EP2378213B1 - Procedure for analysing the thermal behaviour of a construction, and associated system - Google Patents

Description

The present invention relates to the analysis of the thermal behavior of a construction.

Any building delimiting a confined space and including at least one equipment consuming energy, for example electrical, to ensure a thermal environment (heating or cooling) different from that prevailing outside can be seen as a place of exchange and thermal energy circulation.

This is very schematically represented on the figure 1 . The construction 1, which may for example be a building, a room, a room, a room or any other structure defining an enclosed space, contains a heating equipment 2 (boiler, radiator, etc.) or cooling (air conditioning, etc. .).

The heat or freshness produced by the equipment 2 constitutes a heat flow that propagates inside the construction 1, as is symbolized by the arrows 3. Part of this thermal energy is also lost and escapes of construction 1, as is symbolized by the arrows 4.

One way to improve the thermal balance of the construction 1 is to ensure that the losses 4 are minimized, for example by working on the sealing and insulation of the construction 1.

On the other hand, there is currently a strong trend to improve the energy performance of buildings, whether residential, professional, industrial or other.

In the case of construction 1 of the figure 1 , the energy performance is even better than the energy consumption of the equipment 2 is low, while maintaining control of the temperature inside the building 1.

Standards in force or in the process of development thus provide for drastic reductions in average energy consumption in the building sector in the relatively short term.

For these reasons, the design of a construction must now take into account the energy balance. This is usually done using computer simulation tools.

The designers of a construction are even sometimes obliged to engage on an energy balance. For this purpose, they may have to guarantee that a relation between a theoretical consumption of the equipment or devices intended to ensure a thermal environment in the construction and a reference temperature inside the construction satisfies a given criterion. For example, the commitment may consist in guaranteeing a consumption lower than a certain amount of primary energy per unit area and per year (expressed for example in kWhep / m ² / year) for a certain average indoor temperature ( expressed for example in degrees Celsius).

Such a commitment can be provided by a good knowledge by the designers of the physical properties of their construction, which allows to design a thermal model. Hypotheses are also made on the variable parameters that can influence the energy balance, such as weather conditions (level of sunshine, outside temperature, or other). If they are not simply neglected, the variable parameters related to the use of the construction can also be subject to very simplified statistical assumptions. By use of the construction is meant any variable phenomenon that can be modified by human intervention, for example at the initiative of a building occupant, and having an influence on the thermal flows in the building. The thermal model formalizes the relationship between the energy input, the environment, the use of the construction and the indoor temperature.

Once the construction thus conceived has been completed, it may be useful to check whether it satisfies the commitment of its designers in terms of energy balance.

To do this, it is known to monitor the energy consumption of heating or cooling equipment. This is traditionally done using manual meter readings taken at relatively long time intervals, typically of the order of a month or year. Alternatively, appropriate sensors may allow a more regular monitoring of consumption.

The document DE 10 2008 032 880 A1 describes such a monitoring system.

However, the consumption thus obtained is not necessarily exploitable, because it can result from real conditions different from the assumptions fixed during the design. In particular, it may be conditions of use of the construction different from what was envisaged in the design: for example because of the addition or the suppression of curtains of trees nearby which project a shadow on the construction considered, because of the occupation of the building by a number of people higher or lower than the original hypothesis, etc.

It can therefore be difficult to verify whether the commitment made by the designers is satisfied or not.

In the event that the commitment does not seem to be satisfied, for example because the actual energy consumption is higher than the announced threshold, this could sometimes be explained entirely by the difference between the actual conditions of use of the building and the theoretical assumptions retained during the design.

Thus, the known methods do not allow to conclude to the respect or not the commitments in terms of energy balance because they do not make it possible to know the reasons likely to explain an unexpected level of measured consumption. Nor do they allow for a review of performance commitments based on actual conditions of use.

An object of the present invention is to improve this situation by allowing an analysis of the thermal behavior of a construction.

• mesurer une consommation réelle dudit équipement, une température réellement obtenue à l'intérieur de la construction et au moins un paramètre relatif à une utilisation de la construction ;
• estimer un écart entre ladite relation entre une consommation théorique dudit équipement et une température de référence à l'intérieur de la construction d'une part et une relation correspondante entre la consommation réelle dudit équipement et la température réellement obtenue à l'intérieur de la construction d'autre part ; et
• lorsque l'écart estimé dépasse un seuil, estimer une contribution relative à l'utilisation de la construction dans ledit écart en tenant compte dudit paramètre mesuré.

The invention thus proposes a method for analyzing the thermal behavior of a construction delimiting a closed space and including at least one equipment consuming energy to ensure a thermal environment by heating or cooling, the construction being modeled using a thermal model so that a relationship between a theoretical consumption of said equipment and a reference temperature inside the construction satisfies a given criterion. The method comprises the following steps:

• measuring a real consumption of said equipment, a temperature actually obtained inside the construction and at least one parameter relating to a use of the construction;
• estimating a difference between said relationship between a theoretical consumption of said equipment and a reference temperature inside the building on the one hand and a corresponding relation between the actual consumption of said equipment and the temperature actually obtained inside the building on the other hand ; and
• when the estimated deviation exceeds a threshold, estimating a relative contribution to the use of the construction in said deviation taking into account said measured parameter.

