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

乙烯是一种宝贵的化工产品，对加拿大的化工和塑料工业至关重要。它是由乙烷气体和蒸汽在非常高的温度下在蒸汽裂解炉中反应而产生的。该反应的一个不受欢迎的副产品是无定形焦炭逐渐沉积在反应器壁上。结焦降低了炉子的效率，并导致蒸汽裂解过程定期关闭以清除结焦。增加从反应器壁面到炉内气体的换热速率可以降低结焦速率。遗憾的是，传统的提高热流率的方法也会增加炉膛内的摩擦压力损失，这就意味着更高的运行成本。这项研究项目将探索提高乙烯生产炉热传递速率的新方法，使摩擦损失只增加最少。与Quantiam Technologies Inc.合作，来自UBC Okanagan和艾伯塔大学的研究人员将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，并改变了导致气流中热量和动量混合的湍流运动。通过使用高保真计算流体力学模拟和对换热和湍流速度场的实验测量，本研究项目将评估不同织构模式对换热和摩擦损失的影响。这一研究将推进湍流换热基础知识的研究现状。Quantiam Technologies Inc.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.