What are the process steps of a pinch analysis?
First, the material and energy flows of the production and infrastructure system are systematically analyzed in an present state analysis, before savings potential can be identified and concrete suggestions for improvement can be developed in order to improve the energy efficiency and economic viability of the entire system.
1. Present State Analysis
The relevant energy flows are characterized in terms of heat flow, temperature level and time dependence using existing documentation, diagrams and measurement data from the systems to be analyzed. If necessary, measurements are carried out at specific locations in the plant. Based on the information collected, a systematic analysis of the present state is carried out. The necessary calculations (mass, component and energy balances) are completed and the relationships clearly shown in material and energy flow diagrams. The present state analysis also includes clarifying the existing operating cases (e.g. summer / winter). Finally, the time dependencies can be shown in Gantt charts to illustrate the schedule of the production steps.
2. Pinch Analysis
Before the pinch analysis can be started, the process conditions (temperatures, mass flows and the time sequence) must be critically analyzed. In some cases, this analysis can already result in operational optimizations. The process requirements are then derived from the process conditions. Pinch analysis is then used to quantify the potential for increasing efficiency using the PinCH software. In addition, “energetic weak points” can be identified and a system (heat exchanger network, energy supply) developed that fully exploits the energy and economic potential. Heat and cold storage and energy conversion systems such as heat pumps or absorption chillers are also taken into consideration. At this stage, operational boundary conditions are not yet given full consideration as the aim is to show what energy and cost savings potential if a fully optimized process was in operation (i.e. in the optimum case).
3. Variant Study
Based on the pinch analysis, various concepts/variants for energy optimization can be derived that look feasible for implementation. The necessary process engineering calculations, rough designs and clarifications as well as technical-economic assessments must then be carried out for the variants (technical feasibility, reduction in energy requirements, investment and operating costs, etc.). The most promising concepts are then later developed in more detail and implemented.