Mitsubishi develops heat pump truck refrigeration unit

Tokyo, Japan: Mitsubishi Heavy Industries has developed a truck refrigeration unit which enables simultaneous temperature control of two separate cargo compartments with different temperature settings entirely by heat pump. The unit marks the world’s first application of a heat pump for a truck refrigeration unit, the company says.

The heat pump enables effective transfer of thermal energy from the compartment needing a lower temperature to a cargo room requiring higher temperature, and in this way the new unit provides more than double the warming capacity compared with conventional systems that use heat from a compressor for heating.

At maximum, the unit reduces energy consumption by 75% compared with conventional systems; it will also realize significant energy savings and reduced CO2 emissions.  Mitsubishi will have units for sale in Japan from April next year, initially targeting trucks operators in food transport that require multi-temperatures.

The new model, the TDJS35HP series, is a direct drive unit that can maintain 5°C in the front compartment and 20°C in the rear compartment – a temperature suitable for warm rice-based foods and bread – with an ambient temperature range between minus 10°C and 40°C. Rated heating capacity is 5.7kW.

The current model has 2.5kW rated heating capacity and uses hot-gas bypass technology.  Compared with the TDJ301DM, the new model achieves a 130% increase in heating capacity and 35% improvement in energy consumption, and as a result overall it realizes 3.5 times greater efficiency and 70% lower energy consumption.

To cool a compartment and heat a compartment together, previous models required to stop one operation and perform the two tasks in alternating succession.  The TDJS35HP is more efficient in that it transfers the thermal energy from one side where the temperature is lower to the other side in order to raise the temperature of warm compartment.  By performing heating and cooling together, the new model has achieved a 25% improvement in energy consumption, 70% increase in cooling capacity and 380% enhancement in heating capacity.

Overall, the new model is 4.3 times more efficient with 75% lower energy consumption, which also enables a 75% reduction in CO2 emissions.

The needs for a truck refrigeration unit that enables warming, chilling and freezing management in different temperature ranges within one truck has been increasing in the distribution industry in order to boost delivery efficiency in a quest to reduce energy consumption and CO2 emissions.

When chilled products and warm foods, such as rice and bread products, are carried in different compartments, the new unit can meet industry needs by accommodating seasonal ambient temperature changes flexibly and providing optimal operations: for example, cooling of both compartments in summer, heating of both in winter, and simultaneous heating and cooling in spring and autumn.

Mitsubishi and Ryoju Cold Chain will exhibit the new truck refrigeration unit at the 2011 Tokyo Truck Show 27 – 29 October.  Ryoju Cold Chain is a wholly owned subsidiary of Mitsubishi handling domestic marketing of truck refrigeration units.