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Introduction - Where does Pinch Analysis stand in the Thermal Energy Efficiency Universe
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Many
factors may bring energy inefficiencies in industrial processes. Here, we summarize them
by the 6 following principal components:
-
The process' core design: the type of unit operations, equipment technology
and reactors selected. Obviously, not all choices are equal there in terms
of thermal energy requirements.
-
The process design around the process'
core: heat
recovery exchangers network, piping length and diameter, layout constraints,
...
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The imposed operating conditions: flows, temperatures,
pressures, etc.
-
The design and selection of utilities:
steam pressure
levels, heat pumping, CHP (cogen),
condensate collection, make-up water preheating, ....
-
The process dynamics: control strategy and
controllers tune-up, seasonal variations, fluctuations in raw
materials quality, production scheduling (grade changes,... ).
-
Plant maintenance.
Pinch Analysis is a Process / Energy integration approach
suited to handle items 1 to 4 in a very cost-effective way. This means that you can move
a big step ahead in a single study to minimize your energy cost and,
consequently, your greenhouse gases emissions. This is the ideal tool to help
the management taking strategic decisions in energy on a medium to long term
basis.
Being a system approach, an interesting feature of
Pinch Analysis is its capacity to examine a process as a whole in order to find
global optimum solutions, not local ones, for a new design or an existing one.
Also, Pinch Analysis can guide the engineer to identify the required actions to
reduce at its source the energy usage by the modifications of some operating
conditions, by a more appropriate integration of a given unit operation, by the
recycling of some streams like used water, etc. Pinch analysis can do all this
by following a conceptual path that sets energy and capital cost
targets ahead of design. In other words, before we spend
money to install heat exchangers and recover energy, we set targets and make sure we
have found the global optimum solution.
Our
vast experience in the practical application of this discipline has
shown that, in a large majority of cases, Pinch Analysis will lead to the identification
of many low cost projects with a very high return on investment. These
findings may procure a short payback period of a few weeks to a few
months to the study fee.
