FR3029274A1 - ACCUMULATION WATER HEATER - Google Patents

Abstract

The object of the present invention is a storage water heater (1) equipped with a heating means (2), said water heater (1) comprising a tank (3) containing water and a means of electronic regulator (9), characterized in that it furthermore comprises at least three temperature probes (10a, 10b, 10c) arranged inside the tank (3) at different heights and connected to the regulating means (9), the at least three temperature probes (10a, 10b, 10c) comprising a "top tank probe" (10a) disposed at the top of the tank (3) of the water heater (1), a "Bottom tank probe" (10c) disposed at the bottom of the tank (3) of the water heater (1), and a "tank center probe" (10b) disposed at the center of the tank (3) of the water heater (1), the electronic control means (9) comprising a calculation means (12) configured to calculate in real time the volume of water at 40 ° C remaining (V40) that can be supplied by the water heater (1) from temperatures measured by the at least three temperature probes (10a, 10b, 10c).

Description

The present invention relates to the field of water heaters, and relates more particularly to a storage water heater comprising at least three temperature probes and an electronic control means for calculating the volume of water at 40 ° C. ° C remaining V40, the electronic control means that can trigger a restart of heating according to the calculated V40.

There are two main types of storage water heaters: the electric water heater, which has an electrical resistance to heat the water and the thermodynamic water heater. A thermodynamic water heater is a domestic hot water production system using a heat pump (PAC) which draws its calories from the air coming from the outside or from an unheated room, for example of the garage type, to transfer the water through a thermodynamic cycle, the thermodynamic water heater may optionally also include an auxiliary power source for heating the water. The programmed heating resumes of the storage water heater are usually triggered by a control device connected to the storage water heater. It is important to ensure at all times that the storage water heater can supply domestic hot water to the occupants of the building in which the storage water heater is installed, while minimizing the energy consumption of the water heater accumulation, thanks to heating relays triggered exceptionally or automatically by the control device according to the consumption profile of the domestic hot water by the occupants. Existing storage water heaters adjust their heating instructions every day of the week based on usage history. However, these existing water heaters do not trigger exceptional heat recovery in cases where the occupants require a large amount of domestic hot water at a given time.

Other existing storage water heaters can trigger exceptional heat recovery when one of the occupants presses an exceptional boost button for the storage water heaters. However, these existing water heaters need the action of the occupants to trigger exceptional raises, and do not automatically trigger unexpected warm ups. In addition, these existing water heaters do not allow to trigger anticipated heating relays according to the history of consumption of domestic hot water. The volume of water at 40 ° C remaining (or V40), also called volume of hot water mixed at 40 ° C, corresponds to the volume of hot water at 40 ° C that the storage water heater can provide to the occupants for their daily needs (shower, bath, dishes, etc.), and is an important parameter to precisely define the consumption profile of domestic hot water by the occupants. US20060257127 discloses a system for estimating and indicating temperature characteristics of temperature controlled liquids, such as a water temperature change rate of a water heater and a quantity of water in a temperature range. predefined in the water heater, using at least one temperature sensor, the values measured by the at least one temperature sensor can be recorded in a history. However, this system is not designed for a thermodynamic water heater and does not calculate the V40 of the water heater using temperature sensors in order to precisely define the domestic hot water consumption profile. the occupants. In addition, this system does not allow to trigger automatically 10 heatings anticipated in PAC according to the history of the calculated V40. The present invention aims to solve the disadvantages of the prior art by proposing a storage water heater comprising at least three temperature probes arranged inside its tank at different heights and connected to a means the electronic control means being configured to calculate in real time the volume of water at 40 ° C remaining (V40) that can be provided by the storage water heater from the temperatures measured by the at least three temperature probes and optionally the cold water temperature, the electronic control means being configurable to trigger an unexpected warm-up of the storage water heater when the calculated V40 V40c is less than a designated V40 threshold value V40s, and the electronic control means can also be configured to store in a memory a history of the V40 and to trigger an early heating up of the storage water heater according to the history of the V40. The subject of the present invention is therefore a storage water heater, comprising a tank intended to contain water, a cold water inlet at the bottom of said tank, a water outlet on said tank, preferably upper part, a heating means for heating the water in said tank and an electronic control means, characterized in that it further comprises a cold water temperature measuring means and at least three temperature probes disposed at different heights of the tank and each connected to the electronic control means, the at least three temperature probes comprising a "top of tank probe" disposed at the top of the tank, a "bottom tank probe" disposed at the lower level of the tank, and a "tank core probe" disposed at the middle of the tank, the electronic control means comprising a calculation means configured to calculate in real time a volume V40 calculation V40c from the temperatures measured by the at least three temperature sensors and the cold water temperature. Thus, from the temperatures of the water contained in the tank of the storage water heater measured by the temperature probes and the temperature of the cold water, the calculation means calculates in real time the volume of water sanitary hot water at 40 ° C remaining (designated V40c) that can be supplied by the storage water heater to check the availability of hot water that can be drawn by the occupants of the building in which the storage water heater is installed and to precisely define the consumption profile of domestic hot water by the occupants.

