US RE49,883 E1
Water heater with mix tank fluid time delay for causal feedforward control of hot water temperature
Mark Daniels, Valley Cottage, NY (US); and Adrian Voicu, Bloomfield, NJ (US)
Assigned to Watts Regulator Co., North Andover, MA (US)
Filed by Watts Regulator Co., North Andover, MA (US)
Filed on Oct. 26, 2021, as Appl. No. 17/452,265.
Application 17/452,265 is a reissue of application No. 16/227,063, filed on Dec. 20, 2018, granted, now 10,852,008, issued on Dec. 1, 2020.
Int. Cl. F24D 19/10 (2006.01); F24D 3/10 (2006.01); F24D 17/00 (2022.01); F24H 9/13 (2022.01)
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
OG exemplary drawing
 
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.