Method for improving loading performance of supercharged gas engine, gas engine and application

Abstract

The invention relates to the technical field of internal combustion engines, in particular to a method for improving the loading performance of a supercharged gas engine, the gas engine and application. The gas engine is provided with a gas supplementing pipeline, and when the rotating speed reduction ratio of the gas engine is larger than a set limit value and the rotating speed reduction rate is larger than a set rotating speed reduction rate limit value, the gas supplementing pipeline is started; the amount of mixed gas entering the cylinder is increased. The amount of mixed gas entering the air cylinder is supplemented and increased according to the change condition of rotating speed reduction of the gas engine, and the rotating speed recovery capacity of the engine is improved. According to the method, when the load is suddenly increased, the gas homogeneous with the gas pressurized by the gas compressor is automatically supplemented into the pipeline behind the gas compressor of the supercharger, the gas compressor of the supercharger does not need to be pressurized, the load of the gas compressor of the supercharger is reduced, and the working efficiency of the gas compressor during loading is improved; meanwhile, the gas enters an engine cylinder to participate in acting, the engine power is increased, the instantaneous power of the engine is additionally increased, the speed of a supercharger is increased, and the rotating speed recovery time is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engines, and in particular to a method for improving the loading performance of a supercharged gas engine, a gas engine and applications. Background Art

[0002] The market application of supercharged gas engines is constantly expanding due to their energy conservation and environmental protection. However, because they are not as fast as diesel engines in responding to sudden load increases, their application is limited to occasions with large single-load loads, such as drilling machinery power, generator power for electric drilling rigs, and compressor units for compressor stations.

[0003] For diesel engines, the gas entering the cylinder is air, and the temperature after compression is higher than the ignition point of diesel. Diesel is sprayed into the cylinder, and the diesel is atomized and ignited to achieve diffusion combustion. This combustion method can ensure combustion even if the excess coefficient of intake air is large. For gas engines, electric spark ignition is used, and the gas entering the cylinder to do work is a mixture of air and gas. Its compression temperature is lower than the ignition point of the mixture. The combustion is ignited by the electric spark plug, and the flame propagation combustion of the mixture is carried out. This requires the concentration of the mixture to maintain a certain ratio, otherwise the combustion will be abnormal or even unable to ignite and burn normally. Therefore, under no-load conditions, the gas pressure and flow rate of the turbocharged electric spark ignition gas engine entering the cylinder is only equivalent to 30% of that of the supercharged diesel engine. This results in low intake volume of the gas engine when the load is suddenly increased, and the instantaneous work power is less than half of that of the supercharged diesel engine. When the load is suddenly increased, the speed drops greatly, and the speed recovery time is long.

[0004] The existing technical solutions mainly include the following: Taking advantage of the relatively good load responsiveness of non-supercharged spark ignition gas engines, large-displacement non-supercharged spark ignition gas engines are used to replace supercharged ignition gas engines. The disadvantages are large equipment size, low thermal efficiency, and low cost performance.

[0005] The boosted gas generator set is equipped with a resistance load control system, which pre-loads part of the resistance load before loading, and removes this part of the resistance load when the load is suddenly added. The disadvantage is that it needs to be equipped with additional resistance loads and reasonably controlled, and manual intervention is required to load the resistance load in advance according to the changes in working conditions, which is inconvenient to use and reduces economic efficiency.

[0006] The supercharged gas engine (for generator set) is combined with the supercapacitor power storage inverter motor system. The sudden load is first borne mainly by the inverter system and then gradually transferred to the supercharged gas engine. The disadvantage is that the supercapacitor power storage inverter motor system is high in cost and poor in reliability.

[0007] The supercharged gas engine (for generator set) is equipped with a gas replenishment and enrichment device. The disadvantage is that in order to prevent detonation, the engine's air-fuel ratio must be increased, the operating economy is poor, and the amount of replenishment is limited, and the effect is not ideal.

