Heat integration / Pinch analysis
Pinch analysis is a systematic method to evaluate and optimise process energy efficiency. It is a method whereby prior to a detail design the minimum thermodynamic energy consumption of a process can already be calculated. The method also shows how this optimal energy efficiency can be achieved on the basis of the appropriate heat exchange network, what heat recovery is involved, and what utilities are
required do this.
Pinch analysis is also called heat integration or process integration.
With a pinch analysis the various heat flows at a plant are established, being both heat flows between the processes and those in the processes themselves. The data from the various flows is processed, and composite curves are obtained based on the heat loads and
temperatures. Such curves are determined for both the flows to be heated and cooled. The form of these curves and
the temperature at which they (nearly) meet characterise the heat profile of a plant. The heat profile indicates in which temperature zone and which processes the most design constraints exist.
The method allows the objective assessment of the energy consumption of a process, the determining of minimum consumption, and possibly an evaluation of the energy and capital ratio with more or less intensive heat integration. This is even possible in an analysis phase prior to the actual process design based on the energy properties of the process flows, without taking account of the network of heat exchangers.
Pinch analysis gives an understanding of the energy profile of a process, and shows the thermodynamic bottleneck (the “pinch”) that sets a constraint on possible heat integration. This constraint can only be changed with process changes with a positive influence on the pinch. The analysis clearly shows where utilities can be effectively used, where heat from CHP is appropriate, and if so where a heat pump can be useful.
The methodology also gives a number of rules for the design of the heat exchanger network to achieve the energy objectives set. The methodology has in the meantime been successfully applied worldwide.
A pinch analysis is a very powerful resource for the thermal optimisation of Industrial sites.
required do this.
Pinch analysis is also called heat integration or process integration.
With a pinch analysis the various heat flows at a plant are established, being both heat flows between the processes and those in the processes themselves. The data from the various flows is processed, and composite curves are obtained based on the heat loads and
temperatures. Such curves are determined for both the flows to be heated and cooled. The form of these curves and
the temperature at which they (nearly) meet characterise the heat profile of a plant. The heat profile indicates in which temperature zone and which processes the most design constraints exist.
The method allows the objective assessment of the energy consumption of a process, the determining of minimum consumption, and possibly an evaluation of the energy and capital ratio with more or less intensive heat integration. This is even possible in an analysis phase prior to the actual process design based on the energy properties of the process flows, without taking account of the network of heat exchangers.
Pinch analysis gives an understanding of the energy profile of a process, and shows the thermodynamic bottleneck (the “pinch”) that sets a constraint on possible heat integration. This constraint can only be changed with process changes with a positive influence on the pinch. The analysis clearly shows where utilities can be effectively used, where heat from CHP is appropriate, and if so where a heat pump can be useful.
The methodology also gives a number of rules for the design of the heat exchanger network to achieve the energy objectives set. The methodology has in the meantime been successfully applied worldwide.
A pinch analysis is a very powerful resource for the thermal optimisation of Industrial sites.