Gasoline engine bench test intake heating device and control method

Abstract

The application provides a gasoline engine bench test intake air heating device and a control method, rapid control of temperature increase and decrease of the after-intercooling intake air is realized through control of the intake air heating device, the situation that increasing the compression ratio and enhancing the intake air tumble flow ratio significantly increases knocking and significantly deteriorates fuel consumption is solved, the engine is effectively protected during the test process, the harm of over-pressurization, over-manifold pressure, knocking, early combustion, high exhaust temperature and the like to the engine and after-treatment is reduced, and the demand of full MAP fuel consumption test after the intake air temperature is increased is met.

Description

Technical Field

[0001] This invention relates to the field of automotive gasoline engines, and more specifically, to an intake air heating device and control method for gasoline engine bench testing. Background Technology

[0002] Currently, high tumble ratio, high compression ratio, and low-pressure EGR paired with an electric turbocharger have become the mainstream technologies in the development of new energy engines. Their main purpose is to improve the overall vehicle power performance, enabling the engine to operate at its optimal point, thereby improving engine thermal efficiency and enhancing the vehicle's fuel economy.

[0003] However, increasing the compression ratio and enhancing the intake tumble ratio, along with the resulting increase in intake temperature and pressure, often significantly increases the tendency for engine knock. Furthermore, with reduced intake charge, the optimal firing angle (8 degrees after top dead center in the MFB50 or the knock boundary under KP-PK settings) is delayed. Afterburning leads to a significant increase in exhaust manifold and afterburner temperatures, thus worsening fuel consumption. Especially in high-temperature regions, severe engine knock can cause excessive annealing at the firing angle, resulting in insufficient power and significantly worsened fuel economy.

[0004] In existing technologies, with the intercooler components remaining unchanged and the heat dissipation capacity fixed, the temperature after intercooling varies with changes in intake air temperature, intake air flow rate, and the temperature and flow rate of the coolant on the test bench. Current test benches control the coolant flow rate by adjusting the opening of an electromagnetic flow valve, thereby regulating the temperature of the water-cooled intercooler. However, this temperature control method has a limited range and is inflexible, especially in areas where the engine speed is below 2000 rpm and the temperature after intercooling exceeds 40°C, making it difficult to simulate the intake air temperature of the entire vehicle under high-temperature conditions.

[0005] In high-temperature summer environments, due to low intake air volume at low speeds and high ambient temperatures, the engine dissipates heat slowly to the surrounding environment. Combined with heat accumulation in the engine compartment, gas vortices, and hot air recirculation, the engine intake air temperature can reach 60°C or higher. Under operating conditions of 1000-1750 rpm, a load greater than 7 bar, and an intercooler temperature of 60°C, the EGR rate cannot reach the intercooler temperature EGR rate under the original boundary conditions, and the ignition timing cannot be advanced to the original optimal ignition timing.

[0006] Due to the introduction of low-pressure EGR into the cylinder, the exhaust gas concentration is high, and the intake temperature is excessively high. The fresh working fluid expands due to heat, reducing the in-cylinder charge coefficient, slowing combustion, and causing severe afterburning. With constant heat transfer within the cylinder, the temperature of the air-fuel mixture in the cylinder can easily rise to near the ignition point of gasoline, leading to frequent misfires and severe knocking, and even posing a risk of pre-ignition.

[0007] The above phenomena can lead to a rapid deterioration in vehicle fuel consumption. Therefore, it is necessary to conduct a preliminary assessment and prediction of the engine's fuel consumption deterioration on a test bench. This is a key focus of subsequent EGR calibration and engine thermal management work. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the purpose of this invention is to provide a gasoline engine bench test intake air heating device and control method to solve the problem that increasing the compression ratio and enhancing the intake tumble ratio in existing technologies will significantly increase knocking and significantly worsen fuel consumption. During the test, the device effectively protects the engine and reduces the damage to the engine and aftertreatment caused by problems such as over-boosting, excessive manifold pressure, knocking, pre-ignition, and excessive exhaust temperature, while meeting the requirements of full MAP fuel consumption testing after the intake air temperature rises.

