DE4432745C1 - Storage heating device control system - Google Patents

Abstract

The control system uses a central controller (ZSG) coupled to at least one storage heating device (SHG) for supplying it with a control parameter. Within each storage heating device, the received control parameter is converted into a modified control parameter via a regulating device, over a defined interval, with evaluation of the residual heat contained in the storage heating device at the end of this interval, to determine the regulation value for the next interval. Pref. a required value for the residual heat at the end of each interval is calculated within each storage heating device, with modification of this value during heat input and output, the limit value for the heat output preventing the actual residual heat dropping below the required value.

Description

The present invention relates to a method for loading drove a storage heater control according to the generic term of claim 1.

One such is from HLH, Volume 43, 1992 No. 1 - January P. 24-29 - "Weather report controls night storage heating" by H. Erker et al. known.

From DE 34 10 025 A1 is a computer-controlled heating reg ler known for electric storage heaters, the one computer which has the heat demand setpoint of the next Ta totals from the heat consumption values of one or more previous days specifies. This calculator comes with an information store for provided two or more daily heat consumption values and in Furnace core is one of the determination of the respective residual heat arranged temperature sensor, with the help of which the daily Heat consumption value as the difference between the per day led heat and the residual heat is obtained.

From DE 38 23 388 A1 is a single electric storage heater known device in which a charge control unit the core load to a certain loading height and an unloading direction depending on the room temperature, the discharge process right applies. Neither is the concrete evaluation of the residual heat provided at the end of a period of time or the mere type presence of an outside temperature sensor conclusions on give a centrally controlled system with reference variable control. There is also an electronic data storage device provided in the during an unloading process from a Measurable measurement period recorded converted into heat demand values Data can be read. To reduce energy consumption turned to the highest possible heating and operating comfort is a display device connected to the computer provided the remaining heating time at which the turned on set target temperature can be maintained displayed becomes.  

From HLH, volume 43, 1992 No. 1 - January pp. 24-29 - "Wetterbericht controls night storage heating "by H. Erker et al. it is known that with a heating control meteorological Conditions such as outside temperature, sun exposure, wind, etc. as well as resident behavior and its influences as disturbances occur. This document describes how to charge control of an electronic night storage heater with the help of a Weather forecast can be regulated around the Heat requirement of the room for the following day ahead estimate and charge accordingly during night energy. For the control, the previously used outside temperature value said average of the following day, since this is approximately represents the heat requirement of the following day. Here he the storage heater is charged by means of a back forward control, since here the towards the end of the release period maximum core temperature is reached, so that the service life until discharge and thus static discharge via the Surface of the heater is lowest. With this example If the outside temperature drops, even before predict profits are made with relatively large errors, while on days with rising outside temperatures no gain ne more can be achieved. The outside temperature becomes a reference variable for the central control unit here Charge controller of the storage heater determined.

The resident behavior and its influences can be according to this Document, if at all, only with considerable effort will.

In previous systems for electric storage heating, it is common Lich, a target charge level for everyone from the central control unit storage heaters connected to the central control unit admit. This target loading level is for everyone with the central tax connected storage heaters or it will over a group control unit for a group of storage heaters percentage increased or decreased. The characteristics are usually data of the storage heater (heat capacity etc.) due the air conditioning technician's heat demand calculation. Here usually becomes a higher reserve than the security reserve  heat capacity or performance of the Storage heater accepted and the storage heater designed accordingly. The user can then use an on if necessary, reduce the set device. This relative imprecise adaptation to the actual circumstances has ever however, the result is that the storage heater during the release time is usually charged with more energy than the one on it is usually consumed the following day.

The consequence of this is unnecessarily high power consumption because of one insufficient adaptability of the system to the actual conditions.

However, all known methods have the problem that the The individual storage heaters are not supplied with electricity is adequately matched to the actual heat demand. This has the consequence that with irregular heat removal from a individual storage heaters use all of their stored heat have already delivered quantity, although not yet reloaded or there is further heat demand.

The storage heater mentioned at the beginning is used to solve this problem device control operated according to a method, as in Claim 1 is marked.

The invention is intended to be a procedure for operating a Storage heater control for a storage heater system be be provided in which these disadvantages are overcome.  

