DE3309315A1 - Measuring instrument for measuring quantities of heat - Google Patents

Abstract

In order to determine the proportionate heating costs of individual households in a multi-family dwelling, it is necessary to establish the quantity of heat consumed by the respective household. For this purpose, so-called calorimeters are known in which the quantity of heat consumed is established from the volume of a liquid evaporated due to the heat (evaporation meter). However, practice has shown that this measurement is very inaccurate and can also be easily corrupted, which can lead to unfair allocation of the heating costs. In order to eliminate these disadvantages, the invention provides a novel type of measuring instrument which forms the integral from the product of time and temperature. For this purpose, a temperature-dependent time measurement is undertaken. In this regard, the measured variable represented as the measured time value on a display is larger the higher the respective temperature (or vice versa). By comparing the measured values to be ascribed to different heaters, it is possible to determine the heating costs arising at each heater as a proportion of the total heating costs.

Description

Measuring device for measuring amounts of heat

The invention relates to a measuring device for measuring amounts of heat, in particular for radiators in central heating systems.

The measurement of used or generated amounts of heat is in many areas of technology and everyday Of considerable importance. This is particularly true, for example, when determining heating costs in apartment buildings where a central boiler is available as a heat generator. Here comes it is important to determine the heating costs of each household as a proportion of the total heating costs, for which a separate heat quantity measurement is required for each household.

Various measuring methods are already known, and COPY " both with decentralized and centralized heating systems. In the case of decentralized systems (e.g. with electricity or gas) a measurement can be carried out quite easily and precisely with a gas meter or the usual electrical meter carry out.

In contrast, it is in central heating systems where liquids or gases, such as air or water, are used as "Transport medium" for the heat is assumed, until today the measurement of the heat quantities has not been successful to be carried out with the desired accuracy. The most commonly used are the so-called calorimeters, which are arranged on the radiator between two ribs and work according to the evaporation principle.

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The calorimeters have a glass tube with a - ' very slowly evaporating liquid is filled. j

Similar to a thermometer, the liquid level is read, and the amount of evaporated Liquid is used to determine the amount of heat.

The known measuring device has several disadvantages. It should be emphasized as serious that the measurement result is very imprecise because of the evaporation principle used. This can be for the individual household lead to excessive heating costs, which in themselves would not be justified.

The evaporation of a liquid is known to be dependent on the relative humidity, which is present in the heated room. As a result, the measured values can - unintentionally or intentionally - easily falsified for the amount of heat consumed.

Another disadvantage of the known measuring devices in the form of calorimeters is the fact that the Measuring scale for reading off the amount of evaporated liquid is very short, resulting in an inaccurate reading the measured values leads. On the one hand, the formation of a longer scale is ruled out because it means the Measuring device becomes unwieldy, and on the other hand, this would also increase the costs of the measuring device raise. In addition, it is also disadvantageous that the known calorimeters also have the short measuring scale are already relatively expensive.

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In another known measurement method for amounts of heat in hot water heating is in the for Radiator leading heating pipe a water meter used to measure the amount of hot water supplied to obtain. Contrary to actual practice, it is assumed that the inflowing warm water always shows the same temperature.

When using this measuring method, it must be taken into account that the temperature of the in the radiator Inflowing water differs from the temperature of the outflowing water because the radiator heats radiates. Therefore the use of the water meter is also very imprecise.

Another decisive disadvantage is that the water meter is not or only with one allow considerable effort to be retrofitted in heating systems. Even if a water meter right at the beginning when installing the heater is installed, the installation costs are very high, so that this solution is often ruled out for economic reasons.

In summary, it can be stated that the known

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Measuring devices for measuring heat quantities both for economic reasons and for reasons of The accuracy of the reading and the display cannot be satisfactory. Difficulties also crop up when an existing heating system is to be retrofitted with a measuring device. This is just possible with the calorimeter, which is to be regarded as disadvantageous in other respects. In practice there is thus there is a significant need for another measuring device which can overcome the disadvantages described above does not own.

