Reduce size of nonlinear system of equations

[khinkelman]

The 1GDH (DHC.Examples.FirstGeneration.HeatingSystem) have large systems of nonlinear equations, as shown in statistics below. The variables appearing in the nonlinear system of equations (listed below) should be explored to improve numerical performance.

Iteration variables:
bld1.port_a.h_outflow(start = 2777185.596178013)
bld1.port_a.p(start = 1000000)
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bld8.port_a.h_outflow(start = 2777185.596178013)
bld8.port_a.p(start = 1000000)
conBld3.pip_aDisSup.conPipWal[1].port_a.T(start = 288.15)
conBld3.pip_aDisSup.vol[1].T(start = 453.0356323914667)
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conBld3.pip_aDisSup.vol[9].T(start = 453.0356323914667)
conBld3.pipConSup.conPipWal[1].port_a.T(start = 288.15)
conBld3.pipConSup.vol[1].T(start = 453.0356323914667)
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conBld3.pipConSup.vol[9].T(start = 453.0356323914667)
conBld3.port_bDisSup.h_outflow(start = 2777185.596178013)
conBld4.pip_aDisSup.conPipWal[1].port_a.T(start = 288.15)
conBld4.pip_aDisSup.vol[1].T(start = 453.0356323914667)
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conBld4.pip_aDisSup.vol[9].T(start = 453.0356323914667)
conBld4.pipConSup.conPipWal[1].port_a.T(start = 288.15)
conBld4.pipConSup.vol[1].T(start = 453.0356323914667)
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conBld4.pipConSup.vol[9].T(start = 453.0356323914667)
conBld4.port_bDisSup.h_outflow(start = 2777185.596178013)
conBld7.pip_aDisSup.conPipWal[1].port_a.T(start = 288.15)
conBld7.pip_aDisSup.vol[1].T(start = 453.0356323914667)
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conBld7.pip_aDisSup.vol[9].T(start = 453.0356323914667)
conBld7.pipConSup.conPipWal[1].port_a.T(start = 288.15)
conBld7.pipConSup.vol[1].T(start = 453.0356323914667)	
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conBld7.pipConSup.vol[9].T(start = 453.0356323914667)
conBld7.port_bDisSup.h_outflow(start = 2777185.596178013)
conBld8.pip_aDisSup.conPipWal[1].port_a.T(start = 288.15)
conBld8.pip_aDisSup.vol[1].T(start = 453.0356323914667)
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conBld8.pip_aDisSup.vol[9].T(start = 453.0356323914667)
conBld8.pipConSup.conPipWal[1].port_a.T(start = 288.15)
conBld8.pipConSup.vol[1].T(start = 453.0356323914667)
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conBld8.pipConSup.vol[9].T(start = 453.0356323914667)
conBld8.port_bDisSup.h_outflow(start = 2777185.596178013)
conBld12.pip_aDisSup.conPipWal[1].port_a.T(start = 288.15)
conBld12.pip_aDisSup.port_b.h_outflow(start = 2777185.596178013)
conBld12.pip_aDisSup.vol[1].T(start = 453.0356323914667)
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conBld12.pip_aDisSup.vol[9].T(start = 453.0356323914667)
conBld12.pip_bDisSup.conPipWal[1].port_a.T(start = 288.15)
conBld12.pip_bDisSup.vol[1].T(start = 453.0356323914667)
⋮
conBld12.pip_bDisSup.vol[9].T(start = 453.0356323914667)
conBld12.pipConSup.conPipWal[1].port_a.T(start = 288.15)
conBld12.pipConSup.vol[1].T(start = 453.0356323914667)
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conBld12.pipConSup.vol[9].T(start = 453.0356323914667)
conBld56.pip_aDisSup.conPipWal[1].port_a.T(start = 288.15)
conBld56.pip_aDisSup.port_b.h_outflow(start = 2777185.596178013)
conBld56.pip_aDisSup.vol[1].T(start = 453.0356323914667)
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conBld56.pip_aDisSup.vol[9].T(start = 453.0356323914667)
conBld56.pip_bDisSup.conPipWal[1].port_a.T(start = 288.15)
conBld56.pip_bDisSup.vol[1].T(start = 453.0356323914667)
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conBld56.pip_bDisSup.vol[9].T(start = 453.0356323914667)
conBld56.pipConSup.conPipWal[1].port_a.T(start = 288.15)
conBld56.pipConSup.vol[1].T(start = 453.0356323914667)
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conBld56.pipConSup.vol[9].T(start = 453.0356323914667)
conPla.pip_aDisSup.conPipWal[1].port_a.T(start = 288.15)
conPla.pip_aDisSup.vol[1].T(start = 453.0356323914667)
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conPla.pip_aDisSup.vol[9].T(start = 453.0356323914667)
conPla.port_bDisSup.h_outflow(start = 2777185.596178013)
pla.boi.eva.Ta(start = 453.05999999999995)