In particular, only as much as possible should be achieved by the invention Energy from the power grid will be taken over as closest Day is removed. Both should be different Electricity tariffs (night electricity, day electricity) can be taken into account as well as a certain adaptability to the user habits can be achieved.

The predetermined time period T _{n is} usually one day ( 24 h). However, it can also be several days or longer, or only part of a day.

The offset x can also be a day or several days, or can only be a fraction of a day and can be the result of one intended period detection (see below) or is specified by a user. In particular, it can be achieved at a time with a low electricity tariff (at night) the storage heater (SHG) is charged just as far will that - with unchanged removal contract compared to the previous day hold - the charge on this consumption for the next Day is voted.

For this purpose, a safety value (Qsafe) of the heat quantity is defined for each storage heater (SHG), which serves as the target quantity for the residual heat quantity (Qrest _n ) at the end of a period (T _n ). The safety value (Q certain) can be changed during a charging process and / or a discharging process of the storage heater (SHG). A discharge limit (QLeer) of the amount of heat is set, which serves as the characteristic value of a discharged storage heater (SHG), whereby the discharge limit (QLeer) is always set lower than or equal to the safety value (QSicher).

This security value can either be new for each day - depending on feedback from previous days - be assigned, or once specified.

For a storage heater (SHG), the control variable is preferably changed for a later period (T _{n + x} ) in such a way that at the end of the later period (T _{n + x} ), with the same removal as in the previous period (T _n ) , the difference between the safety value (Qsafe) and the residual heat (Qrest _{n + x} ) becomes as small as possible.

In order to be able to make these adjustments, according to the invention, the control variable is determined over a period of time (T _n )

• - the course of the storage tank temperature (VST),
• - the maximum values of the heat quantity (Qmax _n ),
• - the minimum values of the heat quantity (Qmin _n ), and
• - the time of the end of heat extraction (EWE) from the Storage heater (SHG)

determined and recorded in a data memory (DS).

In addition, if the discharge limit (QLeer) is undershot when heat energy is withdrawn / released from the storage heater (SHG) over a period of time (T _n ), the time of the undershoot (t _L ) is determined and the controlled variable as a function of the time of Falling below (t _L ), the course of the storage tank temperature (VST) and the time of the end of heat removal (EWE) changed.

Preferably, in the course of at least one time period (T _n )

• - the times at which heat extraction begins (BWE),
• - the times of the end of heat extraction (EWE),
• - the times of the start of the low tariff release (s) (BNT)
• - the times of the end of the low tariff release (s) (ENT),
• - the dates of the start of the high tariff release (BHT), and
• - The times of the end of the high tariff release (s) (EHT) determined and recorded in a data memory (DS). A periodicity (p) can thus be determined from the course of the times of y past time periods (T _n ) listed here.

A particular advantage of this procedure is that that depending on electricity tariffs and start of heating The previous day, the storage heater was charged (SHG) can be timed so that the time during which Storage heater (SHG) should keep the thermal energy, if possible  is short. This serves in particular to reduce radiation losses minimize.

According to the invention, depending on the periodicity (p), the start and end times of the user withdrawal, cycle time, control parameters, release periods (BNT / ENT / DNT, BHT / EHT / DHT) Qmax _n , Qmin _{n are} stored in a period data memory (PDS) .

The controlled variable at the end of a period (T _n ) is determined for a period (T _{n + 1} ) of the removal / delivery of thermal energy from the storage heater (SHG) as a function of the data contained in the period data memory (PDS). Since the central control unit (ZSG) can also call up data from the other devices (including the sensors) while heat energy is being supplied, there is the option of reacting to changed conditions at short notice and the values transmitted to the storage heater (SHG) for heating it up during the process to change a loading process and / or an unloading process of the storage heater (SHG) from the central control device (ZSG).

Further advantages and configurations of the invention Method for operating a storage heater control for a Storage heater system will be referenced below explained on the drawings, wherein

Fig. 1 shows a schematic circuit diagram for a storage heater control in a first embodiment;

Fig. 2 shows a schematic circuit diagram for a storage heater control in a second embodiment;

Fig. 3 shows a schematic representation of devices of the storage heater control;

Fig. 4 shows a diagram of the actual / target charge as a function of release cycles and thermal energy withdrawals in a charging control device according to the prior art;

Fig. 5 is a diagram of the actual / desired charge in a storage heater according to the invention;

6 is a diagram of the actual / desired charge in a storage heater (with the same heat removal profile as shown in FIG. 5) according to the prior art.

