DE2925119A1 - Heating expenses determination in block of flats - detects temp. difference of each radiator in flat with value multiplied by special factor, and integrated - Google Patents

Abstract

The block of flats, for which the flat-related expenses are to be determined is provided with a central heating plant. The temperature difference of each radiator against a standard value is electronically determined and multiplied by a valuation factor, different for each type, size etc. of each flat. This value is summated for all radiators and integrated over a time period. The proportion of a radiator equal to zero, as long as its temperature is below the standard value. The circuit has temperature sensors, a microprocessor (3) with an oscillator, a multiplexer, an A/D converter, and an electronic counter (4). All temperature sensors of the individual radiators as subsequently interrogated during preset periods. The A/D converter provides from the analog measured value(s) a pulse train with number of pulses proportional to the measure value. From this value a standard value is subtracted by the microprocessor.

Description

Procedure for determining the proportionate heating costs

The invention relates to a method in the preamble of the main claim Art described in more detail.

Heat cost allocators, which are glass tubes, are known and widely used with evaporative fluid. The amount evaporated is used as a relative measure of consumed thermal energy taken. With all the simplicity of this well-known heat cost allocator they have the big disadvantage that every radiator must be provided with it and that all heat cost allocators are read individually and entered on a calculation sheet will.

An electronic heat cost allocator is in DE-OS 27 34 406 described. This is the difference between the radiator temperature and the room temperature detected by appropriately arranged thermocouples, over all to the apartment the associated radiators are summed up and integrated over the period in question. This system requires a because of the temperature measurements using thermocouples relatively large circuit complexity.

The invention is based on the problem of the proportionate heating costs of the individual apartments supplied by a central heating system without much effort to be determined with a central display.

The solution to this problem is carried out by the in the characterizing Features of the main claim listed measures.

The essentials used to carry out the process of the invention Circuit is described in more detail in claim 2.

The big advantage here is through the use of a microprocessor given, which takes over a number of computer and control functions without a larger circuit expenditure would be necessary.

An exemplary embodiment will now be described with reference to the drawing.

The electrical temperature sensors are marked with a1 a2 a3 ... an, which are attached to the individual radiators.

The oscillator 5 controlled by the microprocessor 3 thanks to the left) Multiplexer 1 asks the individual. 3.; - 'temperature sensor with a certain fixed Frequency as well as with predefined query times by the temperature sensor a1. . .an successively connects to A / D converter 2. It is assumed that that the temperature sensors a1 .. .an supply an electrical signal which is transmitted by the Temperature is linearly dependent. This applies e.g. B. for the current to the particular Supply types of NTC resistors. Also with a good approximation for most of them Thermocouples and also for temperature transducers. The latter are so-called ICs and deliver an impressed current which is proportional to the absolute temperature (example type AD 590 from Analog Devices).

It is also assumed here that all copies of a type Temperature sensors agree sufficiently well in terms of thermal and electrical data.

The from the temperature sensors a1 ... an at the output of the multiplexer 1 pending currents or voltages are converted by the analog / digital converter 2 in Impulse follow converted, the frequencies of which are proportional to the heating element temperatures The microprocessor 3 fulfills several functions: a) From the respective The number of pulses corresponding to the temperature value becomes one corresponding to a standard temperature value Number of pulses subtracted.

b) If the radiator temperatures are below the normal value the resulting pulse numbers are suppressed, i.e. not counted.

c) The remaining pulse will be counted during the corresponding Query phase multiplied by a preprogrammed weighting factor, depending on the thermal properties of the radiator in question is specified (e.g. can be taken from tables). These factors are by means of the Programming device 6 adjustable.

d) The microprocessor 3 also includes the function of a frequency divider, whereby it is possible to set the fraction to which the resulting pulse frequency is reduced shall be.

The remaining pulses represent the lowest counting unit of the electronic counter 4 each by one step, so that in this way all 4 impulses arriving at the counter are summed up, d. H. be integrated over time.

Provided that all heat cost allocators in a block of flats have sufficiently good matching display accuracy, can thus be omitted the actual total heating costs incurred, the proportions for the individual Conveniently determine apartment units using the usual, well-known calculation method.

If you want to take into account in practice that one of the supply lines from the radiator sensors a1 .. .an to multiplexer 1 defective, d. H. interrupted is, it must be taken into account that when interrogating the relevant measuring point no Signal, d. H. delivers the primary measured value zero. The microprocessor then inputs Control signal for a signaling system (not shown).

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Claims (3)

Claims Method for determining the proportionate heating costs for the apartments of a block of flats supplied by a central heating system, thereby characterized in that the temperature difference of each radiator compared to an apartment electronically recorded with a standard value, with one of the type, size, etc. dependent, specified weighting factor multiplied and over all radiators are totaled and integrated over time, and that one is the proportion of a radiator is zero in the summation as long as its temperature is below the Normal value lies. 2. Circuit arrangement for performing the method according to claim 1, characterized by the following essential parts: temperature sensor, microprocessor with oscillator, multiplexer, A / D converter and electronic counter, whereby a) means Multiplexer (1) with defined query times the individual temperature sensors (a1 ... an ) the radiators are queried one after the other, b) the A / D converter (2) the resulting converts analog measured value into a pulse train with a pulse number that is proportional the measured value, c) the microprocessor (3) from which the temperature value of each radiator corresponding number of pulses subtracts a number corresponding to the temperature standard value, d) the microprocessor (3) each of these measured value differences with that for the relevant Radiator valid evaluation factor multiplied, e) the microprocessor (3) at the resulting impulse if the radiator temperature is below the normal value numbers suppressed and f) the resulting pulse number by a factor on a practically usable number is reduced by an electronic counter (4) Can be recorded over a certain period of time and the numerical display of the relative heating costs. 3. Circuit arrangement according to claim 2, characterized in that the microprocessor (3) to monitor the lines for defects due to the primary Measured value zero triggers an alarm signal via an electronic control.