Double-area valve type gas fuel generator set control device

Abstract

The utility model discloses a double-area valve type gas fuel generator set control device which comprises a gas fuel inlet pipe, an air inlet pipe and a mixed gas inlet pipe, the gas fuel inlet pipe is communicated with one gas inlet of a mixer, and the air inlet pipe is communicated with the other gas inlet of the mixer. A gas outlet of the mixer is communicated with a fuel inlet of the engine through a mixed gas inlet pipe; a first area valve is arranged on the gas fuel inlet pipe, and a second area valve is arranged on the mixed gas inlet pipe. Under the same flow speed, the gas flow and the effective flow area of the valve form a linear relation, and the air quantity and the gas fuel quantity can be accurately controlled; and accurate combustion is realized. And the flow area can be increased in proportion by adjusting the size to adapt to engines with different displacements.

Description

Technical Field

[0001] The utility model relates to a gas fuel generator set, in particular to a double-area valve type gas fuel generator set control device. Background Art

[0002] In the special operating environment of gas-fired internal combustion generator sets, very high requirements are placed on the safe, reliable and stable operation of gas-fired generators. Due to the large changes in gas concentration and pressure, the difficulty of controlling the air / gas ratio of the engine is increased, and the difficulty of controlling the stability and disturbance of the gas-fired generator set is also increased, which has a particularly large impact on the engine speed. When the gas-fired generator set is connected to the grid for power generation, the power generation fluctuation of the unit is also quite large. When the power is small, it is very likely to cause a reverse power trip. Therefore, the speed control system of the gas-fired generator set is particularly high, and a speed control system with strong reliability, stability and anti-interference needs to be designed to adapt to the control of the gas-fired generator set.

[0003] The current gas internal combustion engines are simply modified from diesel engines, and the control system mainly uses engine management systems from foreign companies such as Woodward and Heinzmann to control the generator set. Therefore, the core technology of gas internal combustion power generation has not yet been mastered, and it is difficult to achieve accurate control of steady-state speed, generator frequency and air / fuel ratio. Utility Model Content

[0004] The utility model aims to provide a double-area valve type gas fuel generator set control device, which can accurately control the amount of air and gas fuel.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A dual-area valve type gas fuel generator control device includes a gas fuel intake pipe, an air intake pipe and a mixed gas intake pipe, wherein the gas fuel intake pipe is connected to one intake port of a mixer, and the air intake pipe is connected to another intake port of the mixer; the outlet of the mixer is connected to the fuel inlet of the engine through the mixed gas intake pipe; a first area valve is provided on the gas fuel intake pipe, and a second area valve is provided on the mixed gas intake pipe. An area valve is a valve with a continuously variable valve port area, such as a commonly used throttle valve, EGR valve, etc.

[0007] In the aforementioned dual-area valve type gas fuel generator set control device, a first temperature / pressure sensor is arranged upstream of the first area valve on the gas fuel intake pipe, and a second temperature / pressure sensor is arranged downstream of the first area valve on the gas fuel intake pipe; a third temperature / pressure sensor is arranged upstream of the second area valve on the mixed gas intake pipe, and a fourth temperature / pressure sensor is arranged downstream of the second area valve on the mixed gas intake pipe.

[0008] In the aforementioned dual-area valve type gas fuel generator set control device, the first area valve and the second area valve both have a DC motor and a position sensor. The DC motor is used to control the opening of the first area valve and the second area valve, and the position sensor is used to detect the opening of the first area valve and the second area valve.

[0009] The control method of the dual-area valve gas fuel generator set control device described above includes the following contents: by collecting the intake end temperature and pressure of the first area valve and the second area valve, the exhaust end temperature and pressure, the inlet and outlet pressure ratio and the flow area, the gas fuel flow rate and the air flow rate are calculated, and by adjusting the opening of the first area valve and the second area valve, the gas fuel flow rate and the air flow rate are adjusted to achieve control of the engine fuel amount.

[0010] In the control method of the aforementioned dual-area valve type gas fuel generator control device, the flow rates of the first area valve and the second area valve are calculated using the following formula:

[0011]

[0012] Where Aeff represents the effective flow area of ​​the gas; Mdot represents the gas flow rate; P1 represents the pressure at the inlet of the small hole; P2 represents the pressure at the outlet of the small hole; T0 represents the gas temperature.

[0013] The control method of the aforementioned dual-area valve type gas fuel generator set control device also includes the following content: controlling the rotation speed of the generator set by adjusting the air volume, gas fuel volume and ignition angle.

[0014] The control method of the aforementioned dual-area valve type gas fuel generator set control device also includes the following content: using a partition control method to control the speed of the generator set, when the speed deviation is within a certain range, the mixture adjustment is mainly used, and when the speed deviation is within another range, the ignition angle adjustment is mainly used.

[0015] Compared with the prior art, the utility model has a linear relationship between the gas flow rate and the effective flow area of ​​the valve at the same flow rate, which can accurately control the amount of air and gas fuel and achieve precise combustion. The flow area can be increased proportionally by adjusting the size to adapt to engines of different displacements. The flow area of ​​the gas fuel far exceeds the nozzle hole of the nozzle, which is conducive to the discharge of gas impurities. The process is simple, cleanable, and has good pollution resistance. The continuous flow fuel supply method has small temperature and pressure fluctuations of the gas fuel during use, and the air-fuel ratio of the engine is stable, which is conducive to reducing pollutant emissions. For low-pressure pipeline gas, there is no need to use a pressurizing device. The system structure is compact, low cost, and high reliability. The speed control accuracy is high by combining air volume adjustment and ignition angle adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the principle of an embodiment of the utility model;

[0017] Figure 2 is a schematic diagram for controlling the opening of the first area valve and the second area valve according to the target flow rate;

[0018] Figure 3 It is a schematic diagram of controlling the speed of the generator set by adjusting the amount of air, fuel and ignition angle.

