FR3011914B1 - METHOD FOR PREDEFINING THE SETPOINT TEMPERATURE OF A HEAT-STORING ENVIRONMENT OF A HEAT ACCUMULATOR AND METHOD OF MANAGING THE SAME - Google Patents

Abstract

A method for presetting a set temperature of a heat transfer medium in a heat accumulator, wherein the heat transfer medium is heated to the set temperature and the set temperature is selected as a function of the temperature of a heat source. heat.

Description

Field of the invention

The present invention relates to a method for presetting a set temperature of a heat transfer medium in a heat accumulator, according to which the storage medium is heated to the set temperature. The invention also relates to a device for implementing such a method.

State of the art

The heat accumulators are, for example, buffer accumulators receiving a heat transfer fluid such as heating water or a sanitary water accumulator with hot water as heat transfer medium. The set temperature makes it possible to regulate the temperature of the heat transfer medium in the heat accumulator. With the aid of a heat source, the heat transfer medium is heated up until its actual temperature (generally starting from a low temperature) reaches its target temperature.

Usually, a set temperature for a heat transfer medium in a heat storage tank is preset manually, consisting in entering or selecting the set temperature on a device for regulating the heat accumulator by the user of that or the user of the heat transfer medium. But often there is also a factory setting of the heat accumulator or regulating device as supplied or on which the regulation comes back when necessary.

In the event of a difference between the actual temperature and the set temperature (if necessary taking into account a certain hysteresis), especially if the set temperature is exceeded, the heat transfer medium is heated with the heat of a source of heat, that is to say that the heat accumulator is charged. The actual temperature then approaches the set temperature. When it reaches the set temperature, the heating of the heat-transfer medium is stopped so that the temperature of the heat-transfer medium is always maintained at the set temperature and at any instant the medium is ready to be used.

There are known heat accumulator regulations that block the heating of the heat transfer medium at certain times and release it to others.

Heat pumps can be used as heat generators to heat the heat transfer medium. Heat pumps often use renewable heat from the environment, such as outside air. The higher the outdoor air temperature, the higher the efficiency and the heat pump will operate economically. Another possible source of heat is the subsoil from which heat is collected using underground collectors. The temperatures of outdoor air, soil and other heat sources are not constant, but subject to natural variations.

Purpose of the invention

The present invention aims to operate a heat accumulator, including a heat accumulator heated by a heat pump so as to save energy. DESCRIPTION AND ADVANTAGES OF THE INVENTION For this purpose, the subject of the present invention is a method for presetting a set temperature of a heat transfer medium in a heat accumulator, according to which the storage medium is heated to the set temperature, which characterized in that the set temperature is selected as a function of at least the temperature of a heat source. The subject of the invention is also a method of managing a heat accumulator according to which the heat transfer medium of the heat accumulator is heated in a controlled manner by a heat source and for the regulation of the heat load a temperature is predefined. setpoint of the heat transfer medium according to the method defined above. Another subject of the invention is a device for presetting the value of the set temperature of a heat transfer medium in which the heat-transfer medium of the heat accumulator is heated to the set temperature, this device applying the method described above. above.

In other words, the method according to the invention for presetting a set temperature of a heat transfer medium for a heat accumulator is characterized in that the set temperature is selected as a function of at least one temperature of the heat source. Thus, the rigid regulation known from the temperature of the heat transfer medium is replaced by variable boundary conditions of the temperature regulation adapted to the heat source. The preset temperature setpoint as a function of at least one temperature of the hot source makes it possible, through a variable, adapted, setpoint temperature, to ensure optimized heating of the heat transfer medium. The heat source is any heat source that provides directly or indirectly, partially or completely the energy used to heat the heat transfer medium.

