# ScrewEconomizerCompressor / ScrewCompressor

Config types: `"ScrewEconomizerCompressor"`, `"ScrewCompressor"`  
Source: `crates/components/src/screw_economizer_compressor.rs`  
Polynomials: `Polynomial2D` bilinear SST/SDT

---

## EN

### Purpose

Twin-screw compressor with **economizer injection** port. Manufacturer performance as **bi-quadratic (bilinear) maps** of SST and SDT.

### Performance maps

```
ṁ_suction = z_flow · (a00 + a10·SST + a01·SDT + a11·SST·SDT)
Ẇ_shaft   = z_power · (b00 + b10·SST + b01·SDT + b11·SST·SDT)
ṁ_eco     ≈ eco_fraction · ṁ_suction   (or eco poly)
```

JSON coefficient names (CLI):

| Mass flow | Power |
|-----------|-------|
| `mf_a00`, `mf_a10`, `mf_a01`, `mf_a11` | `pw_b00`, `pw_b10`, `pw_b01`, `pw_b11` |

### Built-in presets

| `preset` | Meaning |
|----------|---------|
| `bitzer_generic_200kw` | Bitzer-like ~200 kW R134a map |
| `grasso_generic_200kw` | Grasso-like ~200 kW map |
| (empty) | generic defaults |

Explicit `mf_*` / `pw_*` **override** preset values.

### Ports

| Port | Role |
|------|------|
| `suction` / `inlet` | main suction |
| `discharge` / `outlet` | discharge |
| `economizer` / `eco` | intermediate injection |

### Other parameters

| Key | Meaning | Default |
|-----|---------|---------|
| `frequency_hz` | drive frequency | 50 |
| `nominal_frequency_hz` | rated f | 50 |
| `mechanical_efficiency` | η_mech | 0.92 |
| `economizer_fraction` | eco flow share | from preset |

### Calibration Z

| Factor | Default |
|--------|---------|
| `z_flow` | **1.0** |
| `z_flow_eco` | **1.0** |
| `z_power` | **1.0** |
| `z_etav` | 1.0 |

### UI

- Tab **General**: frequency, efficiency, preset  
- Tab **Map (polynomials)**: mf_a** / pw_b** with defaults filled from preset  
- Help documents the bilinear formula  

---

## FR

### But

Compresseur **à vis** 3 ports + injection économiseur.

### Carte

Polynôme **bilinéaire** SST/SDT pour ṁ et puissance. Presets Bitzer / Grasso.

### Coeffs JSON

`mf_a00…a11` (débit), `pw_b00…b11` (puissance).

### Calibration

Z = **1** par défaut.

### Ports

Aspiration, refoulement, économiseur.