According to one particular characteristic of the invention, the calculation of V40c comprises at least the following stages: the determination of the temperature profile of the tank as a function of its height by interpolation between a low temperature of the tank measured by the bottom of the tank probe and a medium temperature of the tank measured by the tank medium probe and by interpolation between the tank medium temperature and a high tank temperature measured by the top of the tank probe; calculating the height h40 of the tank below which the temperature of the water is less than 40 ° C according to said determined temperature profile; and calculating V40c from said temperature profile above said calculated height h40, cross section of the vessel and cold water temperature. As the cold water is generally injected into the tank of the storage water heater at its lower part, the cold water temperature can thus be obtained as the minimum temperature measured by the bottom of the tank probe, or it can be measured by another sensor, directly to the cold water inlet of the storage water heater. Thus, it is possible to obtain the temperature profile along the vertical of the tank of the storage water heater to calculate the height of the tank below which the water contained in the tank is less than 40 ° C. then calculate the V40c that can be supplied by the storage water heater. The interpolation may, for example, be a linear interpolation, without excluding other types of interpolation. The cross section of the tank is understood as the section of the tank in a plane perpendicular to the direction of height of the tank. According to one particular characteristic of the invention, the calculation means is furthermore configured to compare the calculated value V40c in real time with a predefined V40 threshold value V40, the electronic control means being configured to trigger a restart of heating. unexpectedly of the storage water heater when V40c is less than V40s. Thus, a future shortage of domestic hot water 5 is identified by comparison of the calculated V40 V40c to a predefined threshold value V40s and is prevented by triggering an unexpected heating restart by the electronic control means, thus permanently ensuring a hot water availability to 10 occupants. According to a particular characteristic of the invention, the calculation means is furthermore configured to sample the V40c values over a predefined reference period, to record in a memory 15 the V40c values sampled in connection with the corresponding sampling instants. in the reference time period, and to anticipate a heating recovery of the storage water heater to ensure that for each moment of a current period of time 20 corresponding to a sampling time of the predefined period of time reference value, the value V40c is greater than or equal to the value V40c stored in memory for that sampling instant, optionally corrected by an additional margin factor. The reference time period can be slippery. Thus, the sanitary hot water consumption profile by the occupants during the previous reference time period is available in the history of the 30 V40 stored in the memory, which allows the electronic control means to anticipate the consumption of water. domestic hot water during the current period of time by automatically triggering heating restarts based on the history of V40 recorded during the previous reference time period. Thus, sufficient hot water is prepared daily to provide for the occupants, whether they are small or large, and whether they are stable or chaotic. According to a particular characteristic of the invention, the storage water heater has a programmed heating set point, the electronic control means being configured to adjust the programmed heating setpoint of the storage water heater if V40c is less than V40s a predefined number of times over a period of time identical to the reference period. Thus, the water in the tank is heated to just the needs of the occupants, while maintaining a safety margin essential to the unavoidable changes in withdrawal of sanitary water from the occupants, which reduces the power consumption of the heater storage water. In addition, the ergonomics of use of the storage water heater is improved, the user performing less manipulations and adjustments on a control interface of the electronic control means. According to one particular characteristic of the invention, the calculating means is furthermore configured to sample the V40c values over a predefined reference period, to record in a memory the values of V40c sampled in connection with the corresponding sampling instants. in the period of reference time, and for modifying the heating setpoint, upwards or downwards, according to the result of the comparison between each value of V40c sampled with respect to a threshold value V40s, over the period of predefined reference time. According to a particular characteristic of the invention, the electronic control means is configured to trigger a restart of heating if the decrease of V40c is faster than that recorded for the reference time period. Thus, a heating restart is performed if a change in threshold crossing speed by the V40c compared to that recorded in the history of the V40 during the previous reference time period is detected, which makes it possible to anticipate a future shortage of domestic hot water. According to a particular characteristic of the invention, the electronic control means is configured to trigger a restart of heating if the high tank temperature measured by the top of the tank probe is lower than a preset high tank temperature threshold value.