The estimation of a relative contribution to the use of the construction makes it possible to know how the use of this construction could have influenced the consumption of the heating or cooling equipment. As a non-limitative example, the presence of an unusually high number of people in construction, by the heat it produces can explain a particularly low consumption of heating equipment. Conversely, the opening of a large number of windows and / or doors of the construction can explain, particularly when accompanied by a low outside temperature, a particularly high consumption of heating equipment. Many other types of construction use can impact energy consumption in a variety of ways.

Advantageously, the relative contribution to the use of the estimated construction can be used to calculate a corrected difference by subtracting from the estimated difference the contribution relating to the use of the construction. Such a corrected gap is thus supposed to disregard the influence of the use of construction. It reflects a possible drift of the consumption compared to an expected behavior during the design.

This drift may be indicative of improper calibration of the thermal model used in the design of the construction and / or failure to respect any commitment of the designers of the construction. In the first case, the corrected difference can advantageously be exploited to calibrate the thermal model taking into account the actual situation observed. In the second case, the magnitude of the corrected difference, possibly supplemented by additional investigations, can make it possible to apprehend the causes of the drift, or even to treat them.

• on calcule en outre un écart corrigé en soustrayant dudit écart estimé la contribution relative à l'utilisation de la construction ;
• on déduit de l'écart corrigé une conclusion sur la conception de la construction ; on peut ainsi évaluer si des engagements pris à la conception ont ou non été respectées, compte tenu de l'utilisation de la construction ;
• on modifie le modèle thermique pour tenir compte de l'écart corrigé ; on peut ainsi rendre le modèle thermique plus conforme à la situation réelle ;
• on mesure en outre, à l'aide de capteurs correspondants, des paramètres relatifs à l'environnement de la construction, comme des conditions météorologiques ou une ambiance thermique d'une construction adjacente, et ladite relation entre la consommation réelle dudit équipement et la température réellement obtenue à l'intérieur de la construction tient compte de certains au moins de ces paramètres ;
• ledit paramètre relatif à une utilisation de la construction est relatif à l'un au moins parmi : une ouverture/fermeture d'au moins une porte ou fenêtre dans la construction, une occultation d'au moins une porte ou fenêtre dans la construction, une présence d'au moins un individu à l'intérieur de la construction, une présence d'au moins une source indirecte de chaleur ou de fraîcheur à l'intérieur de la construction, un usage d'au moins une consigne de fonctionnement pour ledit équipement ;
• on obtient au moins une image faisant apparaître une répartition thermique dans la construction au moyen d'au moins une caméra thermique, ladite image obtenue étant utilisée pour mesurer ledit paramètre relatif à une utilisation de la construction ; il s'agit là d'une façon particulièrement simple de mesurer ledit paramètre ;
• on mesure ledit paramètre relatif à une utilisation de la construction à partir d'une comparaison entre ladite image obtenue et une image attendue correspondante ;
• ladite image attendue tient compte de la présence et de l'emplacement dans la construction dudit équipement consommant de l'énergie pour assurer une ambiance thermique par chauffage ou refroidissement ;
• ladite image obtenue peut être sous une forme cryptée ;
• la consommation réelle dudit équipement et la température réellement obtenue à l'intérieur de la construction sont mesurés de façon répétée à des instants successifs ;
• ledit écart est estimé de façon répétée à des instants successifs, et dans lequel on analyse une évolution dudit écart dans le temps en vue de détecter d'éventuelles modifications du comportement thermique de la construction, indépendantes de l'utilisation de la construction.

According to other advantageous embodiments which can be combined in any conceivable way:

• a corrected difference is further calculated by subtracting from the estimated difference the contribution relating to the use of the construction;
• a conclusion on the design of the construction is deduced from the corrected difference; it can be assessed whether or not design commitments have been met, given the use of construction;
• the thermal model is modified to take account of the corrected difference; it is thus possible to make the thermal model more consistent with the actual situation;
• in addition, parameters relating to the environment of the building, such as weather conditions or a thermal environment of an adjacent building, and the relation between the actual consumption of said equipment and the temperature are measured with the aid of corresponding sensors. actually obtained within the construction takes into account at least some of these parameters;
• said parameter relating to a use of the construction is relative to at least one of: an opening / closing of at least one door or window in the construction, a concealment of at least one door or window in the construction, a the presence of at least one individual inside the building, a presence of at least one indirect source of heat or coolness inside the building, a use of at least one operating instruction for said equipment ;
• obtaining at least one image showing a thermal distribution in the construction by means of at least one thermal camera, said image obtained being used to measure said parameter relating to a use of the construction; this is a particularly simple way of measuring said parameter;
• measuring said parameter relating to a use of the construction from a comparison between said image obtained and a corresponding expected image;
• said expected image takes into account the presence and location in the construction of said energy consuming equipment to provide a thermal environment by heating or cooling;
• said image obtained may be in encrypted form;
• the actual consumption of said equipment and the temperature actually obtained inside the construction are measured repeatedly at successive times;
• said deviation is estimated repeatedly at successive instants, and wherein an evolution of said deviation over time is analyzed with a view to detecting any changes in the thermal behavior of the construction, independent of the use of the construction.

