Evaluation of Turbulent Heat Transfer Enhancement in Steam-Cracking Furnace Tubes with Modified Internal Textures

乙烯是加拿大化工和塑料工业必不可少的有价值的化工产品。它是由乙烷气体和蒸汽在蒸汽裂解炉的高温下反应产生的。反应的不良副产物是在反应器壁上逐渐沉积无定形焦炭。积炭降低了炉的效率，导致蒸汽裂解过程定期停工以清除积炭。提高从反应器壁到炉内流动气体的传热速率可以降低焦炭的形成速度。不幸的是，提高传热速率的传统方法也增加了炉内的摩擦压力损失，这转化为更高的运行成本。该研究项目将研究增加乙烯生产炉的传热率的新方法，该方法仅产生最小的摩擦损失增加。UBC奥肯那根大学和阿尔伯塔大学的研究人员将与Quantiam技术公司合作，通过在反应堆内壁上放置图案纹理来研究增强传热。这些纹理突出到湍流边界层中，并改变了湍流运动，而湍流运动是气体流动中热量和动量混合的原因。通过高保真的计算流体动力学模拟和传热和湍流速度场的实验测量，研究项目将评估不同纹理模式对传热和摩擦损失的影响。该研究将进一步提高紊流传热的基础知识水平。Quantiam技术公司的研究成果的商业应用将有助于减少与乙烯生产相关的能源需求和温室气体排放。

Ethylene is a valuable chemical product essential to Canada's chemical and plastics industries. It is produced by reacting ethane gas and steam at very high temperatures in a steam cracking furnace. An undesirable by-product of the reaction is the gradual deposition of amorphous coke on the reactor walls. The deposits degrade the efficiency of the furnace and result in periodic shut downs of the steam cracking process to remove the coke deposits. Increasing the heat transfer rate from the reactor walls to the gases flowing inside the furnace can reduce the rate of coke formation. Unfortunately, conventional methods for increasing the heat transfer rate also increase the frictional pressure losses in the furnace, which translates into higher operational costs. This research project will investigate new methods for increasing heat transfer rates in ethylene production furnaces that yield only a minimal increase in frictional losses. In collaboration with Quantiam Technologies Inc., researchers from UBC Okanagan and University of Alberta will investigate heat transfer enhancement by placing patterned textures on the inner walls of the reactor. The textures protrude into the turbulent boundary layer and modify the turbulent motions that are responsible for mixing heat and momentum in the gas flow. By using high-fidelity computational fluid dynamics simulations and experimental measurements of the heat transfer and turbulent velocity field, the research project will evaluate the impact of various texture patterns on the heat transfer and frictional losses. The research will advance the current state of fundamental knowledge of turbulent flows with heat transfer. Commercial application of the research findings by Quantiam Technologies Inc. will help reduce the energy requirements and greenhouse gas emissions associated with ethylene production.