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CQM-III-K

CQM-III-K compact heat meter includes LQM-III-K type heat integrator and velocity-type flow meter with pulse out put placed in one case where computer paired temperature sensors of Pt 500 type are connected.
The above version enables the heat meter of compact type to be mounted on supply and return of the heating system. Heat meters of compact type are designed mainly for heat energy to be measured in detached houses and multi strey houses with horizontal central heating installation. In case of additional flow meter and pair of temperature sensors mounted one can measure heat energy consumed in the second heating system. There is possibility to measure tap water consumption after four additional flow meters have been connected. We offer supplementary equipment to heat meters compact type like valves, filters, and connecting accessories.

Technical data

Item
nominal volumetric flow rate	m³/h
nominal diameter	mm
thread length	mm
weight	kg

Item		CQM-III-K (JS 90-NE)*	CQM-III-K (JS 90-NE)*	CQM-III-K (JS 90-NE)*	CQM-III-K (JS 90-NE)*	CQM-III-K (JS 90-NE)*
nominal volumetric flow rate	m³/h	0.6	1	1.5	1.5	2.5
nominal diameter	mm	15	15	15	20	20
thread length	mm	110	110	110	130	130
weight	kg	0.6	0.6	0.8	0.9	0.9

Principle of operation

The measurement of heat energy consumed consists in measure of volume of heating carrier and temperature difference. The volume of heat energy is limited integral of the volumes resulted from the product of heat coefficient and temperature difference.

In order to measure the volume of flowing heat carrier, velocity-type flow meter with pulse output or ultrasonic flow meter with pulse emitter open pipe type are used. Temperature measurement of heat carrier is synchronised with pulses of the flow meter and then heat energy is calculated.

Heat coefficient "k" is depended on t1and t2 and the place of mounting of water meter. It is designated basing on algorithm developed by designers of the meter. Records in registers of RAM is being transferred to EEPROM non-volatile memory every hour in the moment when the function of transmission of data to reader is activated by the consumer. Calculations of heat energy are omitted in case when t1-t2<0, unless it is programmed as cooling meter.

Growth rates of volume taken from the following periods of integration are the sum of volume of the heat carrier and particular growth rates are designated as products of transducer constant and number of pulses calculated during that period.

Making use of Pt 500 type temperature sensors, LQM-III determines temperature values of the heat carrier with accuracy of 0,01°C on supply (t1) and return (t2). Those data are stored in register of RAM memory. The same method is used to determine the temperature difference.
The instantaneous power is determined after the integration period is over when temperature difference is higher than zero and it is calculated as the quotient of the heat energy growth rate and the length of integration period. Integration period is determined by pulses coming from water meter. Pulses are calculated and when they get the value equal to some constant figure division scale then one integration period will be over and another one wiIl start. After one minute passed from the beginning of the integration period and the amount of calculated pulses is smaller than division scale then the first pulse to be appeared will cause that the period of integration will be completed. The value of instantaneous power for the period of one hour is the maximal power.
The instantaneous and maximal flow rates are calculated by the same method like for suitable power.
There is possibility to measure over threshold energy by LQM-III. In such situation the threshold for power or flow rate should be settled over which over-threshold energy has to be calculated. The integrator counts the over threshold energy only from one threshold settled.

Temperature sensors

Compact heaty meter CQM-III-K working with a couple of sensors type Pt 500 (TOPE 42).

Volume parts

JS90-NE

Working temperature: 90 °C Pressure: PN 16 Working position: H/V

JS90-NE

Working temperature: 90 °C
Pressure: PN 16
Working position: H/V

Standard heat meters combinations

Compact heat meter CQM-III-K contains:

calculator with flow meter,
a couple of temperature sensors Pt 500 (TOPE 42),
mounting tee,
set of links for flow meter.

Type of flow meter	DN [mm]	Q_n[m³/h]	T_max_[°C]	Working position
JS90-0,6 NE	15	0,6	90	H, V
JS90-1 NE	15	1	90	H, V
JS90-1,5 NE	15	1,5	90	H, V
JS90-1,5 G1 NE	20	1,5	90	H, V
JS130-2,5 NE	25	2,5	90	H, V