The method according to the invention is characterized in its preferential development in that the temperature of the heat source (or hot source) is the temperature for a temperature admitted at the current time and / or a desired temperature at a future time. The temperature admitted at the present moment is the temperature which is supposed to exist really at any moment; this assumption may be based on the current measurement of the temperature of the heat source provided by a measurement sensor. In other cases, the assumption may also be based on a well-founded assumption, such as an earlier measure or external information. The desired temperature at a future time is a temperature that will actually exist at a future time; this forecast can be based for example on the experience (such as the statistical probability obtained by the exploitation of the history) and / or by a calculation. The future moment is that of a chronology, for example 1-5 hours (we can also consider shorter or longer durations) after which is the respective current moment (according to the respective present point of view). Thus, advantageously, the predefinition of the set temperature is adapted for a heat transfer medium, to current and future temperature events.

According to another development of the method of the invention, the admitted and / or forecast temperature of the heat source is chosen according to the current calendar date and / or the current time and / or the current location of the heat source. heat accumulator or heat source. There is thus a confirmed relationship between the temperature and the current operation. The calendar date is then a day, week or calendar month or a period of the year. The predictable temperature of the heat source is selected according to a predefined chronological evolution of the foreseeable future with respect to the current moment.

A preferred development is characterized in that the admitted and / or desired temperature of the heat source is a temperature stored in a data memory or temperature selected from a plurality of temperatures stored in a data memory. Thus, the data memory may contain, for example, many experience values for the temperature of the heat source at several calendar dates in practice (in particular for each day of a year) for several moments in practice (especially for each hour , half-hour, quarter of an hour of a calendar day) and / or for several locations in practice (especially for several reference locations of a country or several countries). Characteristic temperature curves can also be recorded based on the location or time of the year. The data memory may be a decentralized data memory at the location of the heat accumulator; it can also be a central data memory to which are connected one or more heat accumulators.

According to a preferred development of the method of the invention, the admitted and / or desired temperature of the heat source is a temperature communicated by a meteorological service and / or a predicted temperature. This avoids a decentralized data memory or measurement sensor installed in the slot.

Another development is characterized in that the admitted and / or desired temperature of the heat source is a temperature among at least one measured and / or stored / communicated and / or predicted temperature. This makes it possible to have measured, stored, communicated or predicted temperatures with a relatively coarse chronological resolution, for example hour values or values over two-hour intervals, which will be transposed by calculation for the application according to the invention, by example calculated by the minute by interpolation and / or extrapolation.

A preferential development of the method of the invention is characterized in that the target temperature is selected in a set temperature range, this range being delimited by a predefined minimum temperature and as the lower limit of the set temperature range and a preset maximum temperature as the upper limit of the set temperature range. The set temperature, in spite of all the dependencies on at least one heat source temperature and the adaptation to variable boundary conditions, always remains in a certain temperature band or temperature spectrum. This ensures the safety for the user of the heat transfer medium that will not be too hot or too cold.

A practical development of the method of the invention is characterized in that the set temperature of the heat transfer medium remains unchanged at start-up or increases by a predefined value for a predefined duration if the desired temperature for the future instant of the heat source is below the temperature of the heat source admitted for the current time, the set temperature returning to the initial value after a determined period. The initial value is, for example, the original setpoint temperature, a user-defined setpoint temperature or a factory setting. The predefined duration and the predefined amplitude are indications supplied for example by a user, corresponding to the factory setting and (predictive value) or by the calculation made for example on the basis of stored data or data of a meteorological service. . The predefined duration ends for example at the arrival of the foreseeable event of the temperature (cooling of the hot spring). The instructions may for example be provided at an interval of 1 to 5 hours and with an amplitude of 2 to 10 K. This leads to a particularly preferred use of a heat source if it provides a more accessible thermal potential of the heat. makes its temperature higher. If it is thus possible to predict that the heat source is cooling in a predicted manner at a future time (its future temperature is lower than the current temperature) then it would be necessary to provide greater means for heating the thermal medium, so that the temperature The heat transfer setpoint will be temporarily increased and this heat transfer medium will heat to a higher temperature and with a higher efficiency before cooling the heat source. Consequently, a cooler heat source temperature and reset must be returned to the set value corresponding to the initial value. The set temperature, reset will not be exceeded down for a long time (it could nevertheless trigger additional heating of the heat transfer medium only at this time). This allows significant peripheral energy savings and increased efficiency.

A practical development of the method of the invention is characterized in that it leaves the coolant setpoint temperature unchanged to the initial value or it decreases for a predefined period of a predefined value if the desired temperature for the moment future heat source is greater than the temperature of the heat source admitted at the present time. Thus, at the end of the preset time, the set temperature is reset to the initial value. Its initial value is, according to the present description, an original setpoint temperature, a setpoint temperature predefined by a user or a factory setting. The predefined duration and the predefined amplitude are setpoints provided, for example by a user, for example corresponding to a factory setting (experience values) or by a calculation based on recorded data or data from a supplier. on duty. The preset time ends, for example, at the arrival of a desired thermal event (preheating of the heat source). These predefinitions can have, for example, a duration of 1 to 5 hours and an amplitude of 2 to 10 K. It thus happens that a heat source will be used in particular if, because of its higher temperature, there is a higher thermal potential. easy to define. If it is not possible for the heat source to heat up as expected for a future time (its future value of temperature is greater than the current value of the temperature) then as less work is done to heat the heat transfer medium the temperature of the heat transfer medium is temporarily lowered and the heating of the heat transfer medium is temporarily stopped, that is to say that it is temporarily pushed back. Then, subsequently, for a certain period of time, it will be necessary to heat in a complementary manner at a higher temperature relative to the heat source and then to lower to the set temperature set to the initial value, for a relatively inexpensive heating, since the temperature The then reduced setpoint will be intentionally exceeded by the actual temperature, which triggers the additional heating of the heat transfer medium. This saves a lot of energy and increases the efficiency.

The selection and predefinement of the duration and the amplitude of the increase or reduction of the heat transfer setpoint temperature make it possible to take account of known or learned heating and drawing behavior or to respond to a problem. user comfort request. If the chronological evolution of the heating or drawing behavior is known, it is possible, for example, to delay even further the return of the set temperature lowered to the initial value. But if the demand for comfort is high, this results in a too short lowering of the set temperature.

Particularly advantageously, the method according to the invention is applied to a heat accumulator heated by a heat pump or a heat transfer medium heated by a heat pump. The source of heat is then, for example, outside air, available, the near depth of the subsoil, running water, well water or groundwater.

The method according to the invention for managing a heat accumulator according to which the heat transfer medium of the heat accumulator is heated in a controlled manner by the heat supplied by a heat source is characterized in that for the regulation of the charge thermal, a set temperature is selected for the heat transfer medium as a function of at least one temperature of the heat source.

The device according to the invention for presetting a set temperature of a heat transfer medium of a heat accumulator according to which the heat transfer medium is heated to a set temperature is characterized in that the device implements the method as defined above. Thus, a device is provided for heating a heat accumulator in a predictive manner and economically for durations with particularly advantageous boundary conditions.

A particularly preferred development of the device according to the invention for presetting the set temperature of a heat transfer medium of a heat accumulator heated by a heat pump is characterized by means for obtaining (that is, receiving, for example, to record from a measurement sensor and / or enter via a manual input unit, such as a keyboard or a rotary knob and / or to receive a signal transmitted by wire or by a wireless link such as a wired telephone or a radio signal) a temperature admitted for the present time of a heat source and / or a desired temperature at a future time for a heat source as well as means for selecting and presetting a set temperature. There is thus a particularly suitable device which allows the heating of a heat accumulator in a predictive and energy efficient way during the time during which the surrounding conditions are particularly advantageous. The invention applies and contains in particular heat accumulators whose heat transfer medium is heated by air heat pumps. The invention is based on the observation that the efficiency (COP coefficient) of an air-heat pump depends on the temperature of the air such that the outside air serving as heat source as well as the temperature of the heat transfer medium (eg heating water or domestic hot water), which serves as a heat sink. Thus, the coefficient COP increases with the increase of the temperature of the heat source and also when the temperature of the heat source decreases.

