基于有限元素方法的核桃干燥装置的热-流体-固体合传热分析和参数优化.
Sanping Li1, Jiamei Qi1, Liguo Wu1,2
1School of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin, 150040, China.
Heliyon
|February 6, 2024
概括
优化核桃干燥对于储存和运输至关重要. 这项研究确定了通过模拟和实验验证实的最佳热空气参数 (393K,1.7 m/s,45分钟) 以实现均干燥.
科学领域:
- 农业工程 农业工程
- 食品科学 食品科学 食品科学
- 热力学是一种热力学.
背景情况:
- 新鲜核桃中的高水分含量需要干燥以防止腐烂.
- 高效的干燥对于储存,运输和保持核桃质量至关重要.
- 现有的干燥方法需要优化,以提高能源效率和产品统一性.
研究的目的:
- 用热空气确定核桃最佳预干燥参数.
- 研究温度,速度和时间对核桃干燥的影响.
- 用实验数据验证模拟结果,以实现可靠的过程优化.
主要方法:
- 采用了三种因素 (入口温度,风速,干燥时间) 的直角实验设计.
- 使用FLUENT软件模拟流体和核桃温度/速度场.
- 模拟核桃作为一个三层球体 (外,空气间隙,内核) 进行准确的模拟.
主要成果:
- 确定了最佳参数:393K的入口温度,1.7米/秒的风速和45分钟的干燥时间.
- 模拟显示在最佳条件下均的温度和速度场分布.
- 实验结果验证了模拟准确性,回归模型R2为0.9966.6.
结论:
- 该研究为优化开放核桃预干操作提供了理论基础.
- 最佳参数确保均的温度分布和高效的湿度去除.
- 这些发现在核桃食品加工行业有实际应用,以提高质量和储存.
相关概念视频
01:14Mechanisms of Heat Transfer I
4.3K
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
4.3K
01:14Mechanisms of Heat Transfer
328
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
328
01:20Mechanisms of Heat Transfer II
3.3K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
3.3K
01:19Mechanism of heat transfer
1.2K
Understanding heat transfer mechanisms is essential for understanding how our bodies maintain balance in different environmental conditions. When the environment is thermoneutral, the body is in a state of balance, neither using nor releasing energy to maintain its core temperature. However, when the environment is not thermoneutral, the body employs four heat transfer mechanisms to maintain homeostasis: conduction, convection, evaporation, and radiation. These mechanisms facilitate heat...
1.2K
01:27Thermal expansion and Thermal stress: Problem Solving
1.2K
San Francisco's Golden Gate Bridge is exposed to temperatures ranging from -15 °C to 40 °C. At its coldest, the main span of the bridge is 1275 m long. Assuming that the bridge is made entirely of steel, what is the change in its length between these temperatures?
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in...
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in...
1.2K
01:12Heat Flow and Specific Heat
5.4K
Heat is a type of energy transfer that is caused by a temperature difference, and it can change the temperature of an object. Since heat is a form of energy, its SI unit is the joule (J). Another common unit of energy often used for heat is the calorie (cal), which is defined as the energy needed to change the temperature of 1 g of water by 1 °C, specifically between 14.5 °C and 15.5 °C, since the energy needed shows a slight temperature dependence. Another commonly used unit is...
5.4K