• au moins un dispositif de mesure pour mesurer une consommation réelle dudit équipement, une température réellement obtenue à l'intérieur de la construction et au moins un paramètre relatif à une utilisation de la construction ;
• une unité d'estimation d'un écart entre ladite relation entre une consommation théorique dudit équipement et une température de référence à l'intérieur de la construction d'une part et une relation correspondante entre la consommation réelle dudit équipement et la température réellement obtenue à l'intérieur de la construction d'autre part ;
• une unité d'estimation, lorsque l'écart estimé dépasse un seuil, d'une contribution relative à l'utilisation de la construction dans ledit écart en tenant compte dudit paramètre mesuré.

The invention also proposes a system adapted for the analysis, in accordance with the above-mentioned method, of the thermal behavior of a construction delimiting a closed space and including at least one equipment consuming energy to ensure a thermal environment by heating or cooling, the construction being modeled with the aid of a thermal model so that a relation between a theoretical consumption of said equipment and a reference temperature inside the construction satisfies a determined criterion. The system includes:

• at least one measuring device for measuring a real consumption of said equipment, a temperature actually obtained inside the construction and at least one parameter relating to a use of the construction;
• a unit for estimating a difference between said relation between a theoretical consumption of said equipment and a reference temperature inside the building on the one hand and a corresponding relation between the actual consumption of said equipment and the temperature actually obtained at the interior of the building on the other hand;
• an estimation unit, when the estimated deviation exceeds a threshold, of a relative contribution to the use of the construction in said deviation taking into account said measured parameter.

This system may advantageously be such that the measuring device comprises, for the measurement of at least one parameter relating to a use of the construction, at least one thermal camera arranged to obtain at least one image showing a thermal distribution in the construction. .

The invention further provides a computer program product comprising code instructions suitable for implementing the above method, when loaded and executed on computer means.

• la figure 1, déjà commentée, est un schéma illustrant les échanges et la circulation d'énergie thermique susceptible d'avoir lieu dans une construction ;
• la figure 2 est un schéma illustrant un exemple de construction relativement à laquelle la présente invention peut être mise en oeuvre ;
• la figure 3 est un schéma illustrant des étapes pouvant être mises en oeuvre dans un mode de réalisation de l'invention.

Other features and advantages of the present invention will become apparent in the following description of nonlimiting exemplary embodiments, with reference to the appended drawings, in which:

• the figure 1 , already commented, is a diagram illustrating the exchanges and circulation of thermal energy likely to take place in a construction;
• the figure 2 is a diagram illustrating an example of construction in relation to which the present invention may be implemented;
• the figure 3 is a diagram illustrating steps that can be implemented in one embodiment of the invention.

The invention relates to the analysis of the thermal behavior of a construction delimiting a confined space. In the example which will be more particularly described later with reference to the figure 2 , the construction considered consists of an office, although any other type of construction (building, room, room, room, structure, etc.) could be envisaged, whatever its destination (residential, professional, industrial or other).

The office of the figure 2 contains two radiators 12 each consuming energy, for example electric or other, to ensure a thermal atmosphere in the office. It should be noted that the number of radiators could be different from two and that any other type of equipment capable of ensuring a thermal environment by heating or cooling could be used (boiler, air conditioning, etc.).

An adjusting member 13 of the temperature of the office, such as a thermostat, can also be used, in connection with the radiators 12.

The office of the figure 2 further contains a number of elements whose characteristics capable of influencing the thermal behavior are known.

• des fenêtres 11, dont les caractéristiques comprennent par exemple une surface, un type de vitrage et/ou un type d'ouverture (coulissant, ouvrant vers l'intérieur, ouvrant vers l'extérieur, etc.),
• une porte 14, dont les caractéristiques comprennent par exemple une surface, un sens d'ouverture, une épaisseur et/ou une matière,
• des luminaires 15, dont les caractéristiques comprennent par exemple une puissance nominale et/ou une intensité lumineuse,
• une lampe de bureau 16, dont les caractéristiques comprennent par exemple une puissance nominale et/ou une intensité lumineuse,
• une chaise ou un fauteuil 18, dont les caractéristiques comprennent par exemple un volume, une matière et/ou le fait de pouvoir être occupé par une personne,
• un revêtement de sol 19, ou plus généralement, une ou plusieurs parois pour les murs et/ou le sol, dont les caractéristiques comprennent par exemple une conductivité thermique, une épaisseur et/ou une matière,
• une armoire 20, ou plus généralement, un ou plusieurs objets inertes thermiquement, c'est-à-dire susceptibles d'être portés à terme à la même température que leur environnement, dont les caractéristiques comprennent par exemple un volume, un poids, une matière et/ou une conductivité thermique.

