Control method and device for alloy tail gas engine

Abstract

The invention discloses a control method of an alloy tail gas engine, relates to the field of engine control, and solves the technical problems of controlling an operation mode and realizing automatic control of a special gas source type alloy tail gas engine. The method comprises the steps that firstly, the initial opening degree of an air valve, the initial opening degree of a gas valve, the initial opening degree of a throttle valve and the initial opening degree of a single-cylinder valve are executed to obtain a proper air-fuel ratio to normally start an engine; and secondly, the air-fuel ratio corresponding to the target power value is obtained, and when the air-fuel ratio is not located in the preset target air-fuel ratio range, an opening degree adjusting strategy is triggered to adjust the opening degree of the air valve and the opening degree of the gas valve. The invention further discloses a control device of the alloy tail gas engine. Automatic control over the air-fuel ratio and automatic control over the single-cylinder valve are achieved, and stable operation of the engine is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of engine control, and more particularly to a control method and device for an alloy exhaust gas engine. Background Art

[0002] Ferroalloy is an essential auxiliary material for steelmaking. A large amount of tail gas is generated during the smelting process. After the tail gas comes out of the electric furnace, it undergoes a water washing and purification process. The purified submerged arc furnace tail gas (also known as ferroalloy coal gas) contains combustible components such as CO, H2, and CH4. The main component is CO, which accounts for about 70% to 80% of the gas volume. It is a highly toxic combustible gas with a calorific value of (2100 to 2400) kcal / Nm 3 (10MJ / m 3 Its main components are: CO: 78%-85%, H2: 2%-8%, CO2: 2%-5%, and N2: 2%-6%. Industrially, CO is oxidized to CO2 at high temperatures in combustion furnaces, and the heat generated is used for power generation or heating, achieving energy recycling. Currently, its primary industrial application is grid-connected power generation. However, most existing alloy exhaust engines have a fixed air source ratio within the cylinder, making it impossible to effectively adjust the intake and combustion of alloy exhaust engines based on specific air sources. This results in low combustion efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a control method for an alloy exhaust gas engine in view of the deficiencies in the existing technology, so as to solve the technical problems of controlling the operation mode and realizing automatic control of the existing special gas source alloy exhaust gas engine.

[0004] The control method of an alloy exhaust engine according to the present invention comprises:

[0005] Step 1: setting the initial opening of the air valve, the initial opening of the gas valve, the initial opening of the throttle valve, and the initial opening of the single-cylinder valve, and executing the initial opening of the air valve, the initial opening of the gas valve, the initial opening of the throttle valve, and the initial opening of the single-cylinder valve to obtain a suitable air-fuel ratio to start the engine normally;

[0006] Step 2: Setting a target power value, obtaining an air-fuel ratio corresponding to the target power value, and triggering an opening adjustment strategy to adjust the opening of the air valve and the opening of the gas valve when the air-fuel ratio is not within a preset target air-fuel ratio range;

[0007] Step 3: obtaining the alloy tail gas source concentration, and triggering the gas source concentration adjustment strategy according to the alloy tail gas source concentration to achieve automatic control of the air-fuel ratio;

[0008] Step 4: Set the dead zone temperature range, obtain the average cylinder exhaust temperature of the engine, and trigger the cylinder exhaust temperature automatic adjustment strategy according to the average cylinder exhaust temperature of the engine and the dead zone temperature range.

[0009] As a further improvement, in step 2, the opening adjustment strategy is:

[0010] When the air-fuel ratio is greater than a maximum value of the target air-fuel ratio range, the opening of the air valve is reduced to a preset third air valve opening, and the opening of the gas valve is increased to a preset first gas valve opening;

[0011] When the air-fuel ratio is less than a minimum value of a target air-fuel ratio range, the opening of the air valve is increased to a first air valve opening, and the opening of the gas valve is decreased to a third gas valve opening.

