pipeflow cancellation if all nodes are out-of-service after the connectivity check

CHANGELOG.rst

@@ -5,6 +5,7 @@ Change Log
 -------------------------------
 - [ADDED] multiple creation of heat exchanger
 - [ADDED] support Python 3.11 (now included in test pipeline)
+- [ADDED] after the connectivity check, intercept the pipeflow if no more nodes are in-service
 - [CHANGED] dropped support for Python 3.7 (no longer included in test pipeline)
 - [CHANGED] connectivity check now separated by hydraulics and heat_transfer calculation, so that also results can differ in some rows (NaN or not)
 - [CHANGED] dynamic creation of lookups for getting pit as pandas tables

pandapipes/multinet/create_multinet.py

@@ -12,8 +12,6 @@
     import logging
 
 logger = logging.getLogger(__name__)
-logger.setLevel(level=logging.WARNING)
-
 
 def create_empty_multinet(name=""):
     """

pandapipes/multinet/timeseries/run_time_series_multinet.py

@@ -19,7 +19,6 @@
     import logging as pplog
 
 logger = pplog.getLogger(__name__)
-logger.setLevel(level=pplog.WARNING)
 
 
 def _call_output_writer(multinet, time_step, pf_converged, ctrl_converged, ts_variables):

pandapipes/pf/pipeflow_setup.py

@@ -498,6 +498,7 @@ def identify_active_nodes_branches(net, branch_pit, node_pit, hydraulic=True):
     mode = "hydraulics" if hydraulic else "heat_transfer"
     net["_lookups"]["node_active_" + mode] = nodes_connected
     net["_lookups"]["branch_active_" + mode] = branches_connected
+    return node_pit[nodes_connected], branch_pit[branches_connected]
 
 
 def branches_connected_flow(branch_pit):

pandapipes/pipeflow.py

@@ -4,7 +4,6 @@
 
 import numpy as np
 from numpy import linalg
-from pandapower.auxiliary import ppException
 from scipy.sparse.linalg import spsolve
 
 from pandapipes.idx_branch import FROM_NODE, TO_NODE, FROM_NODE_T, TO_NODE_T, VINIT, TOUTINIT, VINIT_T
@@ -16,6 +15,7 @@
     initialize_pit, reduce_pit, set_user_pf_options, init_all_result_tables, \
     identify_active_nodes_branches
 from pandapipes.pf.result_extraction import extract_all_results, extract_results_active_pit
+from pandapower.auxiliary import ppException
 
 try:
     import pandaplan.core.pplog as logging
@@ -70,15 +70,22 @@
 
     create_lookups(net)
     node_pit, branch_pit = initialize_pit(net)
-    if (len(node_pit) == 0) & (len(branch_pit) == 0):
-        logger.warning("There are no node and branch entries defined. This might mean that your net"
-                       " is empty")
+    if len(node_pit) == 0:
+        logger.warning("There are no nodes defined. "
+                       "You need at least one node! "
+                       "Without any nodes, you are not able to conduct a pipeflow!")
         return
+
     calculation_mode = get_net_option(net, "mode")
     calculate_hydraulics = calculation_mode in ["hydraulics", "all"]
     calculate_heat = calculation_mode in ["heat", "all"]
 
-    identify_active_nodes_branches(net, branch_pit, node_pit)
+    active_node_pit, active_branch_pit = identify_active_nodes_branches(net, branch_pit, node_pit)
+
+    if (len(active_node_pit) == 0):
+        logger.warning(" All nodes are out of service. Probably they are not supplied."
+                       " Have you forgotten to define an external grid?")
+        return
 
     if calculation_mode == "heat":
         if not net.user_pf_options["hyd_flag"]:

pandapipes/test/pipeflow_internals/test_inservice.py

@@ -9,8 +9,8 @@
 
 import pandapipes
 from pandapipes.pf.pipeflow_setup import get_lookup
-from pandapipes.pipeflow import logger as pf_logger
 from pandapipes.pipeflow import PipeflowNotConverged
+from pandapipes.pipeflow import logger as pf_logger
 
 try:
     import pandaplan.core.pplog as logging
@@ -125,6 +125,29 @@ def create_mixed_indexing_grid():
     return net
 