In the illustrated example, the following elements are distinguished in particular:

• windows 11, the characteristics of which include, for example, a surface, a type of glazing and / or a type of opening (sliding, opening towards the inside, opening towards the outside, etc.),
• a door 14 whose characteristics include, for example, a surface, an opening direction, a thickness and / or a material,
• luminaires 15, the characteristics of which include, for example, nominal power and / or luminous intensity,
• a desk lamp 16, the characteristics of which include for example a nominal power and / or a luminous intensity,
• a chair or chair 18, the characteristics of which include, for example, a volume, a material and / or being able to be occupied by a person,
• a floor covering 19, or more generally, one or more walls for the walls and / or the floor, the characteristics of which include, for example, a thermal conductivity, a thickness and / or a material,
• a cabinet 20, or more generally, one or more thermally inert objects, that is to say capable of being brought to term at the same temperature as their environment, the characteristics of which include for example a volume, a weight, a material and / or thermal conductivity.

In addition to these characteristics, it should be noted that the position of each element within the office is likely to influence the propagation of thermal flows inside this office. In other words, the position of each element is in itself a relevant characteristic vis-à-vis the thermal behavior of the office.

Of course, other types of elements could be contained in the office as a replacement or complement to those described above.

Other characteristics may also be considered, such as physical properties of the office that would not be listed above (presence of thermal bridges in the walls, reflecting power of the outer walls of the office, etc.).

The office considered can be modeled using a thermal model so that a relationship between a theoretical energy consumption of radiators 12 and a reference temperature inside the office satisfies a given criterion. This modeling can be done at the time of the design of the office, or later, that is to say a posteriori.

In other words, the office is supposed to meet specifications in terms of the theoretical energy consumption of radiators 12 and theoretical temperature inside the office.

To do this, the thermal model used advantageously takes into account office characteristics, including all or part of the characteristics of the elements contained in this office, as listed above. For this purpose, these characteristics are for example available as object attributes in a database, and accessible by the thermal model.

The thermal model is for example designed to determine the amount of heat (or on the contrary of freshness) to be generated by the equipment 12, taking into account the characteristics of each element of the office, the influence of each of these characteristics on the generation or the absorption of calories being predefined from theoretical data and / or from experiments. This type of thermal model is well known to those skilled in the art.

There are several software on the market that can achieve this type of thermal model. The document "Peuportier B., Thermal Simulation Software Test Benches, SFT-IBPSA Day" Thermoaerulic Building Simulation Tools ", La Rochelle, March 2005" presents some of them. As an illustrative example of a tool, mention may be made of the COMFIE software which incorporates a thermal model developed by Mines ParisTech. Information about this software is available at: http://www.izuba.com.

The thermal model used may have been developed after learning about the energy behavior of the office, for example by creating voluntarily energy controlled arrivals / departures (opening / closing of doors or windows, lighting / extinguishing of lamps, entry / exit of persons). This learning allows an initial calibration of the thermal model.

In accordance with what was presented in the introduction, the thermal model used to design the office can advantageously also take into account variable parameters that could influence the energy balance, such as the weather conditions (level of sunshine, outside temperature, external humidity). , or other), simplified assumptions about parameters related to the use of construction, or otherwise.

By use of the construction is meant any variable phenomenon that can be modified by human intervention, for example at the initiative of a building occupant, and having an influence on the thermal flows in the building.

The thermal model can formalize, if necessary, the relationship between the energy input, the environment, the use of the construction and the indoor temperature. This model is generally applied to calculate for each time step, the temperatures and the heating powers for each thermal zone, according to assumptions on the building, its environment and its use.

The following is particularly interested in the relationship between the theoretical energy consumption of radiators 12 and reference temperature inside the office. This relationship can take any conceivable form. The thermal model can make it possible to verify that this relation satisfies a criterion determined theoretically.

By way of non-limiting example, this relationship could be expressed as follows: the theoretical consumption C ₀ of the radiators 12 remains lower than a certain amount of primary energy per unit area and per year (expressed for example in kWhep / m ² / year) for a certain reference mean internal temperature T ₀ (expressed for example in degrees Celsius). This relation may take into account a certain scenario on the environmental conditions E _o , and a certain scenario on the use of the construction U ₀ .

According to another expression of said relationship, the ratio C ₀ / T ₀ is less than a determined value V ₀ . In this case, the value V ₀ may possibly depend on assumptions formulated for at least some of the variable phenomena provided by the thermal model described above (in particular E ₀ and U ₀ ).

Other forms of relationship between the theoretical consumption of the heating or cooling equipment (s) and reference temperature inside the building considered, and / or criteria to be fulfilled by said relationship could be used as a replacement or complement, as will be apparent to those skilled in the art.

If the relationship between the consumption of the heating or cooling equipment (s) and a setpoint (temperature objective in the construction considered) is known, then the setpoint can be directly associated with a consumption, so that the person who changes the setpoint can be directly informed of the expected consumption difference accordingly (in absolute value, in percentage, in cost, in weight of CO ₂ , or other) to sensitize it to the consequences of its action. One can thus verify a real behavior relative to a theoretical behavior and give more the way to act on a consumption.

Step 21 of the figure 3 illustrates the satisfaction of a criterion determined by said relationship in the following general form: R (C _0, T ₀₎ ~c _0, where c ₀ represents the criterion that must be completed by the relation R between C ₀ and T _0. This criterion c ₀ possibly depends on at least one of the quantities E ₀ and U ₀ defined above. It will be noted that according to another convention equivalent to the latter, one could consider a relation R (C ₀ , T ₀ , E ₀ , U ₀ ) to satisfy a criterion c ' ₀ independent of the phenomena E ₀ and U ₀ (since these These are then already taken into account in relation R).

