To investigate the influence of geometric parameters on the thermal‑hydraulic performance of pillow‑plate heat exchangers (PPHE),numerical simulation method was used to systematically analyze the flow and heat transfer characteristics under different structural parameters.The structural configurations in existing research are relatively limited;therefore,taking pillow plates with equidistant weld spot arrangement ST=2SL=62 mm,hi=6 mm,Dsp=10 mm as the reference condition,within the Reynolds number range Re=1 000~8 000,the effects of weld spot pattern and other geometric parameter variations on heat transfer performance were mainly investigated.The results show that as the transverse pitch ST increases,both Nusselt number (Nu) and friction factor decrease;increasing the longitudinal pitch 2SL causes the Nu to first increase then decrease,while the friction factor continuously rises;increasing the channel height hi leads to a decrease in Nu but an increase in friction factor,thus causing the overall performance to decrease with increasing hi;increasing the weld spot diameter Dsp enhances disturbance,resulting in improvements in Nu,friction factor,and overall performance.Under low Re conditions,the equidistant weld spot pattern (ST=2SL=62 mm) demonstrates better overall performance;while at high Re,the transverse weld spot pattern performs better than the equidistant and longitudinal patterns.In summary,reducing hi,increasing Dsp,adopting equidistant weld spot arrangement at low Re,and using transverse weld spot arrangement at high Re can help improve the overall performance of pillow‑plate heat exchangers.The research results can provide theoretical basis for the structural design and performance optimization of PPHEs.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |