Research on integrative optimization operation of seawater heat pump, photovoltaic, and cross-seasonal heat storage systems

This paper proposes a novel system that integrates seawater heat pump, photovoltaic, and cross-seasonal heat storage systems for heating, cooling, and power supply. This novel system will be applied to promote the achievement of the "zero carbon" goal and solve the problem of seasonal mismatch and instability between the power demand of heat pumps and photovoltaic power generation. This paper seeks to assess the feasibility of achieving or approaching 'zero carbon' with this innovative system, and the dynamic simulation models were established based on TRNSYS software. Research findings show that having surplus photovoltaic electricity immediately utilized by surrounding users is more beneficial than engaging in cross-seasonal storage of excess photovoltaic generation. However, cross-seasonal energy storage is recommended to reduce dependence on the power grid and improve the flexibility of power grid regulation. It is worth noting that daily thermal storage is recommended for winter, using a small thermal storage water tank. Taking a public building with a floor area of 25,185 m2 as an example, the optimization parameters of the system, aimed at minimizing the annual cost, include: the photovoltaic panel area is 20400 m2, the volume of the thermal storage water body is 29000 m3, the proportion of heating provided by thermal storage water body is 89.29 %, the net carbon reduction rate is 75.59 %, and the investment payback period is 7.41 years, and the novel system is feasible.