【正文】 enser is a heat transfer area of shell and tube heat exchanger of three times the plate evaporator heat transfer coefficient About 1000 ~ 1200 W / ㎡ ? K, the condenser plate heat transfer coefficient of about 1500 ~ 2021 W / ㎡ ? K are shell heat exchanger two to three times the plate on the evaporator used to Refrigerant distributor of liquid evenly distributed devices, when the evaporator plate a few more, may be uneven distribution of liquid refrigerant and can not take full advantage of all the heat and evaporation area, evaporation temperature lower than the calculated design temperature. After a distributor overe these problems. Detection of data on the relevant units, evaporator plate, the plate condenser in the heat transfer coefficient △ tm about ~ 3 ℃ , in 1500 ~ 2021 W / ㎡ ? K between the resistance and small, satisfying the heat pump units Requirements. ⑵ small NTU (∽ ~ 2), the △ tm (∽ 40 ~ 90 ℃ ) of the plate heat exchanger to meet the heat recovery process and the process heating and cooling requirements. When the process in the △ tm conducted under conditions of heat transfer, that driving force, the heat and the smaller, the heat transfer coefficient demand is not high, but that this process or highpressure work, or work High temperature, or process heating and cooling process in the liquid containing fiber diameter or larger particles, the plate heat exchanger, the pressure, temperature and ability to request, the heat exchanger to the plate spacing requirements. ① Pai (breathing) gas water shell heat exchanger (Province can), Pai (breathing) gas shellair heat exchangers (air preheater) is a heat exchanger in Beijing Beijingequipment manufacturers limited liability Portland petrochemical panies and codeveloped a new type of plate heat exchanger, all welded plate heat exchanger in the heat transfer through the medium to achieve the control board, posed of board control by the plate for forming mold suppression, allwelded Beam installed in the pressure shell. Corrugated plate with static mixing, in a very low Reynolds number formed under the turbulence, and low coefficient of dirt, the heat transfer coefficient is the shell and tube heat exchanger of the two or three times. In order to adapt to the heat transfer, fluid pressure on the request, board space, equivalent diameter of about 28 mm. In order to meet the demands of work pressure plate beam (Antipressure) P ≤ Mpa, the pressure plate beam (pressure) with the pressure shell, unrestricted。以前由于板式換熱器的流道?。ò彘g距 ～ ㎜），不適宜于氣 — 氣換熱和蒸氣冷凝；且易堵塞，故不宜用于含懸浮物的流體。出料流量 50t／ h，進、出口溫度 100℃ ，500℃ ，對數(shù)平均溫差約 38℃ ，總傳熱系數(shù)約為 380kcal／㎡波紋板片具有靜攪拌作用，能在很低的雷諾數(shù)下形成湍流，且污垢系數(shù)低，傳熱系數(shù)是管殼式換熱器的 2～ 3 倍。 K 之間，且阻力小，滿足了熱泵機組的要求。 K，板式冷凝器的傳熱系數(shù)約為 1500～ 2021 W／㎡ K，是水平平直波紋板的 2 倍，是人字形波紋板的 倍，在區(qū)域供冷中時，檢測的 △ tm 約為 。 板式換熱器制造技術(shù)的進步，板片種類的增加，提高了板式換熱器對各種工藝過程的適應性。 ℃時， A＝ ㎡，流程數(shù) n＝ 1。 h由于每種板片單程的 NTUe值基本上是定值，如適合表 2中 e 的流量為 25m3／ h 的單程板式換熱器的 NTUe為 17 ㎡。當 NTUE是總數(shù)時，若每 1 流程數(shù)為 NTUe時，則 NTUE＝ n NTUp 是流體溫度的變化與平均溫差的比值，表示的是用 1℃△ tm 的變化引起幾度流體溫度變化的值，當 △ tm 大時， NTUp 則小；當 △ tm 小時，它有變大的傾向。 順流 △ tm＝ [（ thi－ tci）－（ tho－ tco） ] ／㏑ [（ thi－ tci）／（ tho－ tci） ] 逆流 △ tm＝ [（ thi－ tco）－（ tho－ tci） ] ／㏑ [（ thi－ tco）／（ tho－ tci）