DISTRIBUTED AND NON-STEADY-STATE MODELING OF AN AIR COOLER

被引：97

作者：

WANG, H

TOUBER, S

机构：

[1] Laboratory for Refrigeration and Indoor Climate Engineering, Department of Mechanical Engineering, Delft University of Technology, 2628 CD Delft

来源：

INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID | 1991年 / 14卷 / 02期

关键词：

NON-STEADY-STATE MODELING; AIR COOLER; REFRIGERATING SYSTEMS;

D O I：

10.1016/0140-7007(91)90082-R

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

The refrigerant flow inside the coils of a dry expansion plate-finned air cooler can be distinguished into two completely different types: two-phase flow and single-phase flow. The most difficult part of non-steady-state modelling of an air cooler is to describe the liquid and vapour mass transport phenomena occurring in the two-phase flow region, as this determines the boundary position between the two regions and then the superheat temperature, which is in turn the feedback signal of the thermostatic expansion valve. In fact, the mass transport is mainly governed by the momentum exchange between refrigerant liquid and vapour, which is usually called slip-effect. Because the momentum or force equilibrium is so fast compared to the thermal equilibrium, the slip-effect can be considered as a steady-state phenomenon. With this assumption, the mass transport in an air cooler can be described by using a simple propagation equation. The steady-state slip-effect, however, is found by solving the momentum equations for one-dimensional two-phase flow using advanced computer packages such as PHOENICS. This paper presents the derivation of the equations in non-steady-state modelling of an air cooler as well as the results obtained from the model. Because the model is purely distributed, it is applicable to various kinds of tube circuit arrangements of air coolers. The purpose of the model is studying and optimization of non-steady-state behaviour of refrigerating systems with capacity control.

引用

页码：98 / 111

页数：14

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