Control and Auxiliary System Sample Clauses

Control and Auxiliary System. For thermal energy storage unit characterization and validation, an auxiliary system has been constructed at KTH Energy Technology Department. The auxiliary system mainly comprises of controllable heating/cooling device, buffer tanks, flow directional valves, and measurement equipment. The schematic diagram of the auxiliary system is shown in Figure 3-14. When testing a latent heat storage unit for heating applications in a charging mode, the PID-controlled heater (denoted as H in the figure) provides an automatically-controlled amount of heat to the HTF based on its set-point temperature, and the variable-speed pump delivers the HTF to the storage tank with a set flowrate. For discharging, the heat recovered from the storage unit is released into the ambient by a fin-and-coil heat exchanger (Q). Before an actual charging/discharging test starts, water is prepared in the hot or the cold inertia tank at the set supply temperature to avoid high temperature fluctuations in the supply water. The heat pump is activated to assist the electric heater in providing enough heating power required in a charging test. Figure 3-14 Schematics of the Main Existing Auxiliary System The major components in the existing auxiliary system are listed in Table 3-3 with their models and basic information. Table 3-3 Major components in the main auxiliary system. Component Model Description PID-controller Heater Thermia EK 15 E (15 kW) and Pahlen 6 kW A two-step heater with 15+6 kW nominal heating capacity Fin-and-coil heat exchanger Alfa Laval DGS501CD12H Nominal cooling capacity of 12 kW Pump Grundfos MAGMA3 32- 120FN Maximum head of 18 meters. Heat pump Thermia Diplomat Inverter Nominal heating capacity of 12 kW For PUMP-HEAT lab-scale warm TES unit testing, a hydraulic loop is built in parallel to the existing system. The loop is connected with the main auxiliary system through three-way flow directional valves. The connection positions are indicated as A1 and A2 in Figure 3-15. With the three-way valve connections, programmable heating/cooling can be provided to the new storage unit waiting to be tested without affecting the existing configurations of the entire test facility. There are several new features in this parallel hydraulic loop for characterizing the TES with variable boundary conditions. First, a three-way integrated with a temperature-regulating modular, denoted as A3 in Figure 3-15, is designed to be implemented on the return line. This is for controlling the mix...