Aldrich Valloyas

Durian cold storage room

Sizing the refrigeration system for a −20 °C fruit store, selecting compressor and evaporator to meet a 5.7 kW heat load at a COP of about 5.

−20 °C, for up to a year

filed underEnergy & thermal

ProjectDurian cold storage room
CourseThermodynamics
Date2024
TeamTeam of 3
My partMethodology
ToolsDanfoss Coolselector, Excel
Drawn byA. Valloyas
ScaleNTS
Sheet14 of 16
Refrigeration cycle schematic with the matching pressure–enthalpy diagram
cold room −20 °Cevaporatorcompressorcondenserexpansion valveR-134a6.86 kW capacity vs 5.75 kW load · COP ≈ 5.2
the system at a glance

A 4 × 3 × 5 m cold room, insulated with 100 mm of polyurethane, keeping durians at −20 °C for up to a year in 37 °C ambient conditions.

We built up the heat load (walls, floor, product, lighting, twice-daily electric defrost), then used Danfoss Coolselector to choose components. The selected compressor and evaporator deliver about 6.86 kW of cooling against a 5.75 kW requirement, leaving margin, at a COP of about 5.2.

One follow-up we flagged: the R-134a the brief specified has a global warming potential of 1,430, while R-290 (propane) is around 3. It’s worth a look for a system that will run for years.

Scraps from the build

R-134a cycle on the pressure–enthalpy chart.
R-134a cycle on the pressure–enthalpy chart.
Compressor performance across evaporating temperatures.
Compressor performance across evaporating temperatures.