Entropyk/crates/cli/tests/calibration_sdt.rs

//! Calibration redesign (WS-2/WS-3/WS-4) — AC#1: BPHX condenser SDT
//! calibration via plain inverse embedding converges and back-solves z_ua
//! (the case that diverged with a singular Jacobian before the redesign).

use entropyk_cli::run::{run_simulation, SimulationResult, SimulationStatus};
use tempfile::tempdir;

fn run_config(json: &str) -> SimulationResult {
    let dir = tempdir().unwrap();
    let path = dir.path().join("bphx_sdt_calib.json");
    std::fs::write(&path, json).unwrap();
    run_simulation(&path, None, false).unwrap()
}

#[test]
fn bphx_condenser_sdt_calibration_converges_and_solves_z_ua() {
    let json = r#"
{
  "name": "BPHX Water-Cooled Chiller R134a",
  "description": "Full vapor-compression cycle with brazed-plate evaporator and condenser (4-port). Both Bphx units use emergent_pressure so outlet closures (superheat / subcooling) square the DoF like Condenser/Evaporator.",
  "fluid": "R134a",
  "fluid_backend": "CoolProp",
  "circuits": [
    {
      "id": 0,
      "name": "Refrigerant + water loops",
      "components": [
        {
          "type": "IsentropicCompressor",
          "name": "comp",
          "isentropic_efficiency": 0.7,
          "t_cond_k": 318.15,
          "t_evap_k": 278.15,
          "superheat_k": 5.0,
          "emergent_pressure": true,
          "displacement_m3": 6.5e-05,
          "speed_hz": 50.0,
          "volumetric_efficiency": 0.92
        },
        {
          "type": "BphxCondenser",
          "name": "cond",
          "refrigerant": "R134a",
          "secondary_fluid": "Water",
          "n_plates": 40,
          "plate_length_m": 0.4,
          "plate_width_m": 0.12,
          "target_subcooling_k": 5.0,
          "emergent_pressure": true,
          "correlation": "Longo2004",
          "dp_correlation": "SimplifiedChannel",
          "ua": 2500.0
        },
        {
          "type": "IsenthalpicExpansionValve",
          "name": "exv",
          "t_evap_k": 278.15,
          "emergent_pressure": true
        },
        {
          "type": "BphxEvaporator",
          "name": "evap",
          "refrigerant": "R134a",
          "secondary_fluid": "Water",
          "n_plates": 40,
          "plate_length_m": 0.4,
          "plate_width_m": 0.12,
          "target_superheat_k": 5.0,
          "emergent_pressure": true,
          "correlation": "Longo2004",
          "dp_correlation": "SimplifiedChannel",
          "ua": 2000.0
        },
        {
          "type": "BrineSource",
          "name": "cond_water_in",
          "fluid": "Water",
          "p_set_bar": 2.0,
          "t_set_c": 30.0,
          "m_flow_kg_s": 0.4,
          "fix_pressure": false,
          "fix_temperature": true,
          "fix_mass_flow": true
        },
        {
          "type": "BrineSink",
          "name": "cond_water_out",
          "fluid": "Water",
          "p_back_bar": 2.0,
          "fix_pressure": true
        },
        {
          "type": "BrineSource",
          "name": "evap_water_in",
          "fluid": "Water",
          "p_set_bar": 3.0,
          "t_set_c": 12.0,
          "m_flow_kg_s": 0.5,
          "fix_pressure": false,
          "fix_temperature": true,
          "fix_mass_flow": true
        },
        {
          "type": "BrineSink",
          "name": "evap_water_out",
          "fluid": "Water",
          "p_back_bar": 3.0,
          "fix_pressure": true
        }
      ],
      "edges": [
        {
          "from": "comp:outlet",
          "to": "cond:inlet"
        },
        {
          "from": "cond:outlet",
          "to": "exv:inlet"
        },
        {
          "from": "exv:outlet",
          "to": "evap:inlet"
        },
        {
          "from": "evap:outlet",
          "to": "comp:inlet"
        },
        {
          "from": "cond_water_in:outlet",
          "to": "cond:secondary_inlet"
        },
        {
          "from": "cond:secondary_outlet",
          "to": "cond_water_out:inlet"
        },
        {
          "from": "evap_water_in:outlet",
          "to": "evap:secondary_inlet"
        },
        {
          "from": "evap:secondary_outlet",
          "to": "evap_water_out:inlet"
        }
      ]
    }
  ],
  "solver": {
    "strategy": "fallback",
    "max_iterations": 300,
    "tolerance": 1e-06,
    "timeout_ms": 60000
  },
  "controls": [
    {
      "type": "SaturatedController",
      "id": "sdt_calib",
      "measure": {
        "component": "cond",
        "output": "saturationTemperature"
      },
      "actuator": {
        "component": "cond",
        "factor": "z_ua",
        "initial": 0.3,
        "min": 0.05,
        "max": 2.0
      },
      "target": 315.0
    }
  ]
}
"#;
    let result = run_config(json);
    assert!(
        matches!(result.status, SimulationStatus::Converged),
        "BPHX SDT calibration must converge (was the singular-Jacobian case): {:?} ({:?})",
        result.status,
        result.error
    );
    let solved = result
        .solved_variables
        .iter()
        .find(|v| v.variable == "z_ua" && v.component.as_deref() == Some("cond"))
        .expect("solved_variables must contain cond/z_ua");
    assert!(
        solved.value > 0.05 && solved.value < 2.0,
        "z_ua must solve within bounds, got {}",
        solved.value
    );
}