DE102006025048A1 - Device for use as rain measuring instrument for measuring quantity of dripping water flow and condensate volume of fire installation, includes conversion of signal to volume or weight measure of condensate water - Google Patents

Abstract

The device includes conversion of a signal to a volume or a weight measure of condensate water effectively gathered by a collecting surface of a measuring sensor. The signal range is extended, so that the entire condensate volume of a year is collected without counter overflow. The signal is delivered to acquire the measurement values over an electronic divisor inserted in an inlet of sensor electronics or an interference in a display unit.

Description

The invention describes further measuring devices for carrying out the condensate measuring method [1], DE 10 2004 058 520 B3 , for determining the exhaust gas loss (net exhaust gas loss) of combustion plants, in which at least in normal operation part of the water produced during combustion condenses out in the furnace (boiler) or in the exhaust system. In particular, the invention relates to the adaptation and optimization of measuring devices that are commercially available for determining the amount of rain, with regard to the measurement of condensate from combustion plants. Furthermore, information on the electronic determination of the amount of gas and on a cost-effective comprehensive data acquisition for heating operation is given.

0. Close relation to DE 10 2004 058 520 B3

• • Stand der Abgas-Messtechnik (Abschnitt 1 von [1]),
• • Aufgabenstellung und Lösungsansatz (Abschnitt 2 von [1])
• • Bestimmung des Nettoabgasverlustes (Abschnitt 3 von [1])

The following remarks build on the theoretical and practical considerations reported in [1], whereby for the understanding and the integration in the context, in particular the knowledge of the following sections from [1] is important:

• • State of the exhaust gas measuring technology (section 1 of [1]),
• • Task and Approach (Section 2 of [1])
• • Determination of net exhaust gas loss (Section 3 of [1])

1. State of the art and approach For improvement

in the Section 4 ("embodiments for measuring the condensate water ") by [1] was an overview of possibilities for measuring "dribbling Water flows "and several measuring arrangements specified. Under the heading "Controlled Emptying a cache "(paragraph [0068] of [1]) also became pointed out that these devices work in principle like rain gauges.

In [1] were, however, no more detailed information on the involvement of rain gauges specified in the determination of condensate flows; the author was namely erroneous the view, such rain gauge (he only in connection with scientific meteorological measuring stations knew) were too expensive. Indeed but are rain gauges including a convenient transmitter in the electronics retailer extraordinarily Great Prices (for example 30 EUR) available [2]. In paragraph [0070] of [1], therefore, the list of some trigger for the Emptying a clogged with the material to be measured buffer to be supplemented by a seesaw ("tilting rocker"), as used very frequently in rain gauges becomes. Then it is advisable, such rain gauge through to modify minor modifications that she too for the measurement of condensate water from combustion plants comfortable can be used. Because of the big price advantage of already introduced marketable Product "rain gauge" is worthwhile in this Trap a subsequent one Adaptation opposite the new development of a specialized, technically optimized and even simpler product.

Starting point: a commercial one electronic rain gauge:

A commercial rain gauge (eg [3]) consists of a sensor unit ( 1 to 3 ) and an evaluation unit 4 (Image 1). Characteristic element of the sensor is usually a "seesaw" 1 , at each of whose two ends a small scoop-shaped container is attached; Due to the rocker position, only a single container is exposed to the inflow of rainwater. When this container is run full, the rocker tilts and the filled container deflates; then the other container is exposed to the inlet of rainwater.

During the tilting process, a counting pulse is triggered, for example, by a magnet connected to the tilting rocker on a magnetically activatable reed relay 2 is passed. Each emptying process is thus connected to an electrical signal whose information on the sensor electronics 3 to the evaluation unit 4 is transmitted.

The evaluation electronics are already very comfortable today even with very inexpensive devices. The data transmission between sensor unit ( 1 to 3 ) and evaluation unit 4 Frequently via radio (eg 433 MHz); a distance of up to 100 m is permitted. The total rainfall since the start time as well as the individual rainfall of the last days can be displayed. Furthermore, the evaluation unit contains 4 often a clock and one or two additional temperature sensors for measuring the ambient or the medium temperature. As an example, reference is made to a device from Oregon Scientific [3], which is in the sales program of a major German electronics mail-order company.

