Method for operating a chiller

Abstract

The invention provides method of operating a chiller having a closed refrigerant loop including a compressor, a condenser and an evaporator. The refrigerant used in the loop defining a pressure-enthalpy curve representative of different phases (vapor, liquid and vapor, and liquid) of the refrigerant at different combinations of pressure and enthalpy. The loop defines a process cycle (compression, condensation, expansion, and evaporation) of the refrigerant during operation of the loop relative to the pressure-enthalpy curve of the refrigerant. The method includes continuously operating the compressor when a segment of the process cycle corresponds to the refrigerant being in the liquid phase.

Description

Background technique [0001] This application relates generally to refrigeration, air conditioning and cooling liquid systems. The present application relates more particularly to methods of operating refrigeration, air conditioning and coolant systems. [0002] It has been recognized that under certain environmental conditions and reduced system cooling requirements, coolant systems using centrifugal compressors can be Runs at a fraction of the cost. The 2008 ASHRAE Handbook - HVAC Systems and Equipment (page 42.12) states the following: [0003] Cooling of a compressor without running a centrifugal liquid cooler is called free cooling. Some chillers are capable of operating as thermosiphons when a supply of condensate is available at a temperature lower than the desired cooling water temperature. The low temperature condensate condenses the refrigerant which is either drained by gravity or pumped to the evaporator. The higher temperature cooling water evaporates the refr...

AI Technical Summary

Problems solved by technology

[0005] Unfortunately, such environmental conditions occur relatively rarely in many parts of the world, or may be of short duration

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