Role of internal heat exchanger in air conditioning systems

Internal heat exchangers (IHX) has been implemented into refrigeration and air-conditioning industry for a long time because of its ability to improve the efficiency of refrigeration cycles for several commonly used and potential substitution of refrigerants (R134a, R744 and R1234yf among them). It provide extra heat transfer between the high temperature liquid from the condenser and the cold vapor from the evaporator, which can lower the inlet quality to the evaporator and potentially increase system capacity and COP Implementation of IHX in residential systems are commonly seen nowadays while automotive system generally less. The essence of this research is to organize data sets of automotive systems that included internal heat exchangers previously conducted in Air-Conditioning and Refrigeration Center (ACRC) at the University of Illinois at Urbana-Champaign (UIUC) and put them into a sound analysis. Two main objectives were to achieve: First of all, detailed measurements of all available designs. This will allow us to investigate the influence of geometrical effect such as tube diameter, fin features…etc. that will affect heat transfer and pressure drop performance. Moreover, weight penalty of each design upon application were also stressed. Another objective of this research is to develop component model of each IHX design. Work are performed with validation between various experimental data sets on heat transfer and pressure drop characteristic of each IHX design. After validating the IHX models, comparison in common testing conditions were set to analyze the performance of different geometries on heat transfer and pressure loss. The detailed measurements in this work can be used as a reference when internal heat exchangers were considered to be implemented into automotive systems. Moreover, the IHX model of each design can be easily implemented into a system model to observe the benefit of IHX on systems as a preliminary study for system design.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Lin, Chen-Yu

Contributors dc:contributor

• Hrnjak, Predrag S.

• Internal Heat Exchanger
• Automotive Air-Conditioning System

Statement dc:rights

• Copyright 2014 Chen-Yu Lin

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/50579

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/50579