DC-EC · Public read-only demo
Sample network: 4,500 TR community, 2 plants, 9 ETS
This page shows typical DC-EC output for a sample district cooling network, as static text and tables, so reviewers can read it without signing in. The real app is interactive: engineers trace pipes on a satellite map, place plants and ETS rooms, and the app sizes pipes, finds the governing ETS, sets secondary pump head and runs an 8,760-hour simulation. Figures below are illustrative of the sample case.
1. Design basis
| Parameter | Value |
|---|---|
| Community coincident peak | 4,500 TR (15.8 MW) |
| CHW supply / return | 4.5 °C / 12.5 °C (ΔT 8.0 K) |
| Design flow | 472.2 L/s |
| Friction method | Hazen-Williams, C = 130 |
| Velocity limit (mains) | ≤ 2.5 m/s |
| Plants | Plant 1 and Plant 2, 2,250 TR each (3 × 750 TR modules), 50/50 duty share |
| ETS rooms | 9 × 500 TR, mixed office / residential / retail profiles |
| Plant internal loss | 8.0 m |
| ETS design ΔP | 12.2 m (HX + PICV + strainer) |
2. Load split and null point
| Plant | Rating (TR) | ETS served | Served load (TR) | Utilisation |
|---|---|---|---|---|
| Plant 1 | 2,250 | ETS 1–5 | 2,500 | 111 % |
| Plant 2 | 2,250 | ETS 6–9 | 2,000 | 89 % |
Null point (flow boundary between plants) sits at chainage 1,979 m from Plant 1. Plant 1 is overloaded at the design hour; the Plant page flags this and suggests re-routing or adjusting duty shares.
3. Pipe sizing and secondary pump head
| Component | Head (m) |
|---|---|
| Plant internal | 8.0 |
| Main friction to tie-in | 67.4 |
| ETS branch | 1.6 |
| ETS design ΔP | 12.2 |
| Total secondary pump head | 89.3 |
| Option | Main DN | Pump head (m) | Network CAPEX (M $) |
|---|---|---|---|
| Base (adopted) | DN400 | 89.3 | 7.38 |
| +1 size | DN450 | 56.8 | ≈ 8.0 |
| +2 sizes | DN500 | ≈ 44 | ≈ 8.7 |
Second-worst ETS is ETS 9 at 76.6 m (12.7 m margin). The governing ETS is found by evaluating every station, never assumed.
4. Hydraulic grade line and TES overspill check
Supply and return heads are plotted against distance from each plant. Return head lands at each plant's TES tank datum; ETS rooms near a plant receive excess differential pressure that their PICV absorbs.
| ETS | Distance (m) | Available ΔP (m) | Design ΔP (m) | PICV excess (m) |
|---|---|---|---|---|
| ETS 1 | 320 | 71.5 | 12.2 | 59.3 |
| ETS 3 | 980 | 44.0 | 12.2 | 31.8 |
| ETS 5 | 1,850 | 13.8 | 12.2 | 1.6 |
| ETS 9 | 2,600 | 26.5 | 12.2 | 14.3 |
TES overspill: return head at each plant's tie-in is compared with its tank top water level. Sample result — both plants OK.
5. 8,760-hour dynamic operation
| Hour | Load (TR) | Flow (L/s) | Pump head needed (m) | Approx. speed |
|---|---|---|---|---|
| Aug 14:00 (design peak) | 4,500 | 472 | 89.3 | 100 % |
| Apr 12:00 (shoulder) | 3,150 | 331 | 52 | 76 % |
| Jan 03:00 (winter night) | 1,050 | 110 | 24 | 52 % |
The full-year scan reports lowest and highest pump head, hours of TES overspill risk, how often each ETS governs, and a head duration curve.
6. CHW corridor reservation
| Main DN | Insulation (mm) | Pipe gap (mm) | Side clearance (mm) | Cover (m) | Reserve width (m) |
|---|---|---|---|---|---|
| DN400 | 80 | 400 | 500 | 1.50 | ≈ 2.4 |
| DN300 | 80 | 400 | 500 | 1.50 | ≈ 2.2 |
| DN200 | 80 | 400 | 500 | 1.50 | ≈ 1.9 |
ETS branches are treated as road crossings and are not listed as corridors.
7. Network CAPEX build-up
Per segment: trench/m × length + 2 × pipe/m × length (supply + return) + fittings 25 % + testing and flushing/m + valve chambers (one per ETS branch plus each isolation valve dropped on the map), all × (1 + preliminaries 15 %).
| Item | USD M |
|---|---|
| Trench & installation | 2.67 |
| Pipe supply (S + R) | 2.21 |
| Fittings (25 % of pipe) | 0.54 |
| Testing & flushing | 0.14 |
| Valve chambers | 0.84 |
| Preliminaries (15 %) | 0.96 |
| Total | 7.38 |