• 1. Die Anzahl der vom Relais 2 an die Sensorelektronik 3 übermittelten Zählimpulse kann elektronisch verändert werden.
• 2. Die Auswerteeinheit 4 kann eine auf die neue Messaufgabe angepasste Bewertung und Filterung der Eingangssignale hard- oder softwaremäßig vornehmen.
• 3. Der auf die Wippe 1 auftreffende Wasserstrom kann in wohldefinierter Weise verändert werden.
• 4. Die aus Wippe 1 und magnetisch angekoppeltem Reed Relais 2 bestehende Messwertaufnahme kann durch einen externen Zähl-Signalgeber 20 ersetzt werden.

For adaptation of such a rain gauge ( 1 to 4 ) for use as measuring devices for carrying out the condensate measuring method [1], there are several starting points which can also be combined with one another:

• 1. The number of the relay 2 to the sensor electronics 3 transmitted counts can be changed electronically.
• 2. The evaluation unit 4 can perform a hardware or software evaluation and filtering of the input signals adapted to the new measurement task.
• 3. The on the seesaw 1 impinging water flow can be changed in a well-defined way.
• 4. The off seesaw 1 and magnetically coupled reed relay 2 existing measured value recording can be done by an external counting signal generator 20 be replaced.

2. Adjustment and optimization for measuring condensate water

With a rain gauge you can measure not only the amount of rainwater, but in general the amount of a small "trickling" water flow and therefore also the amount of condensate water in a firing system, which is also due to the fact that rainwater has a considerable acidity ("acid rain"). can, and therefore the seesaw 1 and the other water-carrying parts are constructed of plastic. This also meets the requirements for the acid condensate of a firing system.

Other However, characteristics of a rain gauge should be based on the new task as condensate meter adapted and optimized for a firing plant:

2.1 Calibration

The calibration of the rain gauge is usually indicated in millimeters of water. Here, the circular collecting surface of the collecting funnel, which beispielswei se has a diameter d = 100 mm, set in relation to a reference surface of 1 m ² . In the case of H [mm] water column, the circular collecting surface of diameter d is acted upon by the water volume V: V = H · π / 4 · d 2 / 10 6 , (1) where H and d are given in [mm] and wg. of the factor 10 ⁶ the volume V results in [liter].

Conversely, when V [liter] of water is applied to the collecting surface of the rain sensor, an indication of the rain height H of H = V × 4 / π × 10 6 / d 2 (2)

In the chosen one Example with the collecting surface of d = 100 [mm] results for H = 1 [mm] according to equation (1) the value V = 0.00785 [liter]. An ad of 1 mm water column corresponds to an amount of water of 7.85 [ml]. Conversely, then 1 [liter] condensate water according to equation (2) through the display H = 127.3 mm.

To conveniently use the rain gauge as a condensate water indicator, the gauge should be shown directly in liters. This can be easily achieved by the fact that in the input circuit of the pulse counter, which counts the tilting operations of the rain sensor, a suitable electronic divider 30 is inserted. In the above example (with d = 100 [mm]), the previous display "1 [mm]" can be given the meaning of 1 liter, if this input divider by a factor of 127.3 or - rounded up a little - 128, ie Here, one commits only a very small error, which corresponds to the factor 128 / 127.3 After 128 tilting operations, in which a total of V = 128 x 7.85 [ml] = 1.005 liters

Water was dumped, so then switches the divider 30 through and the result can be counted as "1 liter".

Is the input divider by a small switch 31 bridged, so the device can optionally also as a rain gauge or as a condensate meter with large (but noisy) resolution of 7.85 [ml] are used. Of course, depending on the diameter d of the collecting funnel and the desired resolution other disc ratios can be used.