[0008] These technical solutions do not fundamentally solve the problem of poor sudden load responsiveness of the supercharged gas engine itself. Summary of the invention

[0009] The main purpose of the present invention is to provide a method for improving the loading performance of a supercharged gas engine, a gas engine and an application thereof, so as to solve the problem of poor sudden load responsiveness of the supercharged gas engine itself in the prior art.

[0010] In order to achieve the above object, one aspect of the present invention provides a method for improving the loading performance of a supercharged gas engine, wherein the gas engine has a mixer, an intercooler, and a cylinder, and when the load suddenly increases, the engine speed drop value is greater than a set speed drop limit value, and the speed drop rate is greater than a set speed drop rate limit value, the amount of mixed gas entering the cylinder is supplemented. The speed drop rate refers to the value of the engine speed drop per unit time.

[0011] The mixer of the gas engine adopts the Venturi principle. When the load suddenly increases and the throttle valve opening in front of the cylinder increases, the cylinder cannot obtain sufficient required mixed gas because the air supply pipeline cannot be pressurized in time and the gas pressure transmission is delayed, and the speed recovery is slow. When the load suddenly increases, the present invention supplements and increases the amount of mixed gas entering the cylinder according to the speed reduction ratio of the gas engine, thereby helping to recover the engine speed.

[0012] In a further optimization, the method of supplementing and increasing the amount of the mixed gas entering the cylinder is to supplement air before the mixer.

[0013] In a further optimization, the method of supplementing and increasing the amount of the mixed gas entering the cylinder is: supplementing the mixed gas of air and fuel gas after the mixer, and the mixed gas supplemented after the mixer meets the air-fuel ratio requirement of the gas engine.

[0014] Two aspects of the present invention provide a supercharged gas engine with improved loadability, including a mixer, an intercooler, a cylinder, a controller, and an air supply pipeline, wherein the air supply pipeline is connected to the intake pipeline of the cylinder. The controller receives the engine speed through a sensor, calculates the engine speed reduction ratio, and controls the air supply action of the air supply pipeline according to the engine speed reduction ratio when the load suddenly increases.

[0015] As a further improvement, the air supply pipeline is connected before the mixer to supplement and increase air.

[0016] As a further improvement, the air supply pipeline includes an air storage bottle, an air supply solenoid valve, and a nozzle connected in sequence, the nozzle is connected to the intercooler, and the air supply solenoid valve is connected to a controller.

[0017] As a further improvement, the air supply pipeline is connected after the mixer to supplement the mixed gas of air and fuel gas.

[0018] As a further improvement, the gas supply pipeline includes a gas storage bottle, a gas supply solenoid valve, and a nozzle connected in sequence, the nozzle is connected to an additional mixer, and the additional mixer is also connected to the gas supply pipeline through a pressure regulating valve; A pressure balancing pipe is connected between the pressure regulating valve and the additional mixer to make the pressure at the outlet of the pressure regulating valve track the air inlet pressure of the mixer, so that the air-fuel ratio of the mixed gas meets the requirements.

[0019] Three aspects of the present invention provide applications of the above-mentioned supercharged gas engine, including use in drilling machinery, generator sets or transport vehicles.

[0020] The application of the technical solution of the present invention has the following technical effects: (1) When the load suddenly increases, the amount of mixed gas entering the cylinder is increased according to the change in the speed reduction of the gas engine, thereby improving the ability to recover the engine speed.

[0021] (2) When the load suddenly increases, the method of automatically adding gas of the same quality as the gas pressurized by the compressor to the pipeline after the supercharger compressor makes it unnecessary to pressurize the supercharger compressor for the added homogeneous gas, which reduces the load of the supercharger compressor and improves the working efficiency of the compressor when loaded. At the same time, this part of the gas enters the engine cylinder to participate in the work, increasing the engine power; the amount of high-temperature and high-pressure flue gas discharged from the cylinder also increases accordingly, increasing the power of the supercharger turbine. The comprehensive effect is that when the load suddenly increases, the instantaneous power of the gas engine is additionally increased, the supercharger speed is accelerated, the engine speed drop is reduced, and the speed recovery time is shortened.

[0022] (3) When the load suddenly increases, the method of automatically adding mixed gas to the pipeline after the supercharger compressor is more efficient and more conducive to controlling the air-fuel ratio. In addition, the added mixed gas does not pass through the supercharger and has a relatively low temperature, which reduces the temperature of the mixed gas entering the cylinder, which is conducive to increasing the calorific value of the mixed gas per unit volume and further improving the efficiency of speed recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 A schematic diagram of the implementation of a supercharged post-mixed gas engine is shown; Figure 2 A schematic diagram of an implementation of a premixed supercharged gas engine is shown.

[0024] Figure 1 In the middle: 1. Air filter; 2a. A supercharger; 3. A intercooler; 4a. A mixer; 5. Throttle; 6. Cylinder; 7. Gas solenoid valve; 8a. A pressure regulating valve; 9a. A pressure balance pipe; 10a. A controller; 11a. A nozzle; 12a. A air solenoid valve; 13a. A gas cylinder.

[0025] Figure 2 In: 1. Air filter; 2b. B mixer; 3b. B supercharger; 4b. B intercooler; 5. Throttle; 6. Cylinder; 7. Gas solenoid valve; 8. Pressure stabilizing valve; 9. Zero pressure valve; 10b. B pressure regulating valve; 11. Additional mixer; 12b. B pressure balance pipe; 13b. B nozzle; 14. Air supply solenoid valve; 15b. B gas cylinder; 16b. B controller. DETAILED DESCRIPTION

[0026] The following will describe the implementation methods of the present application in detail with the help of accompanying drawings and examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. Example

[0027] The mixer of the gas engine adopts the Venturi principle. When the load suddenly increases and the throttle valve opening in front of the cylinder increases, the cylinder cannot obtain sufficient required mixed gas because the air supply pipeline cannot be pressurized in time and the gas pressure transmission is delayed, and the speed recovery is slow.

[0028] The first embodiment of the present invention provides a method for improving the loading performance of a supercharged gas engine. When the load suddenly increases, the amount of mixed gas entering the cylinder is supplemented and increased according to the speed reduction ratio of the gas engine to help restore the engine speed.

[0029] This example includes two sub-embodiments.

[0030] In a first sub-embodiment, the method for supplementing and increasing the amount of mixed gas entering the cylinder is to supplement air before the mixer.

[0031] When it is detected that the engine speed reduction ratio is greater than the set limit value, and the speed reduction rate is greater than the set speed reduction rate limit value, the compressed air from the air tank passes through the air supply solenoid valve and nozzle, and enters the mixer together with the air pressurized by the compressor. In the mixer, the air and gas form a mixed gas in proportion, and then enter the engine cylinder through the throttle. Since the amount of air entering before the mixer is increased, under the action of the Venturi principle, the amount of gas entering is also proportionally increased, so that the mixer entering the cylinder increases, thereby increasing the engine power output. When the engine speed returns to the set gas stop speed, the air supply operation stops.

[0032] In the second sub-embodiment, the method of supplementing and increasing the amount of the mixed gas entering the cylinder is to supplement the mixed gas of air and fuel gas after the mixer.

[0033] The air flows into the air inlet of the additional mixer after passing through the air filter, and the gas enters the additional mixer (gas inlet) after passing through the gas solenoid valve, the pressure regulating valve and the zero pressure valve. The mixed gas formed by the two flows to the intercooler after being pressurized by the supercharger compressor. When the engine speed drop is greater than the set speed drop limit value and the speed drop rate is greater than the set speed drop rate limit value, the compressed air enters the air inlet of the mixer 1 from the air storage tank through the air supply solenoid valve and the nozzle, and the gas flows into the gas inlet of the additional mixer after being regulated by the pressure regulating valve. The two are mixed into a mixed gas in the additional mixer. After merging with the outlet gas from the compressor in the outlet cavity of the intercooler, it enters the engine cylinder through the throttle. When the engine speed returns to the set gas stop speed, the air supply operation stops.

