Integrating cogeneration systems and thermal chillers into a system

The heat and cooling needed to meet an energy consumer’s demand can be generated in centralized or decentralized manners. In centralized heat or cooling generation, heat or cooling is generated in a centralized plant and then transported via pipelines to one or multiple consumers. In a decentralized model, heat or cooling generation occurs directly at the location of the consumer. Depending on the specific circumstances, each variant has advantages and disadvantages. The terms “central” and “decentral” must be understood within the context of the supply situation. It may apply on the level of individual locations, buildings or rooms. In commercial settings, the differentiation can apply to individual machines within a production hall that are supplied with heat or cooling.

The following graphic shows the basic principle of a decentralized trigeneration unit. The decentralized CHP-unit converts a secondary energy source (fuel) into electrical current and heat for a consumer. Both can be used directly on-site, in order to meet the demand for electricity and heat. Besides this, the CHP-unit delivers heat to the thermal chiller to generate cooling. Optionally, heat or cooling reservoirs may be available, in order to provide a broader supply. The re-cooling system is essential for generating cooling.

Figure 4: Basic principle of a decentralized trigeneration unit