CN108049991A - The engine block of the double injections of hot water mixing in a kind of outer cold water tank of cylinder - Google Patents

Abstract

The invention relates to a diesel engine structure with cold water outside the cylinder and hot water in the cylinder mixed with double injection, including a diesel engine body, an intake manifold and an exhaust manifold, an in-cylinder water sprayer and a fuel injector arranged in the diesel engine body, and The high-pressure water pump unit connected with the sprinkler in the cylinder, the sprinkler outside the cylinder arranged in the intake manifold, the low-pressure water pump unit connected with the sprinkler outside the cylinder, and the water pump unit arranged between the low-pressure water pump unit and the high-pressure water pump unit The heat exchanger, the electronic controller electrically connected with the fuel injector, the water sprayer in the cylinder, the high-pressure water pump unit, the water sprayer outside the cylinder and the low-pressure water pump unit respectively. Compared with the prior art, the present invention utilizes the hot water sprayed into the cylinder to quickly vaporize, absorb heat, reduce the temperature in the cylinder near the top dead center of combustion, and reduce the emission of _NOx . Evaporation absorbs heat, reduces the temperature of the gas entering the cylinder, increases the intake air density, increases the charge coefficient, increases the power per liter of the diesel engine, and improves the power performance.

Description

A Diesel Engine Structure with External Cold Water and In-Cylinder Hot Water Mixed Dual Injection

technical field

The invention belongs to the technical field of internal combustion engines and relates to a diesel engine structure with cold water outside the cylinder and hot water in the cylinder mixed with double injection.

Background technique

The rapid development of motor vehicle technology has brought great convenience to human society, but it has also brought a series of negative effects such as energy and environmental pollution. The energy consumption of motor vehicles has received widespread attention, and fuel consumption and emission standards have become increasingly stringent. Energy saving and emission reduction has become the main theme of the development of the motor vehicle industry.

In order to further improve the working efficiency of motor vehicles and reduce energy consumption, the technology of supercharging and miniaturization of internal combustion engines has been proposed. The miniaturization technology of internal combustion engine can increase the load of common working conditions of internal combustion engine, reduce pumping loss and improve fuel economy. The supercharging technology can make up for the shortcoming of insufficient power due to the miniaturization of the internal combustion engine. However, the thermal efficiency of the small-displacement supercharged diesel engine is limited by _NOx emissions. In order to fully utilize the potential of the small-displacement supercharged diesel engine, water injection technology emerged as the times require. Its feature is to use the cold water injected into the cylinder to absorb heat, thereby lowering the temperature and reducing NO _x emissions, which can further increase the parameters of the diesel engine such as the compression ratio and improve the thermal efficiency. In-cylinder water injection technology has received extensive attention from academia and industry. For example, many research institutions including Germany BMW Group, Germany Bosch Group, South Korea’s Hyundai Motor Group and Japan’s Toyota Motor Group have begun to study in-cylinder water injection technology. Conduct optimization studies. However, the exhaust gas discharged from the cylinder takes away about one-third of the heat in the cylinder. At present, injecting cold water into the cylinder can reduce the end-of-compression temperature in the cylinder and reduce the emission of _NOx , but it still does not solve the problem of a large amount of heat loss in the exhaust gas in the cylinder. , The cylinder exhaust exhaust wastes a lot of energy consumption, which limits the further improvement of the thermal efficiency of the diesel engine.

Contents of the invention

The object of the present invention is to overcome the above-mentioned defects in the prior art and provide a dual-injection system with cold water outside the cylinder and hot water in the cylinder that can effectively improve the thermal efficiency and power per liter of the diesel engine, reduce the NO _x emission of the diesel engine, and have the performance of waste heat recovery. Diesel engine structure.

The purpose of the present invention can be achieved through the following technical solutions:

A diesel engine structure with cold water outside the cylinder and hot water in the cylinder mixed with double injection, the structure includes a diesel engine body, an intake manifold and an exhaust manifold arranged on the diesel engine body, an in-cylinder water injector arranged in the diesel engine body and The fuel injector, the high-pressure water pump unit connected with the water sprayer in the cylinder, the water sprayer outside the cylinder set in the intake manifold, the low-pressure water pump unit connected with the water sprayer outside the cylinder, the water pump unit set between the low-pressure water pump unit and the water sprayer outside the cylinder The heat exchanger between the high-pressure water pump units, the electronic controller electrically connected with the fuel injector, the water sprayer in the cylinder, the high-pressure water pump unit, the water sprayer outside the cylinder and the low-pressure water pump unit respectively.

The exhaust manifold passes through a heat exchanger, and the heat exchanger absorbs the heat of the exhaust gas in the exhaust manifold to heat the water entering the high-pressure water pump unit.