[0034] The second sub-embodiment adopts this method of directly supplementing the mixed gas because in Embodiment 1, when a large amount of air is added to the cylinder in an instant, the adjustment reaction of the gas supply pressure takes time, and it is not possible to quickly follow up and supplement a sufficient amount of gas, which is not conducive to the control of the air-fuel ratio. Supplementing the mixed gas directly after the mixer is not affected by the instantaneous increase of air in the cylinder, which is conducive to controlling the air-fuel ratio. At the same time, the supplemented mixed gas does not pass through the supercharger, and the temperature is relatively low, which is conducive to reducing the temperature of the mixed gas entering the cylinder, increasing the calorific value of the mixed gas per unit volume, and improving the efficiency of speed recovery. Example

[0035] The second embodiment of the present invention provides a supercharged gas engine with improved loading performance, which corresponds to the first embodiment and also includes two sub-embodiments.

[0036] The first sub-embodiment is an implementation scheme of a gas engine with supercharging and post-mixing. In this embodiment, the compressor of the supercharger provides air, so the supplementary air needs to be supplemented with air, and the air in the atmosphere enters the intercooler after being supercharged by the compressor.

[0037] like Figure 1 As shown, the gas engine includes an existing air filter 1, an A supercharger 2a, an A intercooler 3a, an A mixer 4a, a throttle 5, a cylinder 6, a gas solenoid valve 7, a pressure regulating valve 8, and an A pressure balance pipe 9a. The dotted frame is a gas supply device pipeline, including an A gas storage bottle 13a, an air solenoid valve 12, and an A nozzle 11a connected in sequence, and the A nozzle 11a is connected to the A intercooler 3. The A controller 10a controls the A air solenoid valve 12a and is connected to the A throttle 5a.

[0038] A pressure balance pipe is connected between the pressure regulating valve and the mixer, and the gas enters the mixer after passing through the gas solenoid valve and the pressure regulating valve. When the engine load suddenly increases, the controller detects the change in engine speed. On the one hand, it controls the throttle to open wide to control the speed and realize the function of a conventional engine speed controller. On the other hand, when the speed reduction rate is greater than the set limit, the controller will determine that the engine is loaded with a heavy load, and control the power supply of the air supply solenoid valve. The compressed air flows from the gas storage bottle through the air supply solenoid valve into the pipeline after the compressor, merges with the pressurized air, and then passes through the mixer to mix with the gas to form a mixed gas. The mixed gas enters the cylinder through the throttle. When the engine speed returns to the set gas stop speed, the air supply solenoid valve is powered off, the mixer also stops discharging gas, and the engine resumes normal operation.

[0039] The working process is as follows: Under normal operation, the air solenoid valve of the air supply device is in a closed state, and all the air required by the gas engine comes from the compressor. When the engine is subjected to a sudden load increase, the controller detects the change in engine speed and controls the throttle to open wide. On the other hand, when the speed reduction rate is greater than the set limit of the air solenoid valve opening, the air solenoid valve is energized, and the compressed air flows from the gas storage bottle through the air solenoid valve into the pipeline after the compressor, merges with the pressurized air, and then passes through the mixer to mix with the gas to form a mixed gas, which enters the cylinder through the throttle. When the engine speed returns to the set gas stop speed, the air solenoid valve is de-energized and the engine resumes normal operation. Therefore, when the load is suddenly increased, the air entering the engine cylinder includes not only the air pressurized by the compressor, but also the air stored in the gas storage bottle (external air source). With the supplement of this part of air, more mixed gas entering the cylinder can be formed, the engine work is increased, and at the same time, the amount of flue gas entering the supercharger turbine increases, which rapidly increases the speed of the supercharger, promotes the rapid increase in the pressure flow of the pressurized air, and rapidly increases the power of the gas engine, shortening the speed recovery time. Once the speed recovers, the air solenoid valve closes, cutting off the air supply, instantly reducing power and suppressing overshoot of the engine speed.

[0040] In this embodiment, a method is provided for automatically adding gas of the same quality as the gas pressurized by the compressor into the pipeline behind the supercharger compressor when the load suddenly increases, so that the added homogeneous gas does not need to be pressurized by the supercharger compressor, thereby reducing the load of the supercharger compressor and improving the working efficiency of the compressor when loaded; at the same time, this part of the gas enters the engine cylinder to participate in the work, thereby increasing the engine power; the amount of high-temperature and high-pressure flue gas discharged from the cylinder also increases accordingly, thereby increasing the power of the supercharger turbine. The comprehensive effect is that when the load suddenly increases, the instantaneous power of the gas engine is additionally increased, the supercharger speed is accelerated, the engine speed drop is reduced, and the speed recovery time is shortened.

[0041] The second sub-embodiment is an implementation scheme of a gas engine with post-supercharging and mixing. In this embodiment, the compressor of the supercharger provides mixed gas, so the supplementary gas also needs to provide mixed gas.

[0042] like Figure 2 As shown, the gas engine includes an existing air filter 1, a B mixer 2b, a B supercharger 3b, a B intercooler 4b, a throttle 5, a cylinder 6, a gas solenoid valve 7, a pressure regulating valve 8, and a zero pressure valve 9. The air supply pipeline in the dotted frame includes a B gas storage bottle 15b, a gas supply solenoid valve 14, a B nozzle 13b, and an additional mixer 11 connected in sequence. The additional mixer 11 is connected to the intercooler. The additional mixer 11 is also connected to the outlet of the gas solenoid valve through a B pressure regulating valve 10b and is provided with a B pressure balance pipe 12b. The gas supply solenoid valve 14 is controlled by a controller, and the controller is connected to the throttle 5. The mixer 11 adopts a mechanical diaphragm type equal vacuum mixer commonly used in natural gas engines.

[0043] The working process is as follows: Under normal operation, the air supply solenoid valve of the air supply device is in a closed state, and all the mixed gas required by the gas engine comes from the compressor. When the engine load suddenly increases, the controller detects the change in engine speed and controls the throttle to open wide. On the other hand, when the speed reduction rate is greater than the set limit of the air supply solenoid valve opening, the air supply solenoid valve is energized, and the compressed air enters the air inlet of the additional mixer from the gas storage bottle through the air supply solenoid valve and the nozzle, and the gas flows into the gas inlet of the additional mixer through the pressure regulating valve. The two are mixed into a mixed gas in the additional mixer; a pressure balance pipe is connected between the pressure regulating valve and the additional mixer 11, so that the outlet pressure of the pressure regulating valve tracks the air inlet pressure of the additional mixer, so that the air-fuel ratio of the mixed gas is kept reasonable. The mixed gas formed by the additional mixer and the mixed gas from the compressor merge in the intercooler outlet cavity and enter the cylinder through the throttle control. When the engine speed returns to the set gas stop speed, the controller cuts off the power to the air supply solenoid valve and the engine resumes normal operation.

[0044] Therefore, when the load is suddenly increased, the mixed gas entering the engine cylinder includes not only the mixed gas supercharged by the compressor, but also the supplementary mixed gas formed by the air and gas stored in the gas cylinder in the additional mixer 11, thereby increasing the amount of mixed gas entering the cylinder, increasing the engine work, and at the same time, the amount of flue gas entering the supercharger turbine increases, which enhances the work of the supercharger turbine, and the supercharger speed increases rapidly, which promotes the supercharger to supercharge more mixed gas, so that the power of the gas engine is quickly increased and the speed recovery time is shortened. Once the speed is restored, the air supply solenoid valve is closed, cutting off the air supply source, the instantaneous power is reduced, and the overshoot of the engine speed is suppressed.