[0012] Furthermore, when the air-fuel ratio is within the target air-fuel ratio range, the opening of the air valve is maintained at a preset second air valve opening, and the opening of the gas valve is maintained at a preset second gas valve opening.

[0013] Furthermore, in step three, the gas source concentration adjustment strategy is:

[0014] When the alloy tail gas source concentration is greater than a preset alloy tail gas source concentration standard value, the opening of the air valve is increased to a preset air valve third opening, and the opening of the gas valve is reduced to a preset gas valve first opening to reduce the alloy tail gas source concentration;

[0015] When the alloy tail gas source concentration is less than the alloy tail gas source concentration standard value, the opening of the air valve is reduced to the first air valve opening, and the opening of the gas valve is increased to the third gas valve opening to increase the alloy tail gas source concentration;

[0016] When the alloy tail gas source concentration is equal to the alloy tail gas source concentration standard value, the opening of the air valve is maintained at the second air valve opening, and the opening of the gas valve is maintained at the preset second gas valve opening.

[0017] Furthermore, in step 4, the cylinder exhaust temperature automatic adjustment strategy is:

[0018] When the average cylinder exhaust temperature is greater than the maximum value of the dead zone temperature range, reducing the opening of the single cylinder valve according to a preset first opening change rate and a preset first adjustment time so that the average cylinder exhaust temperature is less than or equal to the maximum value of the dead zone temperature range;

[0019] When the average cylinder exhaust temperature is less than the minimum value of the dead zone temperature range, the opening of the single cylinder valve is increased according to the preset second opening change rate and the preset second adjustment time so that the average cylinder exhaust temperature is greater than or equal to the minimum value of the dead zone temperature range.

[0020] Furthermore, the opening change rate is within a preset upper and lower limit range of the adjustment amount.

[0021] Furthermore, in step 1, the initial opening of the air valve is 20%-50% of the rated opening of the air valve; the initial opening of the gas valve is 20%-60% of the rated opening of the gas valve; the initial opening of the throttle valve is 20%-50% of the rated opening of the throttle valve; and the initial opening of the single-cylinder valve is 40%-60% of the rated opening of the single-cylinder valve.

[0022] A control device for an alloy exhaust engine, comprising:

[0023] An air supply module, for providing air to the cylinder;

[0024] A gas supply module, used for providing gas to the cylinder;

[0025] The ECU applies the above-mentioned control method of the alloy exhaust engine to control the air supply module and the gas supply module to adjust the amount of air and gas input into the cylinder.

[0026] As a further improvement, the air supply module includes an air filter, an air supercharger, an air intercooler and an air valve. The air inlet of the air filter is connected to the outside air, the air outlet of the air filter is connected to the air inlet of the air supercharger through a pipe, the air inlet of the air intercooler is connected to the air outlet of the air supercharger through a pipe, the air outlet of the air intercooler is connected to the air intake duct of the cylinder head through a pipe, and an air valve is installed on the pipe between the air outlet of the air intercooler and the air inlet of the cylinder head.

[0027] Furthermore, the gas supply module includes a gas valve, a gas supercharger, a gas intercooler and a throttle. The air inlet of the gas supercharger is connected to the gas input end through a pipe, the air inlet of the gas intercooler is connected to the air outlet of the gas supercharger through a pipe, and the air outlet of the gas intercooler is connected to the air intake duct of the cylinder head through a pipe. A gas valve is installed on the pipe connecting the air inlet of the gas supercharger and the gas input end, and a throttle and a single-cylinder valve are provided on the pipe connecting the gas intercooler and the air intake duct of the cylinder head.

