Slow thermally activated building system and fast air handling unit join forces through the use of model based predictive control

摘要

Thermally Activated Building Systems (TABS) have a large potential for energy use reduction in office buildings, because they fit nicely with low-exergy heat and cold production such as geothermal heat pump systems. However, due to the large thermal capacities, control of TABS should be carefully designed in order to avoid low control efficiencies. Moreover, due to the limited thermal power and the low controllability, TABS cannot always react adequately to occurring peaks in office building heat gains. On the contrary, the Air Handling Unit (AHU), which is installed anyway to guarantee indoor air quality, is a fast reacting system, but requires high-exergy heat and cold production and is thus less energy efficient. How should these two systems cooperate? This paper investigates a Model based Predictive Controller (MPC) which controls the TABS as well as the AHU to guarantee thermal comfort at the lowest possible energy cost. Coupled TRNSYS-MATLAB simulations are used to assess the MPC behaviour. This paper demonstrates that MPC is the required link to unite TABS and AHU into one low-energy office building comfort system.