FIG. 7 shows a diagram of the actual / target charge in a storage heater (with a heat extraction profile that has been changed compared to FIG. 5) according to the invention;

8 is a diagram of the actual / desired charge in a storage heater (with the same heat removal profile as shown in FIG. 5) according to the prior art.

Fig. 9 shows an actual / target charge diagram of a storage heater according to the invention when the outside temperature changes;

Fig. 10 shows a further actual / target charge diagram for a conventional storage heater in a charging control with the same outside temperature profile as in Fig. 9;

FIG. 11 is an actual / target load diagram of a storage heater of the invention, in a charging control according shows that takes into consideration the different electricity rates;

Fig. 12-14 discharge profiles over longer periods and their derivatives show.

Fig. 1 shows a storage heater system with a central control unit ZSG and several storage heaters SHG1. . . SHGn, which are coupled to the control lines Z1 / Z2 for the transmission of messages. The central control unit receives the charging releases from the energy supply company via a tariff switching device. To record the outside temperature, the central control unit ZSG is connected to an outside temperature sensor via other cables. In the figure shown, the central control unit ZSG is connected to a PC via a specially provided interface for convenient parameterization.

For the targeted transmission of messages, the devices are provided with individual addresses, so that, for. B. the central control unit m first sends information a to the storage heater 1 in order to then send information b to the storage heater 2 and finally send information z to the storage heater n. In this way, the different storage heaters are given specific values for them (e.g. different target charge levels).

Fig. 2 shows a storage heater system with a central control unit ZSG and several storage heaters SHG₁. . . SHG _n , which, like the central control unit ZSG, are coupled to the lines L / N via respective coupling transformers via the power supply network. The coupling transformers are used for feeding or for taking messages from the line network. The transmission of messages between the central control unit ZSG and the storage heaters SHG1. . . SHGn is bidirectional, ie messages can be transmitted from the central control device ZSG to the other (set up) devices on the line network L / N, and messages from the other devices on the line network L / N can also be transmitted to the central control device ZSG. The messages can thus also be transmitted individually, as described in FIG. 1. In addition, there is now the possibility of transmitting messages from the storage heaters to other devices, e.g. B. the actual temperatures in the storage heaters can be transferred to the connected PC upon request.

Furthermore, the charging control according to the invention, as shown in FIG. 2, can also have a connection device VG for coupling to other bus or transmission systems. This connection device can be used to exchange information with the outside world, e.g. B. with an energy supply company EVU, with other devices via an EIB bus Electro installation bus, for example to throttle the charging process in a particular storage heater SHG if additional electrical consumers are operated.

This now bidirectional communication between the central control unit and the storage heaters now offers additional advantages:
Function checks or maintenance queries initiated by the central control unit can be implemented in a simple manner with this arrangement, since the individual storage heaters can be transmitted to the central control unit by appropriate messages, their status or the state of individual assemblies in the storage heating units, in order to be processed and z. B. to be displayed.

Fig. 3 shows the components of the device of the Aufladesteuervor direction for a storage heater system with which the communication between the individual devices is carried out. A microcontroller mC is, depending on the type of device. B. connected to a sensor (here storage temperature sensor STF or the like.), And / or the microcontroller is connected to an actuator (here thermal contactor TS, through which the charging of the respective storage heating device is controlled).

In the microcontroller mC, the data for input or for Edition prepared accordingly. To send a message to an the device is sent by the microcontroller mC via ei ne control line SL1 a message generating device ak activated and provided with the necessary information and data hen to the corresponding other device  to be transmitted. The message contains the address of the to device, data and the address of the sender Device. The address of the sending device and the address and function of the receiving device is in the address AS stored.

The outgoing message is sent from the message generating device NEE Message via a line AN (possibly via a coupling transfor mator TR) fed into the respective connection network. With With the help of an address evaluation device AAE, which has a Lei device EN "listens" to incoming messages from the network checks whether the destination address of the incoming message with the own address stored in the address memory AS matches. If so, the incoming message is for that determines the respective device and a control line SL3 becomes active fourth. The corresponding data is (from the microcontroller mC controlled via the line SL2) by the address evaluation unit device forwarded to the microcontroller mC and from there by the processed accordingly.

