FR2812073A1 - Power control system for room heater includes circuit monitoring temperature change to cut heating power when door is left open for ventilation - Google Patents

Abstract

Heater power control system monitors the temperature change within a room. In event of a fall in temperature beyond a set level, it is assumed that a door or window has been left open for ventilation and the heater power is reduced to save energy. When temperature rises again above a certain level, it is assumed that door or window has been closed, and normal heating power may be resumed without waste of energy. The system for management of the power of a at least one radiator heater within a room includes monitoring changes which may arise from opening the door or window. A threshold temperature difference ( DELTA Ts) is chosen (10) and the ambient temperature (T) of the room is memorized during a first time interval (t0). The temperature difference ( DELTA T) between the present instant (t) and the start of the time interval (t0) is determined (12). When the temperature difference ( DELTA T) becomes greater than the threshold temperature difference ( DELTA T greater than DELTA Ts), it is determined (14) that the door or window has been opened and the power of the heating radiator is reduced. The change in temperature (T) of the room during a further time interval (te) is monitored. If the temperature (T) rises during this time, it is determined that the door or window has been re-closed, and the power of the heating radiator is increased.

Description

METHOD AND DEVICE FOR MANAGEMENT

HEATING POWER

ONE OR MORE RADIATORS

PLACES IN A MUNIEED ROOM

OPENING OUTSIDE

DESCRIPTION

  Field of the invention The invention relates to a method for managing the heating power of one or more radiators placed in a room having at least one opening on the outside. It also concerns the

  device for implementing this method.

  The invention has applications in the field of heating and, in particular, electric heating in homes or businesses, where the windows and / or doors to the outside are likely to remain a long time open. State of the art The social habit is that individuals regularly rent their homes, to renew the air. Studies show that windows (or doors) are open daily to air, at least an hour each day, even in

winter.

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  During these openings, heaters equipped with thermostats operate at a higher than normal power, to "compensate" the fresh air entering the room.This leads to overconsumption of heating energy.This phenomenon is further amplified In the case of electric heating, the electric heating has a good dynamic of its regulation, ie when opening a window or a door, electric heating is started. its maximum heating power very quickly, this

  which leads to unnecessary electrical consumption.

  To avoid this over-consumption, most people prefer to turn off the heat when opening a window or door, and then turn it on again when closing the window or door. This need to cut and then restart heating is a constraint

for users.

  To avoid this constraint to users, it is possible to provide each opening (window or door) to the outside of contactors type rebate contacts. These detect, mechanically, the opening of a door or a window and then control the shutdown of the heating, that is to say the power cut of the radiator. This system has the disadvantage of requiring wired links between the contactors and the convector, which, on the one hand, is unsightly

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  and, on the other hand, entails significant installation costs. SUMMARY OF THE INVENTION The purpose of the invention is precisely to remedy the disadvantages of the technique described above. To this end, it proposes a method and an integrated device (that is to say "wireless") for detecting the opening and closing of a door or window facing outside and to control the heating power of the radiator

  according to what has been detected.

  More specifically, the invention relates to a method for managing the heating power of at least one radiator located in a room provided with at least one window or door, characterized in that it consists in: choosing a gap threshold temperature; - memorize the temperature of the room during a time interval t0; - determining a temperature difference between the present moment and the beginning of the time interval t0; as soon as the temperature difference becomes greater than the threshold temperature difference, then consider opening a door or window and reduce the heating power of the radiator; - monitor the evolution of the temperature in the room during a time interval te; and

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  if the temperature increases during this time, then consider that the door or window is closed and increase the power of

heater heater.

  Advantageously, the method consists in: - choosing a second threshold temperature difference, lower than the first temperature difference; and - to check whether the difference in temperature after the time is between the first and the second threshold temperature differences and, if this is the case, to wait for a complementary time tc, then to check, at the end of this time tc, the evolution of the temperature; and - if the temperature has not increased during this time tc, then decrease the power of

heater heater.

  In a preferred embodiment, the method of the invention consists in: - choosing a safety opening time d, with d >> te; and when no decrease in the temperature difference has been detected after this time d, then increasing the heating power for a prescribed time tf and then checking whether the temperature difference decreases: if it is not the case, then decrease to

  new heating power of the radiator.

  According to this method, it is possible to determine a maximum heating power as a function of the average heating power calculated over a wide time interval. The steps of increasing the heating power can then

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  consist of bringing the radiator to its maximum heating power and the steps of decreasing the

  heating power to turn the radiator off.

