Diesel particulate filter regeneration in transport refrigeration system

A method for performing a regeneration cycle for regenerating a diesel particulate filter used for removing particulate matter from a flow of engine exhaust gas from a diesel engine associated with a refrigeration system having a refrigeration unit powered by the diesel engine having a first higher RPM speed and a second lower RPM speed, the method comprising:

• determining whether the diesel engine is operating at the first higher RPM speed;
• if the diesel engine is not operating at the high RPM speed, increasing a refrigeration load on the refrigeration unit until the diesel engine is operating at the first higher RPM speed, and maintaining the increased refrigeration load on the refrigeration unit until the regeneration cycle is terminated;
• and
• if the diesel engine was not operating at the higher RPM initially, following termination of the regeneration cycle, decreasing the refrigeration load on the refrigeration unit;
• wherein the refrigeration system comprises a transport refrigeration system having a refrigeration unit having an evaporator heat exchanger for cooling a flow of air circulating from a refrigerated cargo box in a cooling mode and having an electric resistance heater operatively associated with the evaporator heat exchanger;
• and wherein increasing the load on the refrigeration unit comprises energizing the electric resistance heater operatively associated with the evaporator heat exchanger to heat the circulating air while operating the refrigeration unit in a cooling mode.

A transport refrigeration system comprising:

• a refrigeration unit having an evaporator heat exchanger and an electric resistance heater disposed in association with the evaporator heat exchanger;
• a diesel engine powering the refrigeration unit, the diesel engine having an exhaust system for discharging engine exhaust gas from the diesel engine to the atmosphere;
• a diesel engine exhaust gas treatment unit disposed in the diesel engine exhaust system, the diesel engine exhaust gas treatment unit including a diesel particulate filter;
• and
• a refrigeration unit controller for controlling operation of the refrigeration unit, the refrigeration unit controller configured to perform a regeneration cycle for regenerating the diesel particulate filter during a part-load operation of the refrigeration unit in a cooling mode by selectively increasing the refrigeration load until an operating engine speed of the diesel engine is increased to a target engine speed.