DE4028501A1 - Controlling heating of rooms for economy - using real=time temp. valves and stored building parameters to delay switching of heating appts. for max. period - Google Patents

Abstract

The procedure concerns the control of heating within rooms of buildings to provide the desired temp. for the required periods by delaying the heating of the rooms for as long as possible. The following factors are taken into account: times of occupation; a constant (K1) dependant upon size of building; outside temp (ta): min outside temp value (tamin); desired room temp (tin); 'difference' temp values (delta ta) and power of heat generates. The time (ta) for the heating is derived by a given formula. ADVANTAGE: Takes into account all factors for optimum switching-on time.

Description

The invention initially relates to a method for taxation heating of rooms in a building, in which Temporarily keep the room temperature low Level is lowered, with heating to a Set room temperature, the outside temperature and the actual Room temperature immediately before heating, the target Room temperature for heating operation as well as the programmed Periods of temperature decrease and the periods of High temperature of a controller as well as a building constant te and a minimum outside temperature to calculate the the latest possible start of heating.

Usually a temperature sensor in one of the rooms to be heated in connection with a weather tion-controlled VT controller with an algorithm for self-optimizing heating time calculation.  

Who can be checked with the help of the room temperature sensor the whether and which deviations of the actual room temperature at the programmed time from the target room temperature exist.

In buildings where there is no representative test room for If the room temperature check exists, it is carried out Heating time calculation without room sensor depending on the outside temperature and possibly a fixed or adjustable room setpoint temperature increase. It must All corrections must be made manually by the operator or Service.

The invention is based on the knowledge that this type the dimensioning of the heating-up time is not optimal because et factors necessary for the correct choice of switch-on the time of heating are decisive, but not affected Stay informed and options for self-employment fit are not used. According to the invention provided that the duration of the heating-up time, respectively the time of switching on a heater on the Basis of the functional relationship between the following Factors are determined:

• a) The lowering time, which also includes the heating time, the from the program to be specified by the user (An  start and end of heating)
• b) a variable proportional to the building constant,
• c) the current outside temperature (t _A ),
• d) a minimum outside temperature necessary for the design the heating system is relevant,
• e) the desired target room temperature,
• f) the difference between the target room temperature and the minimum outside temperature (Δ t _A ),
• g) the amount of heat used during heating or a proportional size and
• h) the ratio (f _H ) of the output of the heat generator to the required heating output at the minimum outside temperature.

According to this basic teaching, the optimal duration of the heating-up time can be determined particularly advantageously using the following formula:
Equation (1)

Methods are known in which the time constant for this te is specified and adjusted by hand. As in Glei chung (1), this is not sufficient to to achieve an optimal heating process. Are also significant the factors f) and h), whereby h) also by an equivalent tes f) can be expressed. To simplify the correct selection of this value includes the invention also an automatic adaptation procedure for this.

Starts with a default value from context (1) controlled heating before the programmed time point of reaching the target room temperature.

To determine one of the proportions of heat used tional correction factor, the time span from on switch the heater until the first shutdown will measure, and from the relationship between the on heating time and the measured duty cycle can be a fact  can be determined with which the difference between the target room temperature and the maximum flow temperature of the heater assigned outside temperature mul is multiplied.

In connection with the procedure, the He extends finding a suitable one for its implementation Heating system with a heater, one which is fuel feed to its burner regulating, from a control controlled valve and one with a circulation pump allowed, containing at least one radiator Heating circuit with a temperature sensor in its flow line is arranged, the control of the heater, the Drive of the circulation pump of the heating circuit and the tempera door sensors via control lines with a general Control are connected to the device to enter the target room temperature, an outside temperature sensor and a programmer via control lines are closed.

According to the general control to this additionally an adjustable device for entering a outside corresponding to the maximum of the flow temperature temperature and a device for entering one of the Ge building constant corresponding size via control lines connected.  

The invention will now be described with reference to the drawings explained.

In detail show the

Fig. 1 to 4 based on diagrams, the functional relationship between the above-mentioned, for the determination of an optimal duration of the heating-up characteristic values.

Fig. 5 shows the scheme of a suitable heating system for performing the United method.

First, the diagram according to FIG. 1 shows the functional relationship between the actual height of the outside temperature shown in the abscissa at the beginning and during the course of the heating to the desired room temperature (t _iN ), the minimum outside temperature t _{A min} , the building constant and the ratio of the heating-up time Z _A to the duration of the lowering operation Z _G plotted on the ordinate. The heating-up time Z _{A is} the period within which the actual room temperature rises from the start of room heating to the setpoint value of the room temperature. This duration is given as a percentage of the total lowering time. At the minimum outside temperature t _{A min} , the maximum output required for room heating is achieved at the set room temperature t _iN .

For example, t _{A min} was assumed to be -15 ° C, the target room temperature t _iN is, for example, + 20 ° C. Δ t _A is therefore 35 K. The size K, which is proportional to the building constant, differs and takes into account the individual inertia of the building with regard to heat absorption and storage capacity. K ₁ is greater than K ₂ and K _{2 is} assumed greater than K ₃ .

