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BOILER

BOILERs are subObjects of HEATPLANTs (preceding Section 5.20). BOILERs supply heat, through their associated HEATPLANT, to HW coils and heat exchangers.

Each boiler has a pump. The pump operates whenever the boiler is in use; the pump generates heat in the water, which is added to the boiler's output. The pump heat is independent of load -- the model assumes a bypass valve keeps the water flow constant when the loads are using less than full flow -- except that the heat is assumed never to exceed the load.

boilerName

Name of BOILER object, given immediately after the word BOILER. The name is used to refer to the boiler in heat plant stage commands.

Units Legal Range Default Required Variability
63 characters none Yes constant

blrCap

Type: float

Heat output capacity of this BOILER.

Units Legal Range Default Required Variability
Btuh x \(\gt\) 0 none Yes constant

blrEffR

Type: float

Boiler efficiency at steady-state full load, as a fraction. 1.0 may be specified to model a 100% efficient boiler.

Units Legal Range Default Required Variability
0 \(\lt\) x \(\le\) 1.0 0.8 No constant

blrEirR

Type: float

Boiler Energy Input Ratio: alternate method of specifying efficiency.

Units Legal Range Default Required Variability
x \(\ge\) 1.0 1/blrEffR No constant

blrPyEi=a, b, c, d

Coefficients of cubic polynomial function of part load ratio (load/capacity) to adjust full-load energy input for part load operation. Up to four floats may be given, separated by commas, lowest order (i.e. constant term) coefficient first. If the given coefficients result in a polynomial whose value is not 1.0 when the input variable, part load ratio, is 1.0, a warning message will be printed and the coefficients will be normalized to produce value 1.0 at input 1.0.

Units Legal Range Default Required Variability
.082597, .996764, 0.79361, 0. No constant

blrMtr=name of a METER

Meter to which Boiler's input energy is accumulated; if omitted, input energy is not recorded.

Units Legal Range Default Required Variability
name of a METER none No constant

blrpGpm

Type: float

Boiler pump flow in gallons per minute: amount of water pumped from this boiler through the hot water loop supplying the HEATPLANT's loads (HW coils and heat exchangers) whenever boiler is operating.

Units Legal Range Default Required Variability
gpm x \(\gt\) 0 blrCap/10000 No constant

blrpHdloss

Type: float

Boiler pump head loss (pressure). 0 may be specified to eliminate pump heat and pump energy input.

Units Legal Range Default Required Variability
ft H2O x \(\ge\) 0 114.45* No constant

* may be temporary value for 10-31-92 version; prior value of 35 may be restored.

blrpMotEff

Type: float

Boiler pump motor efficiency.

Units Legal Range Default Required Variability
0 \(\lt\) x \(\le\) 1.0 .88 No constant

blrpHydEff

Type: float

Boiler pump hydraulic efficiency

Units Legal Range Default Required Variability
0 \(\lt\) x \(\le\) 1.0 .70 No constant

blrpMtr=name of a METER

Meter to which pump electrical input energy is accumulated. If omitted, pump input energy use is not recorded.

Units Legal Range Default Required Variability
name of a METER none No constant

The following four members permit specification of auxiliary input power use associated with the boiler under the conditions indicated.

blrAuxOn=float Auxiliary power used when boiler is running, in proportion to its subhour average part load ratio (plr).
blrAuxOff=float Auxiliary power used when boiler is not running, in proportion to 1 - plr.
blrAuxFullOff=float Auxiliary power used only when boiler is off for entire subhour; not used if the boiler is on at all during the subhour.
blrAuxOnAtAll=float Auxiliary power used in full value if boiler is on for any fraction of subhour.
Units Legal Range Default Required Variability
x \(\ge\) 0 0 No hourly

The following four allow specification of meters to record boiler auxiliary energy use through blrAuxOn, blrAuxOff, blrFullOff, and blrAuxOnAtAll, respectively. End use category "Aux" is used.

blrAuxOn

Type: float

Additional input energy used in proportion to part load ratio when coil on, as for induced draft fan, hourly variable for unforeseen applications.

Units Legal Range Default Required Variability
x \(\ge\) 0 0.0 No hourly

blrAuxOnMtr

Type: mtrName

Meter to which to charge auxOn.

Units Legal Range Default Required Variability
name of a METER not recorded No constant

blrAuxOff

Type: float

Additional input energy when off for part or all of subhour.

Units Legal Range Default Required Variability
x \(\ge\) 0 0.0 No hourly

blrAuxOffMtr

Type: mtrName

Meter to which to charge auxOff.

Units Legal Range Default Required Variability
name of a METER not recorded No constant

blrAuxFullOff

Type: float

Additional input energy when off for an entire subhour.

Units Legal Range Default Required Variability
x \(\ge\) 0 0.0 No hourly

blrAuxFullOffMtr

Type: mtrName

Meter to which to charge blrAuxFullOff.

Units Legal Range Default Required Variability
name of a METER not recorded No constant

blrAuxOnAtall

Type: float

Additional input energy used in coil on for any part of subhour, for unforeseen uses.

Units Legal Range Default Required Variability
x \(\ge\) 0 0.0 No hourly

blrAuxOnAtAllMtr

Type: mtrName

MTR for "auxOnAtall"

Units Legal Range Default Required Variability
name of a METER not recorded No constant

endBoiler

Optionally indicates the end of the boiler definition. Alternatively, the end of the definition can be indicated by END or by beginning another object.

Units Legal Range Default Required Variability
none No constant

Related Probes: