DME analysis of POWER-SYSTEM-EIGHT-ONE

Given the CML model of this power cycle, POWER-SYSTEM-EIGHT-ONE, DME formulates the behavior model of the system, and performs simulation. In this case, since the system is in steady state, simulation is terminated after one state.

In the current implementation, DME applies all the model fragments applicable to the given situation, and generates all the equations. It, then, solves the equations for as many variables as possible, regardless of whether it is relevant to the particular analysis objectives. This is partly the reason for the large number of equations and variables. Since the problem statement only gives initial values for a small number of variables (only those that are necessary for computing the variables in the analysis objectives), DME computes only a subset of all the variables in the set of equations generated. However, the subset includes all the variables mentioned in the analysis objectives if there is sufficient knowledge in the model fragment library to solve the problem.

There are 80 model fragment instances activated in this example. Here are some of them:

...
INTERNALLY-REVERSIBLE-ADIABATIC-PROCESS-1
STEADY-FLOW-ADIABATIC-COMPRESSION-1
NON-SATURATED-WATER-STREAM-ENTHALPY-1
SATURATED-WATER-STREAM-ENTHALPY-2
SATURATED-WATER-STREAM-ENTROPY-2
SATURATED-WATER-STREAM-SPECIFIC-VOLUME-2
...

DME generates 193 equations from these model fragments. Here are some of them:

Extracting a consequence of INTERNALLY-REVERSIBLE-ADIABATIC-PROCESS-1 resulted in the equation:

(= (COMPRESSION-ISENTROPIC-EFFICIENCY STEADY-FLOW-ADIABATIC-COMPRESSION-1) 
   (/ (- (IDEAL-ISENTROPIC-ENTHALPY STEADY-FLOW-ADIABATIC-COMPRESSION-1)
         (SPECIFIC-ENTHALPY 2D-STREAM-9)) 
      (- (SPECIFIC-ENTHALPY 2D-STREAM-10) 
         (SPECIFIC-ENTHALPY 2D-STREAM-9))))

Extracting a consequence of INTERNALLY-REVERSIBLE-ADIABATIC-PROCESS-1 resulted in the equation:

(= (ISENTROPIC-EFFICIENCY STEADY-FLOW-ADIABATIC-COMPRESSION-1) 
   (/ (- (SPECIFIC-ENTHALPY 2D-STREAM-10) 
         (SPECIFIC-ENTHALPY 2D-STREAM-9)) 
      (- (IDEAL-ISENTROPIC-ENTHALPY STEADY-FLOW-ADIABATIC-COMPRESSION-1) 
         (SPECIFIC-ENTHALPY 2D-STREAM-9))))

Extracting a consequence of INTERNALLY-REVERSIBLE-ADIABATIC-PROCESS-1 resulted in the equation:
```
(= (SPECIFIC-ENTROPY 2D-STREAM-4) (SPECIFIC-ENTROPY 2D-STREAM-3))
```

DME utilizes the service of MathServ for solving these equations. Here is part of the trace of the communication between DME and MathServ:

Solving for one equation

(KIF:= DME-USER::|w'in{PMP-PRCS[pmp-sys]}| 
       (KIF:* 0.0010084 (KIF:/ (KIF:- 8000000 8000) 1000)))

Sending to MathServ

(EVALUATE :SENDER dme-agent 
	  :RECEIVER mathserv 
	  :CONTENT (SOLVE (LISTOF (== w'in{PMP-PRCS[pmp-sys]} 
                                  (* 0.0010084 (/ (- 8000000 8000) 1000)))) 
			  (LISTOF w'in{PMP-PRCS[pmp-sys]})))

Reply from MathServ

(REPLY :SENDER mathserv
       :RECEIVER dme-agent
       :CONTENT (LISTOF (LISTOF (== w'in{PMP-PRCS[pmp-sys]} 8.0591328))))

Solving for one equation

(KIF:= 8.0591328 (KIF:- DME-USER::|h{OUT[PMP-CV[pmp-sys]]}| 173.88))

Sending to MathServ

(EVALUATE :SENDER dme-agent
	  :RECEIVER mathserv
	  :CONTENT (SOLVE (LISTOF (== 8.0591328 (- h{OUT[PMP-CV[pmp-sys]]}
                                                   173.88)))
                          (LISTOF h{OUT[PMP-CV[pmp-sys]]})))

Reply from MathServ

(REPLY :SENDER mathserv
       :RECEIVER dme-agent
       :CONTENT (LISTOF (LISTOF (== h{OUT[PMP-CV[pmp-sys]]} A))))

Finally, the values of 121 variables were computed out of the total of 217 variables. Here are some of the variable values computed:

(=  (SPECIFIC-ENTHALPY 2D-STREAM-9)   173.88 )

(=  (SPECIFIC-ENTROPY 2D-STREAM-4)   5.7432 )

(=  (THERMAL-EFFICIENCY POWER-SYSTEM-EIGHT-ONE-1)   0.37077558 )