In recent years, some northern cities have explored the recycling of low-grade industrial waste heat for urban heating, yielding remarkable outcomes. Utilizing lowgrade industrial waste heat for heating has proven to be economically and technically feasible as it comes with significantly lower heat source costs compared to traditional methods involving coal and natural gas. Implementing the waste heat utilization project and promoting the centralized recovery and utilization of low-grade waste heat resources in regions with the necessary conditions can not only slash heating costs but also significantly enhance energy utilization efficiency, leading to a substantial reduction in both coal consumption and pollutant emissions. This initiative stands as a pivotal green project, delivering tangible benefits to people.

In early 2016, Harbin Petrochemical initiated discussions with Haode Blue Ocean (formerly known as Harbin Heat Energy) on the waste heat utilization project. After preliminary feasibility studies and process route selection, it confirmed that its circulating water waste heat utilization project had economic and social value and complied with relevant national policies on energy utilization and conservation.

Harbin Petrochemical's production process involves the circulation of approximately 2,700 m3/h of cooling water, maintaining a temperature difference of 7 degrees Celsius, with a supply temperature of 21 degrees Celsius and a return temperature of 28 degrees Celsius. This cooling process is facilitated by mechanical ventilation cooling towers. The waste heat utilization project employs a heat pump cycle to lower the temperature of the circulating water to the required temperature for the process and then returns it to users, turning the surging water vapor into clean thermal energy.

This project, implemented since August 2017 and officially put into operation in December 2017, has been operating safely and stably for six years. As the first project in industrial waste heat recovery for heating in Harbin, it has delivered tangible results. It annually saves about 60,000 tons of water for Harbin Petrochemical and reduces carbon dioxide emissions by about 30,000 tons. Meanwhile, the on-site environment of the circulating water has also been significantly improved.?