 
+@pytest.fixture
+def create_net_wo_external_hydraulic_grid():
+    net = pandapipes.create_empty_network("net", add_stdtypes=False)
+    pandapipes.create_fluid_from_lib(net, "hgas", overwrite=True)
+    pandapipes.create_junction(net, index=3, pn_bar=16, tfluid_k=283, height_m=0,
+                               name="Junction 3", in_service=True,
+                               type="junction", geodata=(0, 0))
+    pandapipes.create_junction(net, index=9, pn_bar=16, tfluid_k=283, height_m=0,
+                               name="Junction 9", in_service=True,
+                               type="junction", geodata=(1, 0))
+    pandapipes.create_junction(net, index=10, pn_bar=16, tfluid_k=283, height_m=0,
+                               name="Junction 10", in_service=True,
+                               type="junction", geodata=(2, 0))
+    pandapipes.create_pipe_from_parameters(net, 9, 10, length_km=1, diameter_m=0.03, k_mm=.1, sections=10,
+                                           alpha_w_per_m2k=1, name="Pipe 6")
+    pandapipes.create_sink(net, 9, mdot_kg_per_s=0.01, name="Sink 3")
+    pandapipes.create_source(net, junction=10, mdot_kg_per_s=0.04, name="Source 3")
+    pandapipes.create_compressor(net, from_junction=9, to_junction=3, pressure_ratio=1.1,
+                                 name="Compressor 0", index=None, in_service=True)
+    pandapipes.create_ext_grid(net, junction=3, t_k=300)
+    return net
+
+
 @pytest.mark.parametrize("use_numba", [True, False])
 def test_inservice_gas(create_test_net, use_numba):
     """
@@ -146,7 +169,7 @@ def test_inservice_gas(create_test_net, use_numba):
     assert np.all(np.isnan(net.res_junction.p_bar.loc[~net.junction.in_service].values))
 
     oos_sinks = np.isin(net.sink.junction.values, net.junction.index[~net.junction.in_service]) \
-        | ~net.sink.in_service.values
+                | ~net.sink.in_service.values
     assert np.all(np.isnan(net.res_sink.loc[oos_sinks, :].values))
 
     assert not np.any(np.isnan(net.res_pipe.v_mean_m_per_s.loc[net.pipe.in_service].values))
@@ -179,7 +202,7 @@ def test_inservice_water(create_test_net, use_numba):
     assert np.all(np.isnan(net.res_junction.p_bar.loc[~net.junction.in_service].values))
 
     oos_sinks = np.isin(net.sink.junction.values, net.junction.index[~net.junction.in_service]) \
-        | ~net.sink.in_service.values
+                | ~net.sink.in_service.values
     assert np.all(np.isnan(net.res_sink.loc[oos_sinks, :].values))
 
     assert not any(np.isnan(net.res_pipe.v_mean_m_per_s.loc[net.pipe.in_service].values))
@@ -214,8 +237,8 @@ def test_connectivity_hydraulic(create_test_net, use_numba):
     assert np.all(np.isnan(net.res_pipe.loc[[1, 2, 3], :].values))
     assert not np.any(np.isnan(net.res_junction.loc[[0, 1, 3, 4], :].values))
     assert not np.any(np.isnan(net.res_pipe.loc[[0, 4],
-                                                ["v_mean_m_per_s", "p_from_bar",
-                                                 "p_to_bar"]].values))
+    ["v_mean_m_per_s", "p_from_bar",
+     "p_to_bar"]].values))
     assert not np.any(np.isnan(net.res_sink.loc[[0, 2], "mdot_kg_per_s"].values))
     assert np.all(np.isnan(net.res_sink.loc[[1, 3, 4], "mdot_kg_per_s"].values))
 
