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CN-122016908-A - Spark plug heat value measurement system and method of controllable activation thermal atmosphere combustor

CN122016908ACN 122016908 ACN122016908 ACN 122016908ACN-122016908-A

Abstract

The invention relates to a spark plug heat value measuring system and method of a controllable activated thermal atmosphere combustor, wherein the system comprises a combustion assembly, a test section, a spark plug clamping and adjusting assembly, a temperature measuring assembly, a cold air rapid cooling assembly and a data acquisition and control assembly, wherein the combustion assembly comprises a controllable thermal atmosphere combustor, the test section comprises a high-temperature-resistant test pipeline vertically arranged above the combustion assembly, the spark plug clamping and adjusting assembly is used for installing and fixing a spark plug and adjusting the insertion depth and the radial position of the spark plug in the high-temperature-resistant test pipeline, the temperature measuring assembly comprises an infrared thermal imager opposite to the high-temperature-resistant window and a thermocouple used for monitoring the temperature, and the cold air rapid cooling assembly is used for instantaneously injecting cooling air into a test cavity after the heating stage is finished and is used for synchronously controlling the power of the combustor and the triggering time sequence of cooling air flow. Compared with the prior art, the invention has the advantages of strong simulation authenticity, high measurement accuracy, high test efficiency, low cost, strong flexibility and adaptability and the like.

Inventors

  • DENG JUN
  • LI LIGUANG
  • JI MENG
  • ZHOU YANXIONG
  • MIAO XINKE

Assignees

  • 同济大学

Dates

Publication Date
20260512
Application Date
20260204

Claims (10)

  1. 1. A spark plug heating value measurement system for a controllably activated thermal atmosphere burner, comprising: The combustion assembly comprises a controllable heat atmosphere combustor (3) which is used for introducing fuel and combustion-supporting gas and igniting the fuel and the combustion-supporting gas to generate high-temperature gas flow so as to form high-temperature activated heat atmosphere simulating the in-cylinder heat environment of the engine; the test section comprises a high-temperature-resistant test pipeline vertically arranged above the combustion assembly, and a high-temperature-resistant window (15) is arranged on the high-temperature-resistant test pipeline and is used for forming a core test cavity so that high-temperature fuel gas flows through a spark plug (16); The spark plug clamping and adjusting assembly is used for installing and fixing the spark plug (16), adjusting the insertion depth and the radial position of the spark plug (16) in the high-temperature-resistant test pipeline, and ensuring that the ignition end of the spark plug (16) is positioned in the heat flow of the central area of the high-temperature-resistant test pipeline; The temperature measuring assembly comprises a thermal infrared imager (1) which is opposite to the high-temperature-resistant window (15) and a thermocouple (4) for monitoring temperature, and is used for non-contact measurement of temperature change of the spark plug in the heating and cooling processes; The cold air rapid cooling assembly is used for instantaneously injecting cooling air with controlled temperature, flow rate and flow state into the test cavity after the heating stage is finished so as to simulate the heat dissipation process of the spark plug during the air inlet stroke of the engine; And the data acquisition and control assembly (17) is used for synchronously controlling the power of the burner and the triggering time sequence of the cooling air flow, and acquiring and recording temperature data to calculate the heat value parameter of the spark plug (16).
  2. 2. The spark plug heat value measurement system of a controllable activated thermal atmosphere burner of claim 1, wherein the fuel introduced by the combustion assembly is a hydrogen-air mixture, and the heat source temperature can be regulated by controlling the flow and the ratio of the fuel to the combustion-supporting gas.
  3. 3. The spark plug heating value measurement system of a controlled activation hot atmosphere burner according to claim 1, characterized in that the combustion assembly is connected to a cooling water tank (2) through a cooling pipe.
  4. 4. The spark plug heat value measuring system of the controllable activated thermal atmosphere burner according to claim 1, wherein the spark plug clamping and adjusting assembly is in a local fixing mode of clamping only the bottom of the spark plug, and has the functions of axial depth adjustment, radial centering adjustment and pivoting.
  5. 5. The spark plug heat value measurement system of the controllable activated thermal atmosphere burner of claim 1, wherein the adjusting part of the spark plug clamping and adjusting assembly is in rod-shaped connection with the clamping part, and a high-efficiency heat insulation layer is arranged at the connection part to block heat from being conducted outwards along the adjusting rod.
  6. 6. The spark plug heating value measurement system of the controllable activated thermal atmosphere burner according to claim 1, wherein thermocouples (4) in the temperature measurement assembly are arranged at a plurality of positions in the test chamber for measuring the heat flux temperature, the cold air temperature, the spark plug surface temperature and the clamping fixture temperature, and the use is limited to monitoring the air flow temperature and the calibration and verification of auxiliary infrared thermal imaging.
  7. 7. The spark plug heating value measurement system of a controlled activation hot atmosphere burner of claim 1, wherein the cold air rapid cooling assembly comprises a blower, a constant temperature air source, a mass flow controller, a solenoid valve (6) and a flow field rectifying nozzle.
  8. 8. A method of measuring the heating value of a spark plug of a controlled-activation thermal-atmosphere burner according to any one of claims 1 to 7, comprising the steps of: S1, mounting and position calibration, namely mounting a spark plug (16) on a spark plug clamping and adjusting assembly, adjusting the position to enable a firing end of the spark plug (16) to be positioned in a central area of a test pipeline, and confirming that the surface of an insulator skirt of the spark plug (16) and an electrode are positioned in a glass observation window through a thermal infrared imager (1); s2, in a heating stage, a controllable thermal atmosphere combustor (3) is started, mixed gas with set flow is introduced, the spark plug (16) is continuously heated, and meanwhile, a data acquisition system synchronously records the temperature rising curve of the spark plug; S3, in a cooling stage, when the temperature of the spark plug (16) is monitored to reach a preset simulated peak temperature Tmax, fuel and air supply is cut off, a cold air rapid cooling component is triggered, cooling air is sprayed into a test pipeline, and the temperature reduction process of the spark plug (16) is continuously recorded until a simulated low temperature boundary Tmin is reached; s4, data processing, namely analyzing an acquired temperature-time curve, and calculating the heating time and cooling time of the spark plug (16); And S5, defining the standard characteristic cooling time ts of the spark plug (16) as the duration required for the temperature to drop from Tmax to Tmin under the standard cooling working condition, and taking the standard characteristic cooling time ts as a heat value parameter.
  9. 9. The method for measuring the heat value of a spark plug of a controlled-activation thermal-atmosphere burner according to claim 8, further comprising the step of evaluating the heat value after S5, wherein the measured standard characteristic cooling time ts is substituted into a pre-calibrated conversion model imep=f (ts), a predicted IMEP value is calculated, and the heat value characteristic of the spark plug (16) is determined according to the comparison relation between IMEP and heat value.
  10. 10. The method for measuring the heating value of a spark plug of a controllable activated thermal atmosphere burner according to claim 8, wherein the temperature of cooling air in the cooling stage is stabilized at 25 ℃ ± 1 ℃, and the flow rate is controlled at 5-40 m/s (±2%).

