A testing method for a single-cylinder combustion test system based on a multi-cylinder engine

Abstract

The present invention discloses a testing method for a single-cylinder combustion test system based on a multi-cylinder engine, comprising a multi-cylinder engine and a dynamometer connected thereto. The intake side of any two adjacent cylinders of the multi-cylinder engine is connected to an intake system, and the exhaust side of any two adjacent cylinders of the multi-cylinder engine is connected to an exhaust system. The intake system includes an intake tank and an intake regulating device connected to the intake tank for regulating intake pressure and intake temperature. The exhaust system includes an exhaust regulating device for regulating exhaust pressure and exhaust temperature. The outlet end of the intake regulating device is connected to the intake side of any two adjacent cylinders of the multi-cylinder engine, and the intake end of the exhaust regulating device is connected to the exhaust side of any two adjacent cylinders of the multi-cylinder engine. The present invention can compare single-cylinder and multi-cylinder operation, providing data support for subsequent multi-cylinder engine testing. This meets the needs of early engine research and development.

Description

Technical Field

[0001] The present invention relates to the technical field of engine testing systems, and in particular to a testing method for a single-cylinder combustion testing system based on a multi-cylinder engine. Background Art

[0002] Currently, there are three main options for converting a multi-cylinder engine to a single-cylinder engine for combustion testing: Option 1: Modify the camshaft profile and piston drilling position on the entire multi-cylinder engine to achieve single-cylinder combustion. Option 2: Connect an external combustion system to overcome friction and create work, using one cylinder of the multi-cylinder engine as a test cylinder and the other cylinders as drag cylinders. A common rail system and fuel control system are also installed on the test cylinder. Option 3: Retain the crankshaft and cylinder block on the multi-cylinder engine, remove the cylinder head and piston connecting rod, and seal the cylinder block. Install the separately processed single-cylinder engine mechanism for testing.

[0003] The patent with application number 201910253285.2 and name "Single-cylinder diesel engine bench test system based on multi-cylinder diesel engine with integral cylinder head" discloses a single-cylinder diesel engine bench test system based on a multi-cylinder diesel engine with integral cylinder head, in which multiple cylinders of the multi-cylinder diesel engine are divided into a test cylinder, and the rest are drag cylinders; the test system includes: a test cylinder air system that supplies air to the test cylinder and controls the pressure, temperature and composition of the air; a test cylinder fuel system that provides high-pressure fuel to the test cylinder; a diesel engine control system that controls the parameters and injection amount involved in the test cylinder injection process; a drag cylinder air system and a drag cylinder fuel system that supply air and high-pressure fuel to the drag cylinder; a data acquisition system for collecting relevant parameters during the operation of the test cylinder; and a dynamometer system for measuring the output power of a multi-cylinder diesel engine.

[0004] The patent with application number 202111548562.6 and name "A Automobile Engine Development and Testing System" discloses an automobile engine development and testing system including a dynamometer, a vacuum pumping device, a high-pressure fuel supply device, a combustion analyzer, an intake pressure control device and a control device; the dynamometer is connected to the single-cylinder engine through a drive shaft; the vacuum pumping device is connected to the engine crankcase; the high-pressure fuel supply device is connected to the intake port of the single-cylinder engine to provide the required fuel supply pressure; the combustion analyzer is connected to the combustion chamber of the single-cylinder engine to collect combustion data; the intake pressure control device is connected to the intake port of the single-cylinder engine to adjust the intake pressure of the single-cylinder engine; the control device is electrically connected to the dynamometer, the high-pressure fuel supply device, the combustion analyzer and the intake pressure control device.

[0005] The existing technical solutions have the following problems: First, a lot of equipment needs to be updated on the original test bench. For example, in the above-mentioned solution one, an electric dynamometer needs to be added, and in solution two, a new fuel injection system and control unit need to be added. Second, the cost of engine modification is high. For example, in solution three, the cylinder head and piston connecting rod need to be removed, the cylinder block needs to be sealed, and the crankshaft and cylinder block need to be retained. Third, some solutions cannot solve the working vibration problem of the single-cylinder engine and the applicability of the dynamometer. Summary of the Invention

[0006] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and provide a testing method for a single-cylinder combustion test system with less modification to a multi-cylinder engine, less additional equipment and low modification cost.

