PCM Cold Store Bench

Encapsulated packed bed · district cooling Change any input on the left. Charge and discharge are re-simulated with a moving-front capsule model and a 40-node packed bed.

Tank

Tank volume m³

Height / diameter ratio

Packing porosity void frac.

Insulation U W/m²K

Ambient °C

Temperatures & flow

Chiller supply, charging °C

Return from network, top °C

Max useful supply °C

Discharge counts only while the tank outlet stays below the max useful supply temperature.

Charging flow m³/h

Discharging flow m³/h

Phase change material

Melting onset °C

Melting complete °C

Freezing onset °C

Freezing complete °C

Latent heat kJ/kg

Density, solid kg/m³

Density, liquid kg/m³

Specific heat kJ/kgK

k, solid W/mK

k, liquid W/mK

Melt convection factor ×k

Natural convection in the molten layer raises effective conductivity during discharge only. 1 = pure conduction.

Capsule & encapsulation

Sphere outer diameter mm

Shell thickness mm

Shell k (HDPE) W/mK

Shell density kg/m³

Shell specific heat kJ/kgK

Fill fraction % of void

Headspace absorbs the volume change on melting — 12.5 % for paraffins.

Operation & economics

Night charge window h

Design discharge duration h

Chiller COP, daytime

Chiller COP, night

On-peak tariff /kWh

Off-peak tariff /kWh

Demand charge /kW/month

Pump efficiency

Operating days / year

Grid intensity gCO₂/kWh

Thermal resistance of one capsule

HDPE shell
converted layer
unconverted core

Tank outlet temperature °C vs hours

State of charge % vs hours

Charge / discharge timing

Power & cost — with PCM store vs chiller-only same delivered cooling

Design checks