In a test setup (Figure 2) was used as an electronic divider 30 CMOS device 4520 directly in series with the magnetic reed relay 2 the rain sensor switched. The output 2Q ₃ receives an output signal through the IC after 128 (7 bit) input signals, which are then used as a new input signal to the electronics 3 of the rain sensor is fed. The output pulse 2Q ₃ is at the same time to reset the counter 30 used (not shown in the picture). Before a start, the reset pulse can also be triggered by a key.

This procedure is the easiest for a subsequent retrofitting, as they no deeper knowledge of the circuit of the rain sensor electronics 3 or the evaluation device 4 requirement. By flipping the bypass switch 31 In addition, the original display for the rain gauge can be switched on again.

In the existing rain gauges can at the evaluation 4 usually the display is switched between millimeters and inches, whereby the display in "inch", for example, is provided with 2 decimal places, which is an indication that the conversion of the signal frequency into the display on the side of the evaluation unit 4 can be adjusted with a factor. When converting from "mm" to "inch" this factor is 25.4 / 100. If d = 100 [mm], the factor would be 1/128 for the display in liters (without decimal place), and a factor of 10/128 for decimal places in liters with one decimal place. Maybe that will be in the area of the evaluation unit 4 for the conversion of the display to the volume of water actually recorded by the sensor water even easier options that are easily recognizable to any person skilled in the electronics and programming of the special display device expert. Since the display "inch" is superfluous in the German and Central European linguistic area, this could be replaced by a display "liter". This would be very convenient, because then you could switch between the calibration as a rain gauge in "mm" and a volume meter in "liter" without a new control switch.

Of the completeness It is also noted that you in front of the rain sensor too could turn on a water divider, whose job is would, from an incoming water flow a certain percentage to gauge forward and cut off the rest directly. Of course, this divider would have to be set to some accuracy. The advantage of this idiot-proof Procedure would exist only in that one does not make any intervention in the original rain gauge needed.

The above shown electronic division or u.U. also the above mentioned change However, the display in the evaluation unit are because of their great simplicity and cheapness preferable.

2.2 Ad Scope

In a well-functioning condensing boiler must be expected with a seasonal condensate of several cubic meters of water. The normal display range of a rain gauge with the above dimension is usually not sufficient. For example, in a commercially available measuring device [3], the global display range is 0-25400 mm at a resolution of 1 mm. With a diameter of the collecting surface of d = 100 mm corresponding to the above example, this corresponds to a swallowed amount of water of 0.2 m ³ , since: V = 25400 · 0.00785 [liter] = 199.4 [liter] = approx. 0.2 m 3 ,

This is for the condensate measurement over a heating season or year is not enough.

For the short-term Display in the daily area is a water quantity of 0-2540 mm, corresponding to 20 l water indicated. Again, this is for the purpose of daily condensate measurement too little: for However, a short-term measurement by service personnel can accept this become.

To remedy this bottleneck, the considerations in section 2.1 on calibration in liters can be used. With a divider of 1: 128 results in d = 100 mm a display size of 22.5 m ³ for the global measurement, which is sufficient even for medium-sized systems in the residential area.

When used as a meter for the heating service can be controlled by an adjustable divider (including bypass switch 31 ) the entire spectrum of the necessary measuring ranges are covered.

2.3 Comfortable time reference

• 1 globale Kondensatmessung seit Beginn der Heizsaison
• (2) Aufrufen von Tagen (1-n) vor heute
• (3) Aufruf von Zeitbereichen, die mit Start- und Stoppzeit oder über Rechner einzugeben sind
• (4) Zeitbereiche mit besonderen Randbedingungen (beispielsweise Zeitabschnitte mit Bereitung des Brauchwassers, Zeitabschnitte mit Unter- oder Überschreitung von Temperaturschwellen).

For the purposes of condensate measurement, other time reference planes would be desirable in addition to the already existing time references of a rain gauge. Overall, the following time reference levels would make a technical sense:

• 1 global condensate measurement since the beginning of the heating season
• (2) Call days (1-n) before today
• (3) Calling of time ranges to be entered with start and stop time or via computer
• (4) Time periods with special boundary conditions (for example, periods of time when the service water is being prepared, periods when the temperature has fallen below or exceeded temperature thresholds).