The microcontroller mC also contains a period data memory (PDS) and a data storage (DS), which explained below Record data.

To fulfill these functions (such as address evaluation direction AAE, message generating device NEE, address Storage AS etc.) are the individual devices with a Micropro processor or microcontroller, which correspond to a of the program contained in a program memory, but can also realized as independent electronic components his.

Since in the process messages about the network all Can be made accessible to participants with regard to Usage habits, electricity tariffs, weather optimized be drive of the storage heating system can be reached. In addition, egg ne individual adjustment of the individual storage heaters (SHG) to the spatial conditions. It is regardless of whether these optimizations and adjustments from the  Central control unit (ZSG), the storage heater (SHG) itself, or via a connection device (VG) to the network paired PC is reached. Likewise is a distributed system conceivable in which the different tasks on different Components of the network are divided.

In this method, the messages are through a device dress part (GAT) and a variable length data part (DT) formed. The device address part (GAT) can be used for each of the individual device of the storage heater system specifically or the device address part (GAT) can be for groups of Devices of the storage heater system must be specific. In particular to send messages to certain devices [e.g. B. all Storage heaters (SHG) or all data distribution devices (DVG), or basically all devices in the network] can be so simple Messages are delivered. The device address part can do so probably the address of the sending device, as well as the address se (s) of the receiving device or group of receiving devices Devices included.

Furthermore, the possibility is provided (for initialization tion / reinitialization of the network) failed (AB) to send to all components of the network that are used for Identification of all components serves. Advantageously, then provide the participants with tables on the function of the whose participants are created together with their addresses.

For the operation of a storage heating system it does not matter which of the components of the network ver federal parameters recorded, processed and on request sends. It is only important that these parameters as messages ver at any time via the network for all other participants are available. Another advantage is that the Possibility exists on short notice on changed circumstances to react.

The higher the storage _temperature T _storage compared to the ambient temperature T _environment , the higher the radiation power P _S

P _S ≈ (T _storage ⁴ - T _environment ⁴)

of a body to its surroundings, as well as the losses due to heat conduction P _W within a solid body

P _W ≈ (T₂ - T₁)

So would be a storage heater that always has too much heat energy is supplied, its heat energy to the environment abstract from a time period that the user does not want len.

Fig. 4 shows the courses in a conventional Speicherheizge device system according to the prior art. The thick dashed line in the lower area of the diagram shows the target charge level SLG as specified by a central control unit (with standard setting at an outside temperature = 0 ° C). The thick solid line shows the actual charge level ILG in the heat storage. The two curves above show the release signal (release for charging the night storage) and the user discharge (actuation of the switch on the room temperature controller). The higher state means "ON", the lower state "OFF").

At t = 0 h, the storage heating system receives from the energy supply undertake the release signal. The at this time from Central control unit ZSG output target level SLG is 0%. The actual loading level is approx. 20%. So the target / actual Value comparison of the (two-point) controller that the memory core no thermal energy has to be supplied. Only at the time approx The target charge level SLG becomes 3.75 h greater than the actual charge level ILG, so that from now on the storage core is heated up. The one there The slightly decreasing course of the actual charge level ILG comes from the radiation of the furnace to its surroundings, the Spei core temperature here is approx. 100 ° C, the maximum storage core temperature here is approx. 480 ° C. So the actual Charge level ILG the target charge level SLG up to the maximum value of 60%  is enough. Overloading (approx. 62%) and cooling (approx. 58%) stems from the hysteresis property of the charge controller.

After the release by the energy supply company has ended (at approx.8.5 h), the storage core cools down by radiation to its surroundings. At a point in time of 16.5 hours, the user actuates the switch on the room temperature controller, so that the actual charge level drops faster for this time range (there will also be heat energy given off by the fan to the room). Only after the room temperature controller has been switched off (at approx. 20 h) will the profile become flatter again (heat is only released to the surroundings by radiation). After a complete cycle ( 24 h), the storage core now has a higher actual charge level than at the beginning of the cycle. This means that more heat energy was supplied to the furnace than was removed during the rest of the day by radiation and intentional heat removal. The consequence of this is unnecessarily high power consumption due to the system's inadequate adaptability to the actual circumstances.

