| 摘要: |
| 绕管式气化器具有高效紧凑、机械强度高的优点，可作为船载LNG气化设备使用，但需要合理设计气化器结构来避免水介质发生冻堵。本文提出一种水加热型绕管式LNG气化器的设计，在满足气化工艺要求的同时防止气化器出现冻堵。首先提出了基于防冻堵的气化器结构设计思路：在保证管侧水温高于冰点和管侧出口水温分布均匀的前提下，设计绕管式气化器的关键结构参数；然后通过三维分布参数模型对气化器换热、压降性能以及防冻堵性能进行校核，并提出结构参数优化调整的方法。采用本文提出的设计方法，对一台已知设计参数的LNG气化器进行算例分析，优化调整后的绕管式换热器热负荷和压降能够满足设计要求，且管侧壁面温度最低温度为7.32 ℃，管侧出口平均温度为31.42 ℃，达到防冻堵的效果。 |
| 关键词: 气化器 设计 防冻堵 绕管式换热器 液化天然气 |
| DOI： |
| 投稿时间：2019-04-03 修订日期：2019-06-11
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| 基金项目: |
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| Design of Marine LNG Spiral Wound Water-bath Heat Exchanger with Freezing Blockage Prevention |
| Xia Jiahui,Duan Zhongdi,Ding Guoliang,Xu Weizhong |
| (Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University;Shanghai Marine Diesel Engine Research Institute) |
| Abstract: |
| Spiral wound heat exchangers are often used for LNG（liquefied naturalgas）vaporization on ships because of the advantages of their high efficiency, compactness, and high mechanical strength. The structure of heat exchangers should be designed properly to prevent the problem of freezing blockage. This paper proposes a design to prevent the freezing blockage when meeting the process requirements. Firstly, the basic idea of designing an anti-freeze heat exchanger is to figure out the key parameters of heat exchangers under the condition that the temperature of water in the tubes is higher than freezing point and the outlet temperature on the tube side is evenly distributed. A 3D-distributed-parameter model is adopted to verify the heat transfer, pressure drop, and anti-freeze performance of the heat exchanger. Finally, the structure readjustment is developed. The proposed design method is used on a practical LNG spiral wound heat exchanger. The designed heat exchanger meets the requirements for preventing freezing blockage, and satisfies the requirements of heat transfer and pressure drop. The design results show that the minimum wall temperature on tube side is 7.32℃,whereas the even outlet temperature on the tube sideis 31.42℃, which achieves the purpose of preventing freezing blockage. |
| Key words: vaporizer design freezing blockage prevention spiral wound heat exchanger liquefied natural gas |
