CPC F24D 19/1051 (2013.01) [F24D 3/1091 (2013.01); F24D 17/001 (2013.01); F24D 17/0031 (2013.01); F24D 17/0078 (2013.01); F24H 9/136 (2022.01); F24D 2220/0207 (2013.01); F24D 2220/0228 (2013.01); F24D 2220/0235 (2013.01); F24D 2220/042 (2013.01); F24D 2220/044 (2013.01); F24D 2220/06 (2013.01); F24D 2240/00 (2013.01)] | 20 Claims |
1. A water heater comprising:
a heat exchanger (hx) having a hx hot water inlet, a hx water return outlet, a hx domestic cold water inlet, and a hx domestic hot water outlet;
a controllable three-way proportional valve having a boiler water hot water inlet adapted to accept a boiler water, and to provide a proportionally controllable flow to said hx hot water inlet and a boiler return water outlet, and said boiler return water outlet adapted to return a boiler return water to a boiler;
a mixing tank (mt) having a mt cold water inlet adapted to receive a cold water from a source of domestic cold water, a mt hot water inlet, and a mt mixed water outlet, said mixing tank to mix said cold water and a hot water from said mt hot water inlet, and said mixing tank to provide a time delayed mixed water;
a constant flow pump fluidly coupled to and disposed between said hx domestic hot water outlet and said mt hot water inlet;
a temperature sensor disposed in or on said mixing tank to measure a temperature of said time delayed mixed water to provide a time delayed mixed water temperature;
a processor operatively coupled to said temperature sensor and operatively coupled to said controllable three-way proportional valve, said processor to run a feedforward control process based on said temperature of said time delayed mixed water to control a flow of boiler water into said heat exchanger; and
wherein said feedforward control process adjusts a proportional operating position of said controllable three-way proportional valve to regulate a temperature of hot water at said hx domestic hot water outlet based on said temperature of said time delayed mixed water temperature.
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