4.49 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=float
Heat output capacity of this BOILER.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| Btuh | x \(\gt\) 0 | none | Yes | constant |
blrEffR=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=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=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=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=float
Boiler pump motor efficiency.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| 0 \(\lt\) x \(\le\) 1.0 | .88 | No | constant |
blrpHydEff=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=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=mtrName
Meter to which to charge auxOn.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| name of a METER | not recorded | No | constant |
blrAuxOff=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=mtrName
Meter to which to charge auxOff.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| name of a METER | not recorded | No | constant |
blrAuxFullOff=float
Additional input energy when off for an entire subhour.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| x \(\ge\) 0 | 0.0 | No | hourly |
blrAuxFullOffMtr=mtrName
Meter to which to charge blrAuxFullOff.
| Units | Legal Range | Default | Required | Variability |
|---|---|---|---|---|
| name of a METER | not recorded | No | constant |
blrAuxOnAtall=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=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: