89 lines
1.9 KiB
C++
89 lines
1.9 KiB
C++
// An open Rankine cycle
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#include <string>
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#include <map>
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#include "cantera/PureFluid.h" // defines class Water
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using namespace Cantera;
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std::map<std::string,double> h, s, T, P, x;
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std::vector<std::string> states;
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template<class F>
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void saveState(F& fluid, std::string name)
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{
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h[name] = fluid.enthalpy_mass();
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s[name] = fluid.entropy_mass();
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T[name] = fluid.temperature();
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P[name] = fluid.pressure();
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x[name] = fluid.vaporFraction();
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states.push_back(name);
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}
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void printStates()
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{
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std::string name;
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int n;
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int nStates = states.size();
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for (n = 0; n < nStates; n++) {
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name = states[n];
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printf(" %5s %10.6g %10.6g %12.6g %12.6g %5.2g \n",
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name.c_str(), T[name], P[name], h[name], s[name], x[name]);
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}
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}
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int openRankine(int np, void* p)
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{
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double etap = 0.6; // pump isentropic efficiency
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double etat = 0.8; // turbine isentropic efficiency
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double phigh = 8.0e5; // high pressure
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Water w;
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// begin with water at 300 K, 1 atm
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w.setState_TP(300.0, OneAtm);
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saveState(w,"1");
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// pump water to 0.8 MPa
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w.setState_SP(s["1"], phigh);
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saveState(w,"2s");
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double h2 = (h["2s"] - h["1"])/etap + h["1"];
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w.setState_HP(h2, phigh);
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saveState(w,"2");
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// heat to saturated vapor
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w.setState_Psat(phigh, 1.0);
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saveState(w,"3");
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// expand to 1 atm
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w.setState_SP(s["3"], OneAtm);
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saveState(w,"4s");
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double work_s = h["3"] - h["4s"];
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double work = etat*work_s;
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w.setState_HP(h["3"] - work, OneAtm);
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saveState(w,"4");
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printStates();
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double heat_in = h["3"] - h["2"];
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double efficiency = work/heat_in;
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std::cout << "efficiency = " << efficiency << std::endl;
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return 0;
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}
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#ifndef CXX_DEMO
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int main()
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{
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try {
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return openRankine(0, 0);
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} catch (CanteraError& err) {
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std::cout << err.what() << std::endl;
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return -1;
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}
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}
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#endif
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