Thus, the fact of triggering a heating restart before the water temperature of the top of the tank reaches a certain threshold temperature prevents the temperature mirror from being broken in the tank of the storage water heater. by limiting the amount of cold water injected into the tank. According to a particular characteristic of the invention, the electronic control means is configured to limit or reduce the heating if the low tank temperature measured by the bottom of the tank probe is greater than a preset tank low temperature threshold value during a period of time. predefined period of time, until the low tank temperature becomes lower than said predefined lower tank temperature threshold value. Thus, the electronic control means can automatically detect a prolonged or permanent absence of the occupants, such as vacations, and disable the adjustment of the programmed heating setpoint and the recording of the history and lower the programmed heating setpoint during this period of absence detected, thus making it possible to minimize the energy consumption during this period of prolonged absence. According to a particular characteristic of the invention, for a thermodynamic water heater, each restart of heating may be a restart of heating in electricity, in heat pump, or electricity and heat pump. Thus, each heat recovery can be carried out in heat pump by the heat pump of the thermodynamic water heater and / or in electricity by an optional auxiliary electric source of the thermodynamic water heater 20, the heat recovery CAP being preferred when this is possible in order to minimize the energy consumption of the thermodynamic water heater. The PAC has the advantage of not mixing the water in the tank to maintain a stratification of temperatures in the tank. The backup power source will cause a movement of water in the tank, which will break the temperature stratification, may distort the calculation of the V40c. According to a particular characteristic of the invention, each temperature probe is disposed in a thermowell. According to a particular characteristic of the invention, the storage water heater is a thermodynamic water heater, the heating means being constituted by the heat pump (PAC) of the thermodynamic water heater, the heat pump comprising a condenser arranged at least on the lower part of the tank of the thermodynamic water heater, the bottom of the tank probe being disposed at the perimeter of the condenser, and the bottom of the tank being placed in the upper half of the condenser. According to a particular feature of the invention, the storage water heater is an electric water heater, the heating means being constituted by an electrical resistance immersed in the tank, or wound around the tank. To better illustrate the object of the present invention, will be described below, by way of illustration and not limited to, a preferred embodiment, with reference to the accompanying drawings. In these drawings: FIG. 1 is a sectional view of a thermodynamic water heater according to the present invention; Figure 2 is an exemplary V40 curve calculated by the thermodynamic water heater according to the present invention for a period of 24 hours; and FIG. 3 is an exemplary histogram of a history of V40 calculated by the thermodynamic water heater according to the present invention for a period of time of 7 days. In what follows, the invention will be described in connection with a thermodynamic water heater. It is understood, however, that the invention also applies H in the case of an electric water heater, and that the electric water heater is within the scope of the present invention. Referring to Figure 1, it can be seen that there is shown a thermodynamic water heater 1 according to the present invention. The thermodynamic water heater 1 is equipped with a heat pump (PAC) 2, said thermodynamic water heater 1 comprising a tank 3 containing water, the cap 2 comprising a condenser 4, a part of which is wound around the lower part of the tank 3 of the thermodynamic water heater 1. The thermodynamic water heater 1 further comprises a cold water inlet 5 and a supplementary heating electric heater 6 arranged at the bottom of the tank 3 , the cold water inlet 5 and the additional heating electrical resistance 6 penetrating into the tank 3 through sealed openings in the bottom of the tank 3. It should be noted that the thermodynamic water heater 1 may not include an electric heater 6, without departing from the scope of the present invention. A metal coating wall 7 surrounds the tank 3 of the thermodynamic water heater 1, an insulating material 8 being disposed between the tank 3 and the coating wall 7, respective openings being made in the coating wall 7 and the insulating material. 8 to pass the condenser 4 of the PAC 2, the inlet 30 of cold water 5 and the additional heating electrical resistance 6. The thermodynamic water heater 1 further comprises an electronic control means 9 in order to regulate the heating temperature of the thermodynamic water heater 1 and to trigger the heat pump 2 and / or the auxiliary heating electric resistance 6 for programmed heating restarts of the thermodynamic water heater 1.