Description

Spark plug heat value measurement system and method of controllable activation thermal atmosphere combustor Technical Field The invention relates to the technical field of detection of parts of internal combustion engines, in particular to a spark plug heat value measurement system and a spark plug heat value measurement method of a controllable activated thermal atmosphere combustor. Background The heat value characteristics of the spark plug, which is used as a key component of an ignition system of a spark ignition engine, directly affect ignition performance, combustion stability and service life. The heat value of the spark plug is a key performance index for measuring the heat dissipation capacity of the spark plug, and is directly related to the performance, the oil consumption and the emission of the engine. The problems of pre-ignition, knocking or carbon deposition can be caused by the fact that the heat value is too high or too low, so that the accurate evaluation of the heat value of the spark plug has important significance for engine research and development, matching and fault diagnosis. At present, the mainstream spark plug heat value testing methods (such as ISO 11565, SAE J549, GB T38184-2019 and the like) are all required to be carried out on a special standard engine rack, and have the limitations of long period, high cost, multiple interference factors and difficulty in separating the influence of specific variables, and the testing needs to consume fuel and can generate emission, so that the requirements of convenience in spark plug detection, low cost, environmental protection, high accuracy, high repeatability and the like cannot be met. Therefore, there is an urgent need in the art for an independent testing platform system for measuring the heat value of a spark plug, which can simulate the thermal working condition of a real engine, has a wide temperature range, wide fuel adaptability, accurate measurement, quick response and environmental protection, and a corresponding proprietary testing method and evaluation index. Some existing spark plug heating value system methods based on a non-engine bench independent test platform, such as an electric heating method, have fundamental limitations in simulating the environment in a real engine cylinder. The method generally carries out static or slowly varying heating on the spark plug through electric heating elements such as resistance wires, and the heat source form of the method is basically different from the dynamic high-temperature gas flow generated by detonation of high-speed and high-pressure gas mixture in the working process of an engine. The electric heating method mainly relies on heat conduction and natural convection, and cannot reproduce strong forced convection heat exchange, severe transient thermal shock and periodic high-frequency thermal cycling processes in a cylinder. Firstly, the direct scouring effect of combustion flame on the skirt part of the spark plug insulator and the electrode cannot be simulated, so that the deviation between the thermal boundary condition and the heat exchange coefficient of the key part of the spark plug and the actual situation is obvious; secondly, the lack of chemical heat atmosphere under the working condition of the engine, namely, the chemical actions (such as catalytic reaction, corrosion and the like) of active free radicals and intermediate products in high-temperature fuel gas on the surface of the spark plug are completely ignored, and thirdly, the high-frequency alternating thermal mechanical load special for the engine is difficult to apply, and the load is a key factor influencing the thermal fatigue and the sealing performance of the spark plug. Therefore, due to the lack of physical and chemical processes of the cores, the measurement of the heat value parameters or the data of the temperature field of the spark plug obtained based on the method (such as an electric heating method) is often not well correlated with the result measured on a real engine bench, the accuracy is not enough, the data can only be used as a preliminary reference, the performance prediction of the spark plug of the target real engine cannot be effectively performed, and the development of a higher-fidelity simulation technology is urgent. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a spark plug heat value measuring system of a controllable activation heat atmosphere burner, which has the advantages of strong simulation reality, high measuring accuracy, high testing efficiency, low cost and strong flexibility and adaptability. The aim of the invention can be achieved by the following technical scheme: The core of the invention is that a controllable activated thermal atmosphere burner is adopted, and the flow and the pressure of fuel and air are precisely controlled, so that high-temperature air flow can be stably and repeatedly generated in a la