According to the invention, for a storage heater (SHG) an individual target charge level (SLG ') for the storage heater is continuously formed during a period (T _n ). The command variable specified by the central control unit (SLG) together with the control variable (SLG _Delta ) leads to the new guide variable (SLG ′) for the storage heater (SHG). The controlled variable (SLG _Delta ) is determined at the end of a period (T _n ) depending on the amount of residual heat (QRest _n ). A conventional PID controller with the control parameters k _p , k _i and k _{d is} advantageously used to form the controlled variable (SLG _delta ); in a simpler version, a P, PI or I controller can also be used. Such a controller could also be supported by non-mathematical algorithms in special exceptional situations. Fuzzy logic would also perform the task of determining the controlled variable (SLG _Delta ).

In this way it is achieved that the controlled variable (SLG _Delta ) is determined so that at the end of a subsequent period (T _{n + x} ) the residual heat quantity (QRest _{n + x} ) is as precisely as possible a predetermined safety charge (QSicher). It is essential here that an automatic intervention (within the framework of the EVU regulations) takes place in such a way that the sum of the heat energy supplies is as close as possible to the sum of the heat withdrawals. The safety value (QSicher) is expediently chosen so that the storage heater (SHG) is not completely emptied in the event of an unexpected additional withdrawal on the following day. This safety value can either be reassigned for each day - depending on feedback from previous days - or it can be predefined once.

For the operation of a storage heating system according to the invention, it does not matter which of the components of the network network involved carries out the necessary calculations. It is only important that the component concerned receives the result (s) as a message or the parameters for calculating the result (s) via the network. In the examples and figures below, it is assumed that the calculations for the controlled variable (SLG _Delta ) and the new reference variable (SLG ') are carried out in the respective storage heater. For the sake of simplicity, a constant safety charge (QSicher) (here 20%) and a periodically recurring charge release time are assumed in all examples. In FIGS. 5 through 9, the time spans (T n. T.. _{N + x)} are taken as a constant (here, 24 hrs).

In the course shown in Fig. 4, two extreme cases are now conceivable:

• 1. The amount of heat supplied is always smaller than that dissipated (see Fig. 7). Here, the storage core is cooled down to an actual ILG charging level of approx. 10%, which corresponds to approx. 50 ° C. This 10% actual charge means that the room can no longer be heated. The memory core is "empty" before the end of the user discharge.
• 2. No heat is removed by the user (see Fig. 9). Only the heat radiation leads to a lowering of the actual charge level ILG, so that at the end of each day an actual charge level ILG of more than 30% remains.

In FIG. 5, the actual / desired charging curve is illustrated the Aufladesteuervorrichtung according to the invention, wherein a central control unit ZSG the current target charge level (SLG) and the load enable for the respective storage heater (SHG) kon continuously specifies for one day.

(Note: In these and the following figures, a nominal charge degree curve (SLG ') is additionally drawn as a thin line, which corresponds to the nominal charge corrected by the charge controller)
In the arrangement described here, the storage heater (SHG) determines the controlled variable (SLG _Delta ) from the residual heat quantity (Qrest _n = 12%) and the safety value (QSicher = 20%) at the end of the first period (T _n ). This corrects the target charge level by the control size (SLG _Delta ) to SLG ′ positive (QRest _n <QSicher). This SLG 'serves as a new reference variable for charging the storage heater (SHG).

This procedure is repeated on the following days, so that at the end of the time period (T _{n + 4} ) the residual heat quantity (QRest _{n + 4} ) almost reaches the value of the safety charge QSicher.

For comparison of FIG. 6 shows the behavior of a herkömm handy storage heater (SHG) according to the prior art un ter same conditions as in Fig. 5.

The above-mentioned second extreme case is illustrated in FIG. 7. No heat energy is taken from the user here (so only the pure radiation comes into play), already at the end of the second period (T _{n + 1} ) there is a residual heat quantity (QRest _{n + 1} ) of only slightly above the safety value (QSicher ) set.

For comparison, FIG. 8, the behavior of a herkömm handy storage heater (SHG) according to the prior art un ter the same conditions as in Fig. 7. Clearly visible here is the residual amount of heat (QRest _{n + 1)} at the end of the time period (T _{n + 1} ) approx. 34%.

