Micro gas turbine cogeneration system with latent heat storage at the University: Part III: Temperature control schedule

In Part III, a temperature control schedule of the system was demonstrated during winter mornings using a new programmable logic controller (PLC). Using a fixed schedule, the MGT-CGS with latent heat storage reduced the CO2 emission when the energy utilization factor was above 50%. The temperature control schedule was considered to be better than the fixed schedule, both in terms of the operational efficiency of the overall system and CO2 reduction. The temperature control schedule was executed using an empirical formula for the temperature rise in a classroom. The restriction on the operation time by the contract with the gas supplier and the low heating capacity of the CGS affected the heating time and temperature rise. The temperature rise in the classroom was almost proportional to the integrated temperature difference across the hot water header of the heating system. On cold days, the rate of temperature rise produced by the CGS was very slow, therefore, additional heat supplied by the original boiler was used to increase the temperature rise. If larger latent heat storage systems will be developed in future, it will be expected that the temperature of the classrooms are kept more comfortable with less energy consumptions and lower CO2 emission.