[0028] Beneficial effects

[0029] The advantages of the present invention are:

[0030] The present invention executes the initial opening of the air valve, the initial opening of the gas valve, the initial opening of the throttle valve and the initial opening of the single-cylinder valve to obtain a suitable air-fuel ratio to start the engine normally; when the air-fuel ratio is not within a preset target air-fuel ratio range, the opening adjustment strategy is triggered to adjust the opening of the air valve and the opening of the gas valve; the gas source concentration adjustment strategy is triggered according to the alloy tail gas source concentration to achieve automatic control of the air-fuel ratio; the dead zone temperature range is set, the average cylinder exhaust temperature of the engine is obtained, and the cylinder exhaust temperature automatic adjustment strategy is triggered according to the average cylinder exhaust temperature of the engine and the dead zone temperature range, thereby achieving automatic control of the air-fuel ratio and automatic control of the single-cylinder valve, and ensuring stable operation of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of the control device of the alloy exhaust engine of the present invention.

[0032] Among them: 1-air filter, 2-air supercharger, 3-air intercooler, 4-air valve, 5-cylinder head, 6-gas valve, 7-gas supercharger, 8-gas intercooler, 9-throttle valve, 10-single cylinder valve. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the embodiments, but this does not constitute any limitation to the present invention. Any limited number of modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0034] See Figure 1 The present invention provides a control method for an alloy exhaust engine, the method comprising:

[0035] Step 1: Set the initial openings of air valve 4, gas valve 6, throttle valve 9, and cylinder valve 10. These settings are executed to achieve a suitable air-fuel ratio for engine startup. By controlling the appropriate air and gas volumes to achieve a suitable air-fuel ratio, ignition is used to achieve a normal engine startup.

[0036] In step 1, the initial opening of the air valve 4 is 30% of the rated opening of the air valve 4; the initial opening of the gas valve 6 is 50% of the rated opening of the gas valve 6; the initial opening of the throttle valve 9 is 30% of the rated opening of the throttle valve 9; and the initial opening of the single-cylinder valve 10 is 50% of the rated opening of the single-cylinder valve.

[0037] Step 2: Set the target power value and obtain the air-fuel ratio corresponding to the target power value. When the air-fuel ratio is not within the preset target air-fuel ratio range, trigger the opening adjustment strategy to adjust the opening of the air valve 4 and the opening of the gas valve 6.

[0038] In step 2, the opening adjustment strategy is:

[0039] When the air-fuel ratio is greater than the maximum value of the target air-fuel ratio range, the opening of the air valve 4 is reduced to a preset air valve third opening, and the opening of the gas valve 6 is increased to a preset gas valve first opening.

[0040] When the air-fuel ratio is less than the minimum value of the target air-fuel ratio range, the opening of the air valve 4 is increased to the first air valve opening, and the opening of the gas valve 6 is decreased to the third gas valve opening.

[0041] The relationship among the first opening of the air valve, the second opening of the air valve and the third opening of the air valve is: the third opening of the air valve < the second opening of the air valve < the first opening of the air valve < the rated opening of the air valve.

[0042] The relationship among the first opening of the gas valve, the second opening of the gas valve and the third opening of the gas valve is: the third opening of the gas valve < the second opening of the gas valve < the first opening of the gas valve < the rated opening of the gas valve.

[0043] Among them, the first opening degree of the air valve, the second opening degree of the air valve, the third opening degree of the air valve, the first opening degree of the gas valve, the second opening degree of the gas valve and the third opening degree of the gas valve are all obtained through experiments.

[0044] When the air-fuel ratio is within the target air-fuel ratio range, the opening of the air valve 4 is maintained at the preset second opening of the air valve 4 , and the opening of the gas valve 6 is maintained at the preset second opening of the gas valve 6 .

[0045] Step 3: Obtain the alloy tail gas source concentration, and trigger the gas source concentration adjustment strategy according to the alloy tail gas source concentration to achieve automatic control of the air-fuel ratio.

[0046] In step three, the gas source concentration adjustment strategy is:

[0047] As the gas source concentration increases, the cylinder exhaust temperature rises and the air-fuel ratio becomes richer. When the alloy exhaust gas source concentration exceeds the preset alloy exhaust gas source concentration standard value, the opening of air valve 4 is increased to the preset air valve third opening, and the opening of gas valve 6 is reduced to the preset gas valve first opening to reduce the alloy exhaust gas source concentration.

[0048] When the alloy tail gas source concentration is lower than the alloy tail gas source concentration standard value, the opening of the air valve 4 is reduced to the first air valve opening, and the opening of the gas valve 6 is increased to the third gas valve opening to increase the alloy tail gas source concentration.

[0049] When the alloy tail gas source concentration is equal to the alloy tail gas source concentration standard value, the opening of the air valve 4 is maintained at the second air valve opening, and the opening of the gas valve 6 is maintained at the second gas valve opening.

[0050] Step 4: Set the dead zone temperature range, obtain the average cylinder exhaust temperature of the engine, and trigger the automatic cylinder exhaust temperature adjustment strategy based on the average cylinder exhaust temperature of the engine and the dead zone temperature range.

[0051] According to the operating conditions of the engine, the exhaust temperature of each cylinder of the engine is monitored and an average exhaust temperature value is obtained.

[0052] In step 4, the automatic adjustment strategy of cylinder exhaust temperature is:

[0053] When the average cylinder exhaust temperature is greater than the maximum value of the dead zone temperature range, the opening of the single-cylinder valve 10 is reduced based on the original opening of the single-cylinder valve 10 according to the preset first opening change rate and the preset first adjustment time so that the average cylinder exhaust temperature is less than or equal to the maximum value of the dead zone temperature range.

[0054] When the average cylinder exhaust temperature is less than the minimum value of the dead zone temperature range, the opening of the single-cylinder valve 10 is reduced according to the preset second opening change rate and the preset second adjustment time so that the average cylinder exhaust temperature is greater than or equal to the minimum value of the dead zone temperature range.

[0055] The first opening change rate and the second opening change rate are both within a preset upper and lower limit range of the adjustment amount, and the upper and lower limit range of the adjustment amount is 1% / s-3% / s.

[0056] A control device for an alloy exhaust engine, comprising:

[0057] Air supply module, used to provide air to the cylinder.

[0058] The gas supply module is used to provide gas to the cylinder.

[0059] The ECU applies the above-mentioned control method of an alloy exhaust engine to control the air supply module and the gas supply module to adjust the amount of air and gas input into the cylinder.

[0060] The air supply module includes an air filter 1, an air supercharger 2, an air intercooler 3 and an air valve 4. The air inlet of the air filter 1 is connected to the outside air, the air outlet of the air filter 1 is connected to the air inlet of the air supercharger 2 through a pipe, the air inlet of the air intercooler 3 is connected to the air outlet of the air supercharger 2 through a pipe, the air outlet of the air intercooler 3 is connected to the air intake duct of the cylinder head 5 through a pipe, and an air valve 4 is installed on the pipe between the air outlet of the air intercooler 3 and the air inlet of the cylinder head 5.

[0061] The function of the air valve 4 is to control the amount of air entering the cylinder; the function of the gas valve 6 is to control the amount of gas entering; the characteristic of the throttle valve 9 is to achieve speed regulation and load control; the function of the single-cylinder valve 10 is to fine-tune the amount of gas entering the cylinder so that the exhaust temperature of each cylinder is as consistent as possible.

[0062] The gas supply module includes a gas valve 6, a gas supercharger 7, a gas intercooler 8 and a throttle 9. The air inlet of the gas supercharger 7 is connected to the gas input end through a pipeline, the air inlet of the gas intercooler 8 is connected to the air outlet of the gas supercharger 7 through a pipeline, and the air outlet of the gas intercooler 8 is connected to the air intake duct of the cylinder head 5 through a pipeline. The gas valve 6 is installed on the pipeline connecting the air inlet of the gas supercharger 7 and the gas input end, and the pipeline connecting the gas intercooler 8 and the air intake duct of the cylinder head 5 is provided with a throttle 9 and a single-cylinder valve 10 connected in sequence.

