Apparatus and method for evaluating performance of centrifugal chiller

Patent metadata

Field	Value
Publication number	US-10378794-B2
Application number	US-201213557874-A
Country	US
Kind code	B2
Filing date	Jul 25, 2012
Priority date	Aug 4, 2011
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

A calculating section 103 calculates a target COP that is a maximum COP that the centrifugal chiller can achieve using an arithmetic expression in which an actual device loss is given as a correction term to an expression that represents a COP characteristic under an ideal lossless environment. Since the arithmetic expression for calculating the target COP includes the heat exchange loss of the evaporator as a correction term, the heat exchange loss being calculated using a function having a load factor as a parameter, the heat exchange loss of the evaporator is reflected in the target COP.

First claim

The invention claimed is:

1. A centrifugal chiller comprising:
a compressor configured to compress a refrigerant;
a condenser configured to perform heat exchange between the refrigerant and cooling water;
an evaporator configured to perform heat exchange between the refrigerant and chilled water; and
a control unit configured to calculate a target COP that is a maximum COP that the centrifugal chiller can achieve by using an following arithmetic expression (1),
COP ct ={( T out+273.15)/( T cout− T out+ Td )}/ Cf   (1)

where COP ct represents the target COP, Tout represents a chilled water outlet temperature, Tcout represents a cooling-water outlet temperature, Td represents a correction term for reflecting heat exchange loss of the evaporator, and Cf represents a correction term for reflecting a device loss due to the device characteristics of the compressor, and the correction term Td is calculated using a function having a load factor as a parameter.

2. The centrifugal chiller according to claim 1 , wherein the correction term is derived from relationships between the load factor and the heat exchange loss of the evaporator obtained at individual cooling-water inlet temperatures.

3. The centrifugal chiller according to claim 2 , wherein the correction term is given by a function approximating a plurality of characteristics showing the relationships between the load factor and the heat exchange loss of the evaporator at the individual cooling-water inlet temperatures to a single characteristic.

Assignees

• Togano Yoshie
• Ueda Kenji
• Mitsubishi Heavy Ind Thermal Systems Ltd

Inventors

• Togano Yoshie
• Ueda Kenji

Classifications

• F25B49/025

  Motor control arrangements · CPC title

• F25B2600/021

  Inverters therefor · CPC title

• F25B1/053 Primary

  of turbine type · CPC title

• F25B2700/197

  of the evaporator · CPC title

• F25B2339/047

  Water-cooled condensers · CPC title