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针对矿用车辆排气系统防爆性能要求高的问题,建立防爆柴油机含水夹套后处理装置流动及传热仿真模型,采用直接耦合法进行数值模拟,并通过试验验证模型准确性。在此基础上对后处理装置的气-水-固耦合传热进行分析,对冷却水流量与温度、水夹套厚度及混合器孔径等影响其流动与传热特性的因素进行深入研究。研究结果表明:水夹套外壳最高温度出现在排气出口处的法兰端面上部,此处超温风险最大;催化器载体表面温度均匀性随冷却水流量升高而降低,随冷却水温度升高而升高;适当增大水夹套厚度既可降低水夹套外壳表面最高温度,又能降低冷却水压降和水泵耗功;混合器虽能提高载体表面温度均匀性,但对水夹套外壳表面最高温度的控制却是不利的,且表面最高温度随着孔径的增大而提高。
In order to solve the problem of explosion-proof performance of mining vehicle exhaust system, a simulation model of flow and heat transfer in an aseptic diesel engine after-treatment device was established. The direct coupling method was used to simulate the model and the accuracy of the model was verified through experiments. Based on this, the gas-water-solid coupling heat transfer in the aftertreatment device is analyzed, and the factors influencing the flow and heat transfer characteristics, such as the cooling water flow and temperature, the water jacket thickness and the mixer aperture, are further studied. The results show that the maximum temperature of the water jacket shell appears at the upper part of the flange end face of the exhaust outlet where the over-temperature risk is the highest. The uniformity of the surface temperature of the catalyst carrier decreases with the increase of the cooling water flow rate, High and increased; appropriately increase the thickness of the water jacket can reduce the maximum jacket surface water jacket temperature, but also reduce the cooling water pressure drop and pump power consumption; although the mixer can improve the carrier surface temperature uniformity, but the water folder Controlling the maximum surface temperature of the casing is disadvantageous, and the maximum surface temperature increases as the pore size increases.