[0009] To achieve the above-mentioned technical effects, the present invention adopts the following technical solution:

[0010] According to a first aspect of the present invention, a method for controlling intake air heating in a gasoline engine bench test is provided, comprising the following steps:

[0011] Step S1: Turn on the ambient air conditioning to adjust the ambient temperature and humidity to summer test conditions; at the same time, fill the circulating water pump with coolant in advance, and use the circulating water pump to introduce the vehicle coolant into the intercooler, and drain the circulating water pump and intercooler.

[0012] Step S2: Close the coolant passage and circulating water pump, and turn on the hot air damper of the blower to quickly heat the intake gas after intercooling to reach the high temperature required for the test;

[0013] Step S3: Control the intake air temperature within the test limits by manually setting and adjusting engine parameters, and conduct combustion and fuel consumption performance tests;

[0014] When the temperature of the heated high-temperature intake air exceeds the experimental requirement by more than 3°C, turn on the circulating water pump, turn off the blower, and introduce coolant into the intercooler to cool the intake air. Set the temperature value on the test bench to cool the intake air to the ambient temperature. After the intake air temperature drops to the ambient temperature after intercooling, turn on the blower to deliver hot air, turn off the circulating water pump, continue heating the intercooled intake air, and start the next working condition test or supplement the test data of this working condition.

[0015] When the intercooled intake air temperature is in the range of 57-63℃ and the preset operating conditions are met during the combustion and fuel consumption performance test, the test ends and the circulating water pump is turned on to cool the intercooled gas.

[0016] Preferably, the ambient temperature in the summer test conditions is 40°C.

[0017] Preferably, the pump head of the circulating water pump is calculated using the following formula: H = 1000(P1-P2) / ρg + (z2-z1) + (v2²-v1²) / 2g, where: H is the pump head in meters (m); P1 is the pump outlet pressure in kilopascals (kPa); P2 is the pump inlet pressure in kilopascals (kPa); and ρ is the density of the coolant in kilograms per cubic meter (kg / m³). 3 z1 and z2 are the vertical height differences from the pump inlet and outlet to the pump center axis, respectively, in meters (m); v1 and v2 are the average flow velocities of the coolant at the pump inlet and outlet, respectively, in meters per second (m / s).

[0018] Preferably, in step S3, the manual setting and adjustment of engine parameters includes manually setting and adjusting the VVT ​​angle, high-pressure fuel rail pressure, injection mode, injection phase, boost pressure and air-fuel ratio control using closed-loop control, disabling knock protection function, and manually adjusting the ignition angle and low-pressure EGR rate.

[0019] Preferably, during the combustion and fuel consumption test in step S3, ECU data is recorded by computer, and the combustion analyzer records the mean indicated pressure (IMEP), mean indicated pressure cycle variation coefficient (CIMEP), knock safety factor (KP-PK), ignition delay period, ignition angle corresponding to 50% heat release, and combustion duration; the test bench calculates the actual low-pressure EGR rate, mean braking effective pressure (BMEP), and fuel consumption.

[0020] Preferably, in step S3, the preset operating conditions that occur during the combustion and fuel consumption performance test include: the boost pressure of the test condition exceeds the upper limit of the MAP operating point, the load exceeds the limit value, the optimal ignition angle is too far behind the original boundary, the temperature after the vortex and the catalytic converter is close to the alarm limit of the bench alarm monitoring equipment, and misfire occurs in the combustion analyzer or PMAX exceeds the safety threshold.

[0021] Preferably, in step S3, the preset operating conditions of the combustion and fuel consumption performance test include: when the engine speed is below 2000 rpm, the exhaust gas recirculation (EGR) rate is too high, resulting in incomplete combustion and misfire; under the same charge and manifold pressure at the original boundary, the engine torque cannot be increased; when attempting to improve torque output by increasing the ignition angle, knocking occurs.

