gas pressure of air pressure system is first reduced by manual pressure regulating valve 1, and then the back pressure is accurately adjusted after high-speed electrical proportional valve 2;When pressure is too high, gas is discharged through overflow valve 3 outlet, thereby releasing the pressure that is too high, and gas can be stored by buffer tank 4, in preferred embodiment, buffer tank 4 pressure transmitter is provided on buffer tank 4, buffer tank 4 pressure transmitter is electrically connected with controller 8, to detect the gas pressure in buffer tank 4, the gas pressure in buffer tank 4 is detected by buffer tank 4 pressure transmitter, to obtain basic pressure;Because the length of pipeline distance is different after discharge, because pipeline starting point pressure transmitter 6 is close to the outlet position of buffer tank 4, and pipeline terminal point pressure transmitter 7 is close to the inlet of injector;The outlet pressure of buffer tank 4 and the inlet pressure of injector are detected by pipeline starting point pressure transmitter 6 and pipeline terminal point pressure transmitter 7 respectively, so as to obtain the pressure loss of output pipeline, and high-speed electrical proportional valve 2 is feedback adjusted by the feedback of pipeline starting point pressure transmitter 6 and pipeline terminal point pressure transmitter 7;

[0026] In the use of the device, the controller 8 can realize the overall control of the system. In the specific control, the pressure P is set, the base pressure P1 is obtained through the buffer tank 4 pressure transmitter, the outlet pressure P2 is obtained through the pipeline end pressure transmitter 7, and when the injector is opened, the pressure of the pipeline start pressure transmitter 6 and the pipeline end pressure transmitter 7 will decrease. At the moment when the injector is opened, the pipeline end pressure transmitter 7 closer to the injector will cause the pipeline pressure to decrease faster, and the pipeline start pressure transmitter 6 far away from the injector will decrease slowly, so the pressure at the pipeline end pressure transmitter 7 will decrease faster than that at the pipeline start pressure transmitter 6. Through the sampling of the pressure data, the respective troughs are obtained through the trough detection, and the time difference between the two troughs is calculated to obtain T1.

[0027] The controller 8 controls the proportional valve through a closed-loop control algorithm:

[0028]

[0029] Ut-the output value of the control loop, as the control amount of the high-speed electric proportional valve 2;

[0030] Kp-proportional gain, used for base control amount calculation;

[0031] Ki-integral time constant, used for eliminating cumulative error;

[0032] Kd-differential time constant, used for system sensitivity adjustment.

[0033] The error input of each section of the closed-loop algorithm uses different current values to calculate the error, and the control amount of the high-speed electric proportional valve 2 is obtained after summation.

[0034] The second embodiment is different from the first embodiment in that:

[0035] The pressure at the outlet of the manual pressure regulating valve 1 is 0.06-0.2 MPa. In the use of the device, the manual pressure regulating valve 1 is opened, the pressure in the pipeline is reduced to 0.1 MPa through the manual pressure regulating valve 1, and the overall pressure in the pipeline is stabilized, and then the high-speed electric proportional valve 2 is used for precise adjustment of the rear-end pressure.

[0036] The injector pulse signal is arranged at the pipeline start point pressure transmitter 6 and the pipeline end point pressure transmitter 7, and is used for high-speed sampling of the pipeline pressure at the pipeline start point pressure transmitter 6 and the pipeline end point pressure transmitter 7 positions, and the injector pulse signal is used as a synchronization signal to improve the accuracy of the change value of the pressure at the pipeline start point pressure transmitter 6 and the pipeline end point pressure transmitter 7, and the output pipeline start point and end point pressures are high-speed collected to calculate the time difference of the pressure drop, thereby assisting the sensitivity adjustment.

[0037] The above merely describes the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, and all of them should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A constant pressure source device for ultra-low pressure gas, comprising a manually adjustable pressure valve (1) near the gas inlet, characterized in that: The output end of the manual pressure regulating valve (1) is sequentially provided with a high-speed electric proportional valve (2), an overflow valve (3), and a buffer tank (4) along the gas conveying direction; The output end of the buffer tank (4) has two branches on the pipeline. The ends of the branches are respectively connected to the pipeline start pressure transmitter (6) and the pipeline end pressure transmitter (7). The pipeline start pressure transmitter (6) is located near the outlet of the buffer tank (4), and the pipeline end pressure transmitter (7) is located near the injector inlet. It also includes a controller (8), and the high-speed electric proportional valve (2), the pipeline starting pressure transmitter (6) and the pipeline ending pressure transmitter (7) are all electrically connected to the controller (8).

2. The ultra-low pressure gas constant pressure source device according to claim 1, characterized in that: The buffer tank (4) is equipped with a buffer tank (4) pressure transmitter.

3. The ultra-low pressure gas constant pressure source device according to claim 2, characterized in that: The pressure transmitter of the buffer tank (4) is electrically connected to the controller (8) to detect the gas pressure inside the buffer tank (4).

4. The ultra-low pressure gas constant pressure source device according to claim 1, characterized in that: The pressure at the outlet of the manual pressure regulating valve (1) is 0.06-0.2 MPa.

5. The ultra-low pressure gas constant pressure source device according to claim 1, characterized in that: Both the pipeline starting pressure transmitter (6) and the pipeline ending pressure transmitter (7) are equipped with injector pulse signals electrically connected to the controller (8) for high-speed sampling of the pipeline pressure at the positions of the pipeline starting pressure transmitter (6) and the pipeline ending pressure transmitter (7).

6. The ultra-low pressure gas constant pressure source device according to claim 3, characterized in that: The overflow valve (3) is connected to a recovery tank at its end.

7. The ultra-low pressure gas constant pressure source device according to claim 1, characterized in that: The buffer tank (4) is equipped with a safety valve.

8. The ultra-low pressure gas constant pressure source device according to claim 1, characterized in that: The buffer tank (4) is equipped with a one-way valve at its outlet.

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