2.4 Storage on data medium

For an in-depth diagnostics of a firing system, storage on data carriers would also make sense. For example, the data could be in the format:
"Date, time, amount of condensate since start" can be stored on an electronic data carrier (eg memo stick or SD card as with an electronic camera) A detailed evaluation of the burner behavior can then be performed after transfer to a computer with the help of, for example, a calculation program (Excel) These options are particularly interesting for knowledgeable operators of heating systems, energy consultants and maintenance personnel.

modern transmit electronic rain gauges the data between sensor and evaluation unit via radio. Now you can well imagine that this convenience also in the case of a condensation meter used with. The transmitter at the burner could therefore be his signal to the evaluation device in the living space, for example at the computer. Then you could Also remember a direct connection between meter and PC to set up.

As well But some users may also decide to do so fault-prone radio connection to replace a fixed line.

2.5 Central measuring unit

• – Temperatur des Heizmediums im Vorlauf und Rücklauf des Kessels
• – Vorlauf-, Rücklauf- und Speichertemperatur des Brauchwasserspeichers
• – Außentemperatur, Innentemperatur im Wohnbereich und Kellertemperatur
• – Stand des Betriebsstundenzählers
• – Stand der Gasuhr (bzw. des Gasverbrauchs seit einem Startzeitpunkt)
• – Abgastemperatur am Kesselausgang und am Kaminausgang;
• – Zulufttemperatur am Kesseleingang
• – und natürlich die Kondensatmenge.

Many rain gauges and low-cost "weather stations" are equipped with a clock and temperature sensors as standard.If we assume that the data acquisition can be extended a bit further, it is obvious, a "wish list" of important signals for the comprehensive assessment of the Operation of a firing system and the entire heating system together. This important information includes the following metrics:

• - Temperature of the heating medium in the flow and return of the boiler
• - Supply, return and storage tank temperature of the dhw storage tank
• - Outside temperature, indoor temperature in the living area and basement temperature
• - Status of the operating hours counter
• - Status of the gas meter (or gas consumption since a start time)
• - exhaust gas temperature at the boiler outlet and at the chimney outlet;
• - Supply air temperature at the boiler inlet
• - and of course the amount of condensate.

These Measured variables could be a central evaluation unit that makes sense with a PC directly or via disk connected being transferred become.

on the other hand there is also the possibility the central evaluation unit for to integrate the heating system into the electronic display of the boiler.

3. External water quantity sensors as a signal generator

The rain gauge sensor consists of the rocker 1 and with this magnetically coupled reed relay 2 , The filling of a small buffer with a well-defined volume at the end of the rocker thus triggers over the relay 2 an electrical impulse. Of course, for the entire downstream electronics and evaluation, it does not matter where the count pulse comes from at its input. In the section "4 exemplary embodiments for the measurement of the condensate waste water and here in particular in the subsection" 4.1 type controlled draining "of [1] several water quantity sensors were indicated, whose output signal is generated by closing the contact of a float switch (indicated by the reference numeral 8 in [1]). The triggering of the float switch indicates the emptying of the respective buffer. Now you just have to choose the volume of the buffer in a suitable manner, for example, exactly 1 liter, to assign the counting pulses the desired unit of measure and thus give the display the desired calibration. The commercial rain gauge then fulfills the function of the counter marked 10 in FIG. 1 in perfect and comfortable form even without any intrusion into the electronics.

The intervention in the existing rain gauge consists only in the exposed and therefore easily accessible relay 2 at the electrical input of the rain sensor 3 to be replaced by the floating switch marked with the reference number 8 in Figure 1 (Figure 3) or to be bridged. For example, you can click on the relay 2 and removes its remaining leads as contact poles for connection to the float switch marked with the reference numeral 8 in [1]; you can even use the relay 2 leave in its place and the supply lines to the float switch parallel to the relay 2 solder or clamp.

4. Provision of gas consumption measurements

• • über eine extern vorgeschaltete Elektronik oder
• • über einen in den Eingang der Sensorelektronik 3 eingefügten elektronischen Teiler 30
• • oder durch einen Eingriff in der Anzeigeeinheit 4 erfolgen (Bild 4).