[0019] Figure markings: 1-first temperature / pressure sensor, 2-first area valve, 3-second temperature / pressure sensor, 4-gas fuel intake pipe, 5-mixer, 6-third temperature / pressure sensor, 7-second area valve, 8-fourth temperature / pressure sensor, 9-engine, 10-air intake pipe, 11-mixed gas intake pipe.

[0020] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods. DETAILED DESCRIPTION

[0021] Embodiment 1 of the utility model: A dual-area valve type gas fuel generator set control device, comprising a gas fuel intake pipe 4, an air intake pipe 10 and a mixed gas intake pipe 11, the gas fuel intake pipe 4 is connected to one air inlet of the mixer 5, and the air intake pipe 10 is connected to the other air inlet of the mixer 5; the air outlet of the mixer 5 is connected to the fuel inlet of the engine 9 through the mixed gas intake pipe 11; a first area valve 2 is arranged on the gas fuel intake pipe 4, and a second area valve 7 is arranged on the mixed gas intake pipe 11.

[0022] A first temperature / pressure sensor 1 is provided upstream of the first area valve 2 on the gas fuel intake pipe 4, and a second temperature / pressure sensor 3 is provided downstream of the first area valve 2 on the gas fuel intake pipe 4; a third temperature / pressure sensor 6 is provided upstream of the second area valve 7 on the mixed gas intake pipe 11, and a fourth temperature / pressure sensor 8 is provided downstream of the second area valve 7 on the mixed gas intake pipe 11. Both the first area valve 2 and the second area valve 7 have a DC motor and a position sensor, the DC motor is used to control the opening of the first area valve 2 and the second area valve 7, and the position sensor is used to detect the opening of the first area valve 2 and the second area valve 7.

[0023] A control method for a dual-area valve type gas fuel generator set control device includes the following contents: by collecting the intake end temperature and pressure of the first area valve 2 and the second area valve 7, the exhaust end temperature and pressure, the inlet and outlet pressure ratio and the flow area, the gas fuel flow rate and the air flow rate are calculated, and by adjusting the opening of the first area valve 2 and the second area valve 7, the gas fuel flow rate and the air flow rate are adjusted to achieve control of the fuel amount of the engine 9.

[0024] The flow rates of the first area valve 2 and the second area valve 7 are calculated using the following formula:

[0025]

[0026] Where Aeff represents the effective flow area of ​​the gas; Mdot represents the gas flow rate; P1 represents the pressure at the inlet of the small hole; P2 represents the pressure at the outlet of the small hole; T0 represents the gas temperature.

[0027] The speed of the generator set is controlled by adjusting the amount of air, gas fuel and ignition angle.

[0028] The speed of the generator set is controlled by using a partition control method, such as Figure 3 As shown in the figure, when the deviation between the target speed and the actual speed is within a certain range, the intake volume is mainly adjusted, the mixed gas volume is adjusted by PID, and the ignition angle remains unchanged. When the speed deviation exceeds this range, the speed is adjusted by adjusting the ignition angle, and the intake volume is not adjusted significantly.

[0029] The working principle of an embodiment of the utility model is: the fuel amount and fresh air amount of the gas fuel engine are accurately controlled by two area valves. The flow area of ​​the area valve is accurately controlled by a DC motor and a position sensor, and the gear / valve stem structure reaches a micron-level matching clearance, which can effectively seal the gas. At the same time, when the pressure at the inlet and outlet ends meets the critical pressure difference, and the input fuel temperature and pressure are stable, the valve port flow area and flow rate meet a linear relationship. By collecting the temperature, pressure, inlet and outlet pressure ratio and flow area of ​​the inlet and exhaust ends, the current gas fuel and fresh air flow rates are accurately calculated to achieve adaptive control of the engine fuel amount.

Claims

1. A dual-area valve type gas fuel generator set control device, characterized in that: The invention comprises a gas fuel intake pipe (4), an air intake pipe (10) and a mixed gas intake pipe (11); the gas fuel intake pipe (4) is connected to one intake port of a mixer (5), and the air intake pipe (10) is connected to the other intake port of the mixer (5); the gas outlet of the mixer (5) is connected to the fuel inlet of the engine (9) through the mixed gas intake pipe (11); a first area valve (2) is provided on the gas fuel intake pipe (4), and a second area valve (7) is provided on the mixed gas intake pipe (11).

2. A dual-area valve type gas fuel generator set control device according to claim 1, characterized in that: A first temperature / pressure sensor (1) is provided upstream of a first area valve (2) on a gas fuel intake pipe (4), and a second temperature / pressure sensor (3) is provided downstream of the first area valve (2) on the gas fuel intake pipe (4); a third temperature / pressure sensor (6) is provided upstream of a second area valve (7) on a mixed gas intake pipe (11), and a fourth temperature / pressure sensor (8) is provided downstream of the second area valve (7) on the mixed gas intake pipe (11).

3. A dual-area valve type gas fuel generator set control device according to claim 2, characterized in that: The first area valve (2) and the second area valve (7) both have a DC motor and a position sensor. The DC motor is used to control the opening of the first area valve (2) and the second area valve (7), and the position sensor is used to detect the opening of the first area valve (2) and the second area valve (7).

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