US 12,188,689 B2
Control of an electric water heater as per a load shedding request signal and a salubrity index
Alain Moreau, Quebec (CA); André Laperrière, Quebec (CA); and François Laurencelle, Quebec (CA)
Assigned to HYDRO-QUÉBEC, Quebec (CA)
Appl. No. 17/269,293
Filed by HYDRO-QUÉBEC, Quebec (CA)
PCT Filed Aug. 30, 2019, PCT No. PCT/CA2019/051211
§ 371(c)(1), (2) Date Feb. 18, 2021,
PCT Pub. No. WO2020/047652, PCT Pub. Date Mar. 12, 2020.
Claims priority of application No. 3016933 (CA), filed on Sep. 7, 2018.
Prior Publication US 2021/0180829 A1, Jun. 17, 2021
Int. Cl. F24H 15/14 (2022.01); F24D 13/00 (2006.01); F24H 1/00 (2022.01); F24H 1/18 (2022.01); F24H 1/20 (2022.01); F24H 9/20 (2022.01); F24H 15/104 (2022.01); F24H 15/108 (2022.01); F24H 15/168 (2022.01); F24H 15/174 (2022.01); F24H 15/225 (2022.01); F24H 15/269 (2022.01); F24H 15/37 (2022.01); F24H 15/421 (2022.01); F24H 15/45 (2022.01); F24H 15/486 (2022.01); H05B 1/02 (2006.01); F24H 15/184 (2022.01)
CPC F24H 9/2021 (2013.01) [F24D 13/00 (2013.01); F24H 1/0018 (2013.01); F24H 1/185 (2013.01); F24H 1/201 (2013.01); F24H 15/104 (2022.01); F24H 15/108 (2022.01); F24H 15/14 (2022.01); F24H 15/168 (2022.01); F24H 15/174 (2022.01); F24H 15/225 (2022.01); F24H 15/269 (2022.01); F24H 15/37 (2022.01); F24H 15/421 (2022.01); F24H 15/45 (2022.01); F24H 15/486 (2022.01); H05B 1/0297 (2013.01); F24D 2200/08 (2013.01); F24H 15/184 (2022.01)] 19 Claims
OG exemplary drawing
 
1. A system for controlling an electric water heater as per a load shedding request signal, the system comprising:
a temperature sensor positioned in order to measure a temperature of water in a lower area of a tank of the water heater;
a switch coupled to an electrical power supply circuit of the water heater, an opening and a closing of the switch being controllable by a control signal in order to interrupt or not interrupt an operation of the water heater; and
a controller connected to the temperature sensor and to the switch, the controller being configured to:
continuously determine a salubrity index of the water heater as a function of the temperature measured by the temperature sensor and a time measurement; and
producing the control signal of the switch so that the switch causes an interruption of the operation of the water heater upon the load shedding request signal only if the salubrity index meets a preestablished criterion, wherein the salubrity index is determined by ratios between a time length during which the temperature measured by the temperature sensor is at a specific temperature degree and a reference time length for the specific degree, the preestablished criterion being a salubrity index having a value of at least one in order to prevent a proliferation of Legionella in the water heater.