[0022] According to a second aspect of the present invention, a gasoline engine bench test intake air heating device is provided for implementing the gasoline engine bench test intake air heating control method according to any of the preceding claims. Specifically, it includes the following components: an intake air conditioner, an intake air temperature sensor, an intercooler, a circulating water pump, a bench cooling control device, an ambient air conditioner, a blower, an ECU control unit, a bench monitoring and alarm device, an engine internal circulation pipeline, an engine second circulation pipeline, an intercooler inlet and outlet water pipes, and an intercooler inlet and outlet air pipes.

[0023] The engine internal circulation pipeline includes the engine main water inlet pipe and the engine main water outlet pipe, which are connected to the bench cooling control equipment. The intercooler is connected to the engine's second circulation pipeline, enabling the bench cooling control equipment to control the coolant required by the intercooler, with unidirectional flow. The intercooler's inlet and outlet pipes are connected to the engine's second circulation pipeline. The circulating water pump is installed on the intercooler's inlet and outlet pipes to provide the power required for coolant circulation in the intercooler.

[0024] The ambient air conditioner provides the required summer ambient temperature and humidity for the test; the blower's hot air baffle heats the gas after intercooling; the intake air temperature sensor records the intake air temperature after intercooling in real time; and the ECU control unit can perform real-time closed-loop control based on the intake air temperature and calibration parameters.

[0025] Preferably, the intercooler is provided with heat insulation cotton, which serves to keep the gas warm and allow the pressurized gas after intercooling to be rapidly heated to the test temperature within a specified time.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) When the intake air heating control method for gasoline engine bench test provided by the present invention needs to reduce the intake air temperature after intercooling, it can quickly control the temperature after intercooling back to the original test boundary conditions of the corresponding speed after switching back to bench intercooling control.

[0028] (2) The gasoline engine bench test intake air heating control method provided by the present invention can quickly switch to the heating mode, and the temperature after intercooling can reach the set temperature of the corresponding speed relatively quickly.

[0029] (3) The gasoline engine bench test intake heating device and control method provided by the present invention can cover the testing of all working conditions of the whole vehicle. The device has a simple structure and the method is easy to use. Attached Figure Description

[0030] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0031] Figure 1 This is a structural diagram of the intake control system for the gasoline engine bench test described in the first embodiment;

[0032] Figure 2 This is a schematic diagram illustrating the implementation of the gasoline engine bench test intake control method described in the second embodiment;

[0033] Figure 3 This is a control flowchart of the gasoline engine bench test intake control method described in the second embodiment;

[0034] Figure 4 This is a flowchart of the steps of the gasoline engine bench test intake control method described in the second embodiment;

[0035] Figure label:

[0036] 1-Intake air conditioning; 3-Intake air temperature sensor; 4-Intercooler

[0037] 5-Circulating water pump; 6-Bench cooling control equipment; 13-Ambient air conditioning.

[0038] 14-Blower; 27-Low-pressure EGR cooler and intake piping; 18-ECU control unit

[0039] 19- Bench monitoring and alarm equipment; 21- Engine main water inlet pipe; 22- Engine main water outlet pipe

[0040] 28-Intercooler inlet / outlet pipes; 23-Second engine coolant inlet pipe; 24-Second engine coolant outlet pipe

[0041] 25 - Intercooler inlet pipe 26 - Intercooler outlet pipe Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0044] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, all directional indications (such as up, down, left, right, front, back, bottom, etc.) in this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indication will also change accordingly. Furthermore, descriptions involving "first," "second," etc., in this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0045] Example 1

[0046] like Figure 1 As shown, this embodiment provides a gasoline engine bench test intake air heating device, including the following components: intake air conditioner 1, intake air temperature sensor 3, intercooler 4 (including intercooler bracket and heat insulation cotton), circulating water pump 5, bench cooling control equipment 6, ambient air conditioner 13, blower 14, combustion analyzer, ECU control unit 18, bench monitoring and alarm equipment 19, engine internal circulation pipeline (including engine main water inlet pipe 21 and engine main water outlet pipe 22), engine second circulation pipeline (including engine second water inlet pipe 23 and engine second water outlet pipe 24), intercooler inlet and outlet water pipes (including intercooler inlet pipe 25 and intercooler outlet pipe 26), and intercooler inlet and outlet air pipes 28.