Based on this observation, the invention develops the idea of a new method for presetting a set temperature for the heat transfer medium stored in the heat accumulator. The application of the method makes it possible to increase the efficiency of the heat pump for heating the heat transfer medium. For example, there is an air heat pump that heats the heat transfer medium of the heat accumulator to the set temperature. The air heat pump draws heat from the outside air by discharging the air at a lower temperature, increases the temperature using mechanical work and supplies this heat to the domestic hot water of the accumulator. hot water. The outside air temperature varies during the day and for a year. Since the efficiency of heat recovery depends on the temperature of the heat source (hot source), the efficiency also varies during the day and during the year. In general, outside air temperatures are highest around noon, so the output is higher than at night when outside air temperatures are low. Similarly, the efficiency of the heat recovery depends on the temperature of the domestic hot water heated by the heat pump. Low domestic hot water temperatures correspond to a higher efficiency than for high domestic hot water temperatures.

According to the invention, the heat accumulator or the regulation of the heat accumulator adapts the temperature setpoint to such relationships to recover the heat with the best efficiency and thus operate as economically as possible from the point of energy view. In addition, the set temperature must be chosen according to at least one heat source temperature. This can be the current temperature of the air (actual temperature) and / or a desired air temperature for the future. If the desired air temperature at a future time is lower than the current air temperature, it is expected that the yield at that future time will be lower than at the present time. This is why the setpoint temperature is raised at the current time. Due to the difference that results between the actual temperature and the set temperature of the heat transfer medium, the heat pump receives a heat demand signal and begins to heat the heat transfer medium of the heat accumulator until it is at the new set temperature, increased. This is done for the current higher yield compared to the low yield, predictable at the future time. The currently accepted temperature is, in the simplest case, the current measurement of the outside air temperature provided by the temperature sensor. The desired temperature for a future time is selected based on the current date, the current time and the location of the heat accumulator or heat pump. The desired temperature may be provided as an experience value corresponding to a predefined chronological evolution of a predictable future with respect to the present state from a data store. In this case, the data memory contains, for example, a table of values or a function by means of which the forecast temperature corresponding to the date, time and place can be predicted or calculated. This table of values and the functional description give experimental values that result from historical observations corresponding to statistically probable temperatures. The forecast temperature can also be provided on a provisional basis by a weather service according to the date, time and place. Thus, for example, the heat accumulator or the heat accumulation regulation recognize that the outside temperature will increase or decrease in two, three or four hours and thus it is possible to lower or raise the set temperature at the instant current. At the end of the predetermined time or when the target temperature is reached, this set temperature will be reset again to the initial value.

According to the invention, it is recommended to provide a set temperature range in which the target temperatures will be chosen. Despite the optimization of the efficiency described above, this allows the heat transfer medium to have at any time a temperature within a predefined temperature range that will be neither too cold nor too hot not to neglect the requirements. of comfort, nor the protection of the user against the risk of scalding. The set temperature range is limited by a maximum temperature and a minimum temperature.

In addition, to ensure comfort and anti-scald protection, a temperature correction is applied, for example in the form of a mixture of cold water is thermostatically, if necessary, with the heat transfer medium pulsed.

drawings

The present invention will be described below in more detail using two flow charts shown in the accompanying drawings and corresponding to the steps of the method of the invention.

