In view of the tendency in the analysis and design of heat exchanger tube sheets to overemphasize technical means while neglecting engineering factors,this paper,based on previous research results combined with three failure cases and relevant engineering experience,identifies the issues worthy of attention in modeling,including non‑pressure‑bearing structural members and the distortion of actual operating conditions.In some cases,the absence of baffles,tie rods,spacer tubes and partition plates in the tube bundle model will lead to analysis results inconsistent with engineering practice.In the analysis and discussion of the cases,analytical models improved to varying degrees are proposed.The synergistic complementarity of finite element secondary analysis technology,conventional design technology and engineering auxiliary technology to the analysis and design technology is a better handling countermeasure.Through the discussion of 7 points of understanding across 3 topics—including the content and integrity of analysis and design,the concept and verification of the analytical model,and the objective resources and subjective awareness of analysis and design—the necessity of adopting the dual criteria of stress and displacement in the analysis and design of tube bundles is put forward.It is suggested that in analysis and design,the cultivation of engineering literacy and the conscious improvement of individual skills should be strengthened.
| 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 |