update RVP calc (#1048)

equinor · Jul 18, 2024 · 417fc8f · 417fc8f
1 parent 26972e2
commit 417fc8f
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Showing 3 changed files with 31 additions and 7 deletions.
diff --git a/src/main/java/neqsim/standards/oilQuality/Standard_ASTM_D6377.java b/src/main/java/neqsim/standards/oilQuality/Standard_ASTM_D6377.java
@@ -51,7 +51,7 @@ public void calculate() {
     TVP = this.thermoSystem.getPressure();
     double liquidVolume = thermoSystem.getVolume();
 
-    this.thermoSystem.setPressure(0.9);
+    this.thermoSystem.setPressure(TVP * 0.9);
     try {
       this.thermoOps.TVflash(liquidVolume * 4.0);
     } catch (Exception ex) {

diff --git a/src/main/java/neqsim/thermodynamicOperations/flashOps/TVflash.java b/src/main/java/neqsim/thermodynamicOperations/flashOps/TVflash.java
@@ -75,8 +75,10 @@ public double solveQ() {
     double oldPres = system.getPressure();
     double nyPres = system.getPressure();
     double iterations = 1;
+    double error = 100.0, errorOld = 1000.0;
     do {
       iterations++;
+      errorOld = error;
       oldPres = nyPres;
       system.init(3);
       nyPres = oldPres - (iterations) / (iterations + 10.0) * calcdQdV() / calcdQdVV();
@@ -88,9 +90,11 @@ public double solveQ() {
       }
       system.setPressure(nyPres);
       tpFlash.run();
-      // System.out.println(" dQdv " + calcdQdV() + " new pressure " + nyPres + " error " +
-      // Math.abs((nyPres-oldPres)/(nyPres)) + " numberofphases "+system.getNumberOfPhases());
-    } while (Math.abs((nyPres - oldPres) / (nyPres)) > 1e-9 && iterations < 1000 || iterations < 3);
+      // System.out.println(" dQdv " + calcdQdV() + " new pressure " + nyPres + " error "
+      // + Math.abs((nyPres - oldPres) / (nyPres)) + " numberofphases "
+      // + system.getNumberOfPhases());
+      error = Math.abs(calcdQdV());
+    } while (Math.abs(error) > 1e-9 && iterations < 200 && error < errorOld || iterations < 3);
     return nyPres;
   }
 

diff --git a/src/test/java/neqsim/standards/oilQuality/Standard_ASTM_D6377Test.java b/src/test/java/neqsim/standards/oilQuality/Standard_ASTM_D6377Test.java
@@ -11,14 +11,34 @@ void testCalculate() {
     SystemInterface testSystem = new SystemSrkEos(273.15 + 2.0, 1.0);
     testSystem.addComponent("methane", 0.0006538);
     testSystem.addComponent("ethane", 0.006538);
-    testSystem.addComponent("propane", 0.006538);
+    testSystem.addComponent("propane", 0.06538);
+    testSystem.addComponent("n-pentane", 0.1545);
+    testSystem.addComponent("nC10", 0.545);
+    testSystem.setMixingRule(2);
+    testSystem.init(0);
+    Standard_ASTM_D6377 standard = new Standard_ASTM_D6377(testSystem);
+    standard.setReferenceTemperature(37.8, "C");
+    standard.calculate();
+    Assertions.assertEquals(0.94552559993, standard.getValue("RVP", "bara"), 1e-3);
+    Assertions.assertEquals(1.666298367, standard.getValue("TVP", "bara"), 1e-3);
+  }
+
+  @Test
+  void testCalculate2() {
+    SystemInterface testSystem = new SystemSrkEos(273.15 + 2.0, 1.0);
+    testSystem.addComponent("methane", 0.026538);
+    testSystem.addComponent("ethane", 0.16538);
+    testSystem.addComponent("propane", 0.26538);
     testSystem.addComponent("n-pentane", 0.545);
+    testSystem.addComponent("nC10", 0.545);
+    testSystem.addTBPfraction("C11", 0.545, 145.0 / 1000.0, 0.82);
     testSystem.setMixingRule(2);
     testSystem.init(0);
+    testSystem.setPressure(100.0);
     Standard_ASTM_D6377 standard = new Standard_ASTM_D6377(testSystem);
     standard.setReferenceTemperature(37.8, "C");
     standard.calculate();
-    //Assertions.assertEquals(0.7298246193, standard.getValue("RVP", "bara"), 1e-3);
-    Assertions.assertEquals(1.8710732396722, standard.getValue("TVP", "bara"), 1e-3);
+    Assertions.assertEquals(3.017010, standard.getValue("RVP", "bara"), 1e-3);
+    Assertions.assertEquals(7.8448385024, standard.getValue("TVP", "bara"), 1e-3);
   }
 }