This is where the invention comes in, the object of which is to provide a measuring device for measuring To create quantities of heat, which provides a very precise measurand for determining the heating costs, and which is still easy to set up and inexpensive to purchase. In addition, the Measuring device can easily be provided retrospectively in already existing heating systems can.

To achieve this object, the measuring device according to the preamble of claim 1 is characterized by a temperature-dependent time interval generator and a counter for counting the dependent time intervals generated by temperature.

The invention takes a completely new approach, the amount of heat not via the temperature-dependent evaporation a liquid or a flow rate measurement, but by a simple time measurement to be determined, the time measurement being carried out as a function of the temperature.

The prior art offers a variety of simple and inexpensive solutions for a time measurement, so that The measuring device according to the invention can also be designed to be simple in structure and inexpensive to purchase ' can. The principle of the invention is thus to perform a time measurement as a function of the temperature. One is particularly simple and advantageous Embodiment of the invention in which a conventional oscillator is used as the basis for the time measurement which depends on the ambient temperature

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rature electrical vibrations are generated, which are counted by an electronic counter and then digitally are displayed. Let us remind you of the well-known digital wristwatches that make it clear that such timepieces can be built inexpensively and in compact dimensions.

The invention makes use of the effect that the frequency generated by the oscillator is temperature-dependent is why usually special temperature stabilization circuits are provided. Such temperature stabilization is deliberately omitted in the invention in order to avoid a dependency between the Temperature and the generated frequency. The higher the ambient temperature, the higher it is also the frequency, that is, the timer counts more oscillations in a given time unit, and the value shown on a digital display will be correspondingly higher.

The invention is based on the knowledge that it is completely sufficient to determine the proportional heating costs is when in an apartment building only the proportional shares of the individual households the total heating costs can be determined exactly. This fundamental idea for which the invention shows astonishingly simple way is explained in more detail below.

With the help of conventional divider stages, the generated by the oscillator as a function of the temperature Frequency are divided down so far that the following electronic counter only the days - that is 365 days a year - counts (of course, other subdivisions are also possible).

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For the sake of simplicity, assume that there are three households with only one radiator each. If now when using the measuring device according to the invention after a year when the consumed Heat quantities are to be read, all three counters have a count of "365", this means that the total heating costs are to be divided equally between 1/3. In the event that a household has consumed a particularly large amount of heat energy, the counter is the associated Measuring device have a correspondingly higher counter reading, which proportionally results in a higher one Can determine the share of the total heating costs.

A significant advantage of the invention is that despite the simple structure and despite the small Cost of the new measuring device can achieve a very high accuracy. This accuracy can be Increase practically arbitrarily if the oscillator has a very high frequency, and if the subsequent one Pitch is reduced. For example, it is possible to use the digital display - not based on a year to supply only 365 impulses, but a multiple of them. The higher the displayed number is chosen, the more precisely the reading - and thus the allocation of quotas to the individual households - can be carried out.

In addition, the invention allows in more advantageous But also wise to display the amount of heat consumed directly. For this purpose it is only necessary to calibrate the new measuring device prior to commissioning by means of an exact heat meter.

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By appropriate selection of the divider stages dividing the oscillations of the oscillator is then also a direct display of the amount of heat in kilocalories (Kcal) possible, whereby the divider steps the conversion factor between the temperature dependence of the Take into account the oscillator and the associated amount of heat.

The measuring device according to the invention can not only be implemented on an electronic basis; It is also a conventional mechanical watch can be used as a timepiece. This is the one known from watches Unrest, for example, designed in such a way that an oscillating axis with lateral arms is provided which weights are attached. The arms are formed by bimetal rods, creating the desired temperature-dependent Timing is achieved. For example, when the temperature increases, they bend the bimetal rods, in such a way that the distance between the swing axis and the weights is reduced will. As a result, the unrest "runs" faster, which leads to the temperature-dependent time measurement.