According to the invention, an analysis is made of the thermal behavior of the construction considered, for example from the office of the figure 2 , as follows.

An actual consumption C ₁ of the radiators 12 is measured, as indicated in step 22 of FIG. figure 3 . This measurement can be made in any conceivable way, for example using a power consumption sensor, a generated heat sensor associated with a heat converter in energy consumption, etc.

Simultaneously and simultaneously (or at moments similar to the time) a temperature T ₁ actually obtained inside the office is measured, as indicated in step 23 of FIG. figure 3 . This measurement of temperature can also be carried out by any conceivable means, for example using a thermometer.

Advantageously, it is also possible to measure, with the aid of corresponding sensors, parameters E ₁ relating to the environment of the construction, such as weather conditions, a thermal environment of an adjacent building, or other. More generally, any parameter taken into account in the thermal model used to design the office can advantageously be the subject of a corresponding measurement using an appropriate measuring means.

In addition, we measure at least one parameter U ₁ relating to a use of the office, as indicated in step 24 of the figure 3 .

Note that the order of steps 22 to 24 is indifferent.

All or part of these measurements can be performed instantaneously or over any relevant period of observation time (for example of the order of a minute, hour, day or more). The various measurements performed are advantageously simultaneously (or almost simultaneously).

Advantageously, the actual consumption C ₁ and the temperature actually obtained T ₁ are measured repeatedly at successive times. It is possibly the same for said parameter relating to a use U ₁ and / or for the environmental conditions E ₁ .

The parameter or parameters relating to a use of the office may for example be related to at least one of: an opening / closing of the door 14 or one or more of the windows 11, a concealment of the door 14 or of one or more of the windows 11 (for example by means of curtains or shutters), a presence of at least one individual inside the office, a presence of at least one indirect source of heat or coolness at inside the office (for example, since the luminaires 15 and / or the lamp 16 are lit), a use of at least one operating instruction for the radiators 12, for example using the thermostat 13. Other parameters of use may be envisaged, in replacement or in addition to these, as will be apparent to those skilled in the art.

Each utilization parameter can be associated with an estimate of its effect on the thermal balance of the office. For example, the loss of thermal energy from the office related to the opening of a window 11, given a difference between the outside temperature and the internal temperature T ₁ , can be estimated. This estimate may result from a theoretical study or measurements made in the office concerned or an equivalent space. In another example, the presence of a person in the office causes the generation of thermal energy, which can be estimated theoretically or by measurement.

The estimation of the thermal effect of each utilization parameter can be stored in a database, which is for example the same as that mentioned above with reference to the elements included in the office. It will be noted that some of these utilization parameters are associated with elements of the office (for example the luminaires 15 and the lamp 16) whose characteristics are known and an estimate of their thermal effect can as such be stored in the database as an attribute of the corresponding element. This estimate may for example have been obtained during the optional learning phase mentioned above, during which an energy signature of certain elements of the office (lamps, door, windows, etc.) has been obtained.

• la résistance thermique de la paroi baisse, et
• le renouvellement d'air neuf est fortement augmenté.

The estimation of the thermal effect of each utilization parameter can relate to a fixed value whose order of magnitude is known (for example a person present in a room dissipates on average 90W, a laptop 50W, etc.). ), or to a variable value depending on other parameters and which in this case must be determined by calculation and can be extremely variable. For example, opening a window has a double effect:

• the thermal resistance of the wall drops, and
• the renewal of fresh air is greatly increased.

The corresponding energy can range from a few watts to several hundred watts depending on the characteristics of the project.

As a variant, the estimate of the thermal effect of at least some of the utilization parameters could not be predetermined and stored in a database, but calculated in a practical manner, for example using appropriate measurements.

Any appropriate measuring means may be used to measure some or all of the usage parameters. By way of non-limiting examples, mention may be made of: opening / closing sensors for a door or window, a motion detector for detecting the presence of an individual, a state detector for a switch controlling an equipment such as a lamp or a luminaire, a detector of a set temperature, etc.

In an advantageous embodiment, one or more thermal cameras 5-6 can be used for the measurement of parameters relating to a use of the office. It can be one of the many thermal cameras available on the market. As examples, the following companies provide thermal imaging cameras that may be used in the context of the present invention: bfi optilas, dbvib, flir systems, fluke, hgh, impac, infraTec, jcm distribution, infrared land, batch oriel, Opto Phase, Synergys Technologies, testo, trotec.

The thermal cameras 5-6 are for example infrared cameras, capable of delivering images that can be used to obtain a temperature measurement directly at each of their points. The resulting images show a thermal distribution in the office, which gives a measure of the temperature of each element of the office.

The positioning of the windows 11 and in particular windows optionally makes it possible to take into account the reflection of the thermal image, so as not to consider as a source of heat an image of a source.

The thermal camera or cameras 5-6 used are for example fixed relative to the office, so that all the objects observed on the images delivered are fixed and known and they correspond to the listed elements of the office.

