Method and device for detecting the amount of limescale in liquid heating devices
AssigneeI.R.C.A. S.P.A. Industria Resistenze Corazzate E Affini
InventorsFederico Zoppas, Antonio De Moliner, Christian Bortoluzzi, Christian Ceotta, Roberto Oboe
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Abstract
A method and device for detecting the amount of limescale that accumulates in liquid heating devices, in particular for heating water. The method is capable of establishing, through simple temperature measurements, if the amount of limescale deposited on the heater element of a device for heating liquids is such as to jeopardize the correct operation thereof and provides the user with information on the need to clean the aforesaid heater.
Claims9
A method for detecting deposits of limescale in liquid heating devices comprising a hydraulic circuit, at least one pump for circulating said liquid inside the hydraulic circuit, a heater for said liquid, and means for measuring the temperature of said liquid, said method comprising:
- Operating, at a time t0, the pump for circulating the liquid;
- Operating, after a first time interval Δ1, at a time t1=t0+Δ1, the heater at a preset power P0;
- Measuring, after a second time interval Δ2, at a time t2=t1+Δ2, the liquid temperature, T2;
- Storing the liquid temperature value, T2;
- Switching off, after a third time interval Δ3, at a time t3=t2+Δ3, the heater;
- Measuring, after a fourth time interval Δ4, at a time t4=t3+Δ4, the liquid temperature value, T4;
- Storing the liquid temperature value, T4;
- Switching off, after a fifth time interval Δ5, at a time t5=t4+Δ5, the liquid circulating pump;
- Calculating the ΔTt2−t4 of the liquid as a difference between the stored values of the temperature values measured at the times t4 and t2, T4−T2;
- Comparing ΔTt2−t4 with predetermined thresholds ΔTA and ΔTB, so as to discriminate three cases:
- a) ΔTt2−t4<ΔTA, in which case the amount of limescale present on the heater is excessive and such as to affect the correct performance thereof, the heater itself needs cleaning;
- b) ΔTA≤ΔTt2−t4<ΔTB, in which case the amount of limescale present on the heater is considerable but not yet such as to affect the correct performance thereof, the cleaning of the heater only is to be considered advisable;
- c) ΔTt2−t4≥ΔTB, in which case the amount of limescale is small and the heater does not need cleaning.
A device for detecting deposits of limescale in liquid heating devices comprising a hydraulic circuit, at least one pump for circulating said liquid inside the hydraulic circuit, a heater for said liquid, and means for measuring the temperature of said liquid, comprising control means configured to:
- operating, at a time t0, the liquid circulating pump;
- operating, after a first time interval Δ1, at a time t1=t0+Δ1, the heater at a pre-set power P0;
- measuring, after a second time interval Δ2, at a time t2=t1+Δ2, the liquid temperature, T2;
- storing the liquid temperature value, T2;
- switching off, after a third time interval Δ3, at a time t3=t2+Δ3, the heater;
- measuring, after a fourth time interval Δ4, at a time t4=t3+Δ4, the liquid temperature value, T4;
- storing the liquid temperature value, T4;
- switching off, after a fifth time interval Δ5, at a time t5=t4+Δ5, the liquid circulating pump;
- calculating the ΔTt2−t4 of the liquid as a difference between the stored values of the temperature values measured at the times t4 and t2, T4−T2;
- comparing ΔTt2−t4 with predetermined thresholds ΔTA and ΔTB, so as to discriminate three cases:
- a) ΔTt2−t4<ΔTA, in which case the amount of limescale present on the heater is excessive and such as to affect the correct performance thereof, the heater itself needs cleaning;
- b) ΔTA≤ΔTt2−t4<ΔTB, in which case the amount of limescale present on the heater is considerable but not yet such as to affect the correct performance thereof, the cleaning of the heater only is to be considered advisable;
- c) ΔTt2−t4≥ΔTB, in which case the amount of limescale is small and the heater does not need cleaning.
Dependencies are inferred from the claim text.