A comparison of Fig. 7 and Fig. 8 shows that the profile of the Istladung (ILG) (NB. The Istladung is proportional to the SpeI chertemperatur) 8 significantly reduced in Fig. 7 with respect to the course of the Istladung (ILG) in Fig. . As mentioned above, the thermal radiation is proportional to the fourth power of the temperature of the radiator, so here the losses due to radiation are significantly lower. Accordingly, the supply of the La is dung in Fig. 7 considerably less than the supply of the charge in Fig. 8.

Fig. 9 illustrates the adaptability of the system to a changing outside temperature. In this example, the outside temperature T _A on the first three days is + 5 ° C, it drops on three consecutive days by 5 ° C to -10 ° C, where it stays for another three days (corresponding to the lower outside temperature) the central control unit specifies higher target degree curves). Although the system according to the invention tends to follow the target charge level (SLG) specified by the central control device (ZSG), it remains well below the target value, especially on the 7th day, but at the same time the charge is still sufficient. On the following three days with the same outside temperature, the system adjusts itself to the safety value (QSicher) with its residual heat quantity (QRest).

In contrast, Fig. 10 shows again the behavior of a conventional system according to the prior art. Here, the actual charge (ILG) increases with its maximum to over 90%, although this thermal energy is not "used" (it is only emitted). The curves in the time periods T _{n + 8} in these figures can be discussed as well as the curves in the time periods T _{n + 4} of FIGS. 7 and 8.

Systems with these properties allow the tem temperature in the storage core (actual charge level) as low as possible, but to keep as high as necessary, and so more efficient Control of a storage heater system, as with conventional devices.  

Because there are different influences on the charge / discharge, so also affect the amount of residual heat (QRest) such as B.

• - outside temperature T _A
• - changing user discharge (time and duration of the removal me)
• - multiple times and durations of the releases
• - Different working prices for high tariff and Niederta reef times

advanced procedures are applied to achieve the above mentioned goal to achieve better. To be able to use these methods, other sizes must be recorded.

• 1. Acquisition of Qmax and Qmin Qmax _n are the maxima (in the mathematical sense) of the actual charging process recorded during a time period T _n ;
  Qmin _n are the minima (in the mathematical sense) of the actual charging process recorded during a time period T _n ;
• 2. Detection of the profile of the storage temperature (VST) or a characteristic variable derived therefrom during a time period T _n .
• 3. Detect the time when the discharge limit QLeer (t _L ) is undershot.
• 4. Detection of the beginning and end of the heat removal by the User (BWE, EWE)

These detected quantities must now be applied to the regulation in a suitable manner Act wisely.

Fig. 11 shows a plot of the curves which takes into account these variables with. Qmax ₁ is determined with approximately 62% at t for approximately 5 h, Qmin ₁ with approximately 26% at t approximately 18 h. Qmax₂ with about 32% at t about 18 h and Qmin₂ with about 28% at t about 24 h (end of the cycle). For the correction value of the target charge level '(SLG'), it is taken into account that the second additional charge of the first cycle would not have been necessary, since the safety value would not have fallen below QSicher without this charging. The consequence is that in the second cycle, even without this additional charge, the residual heat quantity QRest is approximately equal to the safety value QSi cher, the deviation which would still be present being corrected in further cycles.

Now it is also the case that of the energy supply companies take EVU "electricity" is offered at different prices (HT high tariff and NT low tariff). This influencing variable is a another starting point to the operation of such a storage heater to make the system cost-effective.

In a further variant (not illustrated), the system determines, in the event that the user is only discharged after the last charge release by the energy supply company EVU (using the quantities Qmax _n , Qminn, the course of the discharge curve VST, the charge release times BNT, ENT, BHT, EHT and the working prices for low / high tariff ANT, AHT) that it is cheaper to carry out the charging only in a period T _{n + 1} shortly before the removal, but the charging of the storage heater SHG in the period T _n to throttle (Note: T _n is the time period 0 h <= t <BHT, T _{n + 1} is the time period BHT <= t <24 h).

For this purpose, the central storage device (ZSG) charges the electricity tariffs the storage heaters SHG’s communicated (AHT, ANT). Outgoing of the required cargo and taking into account the The SHG storage heater can then determine whether radiation it is cheaper given the different electricity prices, charge during the low tariff period and the unwanted Ab to accept radiation, or whether it is cheaper, the need to carry out agile (recharge) during the high tariff period.  