Another particularly advantageous aspect of the invention should also be mentioned that the new Measuring device is ideally suited for retrofitting to existing heating systems. To this Purpose, the measuring device can be carried by a clamp that is simply attached to the radiator Heating pipe can be laid and fastened.

In the embodiment of the measuring direction according to the invention, which works on an electronic basis can be used as an energy source for the oscillator, the electronic counter

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and the display advantageously a thermocouple can be used, which provides sufficient energy to feed the entire electronics. Here, the heat to be measured is also used as an energy source for the measuring device.

Often there is a desire to measure the amount of heat not on the heating pipe, but on the radiator or to undertake on its ribs itself. If the measuring device is namely on the heating pipe in front of the valve is attached, the measurement may become inaccurate when the valve is closed. The radiator does cool then quickly, but in front of the valve the hot water will initially build up. Then a measurement is on the radiator itself more precisely.

In order to enable this measurement as well, an expedient embodiment of the invention is that the Counter, the time interval generator and the display are part of a terminal that is attached to a rib of the Radiator can be clamped.

Finally, the invention can also be advantageously combined with a conventional thermostat, in which the measuring device is an integral part such a thermostat is formed.

Other advantageous refinements and developments of the invention are set out in the subclaims and in the Drawings indicated.

The invention is described below for a better understanding based on the embodiments shown in the drawings.

examples explained in more detail: They show:

Fig. 1 A principle block diagram of a measuring device,

Fig. 2 and 3 two square waves of different frequency for Clarification of the temperature dependency of the generated vibrations,

4 shows, in partial representation, a perspective view of a mechanical unrest,

Fig. 5 is a cross-sectional view of one wrapped around a heater pipe Clamp with a measuring device,

6 shows a perspective view of the clamp according to FIG. 5,

7 shows a simplified schematic diagram of a heating system with measuring devices, and

Fig. 8 in a schematic view a

the clamp carrying the measuring device.

In Fig. 1 is a principle block diagram of a time interval generator 12, which in this example of COPY management as a quartz-controlled square wave generator below simply referred to as a crystal oscillator - is formed.

With such a quartz oscillator, square waves can be generated as shown in Figs. The crystal oscillator is followed by Counter 14 a timepiece in the form of a conventional electronic counter with divider levels, and for display purposes a digital display is provided for the counter reading.

A decisive feature of the measuring device according to FIG. 1 is that the time interval generator 12 - here the quartz oscillator already mentioned in a thermally conductive connection with a heat source 10 and thus works depending on the temperature. For this purpose, in the electrical circuit of the crystal oscillator a thermistor can be used as a temperature-dependent resistor to influence the frequency. The frequency of the square waves therefore depends on the temperature.

In FIGS. 2 and 3 it is made clear that the j

Frequency of the square waves 18 with increasing j

Temperature increases, as for the square waves 20;

is shown. Conversely, if the temperature decreases, 'also reduces the frequency.

As a consequence of the described temperature dependency COPY ' there are 16 measured values on the digital display, which '

are influenced by the temperature of the heat source 10. The higher the temperature, the higher the displayed temperature Be measured value because the timer 14 then several oscillations or pulses in a unit of time counts.

Crystal oscillators usually work in the KHz or also in the MHz range. To be based on reasonable readings the digital display 16 will come up the frequency

therefore divided down in a known manner by means of divider stages, not shown. One is conceivable, for example such a division that at a given temperature of 15 degrees Celsius four pulses are counted per day, So that the digital display shows the number "4" after one day at this temperature.

The novel measuring device can also be used as a timepiece using a mechanical watch realize. It is well known that mechanical watches have a restlessness that is practically the one mentioned above Time interval generator 12 replaced.

In Fig. 4, a balance 21 is partially shown in a perspective view. It includes one Swing axis 22, which - as indicated by the rotary arrows A and B indicated - rotates back and forth about its longitudinal axis (this rotational movement becomes the oscillating axis 22 mediated by means of a spiral spring, not shown).