[0047] The engine internal circulation pipeline (including the engine main water inlet pipe 21 and the engine main water outlet pipe 22) is connected to the bench cooling control equipment 6. The intercooler 4 is connected to the engine's second circulation pipeline (including the engine's second water inlet pipe 23 and the engine's second water outlet pipe 24), enabling the bench cooling control equipment 6 to control the coolant required by the intercooler 4, allowing for unidirectional flow. The intercooler inlet and outlet pipes 28 are connected to the engine's second water inlet pipe 23, and a circulating water pump 5 is installed on the intercooler inlet and outlet pipes 28, providing the power required for coolant circulation in the intercooler 4. The intercooler 4 is equipped with heat insulation cotton, which serves to keep the gas heated after intercooling rapidly to the test temperature within a specified time.

[0048] The ambient air conditioner 1 provides the required summer ambient temperature and humidity for the experiment. The blower 14's warm air setting simulates the summer ambient intake air temperature, while its hot air setting heats the intercooled gas. The intake air temperature sensor 3 records the intercooled intake air temperature in real time; the ECU control unit 18 uses the intake air temperature and calibration parameters for real-time closed-loop control. The intake air temperature sensor 3, ECU control unit 18, and circulating water pump 5 work together to achieve real-time control of the intake air temperature and heating of the intake air on the test bench.

[0049] When the intake air needs to be heated to the test temperature after intercooling, the circulating water pump 5 stops pumping coolant into the intercooler 4, the coolant passage is closed, and the intercooler 4 loses its cooling function. At the same time, the blower 14 is turned on and set to the hot air baffle to blow directly onto the intercooler 4. Under the condition that the external coolant circulation passage is closed, the intercooler 4 cannot cool the intake airflow. At the same time, the heat insulation cotton on the intercooler 4 also plays a role in heat preservation. Therefore, the pressurized gas after intercooling can be rapidly heated to the test temperature within 15 minutes.

[0050] When the intake air temperature exceeds the test temperature boundary, turn on the circulating water pump 5, and the coolant enters the intercooler 4. At the same time, turn off the blower 14 and set the intake air temperature after intercooling to the ambient temperature on the test bench control panel.

[0051] Example 2

[0052] like Figure 2 As shown, this embodiment provides a method for controlling intake air heating in a gasoline engine bench test. Using the intake air heating device described in the first embodiment, the intake air temperature is first heated from ambient temperature. During this process, blower 14 is turned on and circulating water pump 5 is turned off, allowing the intake air temperature to reach the test boundary temperature. When the intake air temperature is within the test boundary range, a universal characteristic curve is scanned to determine the engine's economic operating range, while simultaneously observing the deterioration of fuel consumption relative to the economic operating range at high intake air temperatures. Next, with the intake air temperature within the test boundary range, the next operating condition test is conducted. When the operating condition test is completed or a specific operating condition occurs, circulating water pump 5 is turned on and blower 14 is turned off, allowing the intake air temperature to cool back to ambient temperature. The method is as follows... Figure 4 As shown, the specific steps include:

[0053] Step S1: In the bench test, to simulate a high-temperature summer environment, the blower 14 is first turned off, and the ambient air conditioner 1 is turned on to adjust the temperature and humidity of the test chamber to summer test conditions (referencing the average temperature in Turpan in July). The intake air is taken from the air heated by the ambient air conditioner 1, and the ambient air temperature is controlled at 40℃. During this process, the intake air temperature sensor 3 on the bench records and monitors the intake air temperature after intercooling in real time.

[0054] Subsequently, the circulating water pump 5 is used to introduce ethylene glycol automotive coolant into the intercooler 4, which is fixed on the tooling bracket, through the intercooler inlet pipe 25, with the water flow direction being bottom in and top out.