  The invention also relates to the device for implementing this method. This device comprises: a probe attached to the radiator for measuring the ambient temperature of the room; means for calculating at least one temperature difference during a time interval te; and means for controlling the heating power of the radiator, as a function of the difference in

determined temperature.

  Advantageously, the radiator is a

electric heater.

  According to one embodiment, the calculation means consist of a microcontroller integrated on

each radiator.

  According to another embodiment, the calculation means consist of a computer controlling

  the control means of one or more radiators.

Brief description of the figures

  - Figure 1 shows schematically the device of the invention; FIG. 2 represents the functional diagram showing the various steps of the method of the invention; and

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  FIGS. 3A and 3B show, in the form of electrical signals, examples of opening and closing of a door and a window, as well as the operation of the radiator as a function of these openings and closures of window and door. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION The invention proposes an integrated device, that is to say "wireless", which makes it possible to manage the heating power of a radiator, or of several radiators, during the heating process. opening and closing of

  windows and / or doors of a room of a dwelling.

In Figure 1, there is shown

  schematically the basic device of the invention.

  This device comprises a radiator 1, provided with a probe 2 for measuring the ambient temperature of the

  room in which is placed the radiator.

  The following description will be

  given for an electric heater, wherein the radiator may be a convector, a radiant panel or any other

radiator said <electric ".

  The probe of this device is a probe insulated in a plastic sheath, that is to say having a double insulation, such as a 10k double insulated CTN probe. Preferably, the probe is placed at the bottom of the radiator at a lateral end, so as not to undergo the hot air flow emitted by the radiator.

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  The device of the invention further comprises means for controlling the heating power of the radiator. As will be seen in more detail later, these control means may be simply an on / off device 3, or a variator 4, or both. The device also comprises calculation means making it possible to calculate the temperature difference between the present moment and a time t0, and to verify whether this difference in temperature is less than, greater than or equal to a difference in

  predetermined temperature, called "threshold gap".

  The details of the calculations made by these calculation means will be described later, during the

  description of the process of the invention.

  These calculation means can be, as is the case in Figure 1, a microcontroller 5, integrated on the radiator. This microcontroller is directly connected to the control means of the radiator. In a variant of the invention, it is possible to place, in the same housing, several radiators each provided with a probe. The information recorded by each probe is then provided to the same calculation means which can be a PC type computer; it is, then, the computer that performs the temperature difference calculations, for each radiator, and which controls the control means of each radiator. FIG. 2 shows the functional diagram showing the different steps

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  of the process of the invention. More specifically, there is shown, solid line, the essential steps in the process of the invention and, in dashed lines, the steps

  of a preferred embodiment of the invention.

  The method of the invention generally consists in determining a temperature difference for a certain period of time, checking whether this temperature difference is greater than a predetermined threshold and, from that, if it is open. or not a window or

of a door.

  To facilitate the description of the process of

  the invention, we consider that the room has a single window opening on the outside and a door opening on a corridor inside the housing; we will also consider that the piece has only one

only electric heater.

  More specifically, the method of the invention consists in choosing (step 10) a threshold temperature difference ΔTs, as well as a first time interval t0 making it possible to determine whether there has been an opening on the outside and a second time interval (te) to determine if this opening

has been closed.

  The method of the invention then consists of a step 11 for storing the ambient temperature of the workpiece T during the time interval t0. It then consists in calculating the temperature difference ΔT between the instant t and the beginning of the time interval t0. For example, tO can be set to 10 minutes with a temperature rise all

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  30 seconds or every minute, so as to memorize the measured temperature 10 minutes before

present time.

  The method of the invention then consists of a test step 13 which consists in checking whether the calculated temperature difference ΔT is greater than the predefined threshold temperature difference Δt. If this is not the case, then the method considers that the window is closed (block 17) and the process loops back to the beginning of step 11. On the contrary, if the result of the test 13 is positive, it is that is to say, if AT> ATs, then the method considers that the window is open and the calculation means control the stopping of the heating, to

step 14.

  It should be noted that in the description of

  Figure 2, it is considered that when a window is open, the heating must be stopped and when the window is closed, the heating must be restarted. It is understood that, as explained above, the radiator can simply undergo a decrease in its heating power (instead of a total stop), when the window is detected open and, conversely, an increase in its heating power (instead of restarting) when the window is closed. This choice depends on

the intended application.

