150 lines
4.7 KiB
Python
150 lines
4.7 KiB
Python
"""Entropyk — Simple Refrigeration Cycle Example.
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This example demonstrates how to use the Python bindings to build and
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(eventually) solve a simple vapor-compression refrigeration cycle:
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Compressor → Condenser → Expansion Valve → Evaporator → (loop)
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Usage:
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python examples/simple_cycle.py
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"""
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import entropyk
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# ── Step 1: Create physical components ──────────────────────────────────
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print("=" * 60)
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print(" Entropyk — Simple Refrigeration Cycle")
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print("=" * 60)
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# Compressor with AHRI 540 coefficients (using defaults)
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compressor = entropyk.Compressor(
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speed_rpm=2900.0,
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displacement=0.0001,
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efficiency=0.85,
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fluid="R134a",
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)
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print(f"\n {compressor}")
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# Condenser coil: UA = 5 kW/K
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condenser = entropyk.Condenser(ua=5000.0)
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print(f" {condenser}")
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# Thermostatic expansion valve
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expansion_valve = entropyk.ExpansionValve(fluid="R134a", opening=0.8)
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print(f" {expansion_valve}")
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# Evaporator coil: UA = 3 kW/K
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evaporator = entropyk.Evaporator(ua=3000.0)
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print(f" {evaporator}")
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# ── Step 2: Build the system graph ──────────────────────────────────────
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print("\n---")
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print(" Building system graph...")
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system = entropyk.System()
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# Add components — returns node indices
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comp_idx = system.add_component(compressor)
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cond_idx = system.add_component(condenser)
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exv_idx = system.add_component(expansion_valve)
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evap_idx = system.add_component(evaporator)
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# Connect them in a cycle
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system.add_edge(comp_idx, cond_idx) # Compressor → Condenser
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system.add_edge(cond_idx, exv_idx) # Condenser → EXV
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system.add_edge(exv_idx, evap_idx) # EXV → Evaporator
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system.add_edge(evap_idx, comp_idx) # Evaporator → Compressor (loop)
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print(f" {system}")
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# ── Step 3: Finalize the system ─────────────────────────────────────────
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print(" Finalizing system topology...")
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system.finalize()
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print(f" State vector length: {system.state_vector_len}")
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# ── Step 4: Configure solver ────────────────────────────────────────────
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print("\n---")
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print(" Configuring solver...")
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# Newton-Raphson solver with line search
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newton = entropyk.NewtonConfig(
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max_iterations=200,
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tolerance=1e-6,
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line_search=True,
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timeout_ms=10000,
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)
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print(f" {newton}")
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# Picard solver for backup
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picard = entropyk.PicardConfig(
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max_iterations=500,
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tolerance=1e-4,
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relaxation=0.5,
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)
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print(f" {picard}")
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# Fallback: try Newton first, fall back to Picard
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fallback = entropyk.FallbackConfig(newton=newton, picard=picard)
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print(f" {fallback}")
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# ── Step 5: Solve ───────────────────────────────────────────────────────
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print("\n---")
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print(" Solving... (requires real component implementations)")
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print(" NOTE: SimpleAdapter placeholders will produce trivial solutions.")
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try:
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result = fallback.solve(system)
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print(f"\n ✅ Solution found!")
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print(f" Status: {result.status}")
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print(f" Iterations: {result.iterations}")
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print(f" Residual: {result.final_residual:.2e}")
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print(f" State vector ({len(result.state_vector)} vars): "
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f"{result.state_vector[:6]}...")
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except entropyk.SolverError as e:
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print(f"\n ❌ Solver error: {e}")
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except entropyk.EntropykError as e:
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print(f"\n ❌ Entropyk error: {e}")
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# ── Working with physical types ─────────────────────────────────────────
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print("\n---")
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print(" Physical types demo:")
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p = entropyk.Pressure(bar=12.0)
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print(f" {p}")
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print(f" = {p.to_pascals():.0f} Pa")
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print(f" = {p.to_kpa():.1f} kPa")
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print(f" = {p.to_bar():.2f} bar")
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print(f" float(p) = {float(p)}")
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t = entropyk.Temperature(celsius=45.0)
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print(f" {t}")
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print(f" = {t.to_kelvin():.2f} K")
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print(f" = {t.to_celsius():.2f} °C")
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print(f" = {t.to_fahrenheit():.2f} °F")
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h = entropyk.Enthalpy(kj_per_kg=420.0)
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print(f" {h}")
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print(f" = {h.to_j_per_kg():.0f} J/kg")
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print(f" = {h.to_kj_per_kg():.1f} kJ/kg")
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m = entropyk.MassFlow(kg_per_s=0.05)
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print(f" {m}")
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print(f" = {m.to_kg_per_s():.3f} kg/s")
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print(f" = {m.to_g_per_s():.1f} g/s")
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# Arithmetic
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p1 = entropyk.Pressure(bar=10.0)
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p2 = entropyk.Pressure(bar=2.0)
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print(f"\n Arithmetic: {p1} + {p2} = {p1 + p2}")
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print(f" {p1} - {p2} = {p1 - p2}")
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print("\n" + "=" * 60)
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print(" Done!")
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print("=" * 60)
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