循环单一敏感性分析与单变量优化demo

brayton_cycle/sensitivity.py

@@ -13,6 +13,14 @@ RC_PARAM_KEYS = (
     "recuperator_eff",
     "highT_recuperator_eff",
 )
+RC_DESIGN_VARIABLES = ("T_low", "T_high", "p_low", "p_high", "ploss", "x")
+RC_COMPONENT_PERFORMANCE_VARIABLES = (
+    "compressor_eff",
+    "recompressor_eff",
+    "turbine_eff",
+    "recuperator_eff",
+    "highT_recuperator_eff",
+)
 
 
 def _require_keys(data, required_keys, data_name):
@@ -48,3 +56,137 @@ def evaluate_rc_efficiency(fixed_params, params, refprop_path=None):
         ploss=fixed["ploss"],
         param=cycle_params,
     )
+
+
+def _set_rc_variable(fixed_params, params, variable_name, value):
+    fixed = dict(fixed_params)
+    cycle_params = dict(params)
+
+    in_fixed = variable_name in fixed
+    in_params = variable_name in cycle_params
+    if in_fixed and in_params:
+        raise ValueError(f"{variable_name!r} exists in both fixed_params and params")
+    if not in_fixed and not in_params:
+        raise ValueError(f"Unknown RC variable: {variable_name}")
+
+    if in_fixed:
+        fixed[variable_name] = value
+    else:
+        cycle_params[variable_name] = value
+
+    return fixed, cycle_params
+
+
+def local_rc_design_sensitivity(
+    fixed_params,
+    params,
+    variables=None,
+    relative_step=0.01,
+    absolute_steps=None,
+    refprop_path=None,
+):
+    """Run one-at-a-time local sensitivity analysis for RC design variables.
+
+    The returned rows use decimal efficiency values. For example, 0.46 means
+    46%. The normalized sensitivity is:
+
+        ((eff_plus - eff_minus) / eff_base)
+        / ((value_plus - value_minus) / value_base)
+
+    so variables with different units can be compared directly.
+    """
+    if relative_step <= 0:
+        raise ValueError("relative_step must be positive")
+
+    variables = variables or RC_DESIGN_VARIABLES
+    absolute_steps = absolute_steps or {}
+
+    base_fixed = dict(fixed_params)
+    base_params = dict(params)
+    base_efficiency = evaluate_rc_efficiency(
+        base_fixed,
+        base_params,
+        refprop_path=refprop_path,
+    )
+
+    rows = []
+    for variable_name in variables:
+        if variable_name in base_fixed:
+            base_value = base_fixed[variable_name]
+        elif variable_name in base_params:
+            base_value = base_params[variable_name]
+        else:
+            raise ValueError(f"Unknown RC variable: {variable_name}")
+
+        step = absolute_steps.get(variable_name)
+        if step is None:
+            step = abs(base_value) * relative_step
+        if step <= 0:
+            raise ValueError(f"Step for {variable_name!r} must be positive")
+
+        minus_value = base_value - step
+        plus_value = base_value + step
+        minus_fixed, minus_params = _set_rc_variable(
+            base_fixed,
+            base_params,
+            variable_name,
+            minus_value,
+        )
+        plus_fixed, plus_params = _set_rc_variable(
+            base_fixed,
+            base_params,
+            variable_name,
+            plus_value,
+        )
+
+        eff_minus = evaluate_rc_efficiency(
+            minus_fixed,
+            minus_params,
+            refprop_path=refprop_path,
+        )
+        eff_plus = evaluate_rc_efficiency(
+            plus_fixed,
+            plus_params,
+            refprop_path=refprop_path,
+        )
+
+        derivative = (eff_plus - eff_minus) / (plus_value - minus_value)
+        if base_value == 0 or base_efficiency == 0:
+            normalized_sensitivity = None
+        else:
+            normalized_sensitivity = derivative * base_value / base_efficiency
+
+        rows.append(
+            {
+                "variable": variable_name,
+                "base_value": base_value,
+                "minus_value": minus_value,
+                "plus_value": plus_value,
+                "base_efficiency": base_efficiency,
+                "minus_efficiency": eff_minus,
+                "plus_efficiency": eff_plus,
+                "derivative": derivative,
+                "normalized_sensitivity": normalized_sensitivity,
+            }
+        )
+
+    return rows
+
+
+def local_rc_component_performance_sensitivity(
+    fixed_params,
+    params,
+    variables=None,
+    relative_step=0.01,
+    absolute_steps=None,
+    refprop_path=None,
+):
+    """Run one-at-a-time local sensitivity analysis for RC component performance."""
+    return local_rc_design_sensitivity(
+        fixed_params=fixed_params,
+        params=params,
+        variables=variables or RC_COMPONENT_PERFORMANCE_VARIABLES,
+        relative_step=relative_step,
+        absolute_steps=absolute_steps,
+        refprop_path=refprop_path,
+    )