Field measurement and energy efficiency enhancement potential of a seawater source heat pump district heating system

• Field measurement was conducted for a seawater source heat pump heating system.
• The energy consumed by the heat pump units dominates the whole system.
• The energy efficiency enhancement potential of the heat pump units was analyzed.

As a renewable energy utilization system, seawater source heat pump district heating system can eliminate the local air pollution compared with the direct combustion of fuel in the conventional boiler house district heating system in northern cold climate area. A field measurement with an emphasis on the energy efficiency of an actual seawater source heat pump district heating system was conducted and analyzed. The field measurement showed that the heat pump units consumed the largest part of energy consumption of the whole system (as high as 78.9% in the project). However, the coefficient of heating performance (COP) of the seawater source heat pump unit was as low as 2.43. Then the energy efficiency enhancement potential of the heat pump unit was carefully analyzed and calculated in the light of the index of Thermodynamic Perfectibility for the heat pump unit. And the results showed that there is about an average of 24.2% energy efficiency enhancement potential of the heat pump units in the project. In the end, a verification case study indicated that the COP of the heat pump units in the project will increase 34.6% if they are substituted by the ones made by another manufacturer.