TY - JOUR

T1 - Experimental Study on CaCO3Fouling Characteristics during Falling Film Evaporation

AU - Ding, Zhikou

AU - Li, Wei

AU - Wang, Lei

AU - Zhao, Limin

AU - Sherif, S. A.

AU - Wang, Rui

AU - Kabelac, Stephan

N1 - Funding Information: This paper is dedicated to the memory of the Late Professor Ralph L. Webb (1934–2011). The corresponding author obtained his M.S. and Ph.D. on fouling with Professor Webb from 1992 to 1998 in Penn State. This work is supported by Sinopec Dalian (Fushun) Research Institute. The experimental setup employed for the falling film evaporation experiments is manufactured by the Hangzhou Yuhu Technology Co., Ltd. The electronic control system in the set up is provided by the Nanjing Jiuchang Electronic Technology Co., Ltd. The authors would like to thank the financial support from the National Natural Science Foundations of China (52076187) and the National Science Foundation of Zhejiang Province (LY19E060004).

PY - 2022/4

Y1 - 2022/4

N2 - Falling film evaporation is widely used in solar desalination systems. Fouling is an important problem to be addressed in many applications involving heat transfer including processes involving the utilization of solar energy in desalination applications. In the research upon which this paper partly reports, an experimental investigation was carried out on a vertical tube in falling film evaporation to determine the effects of temperature, velocity, the use of a porous-sintered tube, and the use of Teflon coating on calcium carbonate deposition characteristics. During the fouling experiments, the pressure inside the test tubes was maintained constant at 101.3 kPa, and the inlet temperature was maintained at 373 K, while allowing the water mass velocity to vary from 0.42 to 1.05 kg m-1 s-1. Results show that the fouling in the test tube becomes more serious as the temperature increases and the flowrate decreases. Compared with stainless-steel tubes, porous-sintered tubes can significantly reduce fouling resistance, but at the same time they bring about a decrease in the heat transfer coefficient. The Teflon coating also has anti-fouling performance but does not affect the heat transfer coefficient in stainless-steel tubes. Through the weighing of local fouling deposits, it has been found that the mass of the fouling deposits in the lower part of the tested tubes is greater than that in the upper part.

AB - Falling film evaporation is widely used in solar desalination systems. Fouling is an important problem to be addressed in many applications involving heat transfer including processes involving the utilization of solar energy in desalination applications. In the research upon which this paper partly reports, an experimental investigation was carried out on a vertical tube in falling film evaporation to determine the effects of temperature, velocity, the use of a porous-sintered tube, and the use of Teflon coating on calcium carbonate deposition characteristics. During the fouling experiments, the pressure inside the test tubes was maintained constant at 101.3 kPa, and the inlet temperature was maintained at 373 K, while allowing the water mass velocity to vary from 0.42 to 1.05 kg m-1 s-1. Results show that the fouling in the test tube becomes more serious as the temperature increases and the flowrate decreases. Compared with stainless-steel tubes, porous-sintered tubes can significantly reduce fouling resistance, but at the same time they bring about a decrease in the heat transfer coefficient. The Teflon coating also has anti-fouling performance but does not affect the heat transfer coefficient in stainless-steel tubes. Through the weighing of local fouling deposits, it has been found that the mass of the fouling deposits in the lower part of the tested tubes is greater than that in the upper part.

KW - anti-fouling tubes

KW - falling film evaporation

KW - fouling characteristics

KW - fouling resistance

KW - heat transfer

UR - http://www.scopus.com/inward/record.url?scp=85127243970&partnerID=8YFLogxK

U2 - 10.1115/1.4052937

DO - 10.1115/1.4052937

M3 - Article

AN - SCOPUS:85127243970

VL - 144

JO - Journal of Solar Energy Engineering, Transactions of the ASME

JF - Journal of Solar Energy Engineering, Transactions of the ASME

SN - 0199-6231

IS - 2

M1 - 021005

ER -