丹东黄海客车独立采暖系统设计.doc

摘 要 预热器是随着汽车行业的迅速发展而演变出来的产物(也称为加热器下文均称为加热器），为了能够低温条件下发动机冷起动，车厢供暖，挡风玻璃除霜，减少发动机的磨损，降低燃油消耗率，增加发动机的工作效率和使用寿命，加热器便由此产生了。喷射雾化式加热器由于燃油跟空气混合充分，燃烧完全，热效率高，有害排放少，所以本次设计研究喷雾雾化加热器用来满足丹东黄海客车加热的需要。针对目前国内使用较多的YJP．Q系列喷射雾化式液体燃油加热器进行了性能摸底调研，掌握了其基本工作规律，并对其进行了相应的改进提高。 根据市场需求在现有技术和产品的基础上对YJP．Q系列燃油加热器进行了各系统尺寸的优化设计。调研发现：燃烧筒在一定长度范围内长度越长，加热器热功率、热效率越高；而小筒则在一定长度范围内长度越短，加热器热功率、热效率越高；存在一最佳尺寸锥形罩使加热器热功率、热效率最高；燃烧筒和小筒的双层燃烧室设计起到了很好的防止通过热辐射使热量流失的作用； 目前大多数液体型燃油加热器均采用螺旋式水腔进行换热，因该类换热器的换热面积受到制约，故热量损失较大。针对现有燃油加热器热交换器所存在的不足，充分的利用所学的知识，联系自己的想法设计了一种换热效率更高的带换热管的燃油加热器用热交换器。此热交换器的换热管位于燃烧器火焰筒中，一方面可以增加加热器的换热面积，充分吸收高温燃气的热能；另一方面，由于换热管直接与燃烧火焰接触，会在管内产生泡态沸腾，从而强化换热，提高加热器整体的热效率。此外，还设计了一系列新型的尾气换热器，充分利用加热器的尾气提前对换热水进行加热，明显提高了加热器的功率、效率，降低了排放。 关键词：车用加热器；换热管；尾气换热器；改进提高 Abstract Preheater, with the rapid development of automobile industry evolved out of the product (hereinafter referred to as the heater is also known as the heater), in order to be able to cold start the engine under low temperature conditions, car heating, defrosting the windshield, reducing engine wear and reduce fuel consumption and increase engine efficiency and service life, resulting in the heater will. As the fuel jet atomization heater air mix with the full, complete combustion, thermal efficiency, less harmful emissions, so this study nebulizer heater designed to meet the heating needs of Dandong Huanghai Bus. For domestic use more YJP. Q series jet atomizing liquid fuel heater performance thoroughly research, mastered the basic work rules, and its corresponding improvement increase.According to market demand in existing technologies and products based on the YJP. Q-Series fuel heater were optimized design of the system size. Research found that: the length of the combustion tube in a certain range the longer the heater thermal power, thermal efficiency is higher; and small tube in a certain length within the length of the shorter heater thermal power, thermal efficiency is higher; there is a best size conical cover so that the heater therma