Advantageously, a conventional image of the office is superimposed with an infrared image delivered by a thermal camera, so as to associate each element of the office with its infrared image. Thermal information is thus visually associated with each listed item in the office.

This information can be made dynamic, if successive thermal images are acquired as time goes by. The analysis of the successive images makes it possible to follow the variation of temperature as a function of time, which can constitute exploitable information (thermal inertia of the objects for example).

The thermal images delivered by the thermal cameras 5-6 can be used to visualize what, in the office, has heated or cooled, for how long, how the flow has diffused because of which objects and which states of object, and under which successive conditions a temperature objective (materialized by a desired instruction by a user) has been achieved or maintained.

In order to protect the identity of the persons likely to be present in the office in question or other types of information that may be confidential, the thermal images delivered by the thermal cameras 5-6 are advantageously obtained in encrypted form, for example using an encryption algorithm. The decryption key of this algorithm would not be public and would be known only to the thermal image analysis program. This prevents claims that thermal images would betray, for example, the activity people in the office.

The thermal images obtained may in particular be used to measure the parameter or parameters U ₁ relating to a use of the office.

To carry out this measurement, one can for example compare a thermal image obtained using a thermal camera with an expected thermal image. The latter for example takes into account the presence and location of the office radiators 12 (or any other equipment consuming energy to ensure a thermal environment by heating or cooling).

The expected image may, for example, show a distribution of the thermal flows in the event of the windows 11 being closed. If, in reality, the windows 11 are open, the thermal image delivered by a thermal camera will show a temperature variation close to these windows. This already gives an indication of use, namely that the windows 11 are open. The comparison between the image delivered and the expected image also makes it possible, for example by direct subtraction between the values measured at each point, to evaluate the magnitude of the temperature variation. This is a relatively precise parameter of use that can be exploited quite easily, to determine the contribution of the opening of the windows in the thermal behavior of the office, a concept which will be detailed below.

A relation between the actual consumption C ₁ of the radiators 12 and the temperature T ₁ actually obtained inside the office, as measured in steps 22 and 23, is then evaluated. This relation can be the same as the relation R satisfied by the theoretical consumption C ₀ and the reference temperature T ₀ , as mentioned with reference to step 21. In a variant, this relation could correspond to the relation R, without necessarily to be identical to him. By way of example, this relation could correspond to the relation R, to a conversion and / or to a near normalization.

When parameters relating to the office environment, such as weather conditions or a thermal environment of an adjacent building, are measured with the aid of corresponding sensors, the relation between the actual consumption C ₁ of the radiators 12 and the temperature T ₁ actually obtained within the office can advantageously take into account at least some of these parameters. By way of example, if the relation R (C ₀ , T ₀ ) used in step 21 has been estimated for an outside temperature of 20 ° C, and the actual outside temperature is only 10 ° C, this temperature difference can be taken into account in the evaluation of the relation R (C ₁ , T ₁ ), so that these two relations can be compared.

The two relations are compared in step 25, to deduce a difference e.

If, for example, the relation mentioned in step 21 refers to the ratio C ₀ / T ₀ (which must for example be less than a value V ₀ ), it is possible to calculate in step 25 the ratio C _{1 /} T ₁ . The difference C ₀ / T ₀ - C _{1 /} T ₁ then gives a gap e between the two relations. If it turns out that the temperature measured in the office equals the reference temperature, ie T ₀ = T ₁ , the difference e then corresponds to a simple difference between the theoretical consumption C ₀ and actual C ₁ of the heating equipment or cooling.

A comparison between the estimated difference e and a threshold S is performed in step 26. The threshold S is advantageously chosen to detect or anticipate a drift of the thermal behavior of the office. Thus, beyond this threshold S, the actual consumption C ₁ could be considered abnormally high compared to the theoretical consumption C ₀ .

The threshold S can take an absolute value or a relative value taking into account for example at least some values V ₀ (or more generally C ₀ ), C ₀ , T ₀ , C ₁ and T ₁ . For example, if the difference e corresponds to a simple difference between the theoretical consumption C ₀ and actual C ₁ of the heating or cooling equipment, the threshold S could correspond to a fixed value, expressed for example in kWh, to a percentage of the theoretical consumption C _o , for example of the order of 10% to 20%, or other.

When the actual consumption C ₁ , the temperature actually obtained T ₁ and possibly said parameter relating to a use U ₁ have been measured simultaneously repeatedly at successive instants, it is advantageous to estimate the gap e also repeatedly at times successive. An analysis of the evolution of this gap over time can be conducted to detect possible changes in the thermal behavior of the office, independent of the use of the office.

If the difference e exceeds the threshold S, which can translate for example a potentially abnormal consumption C ₁ potentially abnormal compared to the theoretical consumption C _o , it is estimated a relative contribution to the use of the office in this gap e, to Step 27. In other words, we are trying to find out if the large value of the difference is due to an atypical use of the office, and in what proportion.

To estimate the contribution of the use of the office in the gap e, we hold account of the parameter (s) U ₁ previously measured, as mentioned with reference to step 24. This estimation can take any conceivable form, depending for example on the nature of the relations R (C ₀ , T ₀ ) and R (C ₁ , T ₁ ), the distance e, and / or the parameter U ₁ itself.