[0055] The working capacity of the circulating water pump 5 determines the pressure difference between the intercooler outlet and the pump inlet, and this pressure difference determines the vertical height relative to the pump centerline. The selection of the circulating water pump 5 cannot be precisely calculated; its head is usually determined experimentally, denoted by H. The pump head refers to the energy head increase achieved by the circulating water pump 5 when it pumps a unit mass of coolant from the pump inlet to the pump outlet. The head determines the capacity of the circulating water pump 5, including its ability to resist fluid resistance and provide pressure. The magnitude of the head directly affects the working efficiency of the circulating water pump 5 and the operating status of the cooling system. The pump head is typically determined experimentally or by calculation. Based on the principle of energy conservation and the basic formulas of fluid mechanics, the pump head can be calculated using the following formula: H = 1000(P1 - P2) / ρg + (z2 - z1) + (v2² - v1²) / 2g, where: H is the pump head in meters (m); P1 is the pump outlet pressure in kilopascals (kPa); P2 is the pump inlet pressure in kilopascals (kPa); and ρ is the density of the coolant in kilograms per cubic meter (kg / m³). 3); g is the acceleration due to gravity, taken as 9.8 m / s²; z1 and z2 are the vertical height differences from the pump inlet and outlet to the pump center axis, respectively, in meters (m); v1 and v2 are the average flow velocities of the coolant at the pump inlet and outlet, respectively, in meters (m / s).

[0056] Draining the circulating water pump 5 and intercooler 4: To prevent cavitation in the circulating water pump 5 and ensure it provides sufficient head, the circulating water pump 5 needs to be filled with coolant before operation. This avoids excessive air, as too much air can lead to insufficient coolant flow, affecting effective cooling of the intake air temperature after intercooling. The specific operation involves: sending coolant into the inlet of the circulating water pump 5, flowing through the pump to the intercooler 4, and then out of the intercooler 4 outlet to the intercooler. The head at the inlet of the circulating water pump 5 can be expressed by the formula Hin =

[0057] The calculation is based on z1 + 1000P1 / ρg + v1 / 2g, while the net positive suction head (NPSH) is calculated as Hin + 1000(P - Penv) / ρg, where P is atmospheric pressure and Penv is the vaporization pressure of water at 25°C in the environmental chamber. After power-on, the circulating water pump 5 operates at the set speed, running continuously until coolant continuously flows from the outlet of the intercooler 4. If no coolant flows from the outlet of the intercooler 4, the operator needs to manually add water to the circulating water pump 5 to ensure the successful purging process of the intercooler 4 and the circulating water pump 5. The flow of coolant from the outlet of the intercooler 4 indicates that the pipes and the intercooler 4 are full of cooling medium, and the circulating water pump 5 and the intercooler 4 have been purged.

[0058] Step S2: Close the coolant passage and stop the external circulation of the circulating water pump 5. Turn on the hot air setting of the blower 14 to quickly heat the intercooled intake gas to reach the required test temperature. Specifically, this includes: closing the coolant switch, stopping the circulating water pump 5 from pumping coolant into the intercooler 4, closing the coolant passage, and rendering the intercooler 4 ineffective. Simultaneously, turn on the blower 14 with the hot air setting blowing directly onto the intercooler 4 while the external circulation is closed. With the external coolant circulation closed, the intercooler 4 cannot cool the intake airflow. Meanwhile, the insulation cotton on the intercooler 4 provides insulation. Therefore, the intercooled pressurized gas can be rapidly heated to the test temperature of 60℃ within 15 minutes. The temperature boundary in the test is 60±3℃. During the closed-loop heating process, the intercooled intake gas temperature needs to be above 40℃, but the maximum intake temperature must not exceed 67℃. The alarm value for the intake temperature is 70℃. If the intake temperature exceeds 70℃, the bench monitoring alarm device 19 will sound an alarm.

