update

src/main/java/neqsim/processSimulation/processEquipment/compressor/CompressorChartGenerator.java

@@ -11,38 +11,42 @@ public CompressorChartGenerator(Compressor inpcompressor) {
     this.compressor = inpcompressor;
   }
 
-  public CompressorChart generateCompressorChart(String string) {
-    CompressorChart compChart = new CompressorChart();
-    compChart.setUseCompressorChart(true);
-
-    int refspeed = compressor.getSpeed();
-
-    double refhead = compressor.getPolytropicHead("kJ/kg");
-    double refflow = compressor.getInletStream().getFlowRate("m3/hr");
-    double minFlow = refflow / 2.0;
-    double maxFLow = refflow * 2.0;
-    double minSpeed = refspeed / 2.0;
-    double maxSpeed = refspeed * 2.0;
+  /**
+   * @param generationOption string to specify how to generate the compressor chart
+   * @return a {@link neqsim.processSimulation.processEquipment.compressor.CompressorChart} object
+   */
+  public CompressorChart generateCompressorChart(String generationOption) {
 
+    // Generation compressor chart
     double[] chartConditions = new double[3];
     chartConditions[0] = compressor.getOutletStream().getFluid().getMolarMass("kg/mol");
 
-
+    int refspeed = compressor.getSpeed();
     double[] speed = new double[1];
     speed[0] = refspeed;
+    double minSpeed = refspeed / 2.0;
+    double maxSpeed = refspeed * 2.0;
 
+    double refflow = compressor.getInletStream().getFlowRate("m3/hr");
     double[][] flow = new double[1][1];
     flow[0][0] = refflow;
+    double minFlow = refflow / 2.0;
+    double maxFlow = refflow * 2.0;
 
+    double refhead = compressor.getPolytropicHead("kJ/kg");
     double[][] head = new double[1][1];
     head[0][0] = refhead;
 
     double[][] polyEff = new double[1][1];
     polyEff[0][0] = compressor.getPolytropicEfficiency() * 100.0;
 
+    CompressorChart compChart = new CompressorChart();
+    compChart.setUseCompressorChart(true);
     compChart.setHeadUnit("kJ/kg");
     compChart.setCurves(chartConditions, speed, flow, head, polyEff);
 
+
+    // Generating surge curve
     double minFlowSurgeFlow = 0.3 * refflow;
     double refSurgeFlow = 0.5 * refflow;
     double maxSurgeFlow = 0.8 * refflow;

src/main/java/neqsim/processSimulation/processEquipment/util/Recycle.java

@@ -302,7 +302,11 @@ public void run(UUID id) {
 
     logger.info("flow rate old in recycle " + outletStream.getFlowRate("kg/hr"));
     SystemInterface thermoSystem2 = streams.get(0).getThermoSystem().clone();
-
+    if (numberOfInputStreams == 1 && thermoSystem2.getFlowRate("kg/hr") < 1e-100) {
+      setError(0);
+      setErrorFlow(0);
+      return;
+    }
     mixedStream.setThermoSystem(thermoSystem2);
     ThermodynamicOperations testOps = new ThermodynamicOperations(thermoSystem2);
     if (streams.size() > 1) {

src/test/java/neqsim/processSimulation/processSystem/CompressorModule.java

@@ -6,8 +6,10 @@
 import neqsim.processSimulation.processEquipment.compressor.Compressor;
 import neqsim.processSimulation.processEquipment.heatExchanger.Cooler;
 import neqsim.processSimulation.processEquipment.heatExchanger.Heater;
+import neqsim.processSimulation.processEquipment.mixer.Mixer;
 import neqsim.processSimulation.processEquipment.separator.Separator;
 import neqsim.processSimulation.processEquipment.separator.ThreePhaseSeparator;
+import neqsim.processSimulation.processEquipment.splitter.Splitter;
 import neqsim.processSimulation.processEquipment.stream.Stream;
 import neqsim.processSimulation.processEquipment.stream.StreamInterface;
 import neqsim.processSimulation.processEquipment.util.Recycle;
@@ -75,10 +77,16 @@ public void testProcess() {
         new ThreePhaseSeparator("inlet separator", valve1.getOutletStream());
     secondStageSeparator.addStream(resycleScrubberStream);
 
+    StreamInterface gasResycleStream = feedStream.clone();
+    gasResycleStream.setFlowRate(1.0, "kg/hr");
+
+    Mixer gasmixer = new Mixer("gas recycle mixer");
+    gasmixer.addStream(secondStageSeparator.getGasOutStream());
+    // gasmixer.addStream(gasResycleStream);
 
     // Setting up compressor module
     Compressor seccondStageCompressor =
-        new Compressor("2nd stage compressor", secondStageSeparator.getGasOutStream());
+        new Compressor("2nd stage compressor", gasmixer.getOutletStream());
     seccondStageCompressor.setUsePolytropicCalc(true);
     seccondStageCompressor.setPolytropicEfficiency(0.9);
     seccondStageCompressor.setOutletPressure(26.0, "bara");
@@ -89,6 +97,20 @@ public void testProcess() {
 
     Separator scrubber1 = new Separator("after cooler scrubber", afterCooler.getOutletStream());
 
+    Stream gasFromScrubber = new Stream("gas from scrubber", scrubber1.getGasOutStream());
+
+    Splitter gassplitter = new Splitter("gas splitter", gasFromScrubber);
+    gassplitter.setSplitFactors(new double[] {0.1, 0.9});
+
+    ThrottlingValve recycleValve =
+        new ThrottlingValve("antisurge valve", gassplitter.getSplitStream(0));
+    recycleValve.setOutletPressure(10.0, "bara");
+
+    Recycle recycle2 = new Recycle("recycle 2");
+    recycle2.addStream(recycleValve.getOutletStream());
+    recycle2.setOutletStream(gasResycleStream);
+
+
     Recycle recycle1 = new Recycle("recycle 1");
     recycle1.addStream(scrubber1.getLiquidOutStream());
     recycle1.setOutletStream(resycleScrubberStream);
@@ -101,9 +123,15 @@ public void testProcess() {
     operations.add(valve1);
     operations.add(resycleScrubberStream);
     operations.add(secondStageSeparator);
+    operations.add(gasResycleStream);
+    operations.add(gasmixer);
     operations.add(seccondStageCompressor);
     operations.add(afterCooler);
     operations.add(scrubber1);
+    operations.add(gasFromScrubber);
+    operations.add(gassplitter);
+    operations.add(recycleValve);
+    operations.add(recycle2);
     operations.add(recycle1);
 
     operations.run();