Research On Performance Of Honeycomb Plate Heat Transfer Elements

The plate as the heat transfer elements of plate heat exchanger is the carrier of heat and momentum exchanging, and the direct determiner of heat transfer and resistance performance of the plate heat exchanger. Compared with other heat transfer elements, existing plate heat transfer elements have the advantages of high heat transfer coefficient, but they also have higher flow resistance. The dimple and protrusion plate (referred to as honeycomb plate) increase in heat transfer, while an increase in flow resistance is not high. The mechanism of heat transfer enhancement in the honeycomb plate channel was analyzed by simulation. The effect of Reynolds number, channel height, honeycomb diameter, honeycomb height and honeycomb pitch on heat transfer, resistance and combined thermal performance was investigated in this paper, which could be used as design reference of new heat transfer elements with high efficiency. The main work and conclusions are summarized as follows:1. On the basis of actual flow and heat transfer characteristics in the channel of honeycomb plate heat transfer elements, the physical and math model were built up; numerical simulation technology and periodic flow theory were applied. In the simulation, RNG k-εturbulence model and periodic boundary conditions were employed. And the simulation was verified by the experimental data.2. Dimple plate has higher and lower heat transfer performance in the latter and first half of dimple. Protrusion plate has higher and lower heat transfer performance in the first half and latter part of protrusion region. Dimple-protrusion plate has higher and lower heat transfer performance in the dimple and the protrusion region. In the all, honeycomb plate has higher heat transfer performance, lower resistance performance and higher combined thermal performance in most of working conditions.3. When 3000≤Re≤40000, with Re increasing, the Nu of honeycomb plate increases exponentially; and its f, Nu/Nuo andηdecrease exponentially. The f/f0 of dimple plate and protrusion plate show different rules, and the f/fo of dimple-protrusion plate decreases exponentially.4. The parameters for numerical simulation were designed by orthogonal experiment design. The heat transfer and resistance comprehensive guidelines for relationship were fitted out.5. The heat transfer, resistance and combined thermal performance are under influence of the Reynolds number, channel height, honeycomb diameter, honeycomb height and honeycomb pitch. It was researched detailedly in this paper.6. Among the three types of honeycomb plates, dimple plate has the best heat transfer performance, the worst resistance performance and the best combined thermal performance when Re≥10000. Protrusion plate has the best heat transfer performance, better and worse resistance performance than dimple-protrusion plate when Re≥10000 and Re≤5000. Dimple-protrusion plate has the middle heat transfer performance and the best combined thermal performance when Re≤5000.