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Refrigeration, TR, COP and applications

Short answer

Refrigeration removes heat from a space to maintain temperature below surroundings. One ton of refrigeration equals 12000 Btu/h (3.517 kW). COP is the ratio of refrigerating effect to work input. Applications include domestic refrigerators, cold storage, air-conditioning, ice manufacture, and medical/vaccine storage.

Define refrigeration. Explain the terms ton of refrigeration and coefficient of performance (COP), and list five applications of refrigeration.

Refrigeration is the process of removing heat from a body or space so that its temperature is lowered below that of the surroundings and maintained there. It needs work (or heat) input and rejects heat to a higher-temperature sink.

Ton of refrigeration (TR)

One TR is the rate of heat removal needed to freeze 1 ton (2000 lb, the US short ton) of water at 0 °C into ice at 0 °C in 24 hours.

1 TR=2000×144 Btu24 h=12000 Btu/h=211 kJ/min=3.517 kW1\ \text{TR} = \frac{2000 \times 144\ \text{Btu}}{24\ \text{h}} = 12000\ \text{Btu/h} = 211\ \text{kJ/min} = 3.517\ \text{kW}

(With a metric tonne of ice per day the value is about 3.87 kW.)

Coefficient of performance

COP=refrigerating effectwork input=QLW\text{COP} = \frac{\text{refrigerating effect}}{\text{work input}} = \frac{Q_L}{W}

For a refrigerator the COP can exceed 1. The reversed Carnot (maximum) value is TL/(TH−TL)T_L/(T_H - T_L).

Applications

  1. Domestic refrigerators and freezers.
  2. Cold storage of food, fruits, vegetables, meat and milk; dairy plants.
  3. Air-conditioning of buildings and vehicles.
  4. Manufacture of ice, and chilling in breweries and chemical plants.
  5. Medical use: vaccine and blood storage, and industrial process cooling.

✓ Answer checked by Claude Opus 5.5 (high effort)

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