From this Fig. 1, the effect under different building constants K on the required heating time can be seen.

The excess power factor f _H at a temperature of t _{A min} is 1.0 in this case, that is, there is no excess, the required heating output is fully covered by the heat generator output. The United course of the curves shown in Fig. 1 results from iteration from the known relationships

therein Tau _{A means} the so-called heating time constant, f _H the ratio of the output of the heat generator to the heating output, which is required at t _{A min} to enable a room temperature of t _iN , t _iO the room temperature after the time Z _E at the beginning of Heating from lowering to the increased room temperature level.

. Also, the Figure 2 shows such a diagram the functional dependence of the heating Z _A of the Au ent temperature t _A, and that - in accordance with Außentemperatu ren of t _{A min} from -10 ° C, -15 ° C and -20 ° C in curves 1 , 2 and 3 .

At each such minimum outside temperature t _{A min} , it is assumed that the maximum power is output by the heater, that is, f _H = 1.

The calculation of the curves in one in heating microprocessor used regulators requires a relative high computing time and a considerable storage space may.

The existing requirements are closed linear equation to be solved much better. According to the invention, this is approximated as follows used:

where Z _{A is} the desired time in hours, K₁ is a dimensionless quantity proportional to the building time constant, Z _{G is} the time span of the deviation from the increased room temperature setpoint t _iN in hours, t _{A is} the current outside temperature in ° C, t _{A min is} the minimum design temperature temperature of the heating system in ° C, Δ t _{A is} the difference between the set room temperature t _iN and the minimum outside temperature t _{A min} in ° C.

This approximate course is shown in FIG. 2 as curve 4 .

The following relationship can be used to adapt the factor K 1 to the physical building time constant K _Geb :

A, B, C and n mean mathematical constants for error-minimal approximation.  

This adjustment can advantageously be done by the computer unit.

In practical systems, it can happen that the power excess factor f _H <1 is at the set minimum outside temperature. The result is that the heating-up time is calculated too long, although the time constant is set appropriately. Since no room sensor can be used for correction, a size that is approximately proportional to the actual heat requirement must be used. It can be entered manually. However, an automatic adjustment to the conditions of the heating system is advantageous.

If, for example, a period of time is measured from switching on the heater until it is switched off for the first time, which is shorter than the calculated heating-up time, there must be an excess of power, i.e. f _H is greater than 1. This means that the actual minimum outside temperature t _{A min} , at which the target room temperature t _{iN can} still be maintained, is lower. The point of curve 2 , in which the heating time is 100% at t _{A min} , could therefore be moved to the left up to curve 3 , which increases the difference Δ t _A to t _{A '} .

This is done by determining a correction factor from the ratio of the calculated heating time to the measured on-time. With this correction factor, a new difference Δ t _{A 'is} calculated and, at a constant target room temperature, a new, lower outside temperature t _{A min is} determined (curve 3 of FIG. 2).

In the diagram according to FIG. 3, the daily course in hours is shown in the abscissa and the temperatures are recorded in the ordinate. The course of the actual room temperature is shown with a full line, the course of the target room temperature t _iN with a long dashed line.

The heating-up time Z _A lies within the lowering time Z _G , after which the room temperature is approximately at the target room temperature of + 20 ° C. In the lower part of Fig. 3, the course of the power (percentage) of the heat generator is shown.

FIG. 4 shows in a diagram how the actual heat requirement can be taken into account by measuring the time period between the switching on of the heater and its first switching off by the boiler or flow temperature controller.

In the upper part of the diagram, the time course of the heating circuit temperature t _{v is} recorded in the abscissa. Line 5 denotes the temperature at which the heater switches on in the heated state by controller 25 and line 6 that temperature t _Vmax at which it switches off. The heating takes place from the temperature t _vi .

In the lower part of the diagram according to FIG. 4, the power P of the heater is recorded in the ordinate, namely with point 7 the 100% nominal power. Riod Z _is between the input and the first off the heater, the yielded amount of heat can firmly make and hence determine the correction factor by the calculated heating time Z _A to Z actual A switching time _one is taken into consideration.

When determining this correction factor must follow cases can be distinguished.

Case 1

The heat generator was switched off before or upon reaching the programmed start of the heating time, curves 2 and 3 in FIG. 4.

In a large part of the outside temperature range, the heating-up time changes almost linearly with the outside temperature. Here, the following relationship can be established between two curves with different Δ t _A :

Therein, Δ t _{AM means} the actual difference between the room temperature setpoint t _iN and the actual minimum outside temperature t _{A min} and Δ t _AE the set difference between the room temperature setpoint t _iN and the actual minimum outside temperature t _{A min} , Z _{AM of} the measured heating-up time, in FIG. 4 the times z _ein2 or z _ein3 and Z _AE the heating-up time calculated from the setting data.

The ratio Z _AE / Z _AM can be used to correct the set value Δ t _AE .

Case 2

The heat generator was switched off after the programmed start of the heating time, curve 1 in FIG. 4.

By extrapolating the flow temperature curve the associated switch-on time is determined.