[0063] Fresh air first passes through the air filter 1 and then enters the air supercharger 2. The supercharged air is cooled by the air intercooler 3. The cooled air is regulated by the air valve 4 and then enters an intake duct of the cylinder head 5 through the intake manifold; the other route is the gas supply side: the gas after filtering and pressure stabilization by the front-end valve group first passes through the gas valve 6 and then enters the gas supercharger 7. The supercharged gas is cooled by the gas intercooler 8. The cooled gas is controlled by the throttle 9 and enters the single-cylinder valve 10 through the gas manifold, and then enters the other intake duct of the cylinder head 5 through the single-cylinder valve 10.

[0064] Based on the characteristics of the gas source, the alloy exhaust engine adopts the currently advanced split-line intake and in-cylinder mixed gas intake system, that is, the air and gas pipelines enter the two intake ducts of the cylinder head independently, and are mixed and burned in the cylinder (due to the presence of H2, the camshaft adopts a small overlap angle, and mixing is carried out in the cylinder to effectively avoid backfire failures). The difference in configuration from conventional natural gas is the addition of a supercharged intercooler system in the gas pipeline, that is, a supercharger and intercooler are added to the gas side, and actuators such as gas valves, throttles and single-cylinder valves are added to the gas side to respectively realize gas quantity control (matching with the air valve to control the air-fuel ratio), speed and load adjustment, and exhaust temperature correction for each cylinder. An air valve is added to the air side to control the air flow and jointly realize air-fuel ratio control with the gas valve.

[0065] The alloy tail gas source of the present invention can realize automatic control of the air-fuel ratio and automatic control of the single-cylinder valve when it changes within a certain range, thereby ensuring the intelligent operation of the engine.

[0066] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention. These modifications and improvements will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A control method for an alloy exhaust engine, characterized in that: The method includes, Step 1: setting the initial opening of the air valve (4), the initial opening of the gas valve (6), the initial opening of the throttle valve (9) and the initial opening of the single-cylinder valve (10), and executing the initial opening of the air valve (4), the initial opening of the gas valve (6), the initial opening of the throttle valve (9) and the initial opening of the single-cylinder valve (10) to obtain a suitable air-fuel ratio to start the engine normally; Step 2: setting a target power value, obtaining an air-fuel ratio corresponding to the target power value, and when the air-fuel ratio is not within a preset target air-fuel ratio range, triggering an opening adjustment strategy to adjust the opening of the air valve (4) and the opening of the gas valve (6); Step 3: obtaining the alloy tail gas source concentration, and triggering the gas source concentration adjustment strategy according to the alloy tail gas source concentration to achieve automatic control of the air-fuel ratio; Step 4: Set the dead zone temperature range, obtain the average cylinder exhaust temperature of the engine, and trigger the cylinder exhaust temperature automatic adjustment strategy according to the average cylinder exhaust temperature of the engine and the dead zone temperature range.

2. The control method of an alloy exhaust engine according to claim 1, characterized in that: In step 2, the opening adjustment strategy is: When the air-fuel ratio is greater than the maximum value of the target air-fuel ratio range, the opening of the air valve (4) is reduced to a preset third air valve opening, and the opening of the gas valve (6) is increased to a preset first gas valve opening; When the air-fuel ratio is less than the minimum value of the target air-fuel ratio range, the opening of the air valve (4) is increased to a first air valve opening, and the opening of the gas valve (6) is reduced to a third gas valve opening.

3. The control method of an alloy exhaust engine according to claim 2, characterized in that: When the air-fuel ratio is within the target air-fuel ratio range, the opening of the air valve (4) is maintained at a preset second air valve opening, and the opening of the gas valve (6) is maintained at a preset second gas valve opening.