[0007] To achieve this purpose, the single-cylinder combustion test system based on a multi-cylinder engine designed in the present invention includes a multi-cylinder engine and a dynamometer connected thereto, the intake side of any two adjacent cylinders of the multi-cylinder engine is connected to an intake system, and the exhaust side of any two adjacent cylinders of the multi-cylinder engine is connected to an exhaust system; the intake system includes an intake tank and an intake regulating device connected to the intake tank for regulating the intake pressure and the intake temperature, and the exhaust system includes an exhaust regulating device for regulating the exhaust pressure and the exhaust temperature; the outlet end of the intake regulating device is connected to the intake side of any two adjacent cylinders of the multi-cylinder engine, and the intake end of the exhaust regulating device is connected to the exhaust side of any two adjacent cylinders of the multi-cylinder engine.

[0008] Furthermore, the intake regulating system includes an intake temperature regulating device whose intake end is connected to the intake tank and an intake pressure regulating device whose intake end is connected to the outlet end of the intake temperature regulating device; the intake sides of any two adjacent cylinders of the multi-cylinder engine are connected to the outlet end of the intake pressure regulating device.

[0009] Furthermore, the intake air temperature regulating device includes an intake air heating device whose intake end is connected to the intake tank and an intake air cooling device which is connected to the outlet end of the intake air heating device.

[0010] Furthermore, the intake pressure regulating device includes an intake pressure stabilizing tank whose intake end is connected to the outlet end of the intake cooling device, and the outlet of the intake pressure stabilizing tank is connected to the intake sides of any two adjacent cylinders of the multi-cylinder engine.

[0011] Furthermore, the exhaust regulating device includes an exhaust pressure regulating device whose intake end is connected to the exhaust side of any two adjacent cylinders of the multi-cylinder engine and an exhaust temperature regulating device connected to the exhaust pressure regulating device; the exhaust pressure regulating device includes an exhaust pressure stabilizing tank, and the exhaust temperature regulating device includes an EGR cooling device.

[0012] Furthermore, a connecting pipeline is connected between the air outlet end of the air intake regulating device and the air intake end of the exhaust regulating device, and an EGR on-off valve is provided on the connecting pipeline.

[0013] The test method of a single-cylinder combustion test system based on a multi-cylinder engine is as follows: the intake system and the exhaust system are turned on, the multi-cylinder engine is ignited and heated, any two adjacent cylinders of the multi-cylinder engine are kept working, the remaining cylinders are disconnected, and the working conditions of the two adjacent cylinders that continue to work are adjusted so that the two adjacent cylinders reach their respective test conditions; the intake system is adjusted to meet the intake boundary conditions, and the exhaust system is adjusted to meet the debugging requirements; the test data is monitored and recorded, and the two adjacent cylinders are disconnected after the test is completed.

[0014] Furthermore, the method of adjusting the working conditions of the two adjacent cylinders that continue to work so that the two adjacent cylinders reach their respective test working conditions is: adjusting the fuel injection amount of the two adjacent cylinders that continue to work, adjusting the two adjacent cylinders from the current thermal engine working condition to the adjustment working condition, adjusting the fuel injection amount of the two adjacent cylinders again, and adjusting the two adjacent cylinders from the adjustment working condition to their respective test working conditions.

[0015] Furthermore, the method for disconnecting the two adjacent cylinders after the test is completed is: after the test is completed, the fuel injection amount of the two adjacent cylinders is adjusted, the two adjacent cylinders are adjusted from the test working condition to the regulation working condition, and the two adjacent cylinders are disconnected.

[0016] Furthermore, in summary, the test method of a single-cylinder combustion test system based on a multi-cylinder engine includes the following steps:

[0017] Step 1: Open the intake and exhaust systems, and ignite the multi-cylinder engine to warm it up;

[0018] Step 2: Keep any two adjacent cylinders of the multi-cylinder engine in operation, and disconnect the remaining cylinders;

[0019] Step 3: Adjust the fuel injection amount of the two adjacent cylinders that continue to work, adjust the two adjacent cylinders from the current hot engine working condition to the adjustment working condition, adjust the fuel injection amount of the two adjacent cylinders again, and adjust the two adjacent cylinders from the adjustment working condition to their respective test working conditions;

[0020] Step 4: Adjust the intake system to meet the intake boundary conditions, and adjust the exhaust system to meet the debugging requirements;

[0021] Step 5: Monitor and record test data, adjust the fuel injection amount of the two adjacent cylinders after the test is completed, adjust the two adjacent cylinders from the test working condition to the regulation working condition, and disconnect the two adjacent cylinders.

