Vehicle air conditioning apparatus

A vehicle air conditioning apparatus comprising:

• a heat-radiating inside-vehicle-compartment heat exchanger adapted to radiate heat of compressed gas-phase refrigerant into an air stream to be blown off to a vehicle compartment for condensing refrigerant;
• expansion means for expanding the refrigerant condensed in the heat-radiating inside-vehicle-compartment heat exchanger:
• a heat-absorbing inside-vehicle-compartment heat exchanger adapted to compel heat of the air stream inside the vehicle compartment to be absorbed by the refrigerant expanded by the expansion means;
• a variable displacement compressor adapted to be driven by an engine to compress the refrigerant evaporated in the heat-absorbing inside-vehicle-compartment heat exchanger;
• blow-off temperature detection means for detecting at least one of a blow-off temperature or a numeric value correlated with the blow-off temperature;
• and
• compressor control means operative to control a discharge refrigerant volume of the variable displacement compressor such that the blow-off temperature lies at a given temperature responsive to a detection result of the blow-off temperature detection means;
• wherein the blow-off temperature detection means includes a sensor that detects a discharge refrigerant temperature of the variable displacement compressor.

The A vehicle air conditioning apparatus comprising:

• a heat-radiating inside-vehicle-compartment heat exchanger adapted to radiate heat of compressed gas-phase refrigerant into an air stream to be blown off to a vehicle compartment for condensing refrigerant;
• expansion means for expanding the refrigerant condensed in the heat-radiating inside-vehicle-compartment heat exchanger;
• a heat-absorbing inside-vehicle-compartment heat exchanger adapted to compel heat of the air stream inside the vehicle compartment to be absorbed by the refrigerant expanded by the expansion means;
• a variable displacement compressor adapted to be driven by an engine to compress the refrigerant evaporated in the heat-absorbing inside-vehicle-compartment heat exchanger;
• blow-off temperature detection means for detecting at least one of a blow-off temperature or a numeric value correlated with the blow-off temperature;
• and
• compressor control means operative to control a discharge refrigerant volume of the variable displacement compressor such that the blow-off temperature lies at a given temperature responsive to a detection result of the blow-off temperature detection means;
• wherein the given temperature includes a target blow-off temperature to be assigned as a setting temperature of a vehicle compartment.

A vehicle air conditioning apparatus comprising:

• a heat-radiating inside-vehicle-compartment heat exchanger adapted to radiate heat of compressed gas-phase refrigerant into an air stream to be blown off to a vehicle compartment for condensing refrigerant;
• expansion means for expanding the refrigerant condensed in the heat-radiating inside-vehicle-compartment heat exchanger;
• a heat-absorbing inside-vehicle-compartment heat exchanger adapted to compel heat of the air stream inside the vehicle compartment to be absorbed by the refrigerant expanded by the expansion means;
• a variable displacement compressor adapted to be driven by an engine to compress the refrigerant evaporated in the heat-absorbing inside-vehicle-compartment heat exchanger;
• blow-off temperature detection means for detecting at least one of a blow-off temperature or a numeric value correlated with the blow-off temperature;
• and
• compressor control means operative to control a discharge refrigerant volume of the variable displacement compressor such that the blow-off temperature lies at a given temperature responsive to a detection result of the blow-off temperature detection means;
• wherein the expansion means includes an expansion valve having a valve-opening characteristic that, in a practical operating area of the variable displacement compressor in a graph where an ordinates axis represents a refrigerant pressure of the heat-absorbing inside-vehicle-compartment heat exchanger and an abscissa axis represents a discharge refrigerant pressure of the variable displacement compressor, does not intersect a control valve characteristic of the variable displacement compressor and has a slope which is inclined downward in proportion to the discharge refrigerant pressure.

A vehicle air conditioning apparatus comprising:

• a heat-radiating inside-vehicle-compartment heat exchanger adapted to radiate heat of compressed gas-phase refrigerant into an air stream to be blown off to a vehicle compartment for condensing refrigerant;
• expansion means for expanding the refrigerant condensed in the heat-radiating inside-vehicle-compartment heat exchanger;
• a heat-absorbing inside-vehicle-compartment heat exchanger adapted to compel heat of the air stream inside the vehicle compartment to be absorbed by the refrigerant expanded by the expansion means;
• a variable displacement compressor adapted to be driven by an engine to compress the refrigerant evaporated in the heat-absorbing inside-vehicle-compartment heat exchanger;
• blow-off temperature detection means for detecting at least one of a blow-off temperature or a numeric value correlated with the blow-off temperature;
• compressor control means operative to control a discharge refrigerant volume of the variable displacement compressor such that the blow-off temperature lies at a given temperature responsive to a detection result of the blow-off temperature detection means;
• and
• intake refrigerant pressure detection means for detecting an intake refrigerant pressure of the variable displacement compressor or a numeric value correlated with the intake refrigerant pressure,
• wherein the compressor control means controls a discharge refrigerant volume of the variable displacement compressor such that, in response to a detection result of the intake refrigerant pressure detection means in addition to the detection result of the blow-off temperature detection means, the blow-off temperature becomes closer to a given temperature while maintaining a compression ratio of the variable displacement compressor at a value below a given value.

A vehicle air conditioning apparatus comprising:

• a heat-radiating inside-vehicle-compartment heat exchanger adapted to radiate heat of compressed gas-phase refrigerant into an air stream to be blown off to a vehicle compartment for condensing refrigerant;
• expansion means for expanding the refrigerant condensed in the heat-radiating inside-vehicle-compartment heat exchanger:
• a heat-absorbing inside-vehicle-compartment heat exchanger adapted to compel beat of the air stream inside the vehicle compartment to be absorbed by the refrigerant expanded by the expansion means:
• a variable displacement compressor adapted to be driven by an engine to compress the refrigerant evaporated in the heat-absorbing inside-vehicle-compartment heat exchanger;
• blow-off temperature detection means for detecting at least one of a blow-off temperature or a numeric value correlated with the blow-off temperature;
• compressor control means operative to control a discharge refrigerant volume of the variable displacement compressor such that the blow-off temperature lies at a given temperature responsive to a detection result of the blow-off temperature detection means;
• inner and outer and air regulating means for regulating a ratio between an inner air stream and an outer air stream to be introduced into an inside-vehicle-compartment air flow passage;
• an outlet temperature detection means for detecting an air temperature at an outlet of the heat-absorbing inside-vehicle-compartment heat exchanger or a numeric value correlated with the air temperature;
• and
• inner and outer air control means responsive to a detection result of the outlet temperature detection means to control the inner and outer air regulating means such that an air temperature at an outlet of the heat-absorbing inside-vehicle-compartment heat exchanger lies at a given value.

A vehicle air conditioning apparatus comprising:

• a subcondenser adapted to radiate heat of compressed gas-phase refrigerant into an air stream to be blown off to a vehicle compartment, by condensing refrigerant;
• an expander configured to expand the refrigerant condensed by the subcondenser;
• an evaporator adapted to compel heat of the air stream inside the vehicle compartment to be absorbed by the refrigerant expanded by the expander;
• a variable displacement compressor adapted to be driven by an engine to compress the refrigerant evaporated by the evaporator;
• a blow-off temperature detector configured to detect at least one of a blow-off temperature or a numeric value correlated with the blow-off temperature;
• a controller configured to control a discharge refrigerant volume of the variable displacement compressor such that the blow-off temperature lies at a given temperature responsive to a detection result of the blow-off temperature detector;
• and
• a heater positioned upstream of the subcondenser in the direction of air flow, configured to provide heat to the subcondenser.