The low-pressure water pump unit includes a water tank, a low-pressure water pump arranged in the water tank, a low-pressure water rail connected with the low-pressure water pump, and a first low-pressure water pipe connecting the low-pressure water rail with the sprinkler outside the tank.

The water inlet of the sprinkler outside the cylinder is connected to the low-pressure water rail through the first low-pressure water pipe, and the water return port of the sprinkler outside the cylinder is connected to the low-pressure water pump through the second low-pressure water pipe.

The low-pressure water pump increases the water pressure to 0.3-1MPa and then delivers it to the low-pressure water rail.

The high-pressure water pump unit includes a high-pressure water pump connected with the low-pressure water pump, a high-pressure water rail connected with the high-pressure water pump, and a first high-pressure water pipe connecting the high-pressure water rail with the in-cylinder sprinkler.

The water inlet of the in-cylinder sprinkler is connected to the high-pressure water rail through the first high-pressure water pipe, and the water return port of the in-cylinder sprinkler is connected to the high-pressure water pump through the second high-pressure water pipe.

The high-pressure water pump pressurizes the water to 35 MPa and then transports it to the high-pressure water rail.

One end of the heat exchanger is connected with the high-pressure water pump, and the other end is connected with the low-pressure water pump arranged in the water tank.

The crankshaft of the diesel engine is provided with a rotational speed sensor electrically connected with the electronic controller, and the water tank is provided with a liquid level gauge electrically connected with the electronic controller.

In the working state, the rotational speed sensor can monitor the rotational speed of the diesel engine in real time and feed back the data to the electronic controller. The liquid level meter monitors the liquid level in the water tank in real time, judges the remaining water volume, and feeds back to the electronic controller in real time. When the liquid level in the water tank is lower than the preset value, an alarm will be issued to prompt that water needs to be replenished to avoid Insufficient water storage occurs.

Both the high-pressure water rail and the low-pressure water rail are provided with a pressure stabilizing valve, which can control the water pressure so that the water pressure is within a suitable range to ensure working stability.

The pressure stabilizing valve is provided with an overflow pipe, and the overflow pipe is provided with an overflow valve, and the overflow pipe communicates with the inside of the water tank. After setting a constant pressure on the pressure stabilizing valve, the output water pressure will not change. If the water pressure in the stabilizing valve is too high, the overflow valve will open, and the excess water will flow back into the water tank through the overflow pipe. It can not only quickly stabilize the water pressure, but also avoid the waste of water.

Described electronic controller controls the amount of sprayed water in the cylinder and outside the cylinder according to the stored calibration MAP diagram (control curve diagrams such as ignition, fuel injection, and water injection of the engine under various operating conditions, called the MAP diagram). There are fuel injection quantity-speed diagram, fuel injection quantity-torque diagram, water spray quantity inside cylinder-speed diagram, water spray quantity outside cylinder-speed diagram, water spray quantity inside cylinder-torque diagram, water spray quantity inside and outside the cylinder-speed diagram picture. The specific control strategy and the principle of signal triggering are similar to the principle of diesel fuel injection control.

In actual application, the low-pressure water pump in the water tank sends part of the water to the low-pressure water rail and stores it in the low-pressure water rail. The low-pressure water rail sends water to the sprinkler outside the tank through the first low-pressure water pipe; The heat exchanger is heated, and the hot water is sent to the high-pressure water pump, and then the high-pressure water pump pressurizes and sends the hot water to the high-pressure water rail, and stores it in the high-pressure water rail. The high-pressure water rail sends hot water to the tank through the first high-pressure water pipe For the water injector, the electronic controller controls the amount of water sprayed into the cylinder block of the diesel engine and the intake manifold according to the stored calibration map.

Compared with the prior art, the present invention has the following characteristics:

1) Use the hot water injected into the cylinder to quickly vaporize and absorb heat, which can not only reduce the temperature in the cylinder near the top dead center of combustion, but also reduce the emission of _NOx ;

2) The heat of heating water comes from the recovery of exhaust gas energy by the heat exchanger, which increases the work medium in the combustion process, achieves recycling, reduces heat loss, improves the thermal efficiency of the diesel engine, and improves fuel economy and emission characteristics;

3) Spray cold water in the intake manifold, the evaporation of water absorbs heat, reduces the temperature of the gas entering the cylinder, increases the intake air density, and increases the charge coefficient, thereby increasing the power per liter of the diesel engine and improving the power performance;

4) Real-time monitoring and control of the diesel engine through the electronic controller to adjust the water injection time and water injection volume, and make the water injection volume match the specific working conditions of the diesel engine, thereby improving the thermal efficiency and liter power of the diesel engine. Application prospects.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the diesel engine structure of the cold water outside cylinder of the present invention mixed with hot water and double injection;