The thermodynamic water heater 1 further comprises three temperature probes 10a, 10b, 10c disposed inside the tank 3 at different heights and connected to the electronic control means 9 via electrical wires 11, the three temperature probes 10a, 10b, 10c comprising a "top tank probe" 10a disposed at the top of the tank 3 of the thermodynamic water heater 1, a "tank core probe" 10b disposed at the middle of the tank 3 thermodynamic water heater 1, and a "bottom probe" 10c disposed at the bottom of the tank 3 of the thermodynamic water heater 1. It should be noted that the thermodynamic water heater 1 could also have more than three probes of temperature disposed within the vessel 3 at different heights, without departing from the scope of the present invention. The low-bed probe 10c is disposed at the perimeter of the portion of the condenser 4 wound around the tank 3, and the tank-center probe 10b is disposed at the upper limit of the portion of the condenser 4 wound around the tank 3. The electronic control means 9 comprises a calculation means 12 configured to calculate in real time the volume of water at 40 ° C remaining (V40c) that can be provided by the thermodynamic water heater 1 from the temperatures measured by the three temperature probes 10a, 10b, 10c. The real-time calculation by the calculation means 12 of the V40c that can be provided by the thermodynamic water heater 1 comprises at least the following steps: the determination of the temperature profile of the tank 3 as a function of its height by linear interpolation between a bottom of the tank temperature measured by the bottom tank probe 10c and a tank medium temperature measured by the tank medium probe 10b and by linear interpolation between the tank medium temperature and a tank top temperature measured by the top of the tank probe 10a ; calculating the height of the tank 3 below which the temperature of the water is below 40 ° C according to said determined temperature profile; and calculating the V40 from said temperature profile above said calculated height, the cross section of the vessel 3 and a cold water temperature, the cold water temperature being the minimum temperature measured by the bottom probe 10c in this embodiment. Interpolation other than linear could be used, and a probe at the cold water inlet could be used to measure the temperature of cold water upon arrival in the water heater. It should be noted that, during the step of determining the temperature profile of the tank 3 as a function of its height, the temperature of the water contained between the bottom of the tank 3 and the lower limit of the condenser 4 is assumed being equal to the cold water temperature, the temperature of the water contained between the lower limit of the condenser 4 and the bottom of the tank probe 10b is assumed to be equal to the low temperature of the tank, and the temperature of the water contained between the top of the tank probe 10a and the top of the tank 3 is assumed to be equal to the top tank temperature.