@@ -496,7 +519,7 @@ def test_mixed_indexing_oos2(create_mixed_indexing_grid, use_numba):
     assert all(np.all(net["res_" + tbl].loc[~oos_func(net, tbl, oos_juncs)].notnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert all(np.all(net["res_" + tbl].loc[oos_func(net, tbl, oos_juncs),
-                                            get_col_slice_null(tbl)].isnull())
+    get_col_slice_null(tbl)].isnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert check_mass_flows(net)
 
@@ -514,7 +537,7 @@ def test_mixed_indexing_oos3(create_mixed_indexing_grid, use_numba):
     assert all(np.all(net["res_" + tbl].loc[~oos_func(net, tbl, oos_juncs)].notnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert all(np.all(net["res_" + tbl].loc[oos_func(net, tbl, oos_juncs),
-                                            get_col_slice_null(tbl)].isnull())
+    get_col_slice_null(tbl)].isnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert check_mass_flows(net)
 
@@ -532,7 +555,7 @@ def test_mixed_indexing_oos4(create_mixed_indexing_grid, use_numba):
     assert all(np.all(net["res_" + tbl].loc[~oos_func(net, tbl, oos_juncs)].notnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert all(np.all(net["res_" + tbl].loc[oos_func(net, tbl, oos_juncs),
-                                            get_col_slice_null(tbl)].isnull())
+    get_col_slice_null(tbl)].isnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert check_mass_flows(net)
 
@@ -550,7 +573,7 @@ def test_mixed_indexing_oos5(create_mixed_indexing_grid, use_numba):
     assert all(np.all(net["res_" + tbl].loc[~oos_func(net, tbl, oos_juncs)].notnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert all(np.all(net["res_" + tbl].loc[oos_func(net, tbl, oos_juncs),
-                                            get_col_slice_null(tbl)].isnull())
+    get_col_slice_null(tbl)].isnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert check_mass_flows(net)
 
@@ -568,7 +591,7 @@ def test_mixed_indexing_oos6(create_mixed_indexing_grid, use_numba):
     assert all(np.all(net["res_" + tbl].loc[~oos_func(net, tbl, oos_juncs)].notnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert all(np.all(net["res_" + tbl].loc[oos_func(net, tbl, oos_juncs),
-                                            get_col_slice_null(tbl)].isnull())
+    get_col_slice_null(tbl)].isnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert check_mass_flows(net)
 
@@ -577,10 +600,22 @@ def test_mixed_indexing_oos6(create_mixed_indexing_grid, use_numba):
     assert all(np.all(net["res_" + tbl].loc[~oos_func(net, tbl, oos_juncs)].notnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert all(np.all(net["res_" + tbl].loc[oos_func(net, tbl, oos_juncs),
-                                            get_col_slice_null(tbl)].isnull())
+    get_col_slice_null(tbl)].isnull())
                for tbl, oos_func in all_tbls_funcs.items())
     assert check_mass_flows(net)
 
 
+@pytest.mark.parametrize("use_numba", [True, False])
+def test_pipeflow_cancellation(create_net_wo_external_hydraulic_grid, use_numba):
+    net = create_net_wo_external_hydraulic_grid
+    pandapipes.pipeflow(net)
+    assert np.all(np.isnan(net.res_junction))
+    assert np.all(np.isnan(net.res_pipe))
+    assert np.all(np.isnan(net.res_ext_grid))
+    assert np.all(np.isnan(net.res_sink))
+    assert np.all(np.isnan(net.res_source))
+    assert np.all(np.isnan(net.res_compressor))
+
+
 if __name__ == "__main__":
     pytest.main([r'pandapipes/test/pipeflow_internals/test_inservice.py'])