  When a window has been detected as open and the heating has been stopped (or the heating power of the radiator decreased), it is necessary to detect the closure of this open window. For

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  this, the process takes into account the fact that the walls have a significant time constant, which can be minimum hours for a new building and more for an old building. Thus, when a window is opened, the ambient air of the room is rapidly cooled; on the other hand, the walls, because of their constant time, do not cool so quickly. Thus, when closing the window, the walls restore their heat, which gives rise to a rise in temperature in the room. The method of the invention therefore proposes to monitor the evolution of the temperature over a time interval te. If the rise in temperature is significant, it is considered that the window has been closed and that the heating

can be restarted.

  For this, the method of the invention consists in monitoring, in step 15, the evolution of the temperature T in the room during a time interval te. If this temperature T increases during this time te, that is to say if T (t)> T (t-te), then we consider that the window has been closed (step 16) and the heating is restarted. If the temperature T has not increased, then the process is looped back to

  level 15, until the answer is yes.

  An alternative to this loopback of test 15 will be

explained later.

  The process, which has just been described,

  corresponds to a basic economic program.

  The invention proposes a program, called comfort, which improves the management of the opening of windows and doors of a room in

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  the sense o it allows not to detect the opening of a door (or a window), overlooking a corridor inside the housing. Indeed, when a door opens on a corridor, there is detection of a difference in temperature, but it is lower than in the case of an opening on the outside. The method of the invention therefore proposes to verify whether the temperature difference calculated between the time t and the beginning of the interval t0 is significant for an opening on the outside, by comparing this difference with two threshold differences ATs. and ATs'. For example, the threshold difference ΔTs may be chosen equal to 1.5 and the threshold difference Δt 'equal to 0.5, so that any difference smaller than 0.5 ° C. is

not considered significant.

  FIG. 2 shows, in dotted lines, the steps of the method of the invention corresponding to this variant. This variant comprises, in addition to steps 10 to 17, a step 20 of choosing a second threshold temperature difference ATs' (with

  ATs' <ATs) and a comfort time interval tc.

  The other steps of this variant are introduced after the test 13, consisting in checking, in step 21, whether the calculated temperature difference AT is greater than the first threshold temperature difference ATs. We saw previously that if AT> ATs, then we consider that the window is open. It will now be seen that if AT is not greater than ATs, it is verified, in step 21, whether this temperature difference AT is between

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  first threshold temperature difference ATs and the second

temperature difference threshold ATs'.

  If this is not the case, that is, if the calculated temperature difference ΔT is both less than ATs and less than ATs', then the window is considered closed and the process is looped back. on the other hand, if the temperature difference ΔT is between the second threshold temperature difference ΔT 'and the first threshold temperature difference ΔTs, then the method of the invention consists in waiting for a time tc (step 22), then to check if the temperature has increased during the time tc (step 23). If this is not the case, then it is considered, in step 24, that the temperature difference is due to the opening of the door to an interior corridor and the process loops back to the beginning of the step 11 of storing temperatures. If the test 23 is positive, then it is considered that the window is open and that the process continues with step 14,

  as for the economic program.

  The method of the invention proposes an additional variant making it possible to start the heating for a certain time (for example beyond one hour), when the window is closed.

  open for a period considered abnormal.

  In other words, if after a period d (with d >> te) the window is still considered open, the method proposes to restart the

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  heating for a short time, which can be 5

at 10 minutes, for example.

  More specifically, this variant of the method of the invention consists, first of all, in selecting and storing, in a timer, a security duration d, and then verifying that: when no decrease in the temperature difference AT has been detected during this period d, then the heating is forced on during an imposed time interval tf (which may be, for example, 5 to 10 minutes); the process then consists of looking at whether the temperature increases during this time tf. If the ambient temperature does not rise, then we consider that the window is always open and the heating is stopped. On the contrary, if the temperature rises, then it is considered that the window has been closed and the heating remains in operation. For example, it can be considered that the rise in temperature is significant, since it reaches 2 C. In applications where the radiator is either at a standstill or in maximum operation, the method of the invention proposes to clamp down the heating power of the radiator, that is to say, to limit the maximum radiator power output. For this, the method of the invention proposes to store, in a memory, different operating points of the radiator, that is to say the values of the heating power of the radiator at different times during a period of time quite important (for example, of the order of 2 to 3 hours). From these data, an average operating rate is calculated. The radiator

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  is then allowed to heat to a maximum rate proportional to the average operating rate. For example, the maximum heating rate imposed can be

equal to the average rate, plus 15%.