[0045] After the speed is restored, the air supply is stopped, and the gas engine's instantaneous work is reduced, effectively avoiding overshoot of the speed. At the same time, due to the effect of air supply, the supercharger has more exhaust gas energy and can provide more pressurized gas, so the engine can generate more power and improve the instantaneous power reserve.

[0046] The present invention is applied to conventional supercharged gas engines, improving the load sudden performance and power reserve of supercharged gas engines, and has the advantages of good reliability, low cost, high degree of automation, and good economy, so that the application occasions of the product are expanded. The compressed air system is equipped at the drilling site and compressor station, ships and vehicles, and is convenient to match. In addition to being able to well meet the above-mentioned drilling site power, compressor station power, and compressor power, the supercharged gas engine and generator set using the present invention can also be used in automotive and marine fields with high loading requirements.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for improving the loading performance of a supercharged gas engine, wherein the gas engine has a mixer, an intercooler, and a cylinder, characterized in that: When the load increases suddenly, the engine speed decrease value is greater than the set speed decrease limit value, and the speed decrease rate is greater than the set speed decrease rate limit value, the amount of mixed gas entering the cylinder is supplemented and increased.

2. The method for improving the loading performance of a supercharged gas engine according to claim 1, characterized in that: The method of supplementing and increasing the amount of the mixed gas entering the cylinder is to supplement air before the mixer.

3. The method for improving the loading performance of a supercharged gas engine according to claim 1, characterized in that: The method of supplementing and increasing the amount of the mixed gas entering the cylinder is to supplement the mixed gas of air and fuel gas after the mixer.

4. The method for improving the loading performance of a supercharged gas engine according to claim 3, characterized in that: The mixed gas added after the mixer meets the air-fuel ratio requirement of the gas engine.

5. A supercharged gas engine with improved loading performance, comprising a mixer, an intercooler, a cylinder, and a controller, characterized in that: It also includes an air supply pipeline, which is connected to the air intake pipeline of the cylinder. The controller receives the engine speed through a sensor, completes the PID speed control of the engine, and calculates the rate at which the engine speed decreases. When the load suddenly increases, it determines whether the engine is loaded with a heavy load that will cause a sharp drop in the engine speed based on the rate at which the engine speed decreases, thereby deciding whether to control the air supply action of the air supply pipeline.

6. The supercharged gas engine with improved loadability according to claim 5, characterized in that: The air supply pipeline is connected before the mixer to supply and increase air.

7. The supercharged gas engine with improved loadability according to claim 6, characterized in that: The air supply pipeline includes an air storage bottle, an air supply solenoid valve, and a nozzle which are connected in sequence. The nozzle is connected to the intercooler, and the air supply solenoid valve is connected to a controller.

8. The supercharged gas engine with improved loadability according to claim 5, characterized in that: The air supply pipeline is connected after the mixer to supply the mixed gas of air and fuel gas.

9. The supercharged gas engine with improved loadability according to claim 8, characterized in that: The gas supply pipeline includes a gas storage bottle, a gas supply solenoid valve, and a nozzle connected in sequence, the nozzle is connected to an additional mixer, and the additional mixer is also connected to the gas supply pipeline through a pressure regulating valve; A pressure balancing pipe is connected between the pressure regulating valve and the additional mixer to make the pressure at the outlet of the pressure regulating valve track the air inlet pressure of the mixer, so that the air-fuel ratio of the mixed gas meets the requirements.

10. The use of the gas engine according to any one of claims 5 to 9, characterized in that: Including for use in drilling machinery, generator sets or transport vehicles.

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