[0022] The beneficial effects of the present invention are as follows: the single-cylinder combustion test system based on a multi-cylinder engine designed by the present invention can realize the cylinder cut-off requirements of different cylinders through the cylinder cut-off mechanism. On this basis, the two cylinders are kept in continuous operation, and the injector is controlled by the ECU control system, so that one of the two cylinders that continue to work is used as a drag cylinder, and the other cylinder is used as a test cylinder. The test bench of the engine is minimally modified. At the same time, the two-cylinder operation is better balanced and has less vibration than the single-cylinder operation, avoiding the problem of coupling damage caused by vibration problems. It effectively reduces the test system's dependence on the intake system and can achieve precise control of the intake volume. The present invention can compare single-cylinder operation and multi-cylinder operation, providing data support for subsequent multi-cylinder engine tests. It meets the research and development needs of the early engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a connection diagram of a single-cylinder combustion test system based on a multi-cylinder engine in the present invention;

[0024] Figure 2 This is a flow chart of the testing method of the single-cylinder combustion test system based on a multi-cylinder engine in the present invention;

[0025] Figure 3 This is a test control flow chart of a multi-cylinder engine in the present invention;

[0026] Among them, 1 - multi-cylinder engine, 2 - dynamometer, 3 - intake tank, 4 - intake heating equipment, 5 - intake cooling equipment, 6 - intake pressure stabilizing tank, 7 - exhaust pressure stabilizing tank, 8 - EGR cooling equipment, 9 - intake air heating equipment, 10 - intake air heating equipment, 11 - intake air heating equipment, 12 - exhaust pressure stabilizing tank, 13 - exhaust pressure stabilizing tank, 14 - exhaust pressure

[0027] —EGR on-off valve, 10—intake air release valve, 11—test cylinder, 12—drag cylinder, 13—ECU, 14—combustion analyzer, 15—back pressure valve. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] like Figure 1The illustrated single-cylinder combustion test system based on a multi-cylinder engine includes a multi-cylinder engine 1 and a dynamometer 2 connected thereto. In the embodiments of the present invention, a six-cylinder engine is used as an example for illustration. The intake side of two adjacent cylinders in the middle of the six-cylinder engine is connected to an intake system, and the exhaust side of two adjacent cylinders in the middle of the six-cylinder engine is connected to an exhaust system. The intake system includes an intake tank 3 and an intake regulating device connected to the intake tank 3 for regulating intake pressure and temperature. The intake regulating system includes an intake temperature regulating device whose intake end is connected to the intake tank 3 and an intake pressure regulating device whose intake end is connected to the outlet of the intake temperature regulating device. The intake side of two adjacent cylinders in the middle of the six-cylinder engine is connected to the outlet of the intake pressure regulating device. The intake side of the intake side of the intake pressure regulating device is connected to the outlet of the intake pressure regulating device. The intake temperature regulating device includes an intake heating device 4 whose intake end is connected to the intake tank 3 and an intake cooling device 5 connected to the outlet of the intake heating device 4. The intake pressure regulating device includes an intake pressure stabilizing tank 6, whose intake end is connected to the outlet of an intake air cooling device 5. The outlet of the intake pressure stabilizing tank 6 is connected to the intake side of two adjacent cylinders in the middle of the six-cylinder engine. The outlet of the intake air cooling device 5 is also connected to an intake purge valve 10.

[0030] The exhaust system includes an exhaust regulating device for regulating exhaust pressure and temperature. The outlet end of the intake regulating device communicates with the intake side of two adjacent cylinders in the middle of the six-cylinder engine, while the intake end of the exhaust regulating device communicates with the exhaust side of two adjacent cylinders in the middle of the six-cylinder engine. The exhaust regulating device includes an exhaust pressure regulating device whose intake end communicates with the exhaust side of two adjacent cylinders in the middle of the six-cylinder engine, and an exhaust temperature regulating device communicated with the exhaust pressure regulating device. The exhaust pressure regulating device includes an exhaust surge tank 7, and the exhaust temperature regulating device includes an EGR cooling device 8.

[0031] A connecting pipeline is connected between the air outlet end of the air intake regulating device and the air intake end of the exhaust regulating device, and an EGR on-off valve 9 is provided on the connecting pipeline.

