Configuration 10 Heat meter for open system of heat supply without cold water pipeline and with water take-off to hot water supply system

Configuration 11 Heat meter for open system of heat supply with cold water pipeline and with water take-off to hot water supply system

Configuration 11/1 Heat meter for open system of heat supply with cold water pipeline and with water take-off to hot water supply system without measurement of hot water temperature

Configuration 12 Heat meter for open system of heat supply without cold water pipeline and with water take-off to hot water supply system without measurement of hot water temperature

The calculation of heat energy in configurations 10 ... 12 is carried out as follows:

Total heat consumption is calculated as follows:

heat consumption by hot water supply system is calculated as follows:

In the expressions stated above Qm is taken with a sign of the flow. Thus signs of the flow are accepted as follows:

•  symbol «+» for the flow, which runs into object of heat supply
•  symbol «–» for the flow, which runs out of heat supply object.

Variants 10, 11, 11/1 and 12 have some operating modes: one winter mode and three summer modes (depending on a mode of heat supply). The total consumed heat energy in all modes is determined as a difference of submitted and removed thermal energy and does not depend on an operating mode (distinction in the formulas resulted below can be explained by simplification of expressions after taking in account a sign of the stream). The winter mode differs from summer modes in follows:components of thermal energy of hot water supply system WHWS and thermal energy of heating Wh are picked out  from a total sum of consumed heat Ws . In summer modes there is no heating and thermal energy of heating Wh is equal to zero.

Operating mode «Winter» - the heat is delivered by supply pipeline, the rest is removed by return pipeline.

Operating mode «Summer 1» - the heat is delivered by supply pipeline, the return pipeline is out of service (the flow rate in the return pipeline is equal to zero or there is no water in it).

Operating mode «Summer 2» - the heat is delivered by return pipeline, the supply pipeline is  out of service (the flow rate in the supply pipeline is equal to zero or there is no water in it).

Operating mode «Summer 3» - тепло подается по подающему и по обратному трубопроводам.

For configurations 10 and 11 the temperature  measurements is carried out in hot water supply system, for configuration 12  the temperature in hot water supply system isn't measured but determined as follows:

The mode	tHWS	The note
Winter,Summer1	=tS
Summer 2	=tR
Summer 3	(M1*tS+M2*tR)/(M1+M2)	Feeding of hot water supply system is delivered simultaneously from two pipelines

Heat calculation formulas for various operating modes for variants  10 ... 12 are listed below.

The mode	Ws	WHWS
Winter	Ws=M1*(hS-hcold)-M2*(hR-hcold)	WHWS=(M1+M2)*(hHWS-hcold)
Summer 1	Ws=M1*(hS-hcold)	WHWS=Ws
Summer 2	Ws=M2*(hR-hcold)	WHWS=Ws
Summer 3	Ws=M1*(hS-hcold)+M2*(hR-hcold)	WHWS=Ws

where Ws is total heat energy,
WHWS is heat energy of hot water supply system,
hS, hR and hHWS are specific water enthalpies for supply, return  pipelines and hot water supply system correspondingly.
hcold – cold water enthalpy. The temperature of cold water for configuration 10 is set in the software by user, cold water temperature for configuration 11 is measured by TS3.
M1 and M2 are water masses in supply and return pipelines correspondingly. The value of mass in all expressions are substituted with a sign '+' or '-'.
Heat energy in winter mode is calculated as Wrem = Ws - WHWS . For all summer modes Wrem=0.

Operating modes are set by user or switched automatically. Criteria of automatic mode switching are following:

The mode	Supply stream	Return stream
Winter	«+»	«-»
Summer 1	«+»	0 or no water
Summer 2	0 or no water	«+»
Summer 3	«+»	«+»

where '+' means that water flows in the object of heat supply,
'-' means that water flows out of the object of heat supply.

At an automatic selection modes are switched within one minute after change of  heat supply mode with fixing date and time of switching in mode log. Last events of mode log are printed out in daily sheets.

Current date is also considered in automatic mode switching. The user sets two dates (date and month) - date of transition to a winter mode and date of transition to a summer mode. Automatic transition to a winter mode occurs only after the set date for a winter mode and fulfillment of transition conditions (signs on streams). Transition to a summer mode - only after date of a summer mode. Transition between various summer modes is possible also only after date of transition to a summer mode. The mode of restriction on dates can be switched-off having set identical date for winter and summer modes.

Alarm conditions:

The mode	Condition	Heat calculation
Winter	Supply direction – «+», Return direction – «+»	Ws=WHWS=M1*(h1-hcold)+M2*(h2-hcold) Wrem=0
Summer 1, 2, 3	Supply direction – « - », Return direction – «+»

Displaying archive data on the indicator and in printouts all current values of flow rates (volume, mass) and integrated values of volume and mass are specified in view of a sign. The positive sign means that a stream flows into object, negative means that a stream flows out. For example, in a Winter mode 'supply'  will be with a sign '+', and 'return' - with a sign '-' (integrated value of volume and mass in return pipeline also will be with a sign '-'. Further at transition to a mode Summer 2 'supply' will be equal to zero (no accumulation of integrated volume and mass in supply pipeline), and 'return' will be with a sign '+'.

All supply variants (configurations)>>