A carrier disk 28, COPY, which has two bimetallic rods at opposite ends, is seated on the oscillating axis 22 24 and 26 wears. Weights 30 and 32 are attached to the outer ends of the bimetal rods 24 and 26.

When the temperature increases, the bimetal rods 24, 26 bend with the result that the distance R between the oscillation axis 22 and the two weights 30 and 32 becomes smaller. This in turn has with the result that the unrest 21 swings faster. By, the use of the bimetal rods 24, 26 is thus the required temperature dependency for the time measurement is achieved.

Both in the first presented embodiment, which works on an electronic basis, as well as in the mechanical solution, the inventive Realized principle of making a temperature-dependent time measurement, so to speak to form the integral of the product of time and temperature. From this integral one can derive ', what amount of heat was measured.

5 and 6, an electronic measuring device 34 is shown with a display 48, wherein the measuring device 34 is carried by a clamp 40. The advantages of this arrangement are above all the compact design and the possibility of subsequently attaching the clamp to a heating pipe 42. The heating pipe 42 leads heated water 44 to a heating body, not shown here. Included the clamp 40 is attached directly to the inlet in the heater body.

In the cross-sectional view according to FIG. 5 it can be seen particularly clearly that the clamp 40 consists of two semicircular parts 36 and 38 which are held together by means of screws or the like are. A seal 46 is provided as a safeguard and control against unintentional removal of the clamp 40, which bridges the two parts 36 and 38 of the clamp 40. COPY

The arrangement of the time interval generator 34 within the clamp 40 is chosen so that a thermally conductive There is contact with the warm water 44 or with the heating pipe 42.

Using FIG. 7, an advantageous possible application of the measuring device is to be explained. Shown is a hot water heating system with a boiler 50 from where hot water is provided via a riser pipe 60 and the heating pipes 4 2 to radiators 52, 54 and 56. Owns in a manner known per se the hot water heater still has an equalizing tank 58 with a vent 62.

At the inlet of each heating element 52, 54 and 56, a clamp 40 is attached to the heating pipes 42, and each clamp 40 carries an electronic measuring device previously described with reference to FIGS. 1-3.

At the beginning of a heating season, at the end of which the heating costs are to be determined, the electronic counter of the measuring devices set to "zero", so that on the respective displays also the "Zero" is displayed. Assuming that all three radiators 52, 54 and 56 have the same amount of heat is consumed in a heating season, the displays of each measuring device will be the same Numerical value shown. For each radiator the same heating costs would be one third accrued.

For example, if the radiator 52 has consumed twice the amount of heat as the radiator 54, is the displayed measured value for the heating element 52 is also twice as large as the measured value for the heating element 54 be.

The above considerations make it clear that the conditions of the measuring device in a simple manner

Amount of heat consumed by each radiator can be determined. The proportional heating costs can be determined from this.

If you take into account that the required building blocks such as crystal oscillator, counter and digital The display can be produced extremely economically and compactly - for example on the digital one Quartz wristwatches referenced - you can see that the entire device including the Clamp can also be built extremely compact and inexpensive. Also makes the use The clamp means that existing heating systems can be retrofitted with the new one at any time Measuring device possible.

In explaining the application of the invention The measuring device based on FIG. 7 was primarily geared towards determining the heating costs as a proportion of the total heating costs. However, the invention is not restricted to this. With the help of a calibration device and appropriate It is also possible to select the divider levels used and the amount of heat consumed on the display • to be displayed directly in kilocalories (kcal). However, it may then still be necessary to use the • To "synchronize" the time interval generator with the controller on the radiators, so that a Time measurement is only carried out when the COPY radiator is in operation.

The energy requirement for the operation of the electronic measuring device is with the technology known today

extremely low. It is completely sufficient at the beginning of a heating season when the consumed Heat quantity is read, insert a new battery.

