Investment in Optimization
Recently, a chief engineer mentioned to me that he is
going to install a heat exchanger to recover heat from the ammonia refrigeration
plant. This plant was operated at condensing pressure of 130 - 170 psig. I have
calculated that potential energy savings of this investment will be 1 - 2 % and
payback will be 8 years.
Another company invested a lot of money in VFDs.
However, achieved energy savings were much less than they expected. Review of
the refrigeration plant operating strategy has shown that additional energy can
be saved by choosing the right strategy. However, even with additional energy
savings payback for these VFDs will be 5 years.
Do
we have a better option to save energy in industrial refrigeration? Yes. This is
optimized operation of the refrigeration plant. Improvement of operation is the
most cost effective way to save energy in our industry. For the first mentioned
refrigeration plant, winter condensing pressure can be lowered to 90 psig and
20% of energy will be saved. Payback of this action is 2 - 3 months. This is much better than 1 - 2% energy
savings and 8 years payback by investing in a heat exchanger.
I
think that every company can afford optimization because it usually costs just
several thousand dollars. However, it is critically important to find the right
person to do this optimization. As far as I know, few people know how to do this
correctly. Optimized operation can be implemented step by step. To test this
energy saving approach, a few initial steps can be implemented first to make
sure that you get real energy savings.
These days, many companies propose energy savings to end
users. Typically, they require significant investments and promise to save a lot
of energy. Unfortunately, very often the promised energy savings were not
achieved.
Make a small investment in optimization and it will be
one of your best investments in energy efficiency.