Abstract: To investigate the influence of the orifice plate on the fish freezing efficiency in the impingement quick-freezing freezer, this paper takes the yellow fish as the research object, analyzes the effects of different orifice plate arrangements, hole diameter and air supply distance on the fish freezing efficiency, and obtains the fish temperature distribution and the evolution of central temperature with time. The results show that the staggered arrangement of the upper and lower orifice plates avoids wind hedging, so the freezing rate is the highest and the freezing time is the shortest. The increase of the orifice plate diameter effectively reduces the fish freezing time in the second stage and the cooling time in the third stage. The shorter the distance between the upper and lower orifice plate from the center of the fish body, the shorter the fish freezing time. The study shows that: screening the structure and parameters of the air supply orifice plate with suitable purpose can provide new process guidance for the freezing of aquatic products and provide technical support for the optimal design of the impact freezer.

Key words: orifice plate, freezing characteristics, impingement quick-freezing freezer, numerical simulation, central temperature

摘要： 为探明冲击式速冻机中送风孔板对鱼体冻结效率的影响，以小黄鱼为研究对象，通过数值模拟和实验验证，研究了送风孔板的排布方式、送风孔板孔径和鱼体中心距上下送风孔板的距离对鱼体冻结效率的影响，分析了不同送风孔板排布方式、送风孔板孔径及送风距离下鱼体的温度分布及中心温度变化情况。结果显示：上下送风孔板交错排布避免了两侧风的对冲损耗，使得冻结速率最高、冻结时间最短；送风孔板孔径的增加有效减小了第二阶段的鱼体冻结和第三阶段的鱼体降温时间；上下孔板距鱼体中心的距离越短，冻结时间越短。研究表明：筛选出适宜旨的送风孔板结构和参数，可为水产品冷冻提供新的工艺指导，为冲击式速冻机的优化设计提供技术支撑。

关键词: 送风孔板；冻结特性；冲击式速冻；数值模拟；小黄鱼；水产品加工