Design And Experiment On A New Type Water Heated Parking Heater And Combustion Chamber Flow One-Dimensional Modeling

In high-latitude regions such as the northeast and northwest,in extremely cold weather in winter,outdoor parked cars have many problems at start-up.Solution is to install a parking heater.The parking heater has the advantages of compact structure,small volume,low fuel consumption and high thermal efficiency,which is consistent with the micro-turbine combustion chamber.This article developed a new type of water heated parking heater production.The designing of parking heater combustion chamber referred to the design experience and guidelines of micro-turbine combustion chamber.Innovatively,an air intake method with counterflow and graded supply was proposed,and corresponding structure was designed.The whole structure of parking heater was completed by numerical simulation and combustion experiment.And its heating and emission performance was measured.besides,a one-dimensional design model for the combustion chamber was proposed based on the fluid network method.Firstly,the working principle and basic theory of the parking heater combustion chamber were analyzed from aspects of fuel mixing,combustion method,flame propagation and stable combustion.According to the empirical formula and criteria of micro-turbine combustion chamber,the flow distribution and the size of flame tube as well as casing were calculated,and the cyclone was designed.Then a new type tail-head was designed to accommodate the new air intake method with counterflow and graded supply.At the end of this section,the preliminary stereotype of the new parking heater combustion chamber structure was completed.Secondly,numerically simulated the flow and combustion of the parking heater after three-dimensional modeling.Through the simulation result of cold flow and recirculation zone distribution,it was concluded that the number of swirler channels must be equal to or multiple of the number of holes in the flame tube.Besides,the combustion chamber adapted the structure of 3% root volume and tail spacing shortened by 10 mm of original structure.Through the numerical simulation result of combustion,the distribution of velocity,temperature and pollutant in combustion chamber at different excess air coefficient were obtained.Thirdly,experiment of parking heater combustion was carried out.Through the open fire observation system,according to the composition and temperature of the outlet smoke,flame combustion status and carbon deposition under different conditions,15 mm atomization net with 50 mesh size and cyclone with 3.5mm offset distance were adapted.And then parking heater combustion chamber was finalized.The heat transfer test was performed using a parking heater equipped with a heat exchanger,and the time required for heating the coolant from the ambient temperature of 17?,8?,0?,and-15? to 70°? were 14 min,16 min.22 min,and 26 min,the heating rate decreased with the decrease of the ambient temperature,and the combustion was insufficient.Finally,based on the fluid network method,the one-dimensional flow in the combustion chamber of the parking heater was analyzed.Through a simplified topology analysis of the combustion chamber,a nodal fluid network diagram was obtained.Based on the relationship between pressure and flow,a balance equation was established,and the matrix equation applicable to the one-dimensional flow description of the combustion chamber of the parking heater was obtained.