Gas consumption is measured by the official and calibrated gas meter. This measurement is the basis of billing. In not too old gas meters can usually retrofit a Aufsteckzähler that provides an electrical meter signal. This counter signal can - in the same manner as shown above for the case of a measured value recording for the condensate water - by the electronics of a "rain gauge" (or other based on the counting of pulses electronic evaluation device) recorded, adapted and evaluated Matching the pulse frequency to the display unit

• • via an external upstream electronics or
• • via one into the input of the sensor electronics 3 inserted electronic divider 30
• • or by an intervention in the display unit 4 take place (Figure 4).

at the direct measurement of the condensate as a measure of the exhaust gas loss can Requirement for the accuracy of the gas meter be reduced. Therefore You can think of it, an extra, non-official and optionally un-calibrated gas quantity pulse generator in the gas line in front of the burner. For this purpose, in principle also small "wind" or "air movement" measuring devices are suitable in a short piece of pipe be fitted. Also the meter pulses of such a gas velocity meter, as set forth above in be connected to the electronic input of a rain gauge.

Lots Burners set a largely optimal gas-air mixture. For this need they are setting signals for the gas supply or for the air supply. These signals are in principle proportional to the gas flow. Therefore can They also serve as a substitute for the gas flow rate be measured or transmitted to the evaluation.

Out the indicated possibilities let yourself foresee that even a low-priced electronic gas meter produced or made of components originally intended for other purposes can be put together.

4. Direct display of the efficiency a furnace

aus dem Verhältnis w des tatsächlich auskondensierten Wassers W zu dem theoretisch maximal auskondensierbaren Wasser WD₀, also aus (vgl. Gl.(11) aus [1]) w = W/WD0 (4)bestimmen. Hierbei gilt nach Gl.(11b) aus [1] WD0 = xV0·VG mit ungefähr xV0 = 1,6 [Liter H2O/mn 3] bei Erdgas, (5)wobei V_G den zeitgleichen Gasverbrauch (in m_n ³) bezeichnet.The exhaust gas loss q _Abg (in percent) of a combustion plant operated with natural gas, in which at least in normal operation partial condensation of the water formed during combustion occurs in the boiler or in the exhaust system can be determined according to Eqs. (43) of [1] in astonishingly good approximation by the rule of thumb

from the ratio w of the actually condensed water W to the theoretically maximum condensable water WD ₀ , ie from (see equation (11) from [1]) w = W / WD 0 (4) determine. In this case, according to Eq. (11b), [1] WD 0 = x V0 · V G with about x V0 = 1.6 [liters H2O / m n 3 ] for natural gas, (5) where V _G denotes the simultaneous gas consumption (in m _n ³ ).

und damit durch wenige Rechenoperationen aus den elektronisch verfügbaren Zählerständen des Gas- und des Kondensatwasser-Zählers elektronisch bestimmen.The exhaust gas loss q _Abg can then be rewritten from (3), (4) and (5) to:

and thus electronically determine by a few arithmetic operations from the electronically available counter readings of the gas and condensate water meter.

literature

• [1] G. Luther: DE 10 2004 058 520 B3 2006.04.13 "Measurement method for determining the exhaust gas loss of condensing boilers", granted on 13.4.2006
• [2] The author thanks Mr. Jürgen Hoppe, Saarbrücken, for the Note that rain gauge with feeler and more convenient electronics are commercially available by mail order.
• [3] Company Oregon Scientific: Instruction manual for rain gauge RGR122 - (Remote Rain Gauge): http://www2.oregonscientific.com/assets/manuals/rgr122.pdf

List of reference numerals and terms

1

seesaw

2

(Reed) relay

3

(Rain) sensor electronics

4

evaluation

20

(External) signaler

30

(E) divider

31

bypass switch

1 and 2

Data logging

1 to 3

sensor unit

1 to 4

rain gauge

Captions and pictures

Figure 1: Block diagram of a commercial rain gauge (prior art):
A standing rocker in the rain 1 generated via a magnetically coupled relay 2 Voltage pulses from the built-in in the rain sensor unit sensor electronics 3 is processed and as information by radio to an evaluation 4 is sent.

