Refrigeration system with consecutive expansions and method

A method for cooling, dehumidification, and heating air with a refrigeration system including a refrigerant circuit and an air circuit;

• the refrigerant circuit including a compressor, a first and second heat exchangers, said first heat exchanger consisting of an auxiliary section and a main section, a first and second expansion devices with the first expansion device located between the first and second heat exchangers and the second expansion device located between the auxiliary and the main sections of the first heat exchanger;
• the air circuit including a fan moving air to be conditioned, the method for operation:
• in a conventional cooling mode, in a cooling mode with enhanced dehumidification, in a conventional heating mode, and in an improved heating mode with increased capacity and efficiency, the method including the steps:
• in the conventional cooling mode:
• compressing refrigerant vapor in the compressor,
• condensing refrigerant vapor after the compressor in the second heat exchanger,
• expanding refrigerant in the first expansion device,
• evaporating a part of liquid refrigerant in the auxiliary section of the first heat exchanger while absorbing heat from conditioning air,
• flowing refrigerant through the second expansion device without expansion,
• evaporating the rest of liquid refrigerant in the main section of the first heat exchanger while absorbing heat from conditioning air,
• returning vapor refrigerant to the compressor,
• moving conditioning air first through the main section and then through the auxiliary section;
• in the cooling with enhanced dehumidification mode:
• compressing refrigerant in the compressor,
• condensing refrigerant vapor after the compressor in the second heat exchanger,
• expanding liquid refrigerant in the first expansion device,
• condensing refrigerant vapor after expansion in the auxiliary section of the first heat exchanger while rejecting heat to conditioning air,
• expanding refrigerant in the second expansion device,
• evaporating liquid refrigerant in the main section of the first heat exchanger while absorbing heat from conditioning air,
• returning vapor refrigerant to the compressor,
• moving air first through the main section and then through the auxiliary section;
• in the conventional heating mode:
• compressing refrigerant in the compressor,
• partly condensing refrigerant vapor after the compressor in the main section of the first heat exchanger while rejecting heat to conditioning air,
• flowing refrigerant through the second expansion device without expansion,
• condensing the rest of refrigerant vapor in the auxiliary section of the first heat exchanger while rejecting heat to conditioning air,
• expanding refrigerant in the first expansion device,
• evaporating liquid refrigerant in the second heat exchanger,
• returning vapor refrigerant to the compressor,
• moving air first through the auxiliary section and then through the main section;
• in the improved heating mode:
• compressing refrigerant in the compressor,
• condensing refrigerant vapor after the compressor in the main section of the first heat exchanger while rejecting heat to conditioning air,
• expanding liquid refrigerant in the second expansion device,
• condensing refrigerant vapor after expansion in the auxiliary section of the first heat exchanger while rejecting heat to conditioning air,
• expanding refrigerant in the first expansion device,
• evaporating liquid refrigerant in the second heat exchanger,
• returning vapor refrigerant to the compressor,
• moving air first through the auxiliary section and then through the main section.

A refrigeration system (heat pump) for conditioning air operating in two heating modes:

• in a conventional heating mode and in an improved heating mode with increased capacity and efficiency, the system including an air circuit with a fan for moving air to be conditioned and a refrigerant circuit, the refrigerant circuit including in serial connections:
• a compressor for compressing refrigerant vapor;
• a first heat exchanger for conditioning air with two sections:
• a main section operating as a first part of a single condenser in the conventional heating mode or as a first condenser in the improved heating mode;
• an auxiliary section operating as a second part of the single condenser in the conventional heating mode or as a second condenser in the improved heating mode;
• a second heat exchanger, operating as an evaporator;
• a first expansion device located between the first and the second heat exchangers in proximity to the second heat exchanger expanding refrigerant before the second heat exchanger;
• a second expansion device located between the auxiliary and the main sections of the first heat exchanger, said second expansion device expanding refrigerant in the improved heating mode and allowing refrigerant to flow through without expansion in the conventional heating mode;
• lines for flowing refrigerant from the compressor through the first and second heat exchangers and the expansion devices back to the compressor;
• refrigeration system auxiliary parts:
• a dryer, an accumulator, and/or a receiver.

A refrigeration system for conditioning air operating in two cooling modes:

• in a conventional cooling mode and in a cooling mode with enhanced dehumidification, the system including an air circuit with a fan for moving air to be conditioned and a refrigerant circuit, the refrigerant circuit including in serial connections:
• a compressor for compressing refrigerant vapor;
• a first heat exchanger for conditioning air with at least two sections:
• an auxiliary section operating as a first part of a single evaporator in the conventional cooling mode or as a second condenser in the cooling mode with enhanced dehumidification;
• a main section operating as a second part of the evaporator in the conventional cooling mode or as a single evaporator in the cooling mode with enhanced dehumidification;
• a second heat exchanger operating as a condenser;
• a first expansion device located between the first and the second heat exchangers in proximity to the first heat exchanger expanding refrigerant before the auxiliary section of the first heat exchanger;
• a second expansion device located between the auxiliary and the main sections of the first heat exchanger, said second expansion device expanding refrigerant in the cooling mode with enhanced dehumidification and allowing refrigerant to flow through without expansion in the conventional cooling mode;
• lines for flowing refrigerant from the compressor through the first and second heat exchangers and the expansion devices back to the compressor;
• refrigeration system auxiliary parts:
• a dryer, an accumulator, and/or a receiver.