Intermittent warning regarding negative timesteps.

[mitchute]

Issue overview

A user sent the following code and loads file, and is getting a warning regarding negative timestep values.

import pandas as pd
from ghedesigner.manager import GHEManager
from pathlib import Path
 
GHEpath = "./8_gshp.csv"
sav_path = "./"
prefix = "_test"
pipe_outer_dia   = 0.02667
pipe_inner_dia   = 0.0216
pipe_rho_cp      = 1542000.0
pipe_k           = 0.4
design_flow_rate = 0.2
buried_depth     = 2
borehole_dia     = 0.150
       
grout_k      = 1
grout_rho_cp = 3901000.0
soil_k       = 1.3
soil_rho_cp  = 2343493.0
UTube_dist   = 0.0323
 
def ghedesigner_caller(GHEpath,sav_path,prefix,pipe_outer_dia,pipe_inner_dia,pipe_rho_cp,UTube_dist, \
                            pipe_k,design_flow_rate,buried_depth,borehole_dia,grout_k,grout_rho_cp,soil_k,soil_rho_cp):
    GHEload = pd.read_csv(GHEpath)
    path = Path(sav_path)
    #ghe = ghedesigner.manager.GHEManager()
    ghe = GHEManager()
    ghe.set_single_u_tube_pipe(
        inner_diameter=pipe_inner_dia, outer_diameter=pipe_outer_dia, shank_spacing=UTube_dist,
        roughness=1.0e-6, conductivity=pipe_k, rho_cp=pipe_rho_cp)
    ghe.set_soil(conductivity=soil_k, rho_cp=soil_rho_cp, undisturbed_temp=16.5)
    ghe.set_grout(conductivity=grout_k, rho_cp=grout_rho_cp)
    ghe.set_fluid()
    ghe.set_borehole(height=96.0, buried_depth=buried_depth, diameter=borehole_dia)
    #ghe.set_simulation_parameters(num_months=240, max_eft=35, min_eft=5, max_height=135, min_height=60)
    ghe.set_simulation_parameters(num_months=240, max_eft=35, min_eft=5, max_height=135, min_height=60)
    #ghe.set_ground_loads_from_hourly_list(self.get_atlanta_loads())
    ghe.set_ground_loads_from_hourly_list(GHEload["VERTICAL GROUND HEAT EXCHANGER:Ground Heat Exchanger Heat Transfer Rate [W](Hourly)"].tolist())
    ghe.set_geometry_constraints_near_square(b=6.5, length=55.7)
    #ghe.set_geometry_constraints_rectangle(length=85.0, width=36.5, b_min=3.0, b_max=10.0)
    ghe.set_design(flow_rate=design_flow_rate, flow_type_str="SYSTEM")
    ghe.find_design()
    ghe.prepare_results("Project Name", "Notes", "Author", "Iteration Name")
    ghe.write_output_files(path,prefix)
    return 0
 
if __name__ == "__main__":
    ghedesigner_caller(GHEpath,sav_path,prefix,pipe_outer_dia,pipe_inner_dia,pipe_rho_cp,UTube_dist, \
                            pipe_k,design_flow_rate,buried_depth,borehole_dia,grout_k,grout_rho_cp,soil_k,soil_rho_cp)

8_gshp.csv

When I refactored the code, tried to at least catch and handle this error by resetting to a reasonable value, but there still could be some other issue going on.