Industrial Process Indicators and Heat Integration in Industries (Brunner/Slawitsch/Giannakopoulou/Schnitzer 2008)

The first tool is the "Matrix of Industrial process indicators - MATRIX", which is a comprehensive database, and was developed in Subtask B as a decision support tool for solar experts. With this MATRIX the work with industry and the identification of suitable solar applications can be facilitated. It will be possible to investigate and calculate the installation of solar heat in production processes without detailed knowledge of the relevant unit operations and production processes.

Some industry sectors such as food, chemistry, plastic processing, textile industry and surface treatment industry have been identified as very promising sectors for solar thermal applications. For these industries detailed information like general benchmark data, temperature levels of the processes, flow sheets of production lines and generic hydraulic schemes for solar integration can be found in the specific Sub-MATRICES.

The investigation of these industries has to focus on an integrated analysis of cooling and heating demands taking into account competitive technologies, when assessing the (economic) feasibility of solar thermal energy. Among those competing technologies are heat integration, co-generation and heat pumps, which also have been described in the relevant parts of the MATRIX. Beside technology optimization, the reduction of energy consumption also has to be achieved by system optimization. Most industries have a heat demand in the production and at the same time a lot of waste heat. The usage of this waste heat has the advantage of being simultaneous with the heat demand of other processes. The reuse of this waste heat has to be done at the highest possible temperature. The most promising methodology to identify the maximum heat recovery in a defined system (for a defined industrial process) is to design a heat exchanger network using the so-called the Pinch Analysis. With this tool a system optimization can by achieved and the minimal external heating demand as well as the minimal external cooling demand can be identified.

Within the work of IEA Task 33/IV the computer programme (Pinch Energy Efficiency - PE²), which calculates the heat recovery potential and designs a technically and economically feasible heat exchanger network for a given process, has been developed. PE² fulfils the need of heat integration calculations in promising industries. The automatic calculation of an ideal heat exchanger network (based on mathematical criteria and aiming at maximum savings in terms of energy savings in kWh per year) is one of the main advantages of the programme. Furthermore the possibility to calculate heat exchanger surfaces and the calculation of a dynamic cost function resulting in the pay-back period for a given heat exchanger network based on user defined economic data as well as the visualisation of energy savings with a Sankey Editor afford a fast energy optimization and documentation of a whole process.

The analysis with PE² shows the remaining energy demand at the corresponding temperature levels after the optimisation of the processes by heat recovery. It gives information on which temperature level external heat/cold is necessary - important information for implementation of solar energy for heating purposes.