Instructions for marks in the figure:

1-water tank; 2-low-pressure water pump; 3-low-pressure water rail; 4-heat exchanger; 5-high-pressure water pump; 6-high-pressure water rail; 7-electronic controller; 8-exhaust manifold; 9-diesel engine body; 10-fuel injector; 11-in-cylinder water sprayer; 12-intake manifold; 13-outside cylinder water sprayer.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example:

As shown in Figure 1, a diesel engine structure with cold water outside the cylinder and hot water in the cylinder mixed with double injection includes a diesel engine body 9, an intake manifold 12 and an exhaust manifold 8 arranged on the diesel engine body 9, and an exhaust manifold 8 arranged on the diesel engine body. The in-cylinder sprinkler 11 and the fuel injector 10 in 9, the high-pressure water pump unit connected with the in-cylinder sprinkler 11, the out-of-cylinder sprinkler 13 arranged in the intake manifold 12, and the out-of-cylinder water spray The low-pressure water pump unit connected with the device 13, the heat exchanger 4 arranged between the low-pressure water pump unit and the high-pressure water pump unit, and the fuel injector 10, the in-cylinder water sprayer 11, the high-pressure water pump unit, and the external cylinder water sprayer 13 respectively and the electronic controller 7 electrically connected to the low-pressure water pump unit. Wherein, the exhaust manifold 8 passes through the heat exchanger 4, and the heat exchanger 4 absorbs the heat of the exhaust gas in the exhaust manifold 8, and heats the water entering the high-pressure water pump unit. One end of the heat exchanger 4 is connected to the high-pressure water pump 5 , and the other end is connected to the low-pressure water pump 2 arranged in the water tank 1 .

The low-pressure water pump unit includes a water tank 1, a low-pressure water pump 2 arranged in the water tank 1, a low-pressure water rail 3 communicating with the low-pressure water pump 2, and a first low-pressure water pipe connecting the low-pressure water rail 3 with the sprinkler 13 outside the cylinder. The water inlet of the sprinkler 13 outside the cylinder is connected with the low-pressure water rail 3 through the first low-pressure water pipe, and the water return port of the sprinkler 13 outside the cylinder is connected with the low-pressure water pump 2 through the second low-pressure water pipe. The low-pressure water pump 2 increases the water pressure to 0.3-1 MPa and then delivers it to the low-pressure water rail 3 .

The high-pressure water pump unit includes a high-pressure water pump 5 communicating with the low-pressure water pump 2 , a high-pressure water rail 6 communicating with the high-pressure water pump 5 , and a first high-pressure water pipe connecting the high-pressure water rail 6 with the in-cylinder sprinkler 11 . The water inlet of the in-cylinder sprinkler 11 is connected with the high-pressure water rail 6 through the first high-pressure water pipe, and the water return port of the in-cylinder sprinkler 11 is connected with the high-pressure water pump 5 through the second high-pressure water pipe. The high-pressure water pump 5 pressurizes the water to 35 MPa and then transports it to the high-pressure water rail 6 .

The crankshaft of the diesel engine is provided with a rotational speed sensor electrically connected with the electronic controller 7 , and a liquid level gauge electrically connected with the electronic controller 7 is arranged in the water tank 1 . In the working state, the rotational speed sensor can monitor the rotational speed of the diesel engine in real time and feed back the data to the electronic controller 7 . The liquid level meter monitors the liquid level in the water tank 1 in real time, judges the remaining water volume, and immediately feeds back to the electronic controller 7. When the liquid level in the water tank 1 is lower than the preset value, an alarm will be issued to prompt that water needs to be replenished to avoid Insufficient water storage occurs.

Both the high-pressure water rail 6 and the low-pressure water rail 3 are provided with a pressure stabilizing valve, which can control the water pressure so that the water pressure is within a suitable range to ensure working stability. An overflow pipe is arranged on the pressure stabilizing valve, and an overflow valve is arranged on the overflow pipe, and the overflow pipe communicates with the inside of the water tank 1 . After setting a constant pressure on the pressure stabilizing valve, the output water pressure will not change. If the water pressure in the stabilizing valve is too high, the overflow valve will open, and the excess water will flow back to the water tank 1 through the overflow pipe , which can not only quickly stabilize the water pressure, but also avoid the waste of water.

The electronic controller 7 controls the amount of water sprayed inside and outside the cylinder according to the stored calibration map. There are fuel injection amount-speed graph, fuel injection amount-torque graph, water spray amount inside the cylinder-speed graph, and external spray volume. Water volume-speed diagram, water spray volume inside cylinder-torque diagram, water spray volume inside and outside the cylinder-speed diagram. The specific control strategy and the principle of signal triggering are similar to the principle of diesel fuel injection control.