Consider, purely for illustrative purposes, a situation where the difference e corresponds to a difference between the actual consumption C ₁ and the theoretical consumption C ₀ of the radiators 12 of 10 kWh (with T ₀ = T ₁ ) _, which exceeds a threshold S for example 8kWh. Furthermore, the parameter U ₁ measured in step 24 reflects an opening of the windows 11 located above the radiators 12.

Such opening of the windows 11, while the outside temperature, possibly measured, is assumed to be colder than the internal temperature T ₁ , has the effect of a loss of thermal energy of the office that can be known, or because an estimate of is already available (for example in the database accessible to the office's thermal model), either because it is the subject of a practical evaluation, for example based on adequate measures.

This loss of thermal energy related to the opening of the windows 11 is offset by an equivalent thermal energy output by means of the radiators 12. The characteristics of the radiators 12 being known, it is easy to deduce the energy consumption of the radiators. 12 necessary for said production of thermal energy.

Suppose that this additional energy consumption of the radiators 12, compared to a situation where the windows 11 would be closed, is estimated at 5 kWh. Comparing this value to that of the gap e which is 10 kWh, we find that the contribution of the opening of windows to this difference is 5 kWh, that is to say 50%.

If no other utilization parameter is available or participates in the gap e, we can deduce that the relative contribution to the use of the office in the gap is 5 kWh, that is to say 50%. If this is not the case, ie if other types of use occur and contribute to the discrepancy e found, the total contribution relating to the use of the office is greater than 5 kWh, and it can be evaluated more finely by an analysis of each individual contribution from each utilization parameter U ₁ measured.

Once the relative contribution to the use of the office in the estimated difference e, one can advantageously calculate a corrected difference e 'to take account of this contribution. Such a corrected difference does not take into account the influence of office use. To do this, one can for example subtract from the gap e, the relative contribution to the use of the office.

In the example described above, the relative contribution to the use of the office was 5 kWh for a gap e of 10 kWh. The corrected difference e ', which corresponds to the difference between its two values, is therefore 5 kWh.

It will be appreciated that subtracting the relative contribution to the use of the desktop from the gap can take other forms than a simple difference between two values, as will be apparent to those skilled in the art.

Several actions are then possible from the corrected difference e ', or from any other quantity that would ignore the influence of the use of the office. Two possibilities for action are mentioned below, although other types of action may be envisaged as will be apparent to those skilled in the art.

According to a first possibility, a conclusion on the design of the office can be deduced from the corrected difference e ', as illustrated in step 28.

This conclusion can for example result from a comparison of the corrected difference e 'with the threshold S mentioned above. In the numerical example considered here, the corrected difference e 'has a value of 5 kWh which is lower than that of the threshold S (namely 8 kWh).

When the threshold S was set to detect a drift in the thermal behavior of the office, the comparison made at step 24 from the gap could have led to the erroneous conclusion that the design of the office did not conform to the specifications (R (C ₀ , T ₀ ) ~C ₀ ).

But taking into account the contribution of the use of the office, in this case of the opening of the windows 11, makes it possible to note that the corrected difference e ', taking account of this use, is actually below the threshold S. In other words, the thermal behavior of the office is in line with expectations if we take into account the effect of the use of this office, which could not be accurately anticipated at the time of conception.

Conversely, a corrected difference e 'still greater than the threshold S could be interpreted as a defect of design of the office, appeared from the origin or resulting from a more or less rapid degradation (which one can detect by example through an analysis of the evolution of the gap over time, as mentioned above). The magnitude of the corrected difference e ', possibly supplemented by investigations (measurement campaign, or other) can help to understand the causes of drift, or even treat them.

According to a second possibility, which is not incompatible with the previous one, the thermal model is modified to take account of the corrected difference e 'as illustrated in step 29.

It is recalled that the thermal model used to design the office formalizes the relationship between energy input, environment, office use and indoor temperature.

The corrected difference e 'allows to know the thermal behavior of the office by ignoring the relative contribution to the use of the office. Too large a value of this corrected difference can be explained by a lack of relevance or reliability of the thermal model used to design the office.

An analysis of the corrected difference e 'then makes it possible, possibly using additional investigations, to calibrate the thermal model so that it better corresponds to reality.

By way of example, the specifications R (C ₀ , T ₀ ) ~C ₀ could be poorly estimated, for example because of a bad taking into account of the elements of the office and / or of some at least of their characteristics by the thermal model. A correction of the thermal model can then be envisaged so that it models more exactly the actual situation observed.

After calibration of the thermal model, the calculated distances e and e 'should better represent the real thermal behavior of the office.

Calibration of the thermal model can be carried out continuously or regularly by successive iterations, for example.

Iterative calibration is usually performed by an expert and consists of manually iterating the input parameters of the thermal model to approximate the truth measured experimentally. For example, if we observe that the energy requirement is higher than expected in a given environmental and usage scenario, it is possible that this is due to the presence of larger thermal bridges than expected, or the use of less expensive materials. insulators than expected. In this case, the expert must analyze the possibilities, carry out verifications to reduce the scope of possibilities, and finally make simulations with different sets of hypotheses to bring the model closer to the measured reality. These iterations can be done manually or programmed to be carried out systematically.

Automatic calibration can also be done by inverting the direct model. Direct thermal models make it possible to calculate a power requirement for a given building, a given temperature set point, a given environment and a given use. An example of an inverse model would be a model whose input data would be the measured environment, the measured use, and the measured temperature set point. In this model, some of the descriptive parameters would be assumed to be known, and another part would be calculated.

It will be noted that the operations described above can be implemented for any simple system (device) or complex system (set of devices), comprising appropriate units (measuring device for C ₁ , T ₁ and U ₁ , unit of estimate of the difference e, unit of estimation of a contribution relative to the use, etc.).

A computer program may be used to implement the present invention when loaded and executed on computer means. It uses appropriate code instructions for this purpose.

Claims (15)

1. Method for the analysis of the thermal behaviour of a structure (1) delimiting an enclosed space and including at least one energy-consuming appliance (2;12) for providing a thermal environment by heating or cooling, the structure being modelled using a thermal model so that a relationship between a theoretical consumption (C ₀) by said appliance and a reference temperature (T ₀) inside the structure satisfies a determined criterion, the method comprising the following step:

   - measuring an actual consumption (C ₁) by said appliance, a temperature actually obtained inside the structure and at least one parameter relating to a use of the structure;

   The method being characterized in that it comprises the following steps:

   - estimating a variation (e) between said relationship between a theoretical consumption by said appliance and a reference temperature inside the structure on the one hand and a corresponding relationship between the actual consumption by said appliance and the temperature actually obtained inside the structure on the other hand; and

   - when the estimated variation exceeds a threshold (S), estimating a contribution relating to the use of the structure to said variation by taking account of said measured parameter.
2. Method according to claim 1, in which a corrected variation (e') is moreover calculated by subtracting from said estimated variation the contribution relating to the use of the structure (1).
3. Method according to claim 2, in which a conclusion is deduced with respect to the design of the structure (1), from the corrected variation (e').
4. Method according to claim 2 or 3, in which the thermal model is modified in order to take account of the corrected variation (e').
5. Method according to any one of the preceding claims, in which moreover, using corresponding sensors, parameters relating to the environment of the structure (1) are measured, such as meteorological conditions or a thermal environment of an adjacent structure, and in which said relationship between the actual consumption (C ₁) by said appliance (2;12) and the temperature (T ₁) actually obtained inside the structure takes account of at least some of these parameters.
6. Method according to any one of the preceding claims, in which said parameter (U ₁) relating to a use of the structure (1) relates to at least one of: an opening/closing of at least one door (14) or window (11) in the structure, covering at least one door or window in the structure, presence of at least one individual inside the structure, presence of at least one indirect source (15-17) of heat or cold inside the structure, use of at least one operational setting for said appliance;
7. Method according to any one of the preceding claims, in which at least one image is obtained displaying a thermal distribution in the structure by means of at least one thermal camera (5-6), said obtained image being used in order to measure said parameter (U ₁) relating to a use of the structure.
8. Method according to claim 7, in which said parameter (U ₁) relating to a use of the structure (1) is measured based on a comparison between said obtained image and a corresponding expected image.
9. Method according to claim 8, in which said expected image takes account of the presence and the location in the structure (1) of said energy-consuming appliance (2;12) for providing a thermal environment by heating or cooling.
10. Method according to claims 7 to 9, in which said obtained image is in an encrypted form.
11. Method according to any one of the preceding claims, in which the actual consumption (C ₁) by said appliance and the temperature (T ₁) actually obtained inside the structure are measured repeatedly at successive instants.
12. Method according to claim 11, in which said variation (e) is estimated repeatedly at successive instants, and in which an evolution of said variation over time is analyzed with the aim of detecting any alterations in the thermal behaviour of the structure (1), that are independent of the use of the structure.
13. System arranged for the analysis, pursuant to the method according to any one of the preceding claims, of the thermal behaviour of a structure (1) delimiting an enclosed space and including at least one energy-consuming appliance (2;12) for providing a thermal environment by heating or cooling, the structure being modelled using a thermal model so that a relationship between a theoretical consumption (C ₀) by said appliance and a reference temperature (T ₀) inside the structure satisfies a determined criterion, the system comprising:

    - at least one measurement device for measuring an actual consumption (C ₁) by said appliance, a temperature (T ₁) actually obtained inside the structure and at least one parameter relating to a use of the structure;

    the system being characterized in that it comprises:

    - a unit of estimation of a variation (e) between said relationship between a theoretical consumption by said appliance and a reference temperature inside the structure on the one hand and a corresponding relationship between the actual consumption by said appliance and the temperature actually obtained inside the structure on the other hand;

    - a unit of estimation, when the estimated variation exceeds a threshold (S), of a contribution relating to the use of the structure to said variation by taking account of said measured parameter.
14. System according to claim 13, in which said measurement device comprises, for the measurement of at least one parameter (U ₁) relating to a use of the structure (1), at least one thermal camera (5-6) arranged in order to obtain at least one image displaying a thermal distribution in the structure.
15. Computer program product comprising suitable code instructions for carrying out, when loaded and run on computerized means, the method according to any one of claims 1 to 12.

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