Modular-Based Computer Simulation of an Air-Cooled Condenser

Ragazzi, F.

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https://hdl.handle.net/2142/9696 Copy

Description

Title

Modular-Based Computer Simulation of an Air-Cooled Condenser

Author(s)

Ragazzi, F.

Contributor(s)

Pederson, C.O.

Issue Date

1991-10

Keyword(s)

condenser performance

Abstract

Due to environmental concerns, several refrigerants currently used by the air-conditioning and refrigeration industry are expected to be gradually phased-out by the turn of the century. Possible ozone-safe replacement refrigerants such as R-134a are being tested to determine their heat transfer and pressure drop characteristics. A computer simulation modeling a typical air-cooled condenser was developed with the goal of providing a faster and less costly alternative to experimental testing. It consists of dividing the total condenser length into an arbitrary number of modules and solving the residual equations obtained from momentum and energy balances on those modules. Existing correlations are used to calculate refrigerant heat transfer coefficients and pressure drop. Air side heat transfer coefficients are evaluated with a correlation developed from experimental data. The input parameters include the condenser's geometric dimensions as well as air and refrigerant inlet conditions. The total capacity and refrigerant pressure drop are calculated, in addition to the length of tube occupied by superheated, condensing and sub-cooled refrigerant. The simulation was validated with an experimental test matrix covering a wide range of conditions. The difference between the calculated and the experimental capacities was within 25% for all test conditions, and within 10% for 86% of them. The larger discrepancies were observed at low air flow rates, suggesting possible experimental errors due to air stratification. The calculated pressure drops were not in agreement with the experimental results, and further testing of the two-phase . refrigerant correlations used is required.

Publisher

Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Air Conditioning and Refrigeration Center TR-07

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/9696

Sponsor(s)/Grant Number(s)

Air Conditioning and Refrigeration Center Project 03

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