Investigation on the urea deposits formation in the selective catalyst reduction system of a marine high-power engine

IF 5.5 3区工程技术 Q1 ENGINEERING, CHEMICAL

Journal of the Taiwan Institute of Chemical Engineers Pub Date : 2025-03-08 DOI:10.1016/j.jtice.2025.106075

Chong Xia , Yuanqing Zhu , Diantao Liu , Song Zhou , Yongming Feng , Jie Shi , Ang Sun , Kai Zhu

{"title":"Investigation on the urea deposits formation in the selective catalyst reduction system of a marine high-power engine","authors":"Chong Xia , Yuanqing Zhu , Diantao Liu , Song Zhou , Yongming Feng , Jie Shi , Ang Sun , Kai Zhu","doi":"10.1016/j.jtice.2025.106075","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>The incomplete decomposition of urea to form urea deposits is a major problem in the application of engine selective catalytic reduction (SCR) technology. To improve the NOx reduction rate of the SCR system, it is necessary to suppress the formation of urea deposits.</div></div><div><h3>Methods</h3><div>The high-pressure SCR system of a 20 MW marine low-speed two-stroke diesel engine was taken as a research object. The positions and shapes of urea deposits formed within the SCR system were investigated through sea navigation experiments. Then, various characterization techniques were used to detect the chemical composition of urea deposits in different regions. Finally, a comprehensive computational fluid dynamics (CFD) simulation method was introduced to model the injection of urea-water solution (UWS), droplet collision, and the formation of urea deposits.</div></div><div><h3>Significant findings</h3><div>The main chemical composition of urea deposits was cyanuric acid (cya, C<sub>3</sub>H<sub>3</sub>N<sub>3</sub>O<sub>3</sub>) and ammelide (C<sub>3</sub>H<sub>4</sub>N<sub>4</sub>O<sub>2</sub>). The simulation results indicated a high level of consistency between the predicted shape, location, and chemical composition of urea deposits and the experimental findings. After adjusting the installation direction of the static mixer, the deposition rate of the liquid film was reduced by about 50%, and the formation of cya and ammelide was effectively suppressed.</div></div>","PeriodicalId":381,"journal":{"name":"Journal of the Taiwan Institute of Chemical Engineers","volume":"171 ","pages":"Article 106075"},"PeriodicalIF":5.5000,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Taiwan Institute of Chemical Engineers","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1876107025001282","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}

引用次数: 0

Abstract

Background

The incomplete decomposition of urea to form urea deposits is a major problem in the application of engine selective catalytic reduction (SCR) technology. To improve the NOx reduction rate of the SCR system, it is necessary to suppress the formation of urea deposits.

Methods

The high-pressure SCR system of a 20 MW marine low-speed two-stroke diesel engine was taken as a research object. The positions and shapes of urea deposits formed within the SCR system were investigated through sea navigation experiments. Then, various characterization techniques were used to detect the chemical composition of urea deposits in different regions. Finally, a comprehensive computational fluid dynamics (CFD) simulation method was introduced to model the injection of urea-water solution (UWS), droplet collision, and the formation of urea deposits.

Significant findings

The main chemical composition of urea deposits was cyanuric acid (cya, C₃H₃N₃O₃) and ammelide (C₃H₄N₄O₂). The simulation results indicated a high level of consistency between the predicted shape, location, and chemical composition of urea deposits and the experimental findings. After adjusting the installation direction of the static mixer, the deposition rate of the liquid film was reduced by about 50%, and the formation of cya and ammelide was effectively suppressed.

Abstract Image

查看原文本刊更多论文

船用大功率发动机选择性催化剂还原系统尿素沉积的研究

尿素不完全分解形成尿素沉积物是发动机选择性催化还原（SCR）技术应用中的主要问题。为了提高SCR系统的NOx还原率，必须抑制尿素沉积的形成。方法以20mw船用低速二冲程柴油机高压SCR系统为研究对象。通过海上航行试验研究了SCR系统中尿素沉积的位置和形状。然后，利用各种表征技术检测不同地区尿素沉积物的化学成分。最后，引入综合计算流体力学（CFD）模拟方法，对尿素-水溶液（UWS）注入、液滴碰撞和尿素沉积形成过程进行了模拟。尿素沉积物的主要化学成分为氰尿酸（cya, C3H3N3O3）和氨酰（C3H4N4O2）。模拟结果表明，预测的尿素沉积的形状、位置和化学成分与实验结果高度一致。调整静态混合器的安装方向后，液膜的沉积速率降低了50%左右，并有效抑制了氰胺和酰胺的形成。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of the Taiwan Institute of Chemical Engineers 工程技术-工程：化工

CiteScore

9.10

自引率

14.00%

发文量

362

审稿时长

35 days

期刊介绍： Journal of the Taiwan Institute of Chemical Engineers (formerly known as Journal of the Chinese Institute of Chemical Engineers) publishes original works, from fundamental principles to practical applications, in the broad field of chemical engineering with special focus on three aspects: Chemical and Biomolecular Science and Technology, Energy and Environmental Science and Technology, and Materials Science and Technology. Authors should choose for their manuscript an appropriate aspect section and a few related classifications when submitting to the journal online.