According to Figure 1 there are five process steps including a first step of obtaining information about the actual temperature T (real) of the heat source (hot source) and a second step to obtain information about the desired temperature T ( future) of the heat source. These two process steps can be done in series in any order or in parallel. In the third step, as a function of the two temperatures of the heat source, the new set temperature T (cons, new) of the heat transfer medium is selected. In the fourth step, the information concerning the set temperature T (cons, new) is provided to the heat accumulator or to the regulation of the heat accumulator and is used for further operation. After a waiting time in the process, during which the heat accumulator is heated according to the new setpoint temperature, for example, a new process path is executed after a dead time given by a delay element 1.

Figure 2 shows further details of a method of the invention. Thus, in the third step, the actual temperature T (actual) and the desired temperature T (future) of the heat source are compared and a new set temperature is selected for the heat transfer medium. If, after step 3.1, the temperatures of the heat sources are the same, the set temperature remains unchanged. When the heat source cools (step 3.2) so that the desired temperature T (future) is lower than the actual temperature T (real), the set temperature is increased, temporarily by an amplitude ΔΤ. If, after the desired temperature T (future), a heating of the heat source is predicted (step 3.3), the set temperature of the amplitude ΔΤ is temporarily reduced. The information relating to the new set temperature is emitted in the fourth step and is predefined by the operation of the heat accumulator. This new set point temperature is valid for a predefined duration and it remains until the end of the duration provided by the delay element giving the dead time 2 (step 4.2). At the end of the preset time, the set temperature returns to the initial setpoint temperature or start value T (cons, old) (step 4.3). At the end of another period (timer element 1, step 5) a new execution of the method is repeated.

Claims (13)

CLAIMS 1 °) A method for presetting a set temperature of a heat transfer medium in a heat accumulator, the method according to which the storage medium is heated to the set temperature, characterized in that the set temperature is selected according to at least the temperature of a heat source. 2) Method according to claim 1, characterized in that the temperature of the heat source is a temperature admitted for the current time and / or the desired temperature for a future time. Method according to claim 2, characterized in that the admitted and / or desired temperature of the heat source is selected according to: the current calendar date and / or the current time and / or location current. 4) Method according to claim 2, characterized in that the allowed temperature and / or the desired temperature of the heat source is a temperature stored in a data memory. 5) Method according to claim 2, characterized in that the allowed temperature and / or the desired temperature of the heat source is a temperature provided by a meteorological data provider and / or a forecast temperature. 6) Method according to claim 2, characterized in that the allowed temperature and / or the desired temperature of the heat source is a temperature selected from a measured temperature and / or stored and / or communicated and / or forecast. Method according to claim 1, characterized in that the set temperature is selected from a setpoint temperature range defined by a predefined minimum temperature and a predefined maximum temperature. Process according to Claim 1, characterized in that the set temperature remains unchanged at an initial value or is increased for a predefined period around a predefined value if the desired temperature for a future instant of the heat source , is below the temperature of the heat source admitted for the current time, the set temperature being reset to the initial value after a predefined time. Method according to claim 1, characterized in that the set temperature remains unchanged at an initial value or is decreased for a predetermined time by a predetermined value if the desired temperature for the future time of the heat source is higher than the temperature of the heat source admitted for the present time, the set temperature being reset to the initial value after a predefined period. Method according to Claim 1, characterized in that the heat accumulator is a heat accumulator heated by a heat pump. 11 °) A method of managing a heat accumulator according to which a heat transfer medium of a heat accumulator is heated with the heat of a heat source, characterized in that for regulating the thermal load, a setpoint temperature for the heat accumulator according to one of claims 1 to 10. 12 °) Device for presetting the set temperature of a heat transfer medium for a heat accumulator according to which the heat transfer medium is heated to the set temperature, characterized in that it carries out a method according to any one of the claims 1 to 10. 13 °) Device according to claim 12 for presetting a set temperature of a heat transfer medium of a heat accumulator heated by a heat pump, characterized by means for recording and / or introducing and / or receiving a temperature admitted for the present time a heat source and / or a desired temperature for a future time of a heat source and means for selecting and presetting a set temperature.