The Physical Desigh Of The Nozzle And The Flow Field Optimization Research Of The LNG Rapidly Carburetor

Nowadays we are facingincreasingly serious energy and environmental problems,the exploit and utileze of the clean energy has been widely concerned,especially Liquefied Natural Gas(LNG),which is taken more and more use.The advantages of LNG are that,it is easy to transport and its volume is much less than the natural gas,which lead to its more and more proportion in the market.And how to gasificate the LNG as quickly as possible has become the focus of study.This paper enumerates the common LNG gasification used at home and abroad.analysises their respective advantage and disadvantages and applicable occasions.Then put forward the study of the new type LNG rapidly carburetor.The principle of the device is that: the flue gas after combustion erupt through a conical nozzle,hit the umbrella rotor device under the water,then impact the water tangential with its guiding role and splashing wet flue gas.Finally the wet flue gas flow up through the heat exchanger and do the heat transfer to gasificate the LNG.LNG rapidly gasification three-dimensional simplified model is established.The flue gas field is defined as the VOF model of flue gas and water flow.The VOF model call in a UDF describe the high temperature flue gas with water and heat transfer and mass transfer at the same time.We use the separating solver to transient solve the problem.Control equations of discrete format using second order format while the pressure difference scheme adopts PRESTO! difference scheme,and the pressure velocity coupling algorithm uses the PISO algorithm.This paper finished the numerical simulation of the flow and heat transfer of the carburetor,and get the flow field,the temperature field distribution of the carburetor.Simulated three different nozzle height and three different water level when the flue gas impact the umbrella rotor and obtain its current situation and temperature fields.It is obvious that when the water level is 70 mm and the nozzle height is 235 mm,the LNG rapidly carburetor has the best working condition by judging the temperature of outlet flue gas and amout of water drop.When the nozzle height is higher or lower than 235 mm,the temperature of the smoke flue into the coil is higher than the safe temperature.When the water level is higher or lower than 70 mm,the water level upon the umbrella rotor device is too thick or too thin,those are bad for colling flue gas.This paper put forward the paramenters and equipment facilities when verify the analog result by experiment.This will lay a solid foundation for the next step study in the future.