污水源热泵淋激式换热器强化传热试验研究

Experimental Study on Enhanced Heat Transfer of Sewage-source Heat Pump Spray-type Heat Exchanger

为避免污水换热器出现结垢、堵塞后难以清理以及腐蚀后难以更换换热管的情况,污水源热泵污水侧推荐采用淋激式换热器。将淋激式换热器换热管(管外为热水、管内为冷水)作为试验对象,分析喷淋热水温度、喷淋强度(即喷淋热水质量流量)对3种管材(紫铜光管、不锈钢光管、不锈钢波纹管)传热系数的影响。在相同试验条件下,不锈钢波纹管的传热系数最高,其次为紫铜光管,不锈钢光管的传热系数最低。紫铜光管的传热系数对喷淋热水温度的变化最敏感,其次是不锈钢光管,不锈钢波纹管对喷淋热水温度的变化最不敏感。不锈钢波纹管的传热系数对喷淋强度的变化最敏感,其次是紫铜光管,不锈钢光管对喷淋强度的变化最不敏感。管材传热系数随喷淋热水温度的增大增幅较小,随喷淋强度的增大增幅明显。试验条件下,当喷淋强度增至某一特定值后,管材传热系数增幅减缓,因此应综合考虑水泵能耗因素,设定合理的喷淋强度。

In order to avoid the fouling of age heat exchanger, difficulty to clean after blockage and difficulty to replace the heat exchange tube after corrosion, the spray-type heat exchanger is recommen- ded to be used at the sewage side of sewage-source heat pump. The heat transfer tube of the spray-type heat ex- changer （hot water outside the tube, and cold water inside the tube） is taken as the test object, and the in- fluence of the sprayed hot water temperature and the spraying intensity （the mass flow rate of the sprayed hot water） on the heat transfer coefficient of 3 kinds oftube materials including copper tube, stainless steel tube and stainless steel bellows is analyzed. Under the same experimental conditions, the heat transfer coeffi- cient of the stainless steel bellows is the highest, fol- lowed by copper tube, and the heat transfer coefficient of stainless steel tube is the lowest. The heat transfer coefficient of copper tube is the most sensitive to change of the sprayed hot water temperature, followed by stainless steel tube, and stainless steel bellows is the most insensitive to change of the sprayed hot water temperature. The heat transfer coefficient of stainless steel bellows is the most sensitive to the change of spra- ying intensity, followed by copper tube, the heat trans- fer coefficient of stainless steel tube is the most insensi- tive to change of spraying intensity. The heat transfer coefficient of tube materials increases slightly with the increase of the sprayed hot water temperature and in- creases significantly with the increase of the spraying intensity. Under the experimental conditions, when the spraying intensity increases to a certain value, the in- crease of heat transfer coefficient of tube materials slows down. Therefore, the energy consumption factors of pump should be comprehensively considered to set a reasonable spraying intensity.