Hybrid Heat Pump Systems

See also

API 레퍼런스: enex_analysis.ashpb_stc_tank, enex_analysis.ashpb_stc_preheat, enex_analysis.ashpb_pv_ess

System Overview

The energy-exergy analysis engine supports various hybrid combinations that integrate renewable energy subsystems with the base air-source and ground-source heat pump boilers. These hybrid configurations aim to enhance the overall system Coefficient of Performance (COP) and reduce the thermodynamic irrationality associated with utilizing high-grade energy for low-grade heating demands.

Currently, the engine provides comprehensive modeling for two major classes of renewable subsystems:

  1. Solar Thermal Collectors (STC): See Solar Thermal Collector (STC).

  2. Photovoltaic Arrays with Energy Storage Systems (PV + ESS): See Photovoltaic and Energy Storage Systems (PV + ESS).

STC Integration Topologies

The integration topology of the STC relative to the main storage tank significantly impacts the system’s exergy efficiency and activation dynamics.

Tank-Circuit Placement (_stc_tank)

In the tank-circuit configuration, the STC loop is directly coupled to the main thermal storage tank.

  • Operation: The STC draws water from the tank, heats it using captured solar energy, and returns it to the tank.

  • Activation Logic: The STC is activated only when the solar collector’s outlet temperature exceeds the current tank water temperature. This prevents reverse heat loss from the tank to the environment.

  • Exergy Boundary: The net heat generated by the STC enters the tank’s boundary directly. The electrical exergy required to run the STC circulation pump is added to the system’s total electrical input.

Mains-Preheat Placement (_stc_preheat)

In the mains-preheat configuration, the STC is placed on the cold water supply line (mains water) upstream of the primary storage tank.

  • Operation: Cold makeup water is preheated by the STC before entering the main storage tank to replace drawn domestic hot water (DHW).

  • Activation Logic: The STC operates whenever there is sufficient solar irradiance and a DHW draw event occurs (which triggers makeup water flow).

  • Exergy Boundary: The preheated water enters the main tank at a higher exergy level than the mains water, effectively reducing the necessary heat load on the heat pump’s condenser.

PV+ESS Integration Logic

In PV+ESS hybrid models, the system dynamically balances the heat pump’s electrical load against the available PV generation and ESS charge status. The complete logic is integrated at each 1-minute time step to determine the final grid dependency (\(E_\text{grid}\)).