There is also a particular advantage of this procedure in that the time between the end of the charge release and the start of the Extraction of thermal energy is as short as possible. This serves in particular in particular to minimize radiation losses.

In the cases considered so far, there was never a "total discharge "of the memory core, with 50 ° C as the storage temperature corresponding to 10% actual charge level ILG considered as total discharge will. In this case, a common (PID) controller would be too long ge to get back into its operating area.

t _L should now be the point in time at which a threshold QEmpty is undershot, whereby the threshold QEmpty can also be QSafe. With this variable, knowledge of the further discharge profile (VST) can now be used to calculate how much the correction value (SLG _Delta ) for the target charge level ′ (SLG ′) is again over the value determined by the control element for a later period (T _{n + x} ) needs to be corrected. This additional correction now brings about a faster approximation to the desired state.

These last described variants require information on about what will happen in the "future". this concerns Time and duration of the user discharge and the others Course of the actual charge level curve.

The latter can be realized in that certain characteristics sizes of the discharge process are stored in a memory. Such parameters can e.g. B. the temperature values of the memory core at certain time intervals, or if these Discharge with a mathematical function is sufficiently precise can be reproduced by means of the mathematical function characteristic parameters, e.g. B. the discharge time at a e-function, or the coefficients of a polynomial function. With With the help of these parameters it is then possible with the help the associated mathematical methods based on a Time / temperature point to calculate the further course.  

The procedure shown so far behaves optimally during the day recurring similar conditions of heat extraction and the supply of heat. With changing user habits (e.g. lower heat demand in the evenings on working days, increased heat demand on weekends throughout the day ges) is now an expanded procedure for consideration of these circumstances.

In the course of at least one time period (T _n )

• - the times at which heat extraction begins (BWE),
• - the times of the end of heat extraction (EWE),
• - the dates of the start of the low tariff release (BNT),
• - the times of the end of the low tariff release (s) (ENT),
• - the dates of the start of the high tariff release (BHT), and
• - The times of the end of the high tariff release (s) (EHT) he averaged and recorded in a data memory (DS).

A periodicity (p) is determined from the course of these times of several (y) past time periods (T _n ).

Depending on the periodicity (p), the start and end times of user extraction, cycle time, control parameters, release periods (BNT / ENT / DNT, BHT / EHT / DHT; Qmax _n , Qmin _n ) are stored in a period data memory (PDS).

Is the period of use (p) of the storage heater (SHG) known, the system can do the same for a day n + 1 Use parameters at the end of the day n + 1 of the previous period were determined.

Schematic representation of the period data memory (PDS)

To determine the usage habits, the Be Start of heat extraction (BWE) and the duration of the heat extraction (as the difference between the end of heat extraction (EWE) and the start heat extraction (BWE)) in a period data memory (PDS) recorded over a certain time y. These values can by examining the actual discharge curve the. The transition from a smaller [neg.] Slope to a larger [neg.] Slope the beginning of a Discharge and vice versa. The difference between the two times is the duration of the discharge. An easier way results yourself when the charge controller is directly connected to the switch of the room temperature controller is coupled. Then switching on means the beginning of the user discharge, the turning off the end of the user discharge.

This data storage (PDS) should be designed for a sufficiently long period of time (e.g. 28 days; an integer multiple of 7 days generally corresponds to the European cycle). These two curves must now be examined with regard to their period duration. In a simple version, the formation of the first (mathematical) derivative leads to usable results. Combining the results of the period durations of both curves, the greatest common period duration is the "period duration of use". Fig. 12 now illustrates such an observation. The bars shown in the lower image area represent the start / end of the usage extraction. B. the bar of the first day, a withdrawal from about 3.15 p.m. to 4.45 p.m. The first derivation of the start times (graph 1 , solid) and the first derivation of the removal times (graph 2 , dotted) are shown in the upper part of the figure. A period of the graph 1 of 7 days is clearly recognizable here, the graph 2 has no peaks in the course, that is to say no repetition, so that the total period of the system is 7 days. In Fig. 13, the graph 1 is again a period of 7 days, the graph 2 a (not out of phase) period of 14 days, so that there is a total period of 14 days.

In Fig. 14, the period of the graph 1 has a period of 7 days. Graph 2 has a period of 7 days, but is 4 days out of phase compared to Graph 1 , so that the total period is 7 days again.

