Phase Change Material in District Heating with Model Predictive Control

Phase Change Material in District Heating with Model Predictive Control

Rapid escalation of building energy use has raised concerns all over the world, and existing predictions express that this increasing trend will aggravate energy crisis and serious environmental problem. The district heating (DH) system that incorporates renewables and the thermal energy storage component shows favorable prospects as a supplier to serve residential and commercial consumers for space heating and domestic hot water. The operation temperature of the DH system is becoming lower to achieve a more energy efficient, sustainable, and eco-efficient system. This trend results in the performance degradation of the thermal storage when integrating the water tank to the DH system, resulting in potential economic losses. Meanwhile, a large heat storage and released rate cannot be achieved for the water tank with the limited size under the low temperature operation conditions. Compared with sensible heat thermal energy storage, the latent heat thermal energy storage (LHTES) is advantaged by its use of phase-change materials (PCMs) with high energy storage density at a near-constant phase-change temperature. To enable an energy efficient low temperature DH system, an appropriate storage medium with great thermophysical properties and low cost will be selected. The technical viability and practical applicability of the entire heating system will be experimentally and numerically investigated. A hybrid agent-based model predictive control (MPC) framework will be further built as a promising solution to achieve an effective energy management for the low temperature DH combined LHTES system. It is projected that the energy and economic performance of the DH combined LHTES system could be guided by the agent-based MPC. The capability of the agent-based MPC for performance enhancement will be finally calibrated and evaluated, and high-quality experimental research will be conducted for the validation of this hybrid control method outputs.