In actual application, the low-pressure water pump 2 in the water tank 1 sends part of the water to the low-pressure water rail 3 and stores it in the low-pressure water rail 3, and the low-pressure water rail 3 sends water to the sprinkler outside the tank through the first low-pressure water pipe 13; The other part of water is heated by heat exchanger 4, and the hot water is delivered to high-pressure water pump 5, and then high-pressure water pump 5 pressurizes and transports the hot water to high-pressure water rail 6, and stores it in high-pressure water rail 6. High-pressure water rail 6 The hot water is delivered to the in-cylinder water injector 11 through the first high-pressure water pipe, and the electronic controller 7 controls the amount of water sprayed into the cylinder body of the diesel engine and the intake manifold 12 according to the stored calibration MAP map.

The above descriptions of the embodiments are for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative effort. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (10)

1. the engine block of the double injections of hot water mixing in a kind of outer cold water tank of cylinder, which is characterized in that the structure includes diesel engine Body (9), the inlet manifold (12) being arranged on diesel-engine body (9) and exhaust manifold (8) are arranged on diesel-engine body (9) Interior in-cylinder water injection device (11) and fuel injector (10), the high-pressure hydraulic pump unit being connected with in-cylinder water injection device (11), be arranged on into The outer water jet (13) of cylinder in gas manifold (12), with the cylinder low-pressure pump unit that water jet (13) is connected outside, be arranged on low pressure Heat exchanger (4) between pump unit and high-pressure hydraulic pump unit, respectively with fuel injector (10), in-cylinder water injection device (11), high pressure water The outer water jet (13) of pump unit, cylinder and the electronic controller (7) of low-pressure pump unit electrical connection.

2. the engine block of the double injections of hot water mixing, feature exist in a kind of outer cold water tank of cylinder according to claim 1 Pass through heat exchanger (4) in, the exhaust manifold (8), which absorbs the tail gas heat quantity in exhaust manifold (8), into The water for entering high-pressure hydraulic pump unit is heated.

3. the engine block of the double injections of hot water mixing, feature exist in a kind of outer cold water tank of cylinder according to claim 2 In, the low-pressure pump unit include water tank (1), the low-pressure pump (2) being arranged in water tank (1), with low-pressure pump (2) phase The low pressure water rail (3) of connection, the first low pressure water pipe that low pressure water rail (3) is connected with the outer water jet (13) of cylinder.

4. the engine block of the double injections of hot water mixing, feature exist in a kind of outer cold water tank of cylinder according to claim 3 In the water inlet of the outer water jet (13) of the cylinder is connected by the first low pressure water pipe with low pressure water rail (3), the outer water jet of cylinder (13) water return outlet is connected by the second low pressure water pipe with low-pressure pump (2).

5. the engine block of the double injections of hot water mixing, feature exist in a kind of outer cold water tank of cylinder according to claim 4 In hydraulic pressure is added to 0.3-1MPa and is delivered to low pressure water rail (3) again by the low-pressure pump (2).

6. the engine block of the double injections of hot water mixing, feature exist in a kind of outer cold water tank of cylinder according to claim 3 In the high-pressure hydraulic pump unit includes the high-pressure hydraulic pump (5) being connected with low-pressure pump (2), is connected with high-pressure hydraulic pump (5) High pressure water rail (6), the first high-pressure water pipe that high pressure water rail (6) is connected with in-cylinder water injection device (11).

7. the engine block of the double injections of hot water mixing, feature exist in a kind of outer cold water tank of cylinder according to claim 6 In the water inlet of the in-cylinder water injection device (11) is connected by the first high-pressure water pipe with high pressure water rail (6), in-cylinder water injection device (11) water return outlet is connected by the second high-pressure water pipe with high-pressure hydraulic pump (5).

8. the engine block of the double injections of hot water mixing, feature exist in a kind of outer cold water tank of cylinder according to claim 7 In water is forced into after 35MPa and is delivered to high pressure water rail (6) again by the high-pressure hydraulic pump (5).

9. the engine block of the double injections of hot water mixing, feature exist in a kind of outer cold water tank of cylinder according to claim 6 In one end of the heat exchanger (4) is connected with high-pressure hydraulic pump (5), the other end and the low-pressure pump being arranged in water tank (1) (2) connect.

10. according to the diesel engine knots that hot water mixing pair is sprayed in cold water tank outside a kind of cylinder of claim 1 to 9 any one of them Structure, which is characterized in that the bent axle of the diesel engine is equipped with the speed probe being electrically connected with electronic controller (7), described Water tank (1) in be equipped with the tank gage that is electrically connected with electronic controller (7).