The duration of the period can be determined by a wide variety of mathematical methods, e.g. B. by Autocorrelati on, comparing the minima and maxima etc. For the individual days of each period, the respective on and off times of the user withdrawals for each day, the daily release times of the energy supply company (EVU), the relevant control parameters are then stored in the data memory of the control element etc. The control variable (SLG _Delta ) is then determined on the basis of this data for each individual day.

Sometimes the EVU approval times are subject (both the Hochta Rifzeiten HT as well as the low tariff times NT) certain time Lichen patterns, so that they also in the period detection can be included to be the most cost effective and  most energy-saving time for charging the storage heater (SHG) to determine.

Claims (8)

1. A method for operating a storage heater control with a central control unit (ZSG) and at least one storage heater (SHG), which is coupled to the central control unit (ZSG) for transmitting a reference variable (SLG), characterized in that

• - The command variable (SLG) transmitted to each storage heater (SHG) by the central control device (ZSG) for a period of time (T _n ) with a controlled variable to a modified reference variable (SLG ') for the respective storage heater (SHG), and
• - For each storage heater (SHG) at the end of this period (T _n ) the value of the amount of residual heat still stored in the storage heater (SHG) (Qrest _n ) is determined, and depending on this the controlled variable for a later period (T _{n + x} ) is determined.

2. A method of operating a storage heater control according to claim 1, characterized in that

• - For each storage heater (SHG), a safety value (Qsafe) of the heat quantity is determined, which serves as the target quantity for the residual heat quantity (Qrest _n ) at the end of a period (T _n ), and
• - The safety value (Qsafety) can be changed during a charging and / or discharging process of the storage heater (SHG), and
• - A discharge limit (QLeer) of the amount of heat is set, which serves as a characteristic value of a discharged storage heater (SHG), and
• - The discharge limit (QEmpty) is always less than / equal to the safety value (QSafe).

3. A method for operating a storage heater control according to one of claims 1 or 2, characterized in that

• - For a storage heater (SHG) the controlled variable for a later period (T _{n + x} ) is changed so that at the end of the later period (T _{n + x} ), with the same removal as in the previous period (T _n ), the difference between the safety value (Qsafe) and the residual heat (Qrest _{n + x} ) becomes as small as possible.

4. A method for operating a storage heater control according to claim 3, characterized in that for determining the re gel size over a period of time (T _n )

• - the course of the storage tank temperature (VST),
• - the maximum values of the heat quantity (Qmax _n ),
• - the minimum values of the heat quantity (Qmin _n ), and
• - The times of the end of the heat withdrawals (EWE) from the storage heater (SHG) determined and recorded in a data memory (DS).

5. A method for operating a storage heater control according to one of claims 1 to 4, characterized in that

• - If the discharge limit (QLeer) is undershot during the removal / delivery of thermal energy from the storage heater (SHG) over a period of time (T _n ), the time of the undershoot (t _L ) is determined, and
• - The controlled variable for a later period (T _{n + x} ) depending on the time of falling below (t _L ), the course of the storage temperature (VST) and the time of the end of heat removal (EWE) is changed.

6. A method for operating a storage heater control according to one of claims 1 to 5, characterized in that in the course of at least one period (T _n )

• - the times at which heat extraction begins (BWE),
• - the times of the end of heat extraction (EWE),
• - the dates of the start of the low tariff release (s) (BNT)
• - the times of the end of the low tariff release (s) (ENT),
• - the dates of the start of the high tariff release (BHT), and
• - The times of the end of the high tariff release (s) (EHT) he averages and recorded in a data memory (DS), and
• - A periodicity (p) is determined from the course of the times listed here from y elapsed time periods (T _n ).

7. A method of operating a storage heater control according to one of claims 1 to 6, characterized in that

• - Depending on the periodicity (p), the start and end times of heat removal, cycle time, control parameters, release periods (BNT / ENT / DNT, BHT / EHT / DHT; Qmax _n , Qmin _n ) stored in a period data memory (PDS) become.

8. A method for operating a storage heater control according to one of claims 1 to 7, characterized in that

• - The controlled variable at the end of a period (T _n ) for a later period (T _{n + 1} ) of the removal / release of thermal energy from the storage heater (SHG) is determined depending on the data contained in the period end memory (PDS).