In which Z _AM the calculated switch-on time of the heat generator, Z _A the set heating time, t _vmax the difference between the maximum temperature of the heating circuit and the heating circuit temperature at the beginning of heating, Δ t _vi the difference between the measured actual heating circuit temperature at the beginning of the time phase with the increased room temperature setpoint and the actual heating circuit temperature at the beginning of the heating.

Using this extrapolated value for Z _AM is again about the relationship

the correction of Δ t _{A is} carried out. In this case, Z _AM corresponds to z _ein1 in FIG. 4.

Fig. 5 shows the schematic of a suitable heating system for carrying out the process with a burner-heated heater, for example a boiler 10 , egg nem regulating the fuel supply to its burner 11 , arranged in a fuel supply line 12 , from egg ner controller 13 via a servomotor or solenoid 14 adjustable valve and equipped with a circulation pump 16 , at least one radiator 17 containing, connected to the heat exchanger 18 of the boiler 10 , a flow line 20 and a return line device 21 comprising heating circuit, in the flow line 20 a temperature sensor 19 is arranged . The control 13 of the boiler 10 , the drive of the circulation pump 16 of the heating circuit 20 to 21 and the temperature sensor 19 are connected via control lines 22 or 23 and 24 with egg ner general control 25 of the heating system, to which a device 26 for arbitrary adjustment of the desired set room temperature t _iN , an outside temperature sensor 27 and a programmer 28 are connected via control lines 29 and 30 , 31 , respectively.

In addition to this general control 25 there is also an adjustable timer 32 for inputting an outside temperature t _{A min} and a device 33 for inputting a variable proportional to the building constant K via control lines 34 and 35 and via line 36 a signal for detecting the state the valve 12 is closed.

In such a heating system, the duration of the heating-up time, and therefore the time for the boiler to be switched on automatically by the controller 25 in the sense of the invention, can be predefined without problems and accordingly.

Claims (4)

1. A method for controlling the heating of rooms in a building which reach a higher room temperature setpoint during occupancy times and a lower room temperature level during a lowering time and which, after the lowering time (Z _G ), reaches the increased room temperature level again and the time period (Z _A ) is to be determined from which the point in time at which a heater must be switched on in order to reach the increased room temperature setpoint with the room temperature again at the desired next start of occupancy can be calculated, characterized in that the time period (Z _A ) for the duration of the heating to the increased room temperature level (t _iN ) is determined according to the following relationship: where Z _{A is} the desired time span in hours, K _{1 is} a dimensionless quantity proportional to the time constant of the building, Z _{G is} the time span of the deviation from the increased room temperature setpoint t _iN in hours, t _{A is} the running outside temperature in ° C, t _{A min} the minimum outside temperature in ° C at which the heating output required by the heating system, which is necessary to reach the target room value t _iN , is just covered by the output of the heat generator, Δ t _A the difference between the room temperature Mean setpoint, t _iN and the minimum outside temperature t _{A min} in K. 2. The method according to claim 1, characterized in that the constant K _{1 is determined} according to the following relationship:
K ₁ = A · K _Geb , where K _{Geb is} the building constant and K _{1 is the} proportionality factor. 3. The method according to claim 1 and 2, characterized in that the period of time from the start of a circuit of the heat generator with the start of the heating time Z _A to the following first time reaching the maximum temperature of the heating circuit, by the design data of the heating system is determined, is measured and in the event that at the beginning of the time phase with the higher room temperature setpoint the heat generator has been switched off above the maximum temperature, with the heating-up process Z _{A used as} the basis for this heating process and that the current difference Δ t _A between the desired room temperature t _iN and the minimum outside temperature t _{A min} in a range limited to low outside temperatures, within which the relationship between the heating time Z _A and the outside temperature t _{A is} approximately linear, is corrected as follows: Δ t _{AM means} the actual difference between the target room temperature t _iN and the actual minimum outside temperature t _{A min} and Δ t _AE the set difference between the target room temperature t _iN and the actual minimum outside temperature t _{A min} . 4. The method according to claim 1 and 2, characterized in that the time span from the start of a circuit of the heat generator with the start of the heating time Z _A until the following first time reaching the maximum temperature of the heating circuit by the design data of the heating system is determined, is measured and in the event that at the beginning of the time phase with the higher room temperature setpoint of the heat generator has not yet been switched off via the maximum temperature, the actual heating-up time Z _{AM is} calculated from the following relationship. where Z _{AM is} the calculated switch-on time of the heat generator, Z _{A is} the set heating time, t _vmax the difference between the maximum temperature of the heating circuit and the heating circuit temperature at the beginning of the heating, Δ t _vi the difference between the measured actual heating circuit temperature at the beginning the time phase with the increased room temperature setpoint and the actual heating circuit temperature at the beginning of the heating mean, and that this calculated time Z _{AM is} related to the heating time Z _{A used} for this heating process, and that the current difference t _A between the target room temperature value t _iN and the minimum outside temperature t _{A min} in a range limited to low outside temperatures, within which the relationship between the heating time Z _A and the outside temperature t _{A is} approximately linear, according to the following Correction is corrected: