❄️ District Cooling — Централизованное холодоснабжение

Модуль #303. План «Астана-Холод» (Эспанаход, Астана-EXPO 2017 area) — централизованное cooling 50 МВт холода для офисных кварталов + EXPO Mall. Reference: ADWEA Empower Dubai (200 кв km coverage), Tabreed UAE 1300 МВт, Helsinki Energy DC. Технология — large chillers York YK 5000 RT (1 RT = 3.5 кВт холода) + ice storage thermal energy storage TES. Холод distributed через insulated chilled water pipe 5-7 °C supply → return 12-14 °C, primary loop с heat exchanger на zonal substations. ASHRAE 90.1 + IDEA District Cooling Best Practices + СНиП 41-01.

1. Состав DC plant 50 МВт холода

Centrifugal chillers York YK 5000 RT: 4 шт × 12.5 МВт холода (3552 RT) каждый, R-1233zd hydrofluoroolefin HFO refrigerant (low GWP=1), COP 6.5 cooling;
Cooling tower: Marley NC8400 induced-draft × 6 cells × 20 МВт thermal reject, water consumption 50 м³/час evaporation, drift loss <0.01%;
Ice TES Thermal Energy Storage: 100 000 кВт·ч ice tank (для peak shaving 4 hr × 25 МВт holiday peak), Calmac Ice Bank tanks, ice formed nighttime cheap electricity, melted daytime;
Primary chilled water pump: 4 шт Sulzer SMS 1000 м³/час × 35 м H VFD ABB, 7 °C supply / 14 °C return;
Distribution loop pre-insulated pipe: Logstor PEX-c HD500 буровое pre-insulated direct burial Ø600 мм × 15 км city loop, 50 мм PUR insulation + HDPE outer 10 mm;
Zonal substations: 50 шт по building blocks, plate heat exchanger Tranter GX-91 200-500 кВт каждый, isolates primary loop от secondary internal building chilled water;
Make-up water: RO + softener для cooling tower water (zero scale + low conductivity), automatic chemistry control bromine biocide;
SCADA + BMS: Siemens DESIGO + Schneider EcoStruxure, real-time load optimisation cells optimization, predictive analytics;
Backup generators: 2× DG 2.5 МВт on 12 hr backup для critical operations;
Loops monitoring: pressure sensors каждые 500 м + leak detection acoustic;
Maintenance shop + spare parts: 500 м², 10% spare compressors stock;
Customer metering: Endress+Hauser BTU meters at each substation для billing per кВт·ч cooling;
Control room 24/7: 4-сменка 16 чел + dispatch optimisation algorithm;
EHS compliance: R-1233zd low GWP, no ozone depletion, F-Gas Regulation EU 517/2014 friendly;
Service tunnels: для multi-utility (DC + power + fiber + telecom) Ø3 м под главные проспекты.

Упражнение 1 — DC vs individual chillers

Always individual chillers per buildingТолько в холодных климатахТолько для residentialDistrict Cooling выигрывает в total opex при density >50 кВт холода/га + 24/7 commercial use: (1) economies of scale chillers 5000 RT @ COP 6.5 vs 500 RT @ COP 5.0 = 30% efficiency gain, (2) diversity factor 60-70% (peaks не одновременно во всех buildings) vs individual 100% sizing, (3) ice TES экономит 25-35% electricity bill через off-peak charging, (4) централизованная ESG reporting + R-1233zd vs scattered R-410A units, (5) lower total CO2 footprint 40-50% vs individual, (6) capital savings 20-30% всему metropolitan area, (7) hot water by-product от waste heat recovery (for nearby industrial), Reference Dubai Empower 200 km² coverage. IDEA District Cooling Best Practices + ASHRAE 90.1

Упражнение 2 — Capacity in RT

50 МВт холода = сколько RT (Refrigeration Tons)? 1 RT = 3.517 кВт холода

Упражнение 3 — Капекс DC 50 МВт

York YK 5000 RT × 4 + R-1233zd refrigerant = 8 млрд
Cooling tower Marley NC8400 × 6 cells = 3.5 млрд
Ice TES Calmac 100 000 кВт·ч + chillers = 4.5 млрд
Distribution loop Logstor PEX-c Ø600 × 15 км = 8 млрд
Zonal substations 50 × plate HE + pumps + valves = 5 млрд
SCADA + BMS Siemens DESIGO + control room = 1.5 млрд
Backup DG + UPS + civil works + проект 5% + PNR = 4.5 млрд

Упражнение 4 — Refrigerant choice

R-22 HCFC устаревшийАммиак NH3 в city centre — toxicR-1233zd HFO Hydrofluoroolefin: GWP=1 (vs R-134a GWP=1430, R-410A GWP=2088), zero ODP, A1 non-flammable safety class, EU F-Gas Regulation 517/2014 compliant до 2030+, оптимально для centrifugal chillers York/Carrier/Trane, COP 6.5 efficient, capacity loss <2% vs R-134a. ASHRAE 34 + EU F-Gas + Kigali Amendment Montreal ProtocolCO2 transcritical для DC

Нормативная база

ASHRAE 90.1 — Energy Standard for Buildings
ASHRAE 34 — Designation Safety Classification of Refrigerants
IDEA District Cooling Best Practices — International District Energy Association
EU F-Gas Regulation 517/2014 — Fluorinated Greenhouse Gases
Kigali Amendment 2016 — Montreal Protocol HFC phase-down
СНиП 41-01-2003 — Отопление, вентиляция, кондиционирование
СН РК 4.02-15 — Холодоснабжение
EN 14511 — Cooling capacity testing