4. The control method of an alloy exhaust engine according to claim 1, characterized in that: In step three, the gas source concentration adjustment strategy is: When the alloy tail gas source concentration is greater than a preset alloy tail gas source concentration standard value, the opening of the air valve (4) is increased to a preset air valve third opening, and the opening of the gas valve (6) is reduced to a preset gas valve first opening to reduce the alloy tail gas source concentration; When the alloy tail gas source concentration is less than the alloy tail gas source concentration standard value, the opening of the air valve (4) is reduced to the first air valve opening, and the opening of the gas valve (6) is increased to the third gas valve opening to increase the alloy tail gas source concentration; When the alloy tail gas source concentration is equal to the alloy tail gas source concentration standard value, the opening of the air valve (4) is maintained at the second air valve opening, and the opening of the gas valve (6) is maintained at the preset second gas valve opening.

5. The control method of an alloy exhaust engine according to claim 1, characterized in that: In step 4, the cylinder exhaust temperature automatic adjustment strategy is: When the average cylinder exhaust temperature is greater than the maximum value of the dead zone temperature range, the opening of the single cylinder valve (10) is reduced according to a preset first opening change rate and a preset first adjustment time so that the average cylinder exhaust temperature is less than or equal to the maximum value of the dead zone temperature range; When the cylinder exhaust temperature average value is less than the minimum value of the dead zone temperature range, the opening of the single cylinder valve (10) is increased according to a preset second opening change rate and a preset second adjustment time so that the cylinder exhaust temperature average value is greater than or equal to the minimum value of the dead zone temperature range.

6. The control method of an alloy exhaust engine according to claim 5, characterized in that: The opening change rate is within a preset upper and lower limit range of the adjustment amount.

7. The control method of an alloy exhaust engine according to claim 1, characterized in that: In step 1, the initial opening of the air valve (4) is 20%-50% of the rated opening of the air valve (4); the initial opening of the gas valve (6) is 20%-60% of the rated opening of the gas valve (6); the initial opening of the throttle valve (9) is 20%-50% of the rated opening of the throttle valve (9); and the initial opening of the single-cylinder valve (10) is 40%-60% of the rated opening of the single-cylinder valve.

8. A control device for an alloy exhaust engine, characterized in that: The device comprises, An air supply module, for providing air to the cylinder; A gas supply module, used for providing gas to the cylinder; The ECU applies the control method of an alloy exhaust engine according to any one of claims 1 to 7 to control the air supply module and the gas supply module to adjust the amount of air and gas input into the cylinder.

9. The control device of an alloy exhaust engine according to claim 8, characterized in that: The air supply module comprises an air filter (1), an air supercharger (2), an air intercooler (3) and an air valve (4); the air inlet of the air filter (1) is communicated with the outside air; the air outlet of the air filter (1) is connected to the air inlet of the air supercharger (2) through a pipe; the air inlet of the air intercooler (3) is connected to the air outlet of the air supercharger (2) through a pipe; the air outlet of the air intercooler (3) is connected to the air inlet of the cylinder head (5) through a pipe; and the air valve (4) is installed on the pipe between the air outlet of the air intercooler (3) and the air inlet of the cylinder head (5).

10. The control device of the alloy exhaust engine according to claim 9, characterized in that: The gas supply module comprises a gas valve (6), a gas supercharger (7), a gas intercooler (8) and a throttle valve (9); the air inlet of the gas supercharger (7) is connected to the gas input end through a pipeline; the air inlet of the gas intercooler (8) is connected to the air outlet of the gas supercharger (7) through a pipeline; the air outlet of the gas intercooler (8) is connected to the air intake duct of the cylinder head (5) through a pipeline; the gas valve (6) is installed on the pipeline connecting the air inlet of the gas supercharger (7) and the gas input end; the throttle valve (9) and the single cylinder valve (10) which are connected in sequence are provided on the pipeline connecting the gas intercooler (8) and the air intake duct of the cylinder head (5).

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