Household electronic mixing-valve device

摘要

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.

主权项

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 expressionθset⁢⁢_⁢⁢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 expressionθset⁢⁢_⁢⁢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.