Under the dual pressures of dwindling fossil fuel resources and climate change, the use of renewable energy is gaining increasing attention. Industrial and municipal wastewater contain a certain amount of heat, much more than the chemical energy of organic matter, and it is more stable and safe. However, due to the lack of systematic understanding and mature technologies, the wastewater thermal energy has not been fully and reasonably utilized. Consequently, wastewater heat is often directly discharged into the ambient air, resulting ina large amount of energy waste. Recovering thermal energy from wastewater pipeline networks can provide substantial energy benefits to water companies.

Urban wastewater thermal energy utilization involves recovering and effectively using the heat from treated or untreated wastewater, which is divided into two ways: direct utilization and indirect utilization. The direct utilization means that the heat in wastewater is recivered by heat pump and directly transported to the heat supply building. The indirect utilization means that after the heat exchange of wastewater though the heat exchanger, the wastewater heat is recoverd and transported to the heat supply building through the heat pump.

However, directly utilizing heat from wastewater pipelines presents challenges such as preventing fouling, clogging, and corrosion of heat exchangers (heat pumps). This requires stringent technical and special materials, which obstacles practical application. Our institute is currently researching on practical engineering solutions for sewerage energy recovery system to solve the energy crisis.

• Map the potential heat energy of the wastewater system based on the information of flow and wastewater temperature, and optimize the design of the heat recovery system

• Compare the efficiency and cost of different heat recovery systems and equipment

• Development of building scale wastewater energy recovery