[0059] Step S3: By manually setting and adjusting engine parameters, control the intake air temperature within the test limits and conduct combustion performance tests, specifically including:

[0060] When the intake air temperature is within the test boundary (60±3℃), manually adjust the VVT ​​angle, high-pressure fuel rail pressure, injection mode, injection phase, boost pressure, and air-fuel ratio control using closed-loop control, disable knock protection, and manually adjust the ignition angle and low-pressure EGR rate to begin combustion and fuel consumption testing. During combustion and fuel consumption testing at the preset intake air temperature, the computer records ECU data, and the combustion analyzer records the mean indicated pressure (IMEP), mean indicated pressure cycle variation factor (CIMEP), knock safety factor (KP-PK), ignition delay period, ignition angle corresponding to 50% heat release, and combustion duration. The test bench calculates the actual low-pressure EGR rate, mean braking effective pressure (BMEP), and fuel consumption, monitors test boundary conditions, and responds to alarm values.

[0061] When the intercooled intake air temperature exceeds the boundary by more than 3°C, the test ends. The circulating water pump 5 is turned on to cool the intercooled gas. At the same time, the proportional solenoid valve starts to work, and the coolant enters the intercooler 4. Meanwhile, the blower 14 is turned off. The intercooled intake air temperature is set to the ambient temperature on the test bench control panel. During this process, the coolant circuit is controlled by the opening and closing of the external switch. The electromagnetic proportional valve adopts PID control, and different coolant flow rates are controlled by different duty cycles.

[0062] After the intake air temperature drops to ambient temperature (ambient chamber temperature 40℃) after intercooling, resume the hot air supply from blower 14, disconnect the circulating water pump 5 switch, continue heating the intake air after intercooling, and start the next operating condition test or supplement the test data for this operating condition (if data that does not meet the boundary conditions is found, the operating condition needs to be redone).

[0063] like Figure 3 As stated above, the intercooled intake air temperature is within the test boundary, i.e., the range of 57-63℃. However, if the following conditions occur, the test ends, and the circulating water pump 5 is turned on to cool the intercooled gas:

[0064] (1) If the test condition boost pressure exceeds the upper limit of the MAP condition point, the load exceeds the limit, the optimal flame angle is too far behind the original boundary, the temperature after the vortex and the catalytic converter is close to the alarm limit of the bench alarm monitoring equipment 19, or a misfire occurs in the combustion analyzer or PMAX exceeds the safety threshold (large compression ratio, safety factor set to 1), the test ends, the circulating water pump 5 is turned on to cool the gas after intercooling.

[0065] (2) When the engine speed is below 2000 rpm, the exhaust gas recirculation (EGR) rate is too high, resulting in incomplete combustion and misfire. Under the same charge and manifold pressure at the original boundary, the engine torque cannot be increased. When an attempt is made to improve the torque output by increasing the ignition angle, knocking is triggered. The test ends, the data is recorded, and the circulating water pump 5 is turned on to cool the gas after intercooling.

[0066] This application solution can effectively protect the engine during the test, reducing the damage to the engine and aftertreatment caused by problems such as overboost, excessive manifold pressure, knock, pre-ignition, and excessive exhaust temperature. At the same time, the control strategy can meet the requirements of full MAP fuel consumption test after the intake air temperature rises.

[0067] The specific embodiments of the present invention have been described above. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of the present invention.

Claims

1. A gasoline engine bench test intake air heating control method, characterized by, The method comprises the following steps: Step S1: open the environmental air conditioner to adjust the temperature and humidity of the environment to the summer test condition; meanwhile, fill the cooling liquid in the circulating water pump in advance, and use the circulating water pump to introduce the vehicle cooling liquid into the intercooler, and empty the circulating water pump and the intercooler; Step S2: close the cooling liquid channel and the circulating water pump, and open the hot air baffle of the air blower to quickly heat the intercooled intake air to reach the high temperature required by the test; Step S3: control the intake air temperature within the test boundary by manually setting and adjusting the engine parameters, and test the combustion and fuel consumption performance; When the high-temperature intake air after heating exceeds the required temperature by more than 3℃, open the circulating water pump, close the air blower, introduce the cooling liquid into the intercooler to cool the intake air, and set the temperature value on the test bench to cool the intake air to the ambient temperature; after the temperature of the intake air after intercooling drops to the ambient temperature, restore the air blower to send hot air, close the circulating water pump, continue to heat the intake air after intercooling, and start the next test condition test or supplement the data of the current test condition test; When the temperature of the intake air after intercooling is within the range of 57-63℃, but the preset test condition occurs during the combustion and fuel consumption performance test, the test is ended, the circulating water pump is opened to cool the intake air after intercooling, and the preset test condition includes: (1) the test condition exceeds the upper limit of the MAP working condition point, the load exceeds the limit value, the optimal ignition angle is too late relative to the original boundary, the temperature after the turbine and the catalyst is close to the alarm limit of the alarm monitoring equipment on the test bench, the combustion analyzer appears misfire or PMAX exceeds the safety threshold; or (2) when the engine speed is below 2000 rpm, the EGR rate is too high, which leads to incomplete combustion and misfire; under the same charge and manifold pressure of the original boundary, the engine torque cannot be increased; or the ignition angle is tried to be improved to improve the torque output, but it causes the knocking problem.

