Component 74: Block Heating Power Plant (BHPP)

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Component 74: Block Heating Power Plant (BHPP)

Specifications

Line connections
1	Air inlet
2	Flue gas outlet
3	Fuel inlet
4	Power output at generator terminals
5	Regulating information for power output
6	Inlet heat loop 1
7	Outlet heat loop 1
8	Inlet heat loop 2
9	Outlet heat loop 2

General User Input Values Characteristic Lines Physics Used Displays Example

General

Component 74 does not calculate the individual aggregates of the block heating power plant, but instead uses all values from characteristic fields that must be provided by the manufacturer of the machine. In this way, it is assured that the specifications of the manufacturer remain unchanged during the calculation. This allows a good adaptation to the warranty conditions.

The flue gas composition is determined by a combustion calculation under consideration of the air ratios and fuel analysis.

The flue gas temperature is calculated by using the values of the characteristic fields and the energy balance.

As a heat transfer medium for the block-type thermal power station (heating circuit 1 and heating circuit 2), all substances can be used in both heating circuits (see also material value input).

Specification of voltage, frequency and type of current in the component:

There is the option of specifying the voltage (VOLT), frequency (FREQ) and type of current (NPHAS) as the default value in the component.

The flags FVOLT and FFREQ are used to set whether the specification is to be made by the new specification values VOLT and FREQ respectively (0) or externally as a measured values on the electrical line (-1).

User Input Values

FMODE	Flag for calculation mod Like in Parent Profile (Sub Profile option only) Expression =0: GLOBAL =1: local off-design
ALAM	Air ratio (air to air stoichiometric)
DP67N	Pressure loss line 6 to 7 (nominal)
DP89N	Pressure loss line 8 to 9 (nominal)
T7MAX	Maximum of the outlet temperature line 7
T9MAX	Maximum of the outlet temperature line 9
T2MIN	Minimum of the outlet temperature line 2
T2MAX	Maximum of the outlet temperature line 2
FVOLT	Flag for the method for specification of voltage Like in Parent Profile (Sub Profile option only) Expression =0: Defined by specification value VOLT =-1: Voltage given externally on electrical outlet
VOLT	Voltage (on electric lines)
FFREQ	Flag for the method for specification of frequency Like in Parent Profile (Sub Profile option only) Expression =0: Use specification value FREQ =-1: Frequency given externally on electrical outlet
FREQ	Generator frequency
NPHAS	Type of current Like in Parent Profile (Sub Profile option only) Expression =0: Direct current =1: One-phase alternating =3: Three-phase alternating
QN	Nominal power
M6N	Mass flow in the line 6 and 7
M8N	Mass flow in the line 8 and 9
V6N	Specific volume at inlet 6
V8N	Specific volume at inlet 8

The identification values marked in blue are reference quantities for the off-design mode. The actual off-design values refer to these quantities in the equations used.

Generally, all inputs that are visible are required. But, often default values are provided.

For more information on colour of the input fields and their descriptions see Edit Component\Specification values

For more information on design vs. off-design and nominal values see General\Accept Nominal values

Characteristic Lines

Characteristic line 1, CQ3NCV : Demand of fuel heat Q3NCV / Q5 = f(Q5/QN)

     X-axis          1         Q5 / QN                     1^st point
                        2          Q5 / QN                    2^nd point
                        .
                      N         Q5 / QN                    last point

     Y-axis          1          Q3NCV / Q5              1^st point
                        2          Q3NCV / Q5              2^nd point
                        .
                        N         Q3NCV / Q5               last point

Characteristic line 2, CQ67: Heat absorption of cooling 1 Q67 / Q5 = f(Q5/QN)

     X-axis          1         Q5 / QN                       1^st point
                        2          Q5 / QN                      2^nd point
                        .
                      N         Q5 / QN                      last point

     Y-axis        1          Q67 / Q5                    1^st point
                        2          Q67 / Q5                    2^nd point
                        .
                        N         Q67 / Q5                    last point

Characteristic line 3, CQ89: Heat absorption of cooling 2 Q89 / Q5 = f(Q5/QN)

     X-axis          1         Q5 / QN                      1^st point
                        2          Q5 / QN                     2^nd point
                        .
                      N         Q5 / QN                     last point

     Y-axis          1          Q89 / Q5                   1^st point
                        2          Q89 / Q5                   2^nd point
                        .
                        N         Q89 / Q5                    last point

Characteristic line 4, CQLOSS : Heat loss QL / Q5 = f(Q5/QN)

     X-axis          1         Q5 / QN                    1^st point
                        2          Q5 / QN                     2^nd point
                        .
                      N         Q5 / QN                      last point

     Y-axis        1          QL / Q5                     1^st point
                        2          QL / Q5                     2^nd point
                        .
                        N         QL / Q5                      last point

Physics Used

Equations

Design case

(Simulation flag:

GLOBAL = Design case

AND

FMODE = Design case)

The following values are specified by start and boundary values {

- all pressures

- the composition of flow 1, 3

- the composition of flow 2 is calculated from the measurement of the balances of the mass flows 1, 3 }

M3 from characteristic line fuel energy requirement

Q3NCV / Q5 = f(Q5/QN) characteristic line 1

M3 = QN * Q3NCV/Q5 / NCV3

M1 from combustion calculation

M1 = M3 * f(X1i,X3i,ALAM)

M2 from mass balance

M2 = M1 + M3

M6 = M7

M8 = M9

M4 = 1.0

M5 = 1.0

M6R = M6/M6N

F1 = (M6R ** 2) * (V6/V67N)

if GLOBAL = design, then F1= 1.0

DP67 = DP67N* F1

P7 = P6 DP67

M8R = M8/M8N

F2 = (M8R ** 2) * (V8/V89N)

if GLOBAL = design, then F2= 1.0

DP89 = DP89N* F2

P9 = P8 DP89

P4 = 0.01

P5 = 0.01

Remaining heat in the flue gas

Q3D = Q3NCV

Q2 = Q1 + Q3 + Q3D-(Q4 + Q67 + Q89 + QL)

(with Q67, Q89, QL from characteristic lines)

H2 = Q2/M2

M7*H7-M6*H6=Q67

M9*H9-M8*H8=Q89

H4 = H5

Component Displays

Display Option 1

Example

Click here >> Component 74 Demo << to load an example.