A thermocouple can advantageously also be used to supply energy to the electronic measuring device use which converts thermal energy into electrical energy.

8 shows a terminal 62 which carries the measuring device with the digital display 16. the Clamp 62 allows the measuring device to be attached to the ribs to attach a radiator in order to measure the amount of heat consumed.

With the previously described fastening of the clamp to a heating pipe, an inaccuracy in the measurement may occur under certain circumstances. If the clamp is arranged in front of the heating valve and when the valve is closed, the hot water accumulates in front of the valve while the radiator cools down. This can lead to certain inaccuracies when measuring the amount of heat consumed. Therefore, there is often a desire to measure the amount of heat on the COPY ribs of the radiator itself. ~ ^ ~ ^

This can be achieved in a simple manner with the clamp 62 which is attached to one or more ribs of the radiator can be clamped. The clamp 62 has two resilient side arms 64 and 66 which are adapted to the shape of the usual ribs of a radiator. Against the resilient force of the two arms 64 and 66, the clamp can thus be clamped onto a heating rib.

The electronic embodiment of the measuring device Incidentally, advantageously allows a connection to a so-called home computer, which today is already being used increasingly in private households. The electrical signals for the digital Display 16 can easily be fed to the home computer, so that the user can save heating costs can calculate yourself.

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Claims (14)

PATENT AGENT- "·" 330931 DIPL.-ING. UWE THÖMEN EUROPEAN PATENT ATTORNEY Lausberg, Klaus-Jürgen Schmitt, Wilhelm 377/1 Weman, Per Olof Claims _t - · - ■ *.
/ 1 .J Measuring device for measuring amounts of heat, especially special for radiators in central heating systems, ae j characterized by a temperature-dependent time in \ interval generator (12) and a counter (14) for ' Counting the number of ■ generated depending on the temperature ten time intervals. : 2. Measuring device according to claim 1, characterized in that the time interval generator (12) is designed as a balance (21) of a clock. 3. Measuring device according to claim 2, characterized in that the balance (21) has an oscillation axis (22) with lateral arms on which weights (30,32) COPY are attached, and that the arms are made of bimetal rods (24,26) exist. 4. Measuring device according to claim 1, characterized in that the time interval generator (12) is formed by an electrical vibration generator, which is followed by an electronic counter (14). 5. Measuring device according to claim 4, characterized in that the vibration generator (12) is formed by a temperature-dependent oscillator / in particular solid-state oscillator. 6. Measuring device according to claim 4 or 5, characterized in that the electronic counter (14) is followed by a digital and / or analog display (16). . characterized by . 7. Measuring device according to claim 6, Vdaß as an energy source for the oscillator (12) the electronic counter (14) and the display (16) a thermocouple is provided is. 8. Measuring device according to one of the preceding claims, characterized in that the counter (14), the time interval generator (12) and the display (16) are attached to a clamp (40) which can be attached to a heating pipe (42). 9. Measuring device according to one of the preceding claims 1 to 7, characterized in that the counter (14), the time interval generator (12) and the display (16) are attached to a clamp (62) which is attached to a rib of a radiator (52 , 54,56) can be attached. ■ 10. Measuring device according to claim 8 or 9, characterized in that the time interval generator (12) is in thermally conductive connection with the heating pipe (42) or the radiator (52,54,56). COPV 11. Measuring device according to claim 8, characterized in that the clamp (40) consists of two semicircular parts (36, 38) secured against removal from the heating pipe (42) by means of a seal (46). 12. Measuring device according to claim 8, characterized in that the time interval generator (12) the counting; Werk (14) the digital display (16) and the clamp (40) are combined into a retrofittable unit. 13. Measuring device according to claim 9, characterized in that the time interval generator (12), the counter (14), the display (16) and the terminal (62) are combined into a retrofittable unit. 14. Measuring device according to one of the preceding claims, characterized in that it is designed as an integral part of a thermostat. COPY ■ J