Pinch Analysis

A modern tool for the systematic improvement of process integration

The Pinch Analysis is a modern tool for the systematic analysis of heat recovery opportunities in processes and integrated systems. The methodology is based on simple thermodynamic principles.  It comprises 3 steps:

1. Data Analysis
– Data Extraction and Energy Balancing
2. Targeting
– What is the minimum achievable energy consumption of the current process?
– What is the most economic mix of utilities for the current process?
3. Improvement
– How should we modify the process to improve its efficiency?

Surplus heat is available In many technical processes. The import of external utilities could be significantly reduced, if this surplus heat would be utilized, thus reducing costs and environmental impact of the operation. Unfortunately, for many processes it is not a simple task to determine, where the excess heat can be employed best.

The Pinch Analysis helps by being able to determine the absolute minimum amount of external energy the process can be run with, based on the data for process heating and cooling demands. This minimum demand – the target – though based on thermodynamic ground principles is not just a theoretical value. The target can actually be met. Using a relatively simple set of rules, the process can be deigned or modified to make maximum use of heat sources available and hit the minimum energy consumption target.

TH-diagram, the key to zur Pinch Analyse

Who should use Pinch Analysis?

Pinch Analysis is an outstanding tool for all heat consuming or generating enterprises that would like to raise their energy efficiency and thus reduce costs and energy related emissions.

The energy saving result is hard to generalize upfront. Pinch Analysis results in a practically attainable minimum energy demand as a benchmark. For some few processes that are already operated very efficiently, less improvement opportunities will be identified and the result of the energy analysis can be used as a confirmation of the current high efficiency.  However on average, potential improvement in the range of 10 % can be identified while 30 % savings and more can also be demonstrated.

What is needed?

For simple cases, the collection of the amounts of heat available and needed at their respective temperatures for operation, i.e. heating, cooling, ventilation, air conditioning, drying, separation, …, can very quickly lead to the determination of how energetically efficient the process is currently run and what energy savings are possible.

For that, Pinch Analysis summarizes the heat demands and supplies in the process specific temperature intervals. Based on the simple understanding that heat flows only from higher to lower temperatures, the Pinch Analysis can calculate the minimum overall heating demand by cascading heat surplus amounts through the temperature intervals from high to low. We are glad to help with the process of doing that.

A number of stand-alone software products for Pinch Analysis with high functionality and some add-on routines to process simulation environments exist on the market. We use a lower complexity self-programmed Excel Add-In that allows to generate first assessments of the energy saving potential for most users, but are also able to use commercial applications. The Excel Add-in can be downloaded from here.

Want to know more? The FFE (Forschungsgesellschaft für Energiewirtschaft mbH) provides another very good description.