TY - JOUR
T1 - Understanding the transient behavior of the dew point evaporative cooler from the first and second law of thermodynamics
AU - Lin, Jie
AU - Thu, Kyaw
AU - Karthik, Somasundaram
AU - Shahzad, Muhammad Wakil
AU - Wang, Ruzhu
AU - Chua, Kian Jon
N1 - Generated from Scopus record by KAUST IRTS on 2023-09-23
PY - 2021/9/15
Y1 - 2021/9/15
N2 - Owing to its high energy efficiency without using greenhouse gases, dew point evaporative cooling offers a desired solution for thermal management of electronic and electrical devices. This paper elucidates the transient behavior of a dew point evaporative cooler and its significant influence on the dynamic cooling performance. A large time constant (400 s) of the product air temperature was observed under a zero-state response, leading to a pronounced deviation of the time-average cooling performance below its steady state by 13.8%–26.4% over a long period (2500 s). To capture this phenomenon, a modified transient lumped parameter model and a new partial differential exergy model were developed. An air mixing process in the dry channel was identified to account for the slow cooler's transient responses. A detailed exergy analysis revealed that the specific exergy destruction at the dry channel entrance was above 400 W/kg, owing to the air mixing. This finding demonstrates that the transient behavior should be judiciously considered in the cooler design and optimization, together with the steady-state performance. Accordingly, a detailed sensitivity analysis of the cooler's objective variables is proposed to gain insights into the future improvement of the dew point evaporative cooler.
AB - Owing to its high energy efficiency without using greenhouse gases, dew point evaporative cooling offers a desired solution for thermal management of electronic and electrical devices. This paper elucidates the transient behavior of a dew point evaporative cooler and its significant influence on the dynamic cooling performance. A large time constant (400 s) of the product air temperature was observed under a zero-state response, leading to a pronounced deviation of the time-average cooling performance below its steady state by 13.8%–26.4% over a long period (2500 s). To capture this phenomenon, a modified transient lumped parameter model and a new partial differential exergy model were developed. An air mixing process in the dry channel was identified to account for the slow cooler's transient responses. A detailed exergy analysis revealed that the specific exergy destruction at the dry channel entrance was above 400 W/kg, owing to the air mixing. This finding demonstrates that the transient behavior should be judiciously considered in the cooler design and optimization, together with the steady-state performance. Accordingly, a detailed sensitivity analysis of the cooler's objective variables is proposed to gain insights into the future improvement of the dew point evaporative cooler.
UR - https://linkinghub.elsevier.com/retrieve/pii/S0196890421006476
UR - http://www.scopus.com/inward/record.url?scp=85108986118&partnerID=8YFLogxK
U2 - 10.1016/j.enconman.2021.114471
DO - 10.1016/j.enconman.2021.114471
M3 - Article
SN - 0196-8904
VL - 244
JO - Energy Conversion and Management
JF - Energy Conversion and Management
ER -