TABLE OF CONTENTS

The warm system is used for defrosting the air coolers and heating of the air- handling
units in the cleaning mode of the areas. This warm system is heated by means of heat
recovery of the oil cooling system of the compressors and a desuperheater in the
ammonia discharge line.
During the process of the erection of the plant the demand for more cooling grew. At
the end of the second phase of the project in 2010 the installed cooling-capacity on
air coolers, heat exchangers and air handling was increased to over 3MW while the
installed refrigeration machinery was still the initial 1.600kW
Results
GEA Grenco has a long history in the design, erection, operation and maintenance of
ammonia plants. Ammonia is considered to be a safe and very efficient refrigerant.
Vezet is familiar with the ins and outs of ammonia and have operated a large icewater
plant with ammonia since the mid 90’s.
In the Netherlands refrigeration plants operated with natural refrigerants, such as NH 3
,
can be subject to tax deduction on the investment if certain design parameters are
followed.
COP’s are usually better with ammonia compared to most other refrigerants. In this
particular case the efficiency of the whole of the plant should be taken in account.
By means of a sophisticated control system with GEA Grenco software design, the
use of proportional controls on valves, fans and pumps and an adaptive evaporation
temperature control, it was possible to dose the cooling demand in such a manner that
the plant was never operated at its limits so energy consumption is consequently low.
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Vezet is very satisfied with the performance of the plant and the support of the GEA
Grenco organization. GEA Grenco is now in a quotation process for the next steps in
establishing the master plan.
In the phase coming up now a new refrigeration compressor room of ~ 4MW will be
installed. A next step will be the phase out of the remaining HCFC/HFC installations and
replace these with another NH 3
-Temper plant.