초록 ▼

A household electronic mixing-valve faucet for controlling a temperature of a mixed stream discharging from the faucet, including: (a) a faucet body; (b) a controller; (c) a first powered valve fluidly connected to the hot water flowpath; (d) a second powered valve fluidly connected to the cold wate

A household electronic mixing-valve faucet for controlling a temperature of a mixed stream discharging from the faucet, including: (a) a faucet body; (b) a controller; (c) a first powered valve fluidly connected to the hot water flowpath; (d) a second powered valve fluidly connected to the cold water flowpath; (e) an arrangement adapted to determine extents of opening of the valves; (f) temperature sensors, operative to sense a temperature of fluids within the hot and cold water flowpaths; and pressure sensors; the controller adapted to maintain a difference between an actual temperature of the mixed stream and a setpoint temperature thereof within a particular range.

대표청구항 ▼

1. A household electronic mixing-valve faucet for controlling a temperature and flowrate of a mixed stream discharging from the faucet, the faucet comprising: (a) a faucet body including: (i) a hot water inlet, adapted to connect to a hot water source, and fluidly connected to a hot water flowpath;(

1. A household electronic mixing-valve faucet for controlling a temperature and flowrate of a mixed stream discharging from the faucet, the faucet comprising: (a) a faucet body including: (i) a hot water inlet, adapted to connect to a hot water source, and fluidly connected to a hot water flowpath;(ii) a cold water inlet, adapted to connect to a cold water source, and fluidly connected to a cold water flowpath,said inlets fluidly connecting at a junction on said faucet body; and(iii) a faucet outlet, adapted to deliver a stream received from said water flowpaths, via said junction;(b) a controller;(c) a first powered valve fluidly connected to said hot water flowpath, said valve being (i) characterized by a first valve flow coefficient function CH(θH) that describes a flow-capacity of the valve as a function of valve position θH and (ii) responsive to said controller;(d) a second powered valve fluidly connected to said cold water flowpath, said second valve being (i) characterized by a second valve flow coefficient function CC(θC) that describes a flow-capacity of the valve as a function of valve position θC and (ii) responsive to said controller;(e) a first temperature sensor and a second temperature sensor, said sensors associated with said faucet body, and operative to sense, respectively, a first measured temperature TH of a first fluid within said hot water flowpath, upstream of said first powered valve and a second measured temperature TC of a second fluid within said cold water flowpath, upstream of said second powered valve; and(f) a first differential pressure sensor unit, associated with said faucet body, said first differential pressure sensor unit adapted to obtain a direct measurement of a first pressure drop ΔPH=(Ph-Pmix) across said first powered valve; and a second differential pressure sensor unit, associated with said faucet body, said second differential pressure sensor unit adapted to obtain a direct measurement of a second pressure drop ΔPC=(Pc-Pmix) across said second powered valve;said controller being adapted to receive: (i) said first measured temperature TH from said first temperature sensor;(ii) said second measured temperature TC from said second temperature sensors;(iii) said first directly-measured pressure-drop ΔPH from said first differential pressure sensor unit;(iv) said second directly-measured pressure-drop ΔPC from said second differential pressure sensor unit; and(v) a temperature set-point Tset and a flow-rate set-point Oset;said controller being further adapted to: (i) compute desired flows Oset_h and Oset_c respectively through the hot and cold inlets, from said temperature set-point Tset and said flow-rate set-point Qset, and by using heat-conservation and mass-conservation relations of the faucet;(ii) calculate a first extent-of-opening set-point θset_H by computing a first expression θset⁢⁢_⁢⁢H=CH-1⁡(Qset⁢⁢_⁢⁢HΔ⁢⁢PH)wherein CH−1 is an inverse of said first valve flow coefficient function CH(θH);(iii) in response to the calculation of said first expression, operate said first powered valve to said first calculated extent-of-opening set-point θset_c;(iv) calculate a second extent-of-opening set-point θset_c by computing a second expression θset⁢⁢_⁢⁢c=CC-1⁡(Qset⁢⁢_⁢⁢cΔ⁢⁢PC)wherein CC−1 is an inverse of said second valve flow coefficient function CC(θC); and(v) in response to the calculation of said second expression, operate said second powered valve to said second calculated extent-of-opening set-point θset_c. 2. The faucet of claim 1, further comprising a third temperature sensor, disposed downstream from said junction. 3. The faucet of claim 2, said controller adapted to modify said extent-of-opening set-points based on a feedback control scheme utilizing an input from said third temperature sensor. 4. The faucet of claim 1, said first extent-of-opening set-point being an explicit function of said first pressure drop and said first desired flow (Qset_h). 5. The faucet of claim 3, said controller adapted, within a particular loop iteration, to produce a calculated feed forward control result from said first and second pressure drops and said temperature information; to effect, within said particular control loop iteration, a combination of said calculated feed forward control result and a calculated feed back control result from said feedback control scheme; and to calculate said extent-of-opening set-points of said powered valves based on said combination. 6. The faucet of claim 1, pressure dependency of said first extent-of-opening set-point of said first powered valve being solely a function of said first pressure drop. 7. The faucet of claim 1, said controller further adapted to control said powered valves based on said extent-of-opening set-points, whereby a difference between the flowrate of the mixed stream and a set-point flowrate thereof, is kept within a second particular range. 8. The faucet of claim 1, wherein said first and second pressure drops form at least part of an aggregate differential pressure term, said extent-of-opening set-points depending on said aggregate differential pressure term, and wherein pressure dependency of said extent-of-opening set-points on discrete pressure is less than 10%, in absolute terms, of said aggregate differential pressure term. 9. The faucet of claim 1, wherein said first and second pressure drops form at least part of an aggregate differential pressure term, said extent-of-opening set-points depending on said aggregate differential pressure term, and wherein pressure dependency of said extent-of-opening set-points on discrete pressure is less than 5%, in absolute terms, of said aggregate differential pressure term. 10. The faucet of claim 1, wherein said extent-of-opening set-points and said first and second pressure drops form at least part of an aggregate differential pressure term, said extent-of-opening set-points depending on said aggregate differential pressure term, and wherein pressure dependency of said extent-of-opening set-points on discrete pressure is less than 3%, in absolute terms, of said aggregate differential pressure term. 11. The faucet of claim 1, pressure dependency of said first extent-of-opening set-point of said first powered valve being devoid of a contribution from discrete pressure. 12. The faucet of claim 1, pressure dependency of said first extent-of-opening set-point of said first powered valve being devoid of a contribution from discrete pressure information.