Liquid receiver

[mcgru-]

Dear moderator, i'm sorry for this big message. If it will not fit in forum rules, i'll (or you, please) delete it... Thank you for your patience.

I would be interested to discuss some of the simulations you did for the:

some code from compressor simulating program:

# ---------------------------------------------------------------------------
#
# START OF ROTATION
#
  for ($a=0; $a<=360; $a+=$anglestep) {
		$curr{a} = $a;

%prev = %curr;

# Heat transfer to wall
	$curr{S} = $curr{pos} * 2*3.14159*$Radius +  2*$Scyl;

   %curr = HeatTransfer(\%curr,$Twalls,$tau);

# Leakage between piston and cylinder wall

	if (($curr{P}>$Pin) and (not $discharge)) {
		$wleak = sqrt(2.0*($curr{P}-$Pin)*101300/$curr{D});
		$wleak=180 if ($wleak>180);
		$dMsuction = $wleak * $Sleak * $curr{D} * $tau;
	}else{
		$dMsuction = 0;
	}
	$curr{m} -= $dMsuction;
	$curr{P}*= $curr{m}/$curr{V}/$curr{D};
	$curr{D} = $curr{m}/$curr{V};
	$Mleak+=$dMsuction;

#print "dMsuction:$dMsuction\n";
#PrintPoint("      leakage:");


# Expansion

		%next = %curr;

	$next{a} =  $curr{a} + $anglestep;
	$next{pos} = ($Stroke / 2.0) * (1-cos($next{a}*3.14159/180));
	$dpos = $next{pos}-$curr{pos};
	$dVprev = $dV;
	$dV = $dpos * $Scyl;
		if (($dVprev/$dV)<0) {
			$suction 		= undef;
			$discharge	= undef;
		}
	$next{V} = $curr{V} + $dV;
	$dVv = $dV/$tau;
	$next{D} = $next{m} / $next{V};

	$gamma = getG($curr{P},$curr{T});
	$Pshouldbe = $curr{P} * ($curr{V}/$next{V})**$gamma;
	if ((not $suction) and (not $discharge)) {
		$next{P} = $Pshouldbe;
		$next{T} = getTbyS($next{P},$next{enthr});
		$next{H} = getH($next{P},$next{T});
	}



	%curr = %next;

#PrintPoint("    expansion:");

# Suction and discharge


	if ($curr{P}<=$Pin) {
		$w = $dVv / $Ssuc;  ## here the crsection of input equalized to Scyl/2
#		$w = $dVv / $Scyl;
		$wv = $dVv / $Svalve;
#		$maxw = 0.95 * getSS($curr{P},$curr{T});
#			if ($wv>$maxw) { 		## should not be supersonic
#				$dVsuccoeff=$maxw/$wv;
#			}else{
#				$dVsuccoeff=1;
#			}
		$dPin = $DefaultPressureDropSuction + $dPsuc + $dzeta * $Din * ($w*$w)/2.0 				/101300;
		$Psuc = ($Pin -$dPin);  # values that should be to start process
print "dPin=$dPin; Psuc=$Psuc;\n";
		$suction = 1		if ($curr{P}<=$Psuc);
	}

	if ($curr{P}>=$Pout) {
		$w = $dVv / $Ssuc/1.5;
#		$w = $dVv / $Scyl;
		$dPout = $DefaultPressureDropDischarge + $dPdis + $dzeta * $curr{D} * ($w*$w)/2.0	/101300;
		$Pdis = ($Pout+$dPout);
print "dPout=$dPout; Pdis=$Pdis;\n";
		$discharge = 1	if ($curr{P}>=$Pdis);
	}


	if ($suction) {	
#		$dVsuc = $dV * ($curr{P} - $dPin) / $Pin;
		$dVsuc = $dV * ($Psuc - $dPin) / $Pin;
		$dm = $Din * $dVsuc;
	$Vsuc+=$dVsuc;
		$next{m} += $dm;
		$next{enthr} = 	($curr{enthr}*$curr{m} + $Sin*$dm)/$next{m};
		$next{H} = 			($curr{H}*$curr{m} + $Hin*$dm)		/$next{m};
		$next{T} = 			($curr{T}*$curr{m} + $Tin*$dm)		/$next{m};
		$next{D} = $next{m} / $next{V};
		$next{P} = $Psuc;
print "suction @ $Psuc! dVsuc=$dVsuc; Vsuc=$Vsuc; w=$w:$wv dP=$dPin\n";
#		$Pupper = $Pin;
	}


	if ($discharge) {
#		$dVdis = $dV * ($curr{P} - $dPout) / $Pout;
		$dVdis = $dV * ($Pdis - $dPout) / $Pout;
		$dm = $curr{D} * $dV;
		$next{m} += $dm;
		$next{D} = $next{m} / $next{V};
		$next{P} = $Pdis;
print "discharge @ Pdis=$Pdis! dV=$dVdis; dVv=$dVv; w=$wout; dP=$dPout\n";
#		$Pupper = $Pout;
	}

	%curr = %next;
	
PrintPoint("      suc|dis:");

	$arm = sin(3.14159*$a/180);#*$Stroke/2.0;
	$direction = $arm/abs($arm) if (abs($arm)>0);
	$arm = abs($arm);

	$InnerGasWork = ($curr{P} - $Pin) * $dV * 101300 ;

	$MotorWork = - $InnerGasWork +  $FrictionForce * abs($dpos);
#	$MotorWork *= $arm ;
	$MotorWork = 0 if ($MotorWork<0);

	$MotorPower = $MotorWork / $tau;
	$MotorWorkTotal += $MotorWork;

#	print "			MotorPower: $MotorPower\n";


#	print "angle:$a\n";
	}


$Vreturned = $Mleak/$Din;
$Vsucreal = $Vsuc - $Vreturned;
$Veff = $Vsucreal / $Vcyl;

#printf "Vsuc=%.4e; Vsucreal=%.4e; Veff=%.4f\n", $Vsuc, $Vsucreal, $Veff;
printf "Veff=%.4f\n", $Veff;

printf "Total Veff: %.4f\n", $Veff*$Veff2;

printf "Compressor displacement (one piston): %.2f m3/h\n", $Vcyl/(60/$W)*3600;
printf "Compressor volume capacity (per piston): %.1f m3/h\n", $Vcyl/(60/$W)*3600*$Veff*$Veff2;

printf "Compressor displacement: %.2f m3/h\n", $Vcyl/(60/$W)*3600*$NumberOfCylinders;
printf "Compressor volume capacity: %.1f m3/h\n", $Vcyl/(60/$W)*3600*$Veff*$Veff2*$NumberOfCylinders;


$MotorPowerAverage = $MotorWorkTotal / ($tau*360/$anglestep);
print "Mean crankshaft power (per piston): $MotorPowerAverage\n";

$MotorHeatAverage = $MotorPowerAverage / 0.95 / $MotorPowerEfficiency;
print "Mean motor heat power (per piston): $MotorHeatAverage\n";
printf "Mean motor heat power: %.0f\n", $MotorHeatAverage*$NumberOfCylinders;

I have to say, that result of ruuning ths program is not true as i wanted It should be reworked, but in 2003 i went to another kind of job...