It should be noted that each temperature probe 10a, 10b, 10c could be disposed in a thermowell, without departing from the scope of the present invention. The calculation means 12 is further configured to compare in real time the calculated V40 V40c with a predefined threshold value V40 V40s, the electronic control means 9 being configured to trigger an unexpected heating restart of the thermodynamic water heater 1 when V40c is less than V40s. The calculating means 12 is further configured to store in a memory a history of the V40 over a predefined sliding reference time period, the electronic control means 9 being configured to trigger, during the current period of time, a restart. of advance heating of the thermodynamic water heater 1 according to the history of the V40 over the previous reference time period. The electronic control means 9 is furthermore configured to adjust a programmed heating setpoint 20 of the thermodynamic water heater 1 if the calculated V40 V40c is smaller than the predefined V40 threshold value V40s a predefined number of times in the history of the V40 over the previous reference time period. The electronic regulating means 9 is further configured to trigger a heating restart if the decrease of the calculated V40 V40c is faster than that recorded in the V40 history over the previous period of time. The electronic control means 9 is further configured to trigger a heating restart if the high tank temperature measured by the top tank probe 10a is less than a preset tank top temperature threshold value. The electronic control means 9 is furthermore configured to deactivate the adjustment of the programmed heating set point 5 and the recording of the history of the V40 and to lower the programmed heating setpoint, if the low tank temperature measured by the Bottom probe 10c is greater than a predefined bottom tank temperature threshold value for a predefined period of time, until the bottom tank temperature becomes lower than said bottom tank temperature threshold value. predefined. It should be noted that each aforementioned booster heater may be a booster heating in electricity (by the additional heating electrical resistance 6), in heat pump (by the heat pump 2), or in electricity and heat pump (simultaneously by the heat pump 2 and the auxiliary heating electric heater 6). Referring to Fig. 2, it can be seen that there is shown a Cl curve as an example of the V40 calculated by the thermodynamic water heater 1 according to the present invention for a period of time of 24 hours. hours. The calculation means 12 compares in real time the calculated V40 to a predefined V40 threshold value. When the calculated V40 is lower than the threshold value of V40 due to a large draw of hot water by the occupants of the building in which the thermodynamic water heater 1 is installed, at 6:30 and 19:30 on the Cl curve of Figure 2, the electronic control means 9 triggers two unexpected heating resumptions R1 and R2 of the thermodynamic water heater 1 at 6h and 19h30 respectively.

Thus, a shortage of domestic hot water is prevented by heating recovery before the calculated V40 reaches a critical value, which improves the comfort of domestic hot water for occupants.

Referring to Figure 3, it can be seen that there is shown therein a histogram as an example of a history of the V40 calculated by the thermodynamic water heater 1 according to the present invention for a period of time 7 days.

The calculating means 12 stores in a memory a history of the V40 over a predefined sliding reference time period, the predefined sliding reference time period being 7 days in the histogram of Figure 3.

In this histogram by way of example, each bar corresponds to the minimum daily value of the calculated V40 recorded in the V40 history during the previous reference time period. It can be seen from the histogram of FIG. 3 that on the fifth day of the previous reference time period, the value of the minimum calculated V40 fell below the threshold value of V40. During the current period of time, the electronic control means 9 therefore triggers an anticipated R3 heating restart of the thermodynamic water heater 1 on the fifth day of the current period of time in order to prevent a possible shortage of identical domestic hot water. to that which occurred on the fifth day of the previous reference period. The history of the registered V40 makes it possible to anticipate hot water shortages taking into account, during the current period of time, the variations of the V40 during the period of previous reference time.

The thermodynamic water heater 1 according to the present invention makes it possible to permanently guarantee the availability of the domestic hot water while minimizing the energy consumption of said thermodynamic water heater 1, the measurement of the three temperatures in the tank 3 allowing: - the identification of criteria illustrating the use of the thermodynamic water heater 1 and the consumption profile of the hot water by the occupants; and - by analyzing these criteria, an adaptation of the operating parameters of the thermodynamic water heater 1 in order to guarantee the availability of domestic hot water with the minimum consumptions by the adjustment of the set point and the anticipated revolutions of the PAC 2 The present invention makes it possible to: - improve the comfort of hot water (more hot water available thanks to reminders triggered exceptionally and automatically if necessary, and automatically taking into account changes in needs) ; to reduce the electrical consumption of the thermodynamic water heater 1 (heating the water to the necessary need, while maintaining a safety margin essential to the unavoidable variations of withdrawal of the 25 occupants); improve the ergonomics of use (fewer manipulations and adjustments by the user on a control interface of the electronic control means 9); and to have a high reliability (by reducing the set point, when this is not done to the detriment of the hot water comfort and the unavoidable reliability conditions of the thermodynamic water heater 1, and therefore by improving the conditions operating mode of the heat pump 2 (compression ratio and reduced load rate), and giving priority to daytime heating in order to improve the COP (coefficient of performance) and to reduce the heating time). Described below are various exemplary functions that can be performed by the electronic control means 9 of the thermodynamic water heater 1: 10 - adjustment of the setpoint by: o use of the three probes and the water temperature cold to estimate in real time the remaining V40; o comparison of this remaining V40 with respect to a threshold (e.g., 100L of V40) at a defined frequency (e.g. 10s with filtering of measurements); o creation of a counter exceeding this threshold over a rolling period, for example 10 days 20 (maximum 1 time per day); and o using the sum of all these values to decide whether the setpoint is adapted or not, the decision being made by a correction table, a PI 25 regulator (proportional-integral), or other types of corrector ; restarting of heating on "probe mid-tank": recovery of heating in CAP at 45 ° C if the consumption of the first half-balloon is faster than usual (compared to a sliding history of 10 days for example) by analyzing the evolution of the history of the duration between reaching the set point at the middle of the tank and the passage of this setpoint below a threshold illustrating that the cold water front reached the middle probe; - restart of heating on "top of tank probe": heating recovery at 45 ° CAC and electricity if the high temperature of the tank is below a threshold (for example, 40 °); - automatic absence detection: o if it is detected that the temperature measured by the low cell probe never drops below a threshold (for example, 35 °) for n consecutive days (for example, 6 consecutive days), o after detection: inhibition of the parameters of automatic adjustment of the setpoint and recording of the V40, and lowering of the heating setpoint to 45 ° until detection of the next withdrawal (that is to say, when the measured temperature by the low cell probe passes under a threshold (for example, 40 ° C 30 ° C)); and - restart of heating if the setpoint is already at maximum (62 °): recovery in PAC at 45 ° as soon as the remaining V40 is below a threshold (for example, 100L). The object of the present invention is not to provide exactly the profile of the customer, but to provide sufficient hot water prepared daily to meet his needs, whether they are small or large, and especially that they are stable (repeatable) or chaotic. It should be noted that the heating set point is always between 50 and 62 ° C: - 50 ° C being a minimum for storing a quantity of hot water sufficient for the customer, and - 62 ° C being a high limit for ensure the good reliability of the thermodynamic water heater 1 (aging joints, enamel, heat stress, etc.).

The self-adjusted setpoint is therefore always between these two values for the main heat generation (that resulting from the signal full hours / off-peak hours (HP / HC) or programmed manually by the customer).

Claims (10)