  Such a clamping power limits the power of the radiator in case of non-detection of window opening (for example in mid-season). FIGS. 3A and 3B show test sequences, respectively, in the case of the economic program and in the case of the comfort program. In these figures, on the abscissa, the time is represented and, on the ordinate, the temperature. The curve C1 shows the ambient temperature of the part, that is to say the temperature measured by the probe of the

  radiator, when the window is open and / or closed.

  This curve C1 shows that, between the points Pi and P2, the window is open, between the points P2 and P3, the window is closed and between the points P3 and P4, the

window is open again.

  Curve C2 shows the operation of the radiator, depending on the evolution of the temperature of the room. When curve C2 is sinusoidal, it means that the radiator emits heat; when the curve C2 is flat, it means that the radiator is stopped. The opening of the window at the point P1, on the curve C1, is detected at time t1; the radiator is then stopped. At time t2, the radiator is forced on by the timer to check

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  that the window is really always open. At time t3, there is confirmation that the window is

  always open; the heating is stopped again.

  At time t4, the window closure is detected (point P4 on the curve C1); the heating is then

  restarted, with clamping power.

  FIG. 3B shows the evolution of the ambient temperature by the curve C3 and the operation of the radiator by the curve C4. In Figure C3, the point P5 corresponds to the opening of an inner door; in this case, a temperature difference is detected, but it is relatively small. It is then seen, on the curve C4, that the heating is in operation since the instant t5 o the opening of the door has been detected until time t6, o a temperature drop is detected; the radiator is then put in stop. At time t7, the radiator is again forced on (without power clamping), by the timer, to verify that the window is actually still open; the confirmation of the still open window is given at time t8; the radiator is then again stopped, then at time t9, the device detects a new rise in temperature (point P7), which means that the window has just been closed. The

heating is restarted.

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Claims (10)

  1. A method for managing the heating power of at least one radiator (1) located in a room provided with at least one window or door, characterized in that it consists in: - choosing (10) a difference of threshold temperature (ATs); - memorize (11) the room temperature (T) of the room during a first time interval (tO); determining (12) a temperature difference (AT) between the instant present (t) and the beginning of the time interval (t0); - as soon as the temperature difference (AT) becomes greater than the threshold temperature difference (AT> ATs), then consider (14) that there is opening of a door or window and decrease the heating power of the radiator; - monitor (15) the evolution of the temperature (T) in the room during a time interval (te); and if the temperature (T) increases during this time, then consider (16) that the door or window is closed and increase the heating power of the radiator.   2. Method according to claim 1, characterized in that it consists of: B 13566.4 BM   - to choose (20) a second threshold temperature difference (ATs'), lower than the first difference (ATs); and - to check (21) whether the temperature difference (AT) after time is between ATs and ATs' and, if so, to wait (22) for a complementary time (tc) and then to check (23), at the end of this time tc, the evolution of the ambient temperature difference (T); and if the temperature (T) has not increased during this time tc, then decrease the power of heater heater.   3. Process according to any one of   Claims 1 and 2, characterized in that it consists   to: - choose a safety opening time d, with d >> te; and when no decrease in the temperature difference ΔT has been detected after this time d, then increasing the heating power for a prescribed time (tf) and checking whether the difference ΔT decreases: if it is not the case, then decrease again the heating power of the radiator.   4. Process according to any one of   Claims 1 to 3, characterized in that it consists   to determine a maximum heating power according to the calculated average heating power over a wide range of time.   5. Method according to claim 4, characterized in that the steps of increasing the B 13566.4 BM   heating power consist of wearing the radiator to its maximum heating power.   6. Method according to claim 5, characterized in that the steps of decreasing the heating power consist in putting the radiator at a standstill. 7. Device for managing the heating power of at least one radiator (1) located in a room provided with at least one door or window, characterized in that it comprises: - a probe (2) fixed on the radiator for measuring the ambient temperature of the room; - calculating means (5) of at least one temperature difference during a time interval (te); and control means (3, 4) for the heating power of the radiator, as a function of   the temperature difference determined.   8. Device according to claim 7, characterized in that the radiator is an electric heater. 9. Device according to any one of   claims 7 and 8, characterized in that the means   of calculation consist of a microcontroller integrated on each radiator.   10. Device according to any one of   claims 7 and 8, characterized in that the means   calculation consists of a computer controlling the   control means for one or more radiators. B 13566.4 BM