[0032] The test method for the single-cylinder combustion test system based on the multi-cylinder engine includes the following steps:

[0033] Step 1: Open the intake and exhaust systems, and ignite the six-cylinder engine to warm up (in the test preparation stage, the six cylinders are running to complete the warm-up work, which reduces the warm-up time and improves the test efficiency);

[0034] Step 2: Keep the two adjacent middle cylinders of the six-cylinder engine in operation, and disconnect the other cylinders (after the warm-up is completed, shut down the other four cylinders, and only two cylinders remain in operation. The engine adjustment parameters are the same as those of the six-cylinder warm-up engine, which is different from the traditional single-cylinder operation and reduces the requirements for the dynamometer 2. The principle is that the existing single-cylinder operation cannot effectively overcome the friction torque of the engine, and the dynamometer 2 needs to be operated at the same time. Under the condition of meeting the working conditions of the entire engine, the test bench torque value is usually negative. Using two-cylinder operation can effectively overcome the friction torque and reduce the capacity requirements of the dynamometer 2);

[0035] Step 3: Adjust the fuel injection amount of the two adjacent cylinders that continue to work, adjust the two adjacent cylinders from the current hot engine working condition to the adjustment working condition (a transition working condition between the hot engine working condition and the operating condition. After running to the adjustment working condition, keep the load of the whole machine appropriate. Under this working condition, adjust the speed. After reaching the required speed, carry out load adjustment to reduce the vibration impact caused by the sudden change of working condition). Adjust the fuel injection amount of the two adjacent cylinders again, and adjust the two adjacent cylinders from the adjustment working condition to their respective test working conditions (one cylinder is the drag cylinder and the other cylinder is the test cylinder. Figure 1 As shown, the ECU 13 connected to the two cylinders controls the fuel injection amount of the two cylinders so that each reaches its own test condition);

[0036] Step 4: Adjust the intake system to meet the intake boundary conditions, and adjust the exhaust system to meet the debugging requirements;

[0037] Step 5: Monitor and record the test data (obtained through the combustion analyzer 14 and dynamometer 2 connected to the two cylinders). After the test is completed, adjust the injection amount of the two adjacent cylinders, adjust the two adjacent cylinders from the test condition to the adjustment condition, and run the two cylinders at idle speed, then shut down and turn off the flameout.

[0038] The single-cylinder combustion test system designed by the present invention based on a multi-cylinder engine can realize the cylinder cut-off requirements of different cylinders through the cylinder cut-off mechanism. On this basis, the two cylinders are kept in continuous operation, and the injector is controlled by the ECU control system, so that one of the two cylinders that continue to work is used as a drag cylinder and the other cylinder is used as a test cylinder. The test bench of the engine is minimally modified. At the same time, the two-cylinder operation is better balanced and has less vibration than the single-cylinder operation, avoiding the problem of coupling damage caused by vibration problems. It effectively reduces the test system's dependence on the intake system and can achieve precise control of the intake volume. The present invention can compare single-cylinder operation and multi-cylinder operation, providing data support for subsequent multi-cylinder engine tests. It meets the research and development needs of the early engine.

[0039] It should be noted here that the description of the above technical solutions is exemplary, and this specification can be embodied in different forms and should not be interpreted as being limited to the technical solutions set forth herein. On the contrary, providing these descriptions will make the disclosure of the present invention thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solutions of the present invention are limited only by the scope of the claims. When using "including", "having" and "comprising" described in this specification, there may also be another part or other parts, and the terms used may generally be singular but may also represent plural forms. Finally, it should be pointed out that the above embodiments are only more representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments, and there may be many variations. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention should be deemed to fall within the scope of protection of the present invention.

