초록 ▼

A method and system for executing a hot gas heating cycle in a mobile refrigeration unit includes diverting a flow of hot gas by bypassing a condenser into a receiver and restricting the flow, thereby raising a discharge pressure and temperature of the unit. The discharge pressure of the unit is mon

A method and system for executing a hot gas heating cycle in a mobile refrigeration unit includes diverting a flow of hot gas by bypassing a condenser into a receiver and restricting the flow, thereby raising a discharge pressure and temperature of the unit. The discharge pressure of the unit is monitored, and the restriction is regulated when the discharge pressure reaches a predetermined pressure. A combination of small and large orifice hot gas valves is used, or optionally a hot gas stepper valve. A solenoid valve or an evaporator expansion valve is optionally used to meter refrigerant into the heat loop.

대표청구항 ▼

A method and system for executing a hot gas heating cycle in a mobile refrigeration unit includes diverting a flow of hot gas by bypassing a condenser into a receiver and restricting the flow, thereby raising a discharge pressure and temperature of the unit. The discharge pressure of the unit is mon

A method and system for executing a hot gas heating cycle in a mobile refrigeration unit includes diverting a flow of hot gas by bypassing a condenser into a receiver and restricting the flow, thereby raising a discharge pressure and temperature of the unit. The discharge pressure of the unit is monitored, and the restriction is regulated when the discharge pressure reaches a predetermined pressure. A combination of small and large orifice hot gas valves is used, or optionally a hot gas stepper valve. A solenoid valve or an evaporator expansion valve is optionally used to meter refrigerant into the heat loop. n timing, and a trailing fuel injection during a trailing period of an expansion stroke of the piston after the ignition timing, during a predetermined operating condition where the exhaust-gas purification catalyst is to be activated during engine cold start, and said fuel injection controller controls the fuel injector and the intake-air controller controls the amount of intake-air so that the excess air ratio in the combustion chamber is larger than 1 when the combustion of the fuel by the trailing fuel injection and the leading fuel injection completes, so that the turbine agitating the exhaust gas generates an after-burn causing a temperature rise of the exhaust gas being discharged to the exhaust gas purification catalyst disposed at the downstream side of said turbine. 2. The direct-injection spark-ignition engine of claim 1, wherein the predetermined operating condition occurs when said exhaust-gas purification catalyst is in an inactivated state, and wherein in an early stage of the inactivated state, said ignition controller causes the ignition device to ignite after MBT by a predetermined period and said injection controller causes the fuel injector to inject fuel prior to the ignition timing, and wherein in a late stage of the inactivated state, and said fuel injection controller controls the fuel injector and said intake-air controller controls the amount of intake-air so that an exhaust-gas air-fuel ratio after the combustion of the fuel by the trailing fuel injection is lean of the stoichiometric air-fuel ratio. 3. The direct-injection spark-ignition engine of claim 1, wherein at low engine rotational speed and low engine load, said fuel injection controller controls the fuel injector and said intake-air controller controls the amount of intake-air so that the excess air ratio in the combustion chamber is within the range of about 2 to 3, when the fuel of said leading fuel injection combusts. 4. The direct-injection spark-ignition engine of claim 3, further comprising a required engine-output monitoring device for monitoring the required engine output, wherein said intake-air controller is disposed in an intake-air passage leading to an inlet of the combustion chamber, and said fuel injection controller determines the amount of fuel by said leading fuel injection based on the required engine-output. 5. The direct-injection spark-ignition engine of claim 3, wherein said fuel injection controller controls the fuel injector and said intake-air controller controls the amount of intake-air, so that the excess air ratio in the combustion chamber is less than 2, when the fuel delivered by said trailing fuel injection combusts. 6. The direct-injection spark-ignition engine of claim 3, wherein said fuel injection controller sets the amount of fuel delivered by said leading fuel injection to be equal to or greater than the fuel delivered by said trailing fuel injection. 7. The direct-injection spark-ignition engine of claim 3, wherein said fuel injection controller sets the starting timing of the trailing fuel injection to be within the range of about 30° to 90° ATDC crank angle. 8. The direct-injection spark-ignition engine of claim 3, wherein said ignition controller sets an ignition timing by the ignition device to occur prior to the top-dead-center position of the piston during the compression stroke. 9. A direct-injection spark-ignition engine with a turbo-charging device, comprising: a fuel injector for directly injecting fuel into a combustion chamber; a piston for compressing the injected fuel; an ignition device for igniting the injected fuel; an exhaust-gas purification catalyst disposed downstream of a turbine of the turbo charging device in an exhaust-gas passage of the engine; a fuel injection controller for controlling an amount and a timing of fuel injection by said fuel injector; an ignition controller for controlling a ignition timing by said ignition device; and an intake-air controller for