2. The gasoline engine bench test intake air heating control method according to claim 1, characterized by, The ambient temperature in the summer test condition is 40℃.

3. The gasoline engine bench test intake air heating control method according to claim 1, characterized by, The pump head of the circulating water pump is calculated by the following formula: H=1000(P1-P2) / ρg+(z2-z1)+(v2²-v1²) / 2g, wherein: H is the pump head, unit: meter (m); P1 is the pressure at the outlet of the water pump, unit: kilopascal (kPa); P2 is the pressure at the inlet of the water pump, unit: kilopascal (kPa); ρ is the density of the cooling liquid, unit: kilogram per cubic meter (kg / m³); z1 and z2 are the vertical height difference between the inlet and outlet of the water pump to the central axis of the water pump, unit: meter (m); v1 and v2 are the average flow rate of the cooling liquid at the inlet and outlet of the water pump, unit: meter per second (m / s).

4. The gasoline engine bench test intake air heating control method according to claim 1, characterized by, In step S3, the manual setting and adjustment of the engine parameters include manual setting and adjustment of the VVT angle, the high-pressure oil rail pressure, the injection mode and the injection phase, the closing of the knock protection function, and the manual adjustment of the ignition angle and the low-pressure EGR rate.

5. The gasoline engine bench test intake air heating control method according to claim 1, characterized by, In step S3, when the combustion and fuel consumption test is carried out, the ECU data is recorded by computer, the average indicated pressure IMEP, the average indicated pressure cycle variation coefficient CIMEP, the knock safety factor KP-PK, the ignition delay, the 50% heat release corresponding ignition angle and the combustion duration are recorded by the combustion analyzer; the actual low pressure EGR rate, the average brake effective pressure BMEP and the fuel consumption are calculated by the bench.

6. A gasoline engine bench test intake air heating device characterized by comprising: The gasoline engine bench test intake air heating control method for implementing any one of claims 1 to 5, specifically comprising the following components: An intake air conditioner, an intake temperature sensor, a intercooler, a circulating water pump, a bench cooling control device, an environmental air conditioner, a blower, an ECU control unit, a bench monitoring and alarming device, an engine internal circulation pipeline, an engine second circulation pipeline, an intercooler inlet and outlet water pipeline and an intercooler inlet and outlet air pipeline; The engine internal circulation pipeline comprises an engine main inlet water pipeline and an engine main outlet water pipeline, the engine internal circulation pipeline is connected with the bench cooling control device, the intercooler is connected with the engine second circulation pipeline, the intercooler inlet and outlet water pipeline is connected with the engine second circulation pipeline, and the circulating water pump is installed on the intercooler inlet and outlet water pipeline to provide power required for circulating coolant of the intercooler; The environmental air conditioner is used to provide the required summer environment temperature and humidity, the hot air of the blower is used to heat the air after intercooling, the intake temperature sensor is used to record the temperature of the air after intercooling in real time, and the ECU control unit can realize real-time closed loop according to the intake temperature and calibration parameters.

7. The gasoline engine bench test intake air heating device according to claim 6, characterized by The intercooler is provided with heat insulation cotton, the heat insulation cotton plays a heat preservation role, and the pressurized air after intercooling can be quickly heated to the test temperature within a specified time.

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