Air-side performance evaluation of three types of heat exchangers in dry, wet and periodic frosting conditions

Abstract

The performances of three types of heat exchangers that use the louver fin geometry: 1. parallel flow parallel fin with extruded flat tubes heat exchanger (PF 2 ), 2. parallel flow serpentine fin with extruded flat tubes heat exchanger (PFSF) and 3. round tube wave plate fin heat exchanger (RTPF) have been experimentally studied under dry, wet and frost conditions and results are presented. The parameters quantified include air-side pressure drop, water retention on the surface of the heat changer, capacity for air face velocity 0.9, 2 and 3 m/s, air humidity 70% and 80%. The performances of three types of heat exchanger are compared and the results obtained are presented. The primary goal of this project is to explore the thermal hydraulic performance of PF 2 heat exchanger in refrigeration and heat pump systems. Using both the dip testing method and wind tunnel experiment assess the condensate drainage behavior of the air-side surface of these three heat exchanger types.

Airside heat transfer and pressure drop of louver-finned parallel flow heat exchanger having a drainage channel

“…The literature shows very limited information on louver fins having drainage passages. Zhang and Hrnjak (2009) introduced a parallel louver fin (PF2) where arc-shaped rectangular louver fins are connected by a downstream plate of 2.0 mm width, which serves a drainage passage. The sketch of PF2 is shown in Fig.…”

Spatial optimization of an underhood cooling module – Towards an innovative control approach

“…HXs are used in a wide variety of applications, among them military and aerospace, power plants, nuclear reactors, chemical and biomedical processes, the food and automobile industries, robotics and metrology [1][2][3][4][5][6][7][8][9][10]. The current trend is to reduce their volume and weight while maintaining sufficient thermal efficiencies.…”

“…HXs fall into different categories according to the way that cold and hot streams interact. Among the most common are the tube-and-fin HXs, counterflow channels and micro-channels, reactors, shell and tube coil exchangers, and multifunctional HXs [1][2][3][4][5][6][7][8][9][10]. The tube-and-fin HX is composed of different tubes of elliptical cross-section across which are positioned several continuous parallel fins (which can be simple, crimped, shutters, with delta wings longitudinal vortex generators, etc.).…”

Air-side performance of a parallel-flow parallel-fin (PF2) heat exchanger in sequential frosting

“…One of the excellent potential features of the PF 2 design is that it extends fins beyond the tube and uses that part of the fins as a "downspout", a drainage facilitator for the condensate or defrost water. PF 2 offers great improvement in water removal either in dehumidification or defrost mode compared to a folded (serpentine) fin type heat exchanger where the flat tube is horizontal (Zhang and Hrnjak, 2009).…”

“…The comparison of FP 2 heat exchanger to a conventional round-tube-plate fin heat exchanger (RTPF) and parallel-fin serpentine-fin (RTPF) with flat-tube heat exchanger was presented earlier, in Zhang and Hrnjak (2009). This paper focuses on evaluating the air-side performance characteristics of PF 2 heat exchanger under frosting conditions, with attention to defrost and refrost effects.…”