CLAIMS1 - Storage water heater (1), comprising a tank (3) intended to contain water, a cold water inlet at the bottom of said tank (3), a water outlet on said tank ( 3), a heating means (2) for heating water in said tank (3) and an electronic control means (9), characterized in that it further comprises a temperature measuring means of cold water and at least three temperature probes (10a, 10b, 10c) arranged at different heights of the tank (3) and each connected to the electronic control means (9), the at least three temperature probes (10a, 10b , 10c) comprising a "top tank probe" (10a) disposed at the top of the tank (3), a "bottom tank probe" (10c) disposed at the bottom of the tank (3), and a "Mid-tank probe" (10b) disposed at the middle of the tank (3), the electronic control means (9) comprising a calculating means (12) configure in to calculate in real time a calculated volume V40 V40c from the temperatures measured by the at least three temperature probes (10a, 10b, 10c) and the cold water temperature. 2 - storage water heater (1) according to claim 1, characterized in that the calculation of V40c comprises at least the following steps: the determination of the temperature profile of the tank (3) as a function of its height by interpolation between a low tank temperature measured by the bottom tank probe (10c) and a tank medium temperature measured by the tank medium probe (10b) and by interpolation between the tank core temperature and a measured tank top temperature by the top of the tank probe (10a); calculating the height h40 of the tank (3) below which the temperature of the water is less than 40 ° C according to said determined temperature profile; and calculating V40c from said temperature profile above said calculated height h40, tank cross section (3), and cold water temperature. 3 - storage water heater (1) according to one of claims 1 and 2, characterized in that the calculation means (12) is further configured to compare in real time the calculated value V40c to a threshold value predefined V40 V40s, the electronic control means (9) being configured to trigger an unexpected warm-up of the storage water heater (1) when V40c is less than V40s. 4 - storage water heater (1) according to one of claims 1 to 3, characterized in that the calculation means (12) is further configured to sample V40c values over a predefined reference period of time, recording in a memory the values of V40c sampled in connection with the corresponding sampling times in the reference time period, and to anticipate a heating restart of the storage water heater (1) to ensure that for each instant of a current period of time corresponding to a sampling instant of the predefined reference period of time, the value V40c is greater than or equal to the value V40c stored in memory for this sampling instant. 5 - storage water heater (1) according to claim 4 taken in dependence on claim 3, characterized in that the storage water heater (1) has a programmed heating setpoint, the electronic control means (9) ) being configured to adjust the programmed heater heating line accumulation (1) if V40c is less than V40s a predefined number of times over a period of time identical to the reference period. 6 - storage water heater (1) according to claim 5, characterized in that the calculation means (12) is further configured to sample V40c values over a predefined reference period of time, record in a memory the sampled V40c values in connection with the corresponding sampling times in the reference time period, and to change the heating setpoint, up or down, according to the result of the comparison between each V40c value sampled by to a threshold value V40s over the predefined reference period. 7 - storage water heater (1) according to one of claims 4 or 5, characterized in that the electronic control means (9) is configured to trigger a heating restart if the decrease of V40c is faster than the one recorded for the reference time period. 8 - storage water heater (1) according to one of claims 1 to 7, characterized in that the electronic control means (9) is configured to trigger a restart of heating if the high tank temperature measured by the upper tank probe (10a) is lower than a preset high tank temperature threshold value. 30 9 - storage water heater (1) according to one of claims 5, 7 and 8, characterized in that the electronic control means (9) is configured to limit or reduce the heating if the low temperature cuvemesurée by the bottom of the tank probe (10c) is greater than a predefined low tank temperature threshold value for a predefined period of time, until the bottom tank temperature becomes lower than said low temperature threshold value. preset tank. - Storage water heater (1) according to one of claims 1 to 9, characterized in that each temperature sensor (10a, 10b, 10c) is disposed in a thermowell. 10 11 - storage water heater (1) according to one of claims 1 to 10, characterized in that the storage water heater is a thermodynamic water heater, the heating means (2) being constituted by the pump heat pump (PAC) of the thermodynamic water heater, the heat pump (2) comprising a condenser (4) disposed at least on the lower part of the tank (3) of the thermodynamic water heater (1), the bottom of the tank ( 10c) being disposed at the perimeter of the condenser (4), and the middle tank probe (10b) being disposed in the upper half of the condenser (4). 12 - storage water heater (1) according to one of claims 1 to 10, characterized in that the storage water heater (1) is an electric water heater, the heating means (2) being constituted by an electrical resistance immersed in the tank (3), or wound around the tank (3).