Claims

1. A testing method for a single-cylinder combustion test system based on a multi-cylinder engine, the single-cylinder combustion test system based on a multi-cylinder engine comprising a multi-cylinder engine (1) and a dynamometer (2) connected thereto, characterized in that: The intake side of any two adjacent cylinders of the multi-cylinder engine (1) is connected to an intake system, and the exhaust side of any two adjacent cylinders of the multi-cylinder engine (1) is connected to an exhaust system; the intake system includes an intake tank (3) and an intake regulating device connected to the intake tank (3) for regulating intake pressure and intake temperature, and the exhaust system includes an exhaust regulating device for regulating exhaust pressure and exhaust temperature; the outlet end of the intake regulating device is connected to the intake side of any two adjacent cylinders of the multi-cylinder engine (1), and the intake end of the exhaust regulating device is connected to the exhaust side of any two adjacent cylinders of the multi-cylinder engine (1); The test method of the single-cylinder combustion test system based on a multi-cylinder engine includes opening an intake system and an exhaust system, igniting a hot engine of the multi-cylinder engine (1), keeping any two adjacent cylinders of the multi-cylinder engine (1) in continuous operation, disconnecting the other cylinders, adjusting the working conditions of the two adjacent cylinders that continue to operate so that the two adjacent cylinders reach their respective test working conditions; adjusting the intake system so that it meets intake boundary conditions, and adjusting the exhaust system so that it meets debugging requirements; monitoring and recording test data, and disconnecting the two adjacent cylinders after the test is completed; the method of adjusting the working conditions of the two adjacent cylinders that continue to operate so that the two adjacent cylinders reach their respective test working conditions is: adjusting the fuel injection amount of the two adjacent cylinders that continue to operate so that the two adjacent cylinders reach their respective test working conditions, adjusting the fuel injection amount of the two adjacent cylinders that continue to operate so that the two adjacent cylinders reach their respective test working conditions from the current hot engine working condition to the adjustment working condition, and adjusting the fuel injection amount of the two adjacent cylinders again so that the two adjacent cylinders adjust the adjustment working condition to their respective test working conditions; the method of disconnecting the two adjacent cylinders after the test is completed is: adjusting the fuel injection amount of the two adjacent cylinders so that the two adjacent cylinders adjust the test working condition to the adjustment working condition after the test is completed, and disconnecting the two adjacent cylinders.

2. The testing method of a single-cylinder combustion test system based on a multi-cylinder engine according to claim 1, characterized in that: The air intake regulating system comprises an air intake temperature regulating device whose air intake end is connected to the air intake tank (3) and an air intake pressure regulating device whose air intake end is connected to the air outlet end of the air intake temperature regulating device; the air intake sides of any two adjacent cylinders of the multi-cylinder engine (1) are connected to the air outlet end of the air intake pressure regulating device.

3. The testing method of a single-cylinder combustion test system based on a multi-cylinder engine according to claim 2, characterized in that: The intake air temperature regulating device comprises an intake air heating device (4) whose intake end is connected to the intake tank (3) and an intake air cooling device (5) which is connected to the outlet end of the intake air heating device (4).

4. The testing method of a single-cylinder combustion test system based on a multi-cylinder engine according to claim 3, characterized in that: The intake pressure regulating device comprises an intake pressure stabilizing tank (6) whose intake end is connected to the outlet end of the intake cooling device (5), and the outlet of the intake pressure stabilizing tank (6) is connected to the intake sides of any two adjacent cylinders of the multi-cylinder engine (1).

5. The testing method of a single-cylinder combustion test system based on a multi-cylinder engine according to claim 1, characterized in that: The exhaust regulating device comprises an exhaust pressure regulating device whose intake end is connected to the exhaust sides of any two adjacent cylinders of the multi-cylinder engine (1) and an exhaust temperature regulating device connected to the exhaust pressure regulating device; the exhaust pressure regulating device comprises an exhaust pressure stabilizing tank (7), and the exhaust temperature regulating device comprises an EGR cooling device (8).

6. The testing method of a single-cylinder combustion test system based on a multi-cylinder engine according to claim 1, characterized in that: A connecting pipeline is connected between the air outlet end of the air intake regulating device and the air intake end of the exhaust regulating device, and an EGR on-off valve (9) is provided on the connecting pipeline.

7. The testing method of a single-cylinder combustion test system based on a multi-cylinder engine according to claim 1, characterized in that: The steps include: Step 1: Open the intake system and exhaust system, and ignite the multi-cylinder engine (1) to heat up the engine; Step 2: Keep any two adjacent cylinders of the multi-cylinder engine (1) in operation, and disconnect the remaining cylinders; Step 3: Adjust the fuel injection amount of the two adjacent cylinders that continue to work, adjust the two adjacent cylinders from the current hot engine working condition to the adjustment working condition, adjust the fuel injection amount of the two adjacent cylinders again, and adjust the two adjacent cylinders from the adjustment working condition to their respective test working conditions; Step 4: Adjust the intake system to meet the intake boundary conditions, and adjust the exhaust system to meet the debugging requirements; Step 5: Monitor and record test data, adjust the fuel injection amount of the two adjacent cylinders after the test is completed, adjust the two adjacent cylinders from the test working condition to the regulation working condition, and disconnect the two adjacent cylinders.

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