Figure 2: Subsequent adaptation of a rain gauge to display the collected amount of condensed water: A divider 30 (here the CMOS module 4520) reduces the voltage from the relay 2 outgoing voltage pulses and thereby changes the calibration of the evaluation unit 4 , The pulses of the relay 2 are caused by the tilting of the rocker 1 triggered. Through the bypass switch 31 the original "rainwater" calibration can be switched on again.

Fig. 3: On to the given evaluation of the input signals by the evaluation unit 4 the rain gauge adapted signal generator 20 replaces the relay 2 of the original rain gauge. As a signal generator 20 For example, suitable devices for registering the controlled emptying of a buffer (according to Section 4 of [1]) or else already suitably prepared signals of any sensors may be used.

Fig. 4: Using the electronics of a rain gauge to display the gas consumption with subsequent adaptation of the input stage of the sensor electronics 3 : A divider 30 (eg based on the CMOS 4520) fits the signal generator 20 a gas meter issued counts to the display of the evaluation 4 of the rain gauge. - Also signals from any other count signalers 20 can be processed in this way

Claims (8)

Device which measures the amount of small "trickling" water streams as a rain gauge, characterized in that it is used to measure the amount of condensate of a combustion plant, which comes in the boiler or in the exhaust system, at least during normal operation for partial condensation of the water formed during combustion , and the derived therefrom determination of the exhaust gas losses of the furnace according to one of the in DE 10 2004 058 520 B3 specified method. Apparatus according to claim 1, characterized in that the commercial rain gauge is optimized to the particular requirements for measuring the amount of condensate of a furnace through one or more of the following measures: • conversion of the display to a volume or weight measure (in particular to "liter" or " kg ") of the condensate water actually absorbed by the collecting area of the measuring sensor, • Extension of the display area so that the entire condensate quantity of a year can be recorded without counter overflow, and that the 1 and 2 ) • via one in the input of the sensor electronics 3 inserted electronic divider 30 • or by an intervention in the display unit 4 is processed accordingly. Device which is designed as intended as a "rain gauge", characterized in that as an electronic input of the sensor electronics 3 via a supply line of the float switches (reference numeral 8 in FIG DE 10 2004 058 520 B3 ) in claim 4 of DE 10 2004 058 520 B3 specified external sensors for the registration of condensate water quantities is turned on. Device which is designed as intended as a "rain gauge", characterized in that as an electronic input of the sensor electronics 3 the counter output of a gas meter is switched on. Device according to one of claims 3 to 4, characterized in that the counter signals from the external sensors • via an externally upstream electronics • or via a in the input of the sensor electronics 3 inserted electronic divider 30 • or by an intervention in the display unit 4 be processed so that the electronic processing of these signals lead to a suitable for measuring the condensate water quantity or gas consumption measuring range and a display suitable for this purpose. Device, the commercial "climatic station" next to a rain gauge yet another or several temperature sensors comprises, characterized in that this device on the special requirements for measuring the amount of condensate and others Operating parameters of a heating system through one or more the following measures is optimized: • Optimization The condensate measurement according to claim 2 or 3 or the gas measurement according to claim 4 and 5 • Commitment the temperature sensor for measuring the exhaust gas and supply air temperature of the combustion plant, the flow and return temperature the heating system and the supply, return and storage temperature the water heating Device according to one or more of claims 2 to 6 characterized in that the time ranges of the display quantity determination, one or more of the following options include: • Time range with freely selectable Start and stop time • Not necessarily more coherent Time range, which by the presence of certain conditions such as Under- or crossing of temperature thresholds, heating times, fixed time periods, charging time the hot water tank is marked. Device according to one of claims 2 to 7, characterized in that the measurement data including the measurement time on data carriers, for example, a standard in digital cameras SD card, are stored or directly via an electronic interface to an external storage medium, such as a PC, can be transmitted.