A heat exchanger includes a plurality of principal heat exchange sections and auxiliary heat exchange sections. Each of the auxiliary heat exchange sections is in series connection to a corresponding one of the principal heat exchange sections. Tube number ratios of the principal heat exchange sections are obtained by dividing the number of the flat tubes constituting each of the principal heat exchange sections by the number of the flat tubes constituting a corresponding one of the auxiliary heat exchange sections. Of the principal heat exchange sections, the first principal heat exchange section, which is the lowermost one, has the smallest tube number ratio. Consequently, discharge of liquid refrigerant from a lower portion of the first principal heat exchange section is accelerated during defrosting, thereby shortening the time required for defrosting.

The present invention provides an evaporator comprising: an evaporator case having first and second case sheets coupled to each other and bent such that both sides of the evaporator case are open, thereby forming a box shape, a food storing space being formed inside the evaporator case; a cooling tube provided as an empty space between the first and second case sheets, thereby forming a cooling channel through which a refrigerant flows; and a heating tube formed as an empty space between the first and second case sheets so as not to overlap with the cooling tube, thereby forming a heating channel for defrosting, wherein the cooling tube and the heating tube are shaped to protrude to the outside of the evaporator case, and the evaporator case has an inner surface formed to be flat.

A laminated header includes: a first passage plate having a flat-plate shape in which a first passage is formed; a second passage plate having a flat-plate shape in which a plurality of second passages are formed; a third passage plate having a flat-plate shape in which a plurality of third passages are formed; a first branch passage plate having a flat-plate shape in which an upstream side branch passage is formed, the upstream side branch passage branching the first passage into the plurality of second passages; and a second branch passage plate having a flat-plate shape in which a downstream side branch passage is formed, the downstream side branch passage branching one of the plurality of second passages into the plurality of third passages.

A motor vehicle heat exchanger system includes a closed circuit for a working medium and an evaporator for evaporation of the working medium. The evaporator includes at least two evaporator cassettes having an exhaust gas channel formed between the evaporator cassettes. Each evaporator cassette includes a capillary structure and a liquid side and a vapor side. A medium feed is provided on the liquid side for liquid working medium. Each evaporator cassette includes a vapor collector.

A refrigeration cycle apparatus including a refrigerant circuit including a compressor, an indoor heat exchanger, an expansion device, an outdoor heat exchanger, an outside air temperature sensor, and a controller configured to perform a hot gas defrosting operation and a reverse-defrosting operation based on a temperature obtained by the outside air temperature sensor. In the hot gas defrosting operation, hot gas discharged from the compressor without passing through the indoor heat exchanger is supplied to the outdoor heat exchanger. In the reverse-defrosting operation, refrigerant passing through the indoor heat exchanger is supplied from the compressor to the outdoor heat exchanger. The controller has at least a mixed defrosting operation mode in which the hot gas defrosting operation and the reverse-defrosting operation are performed in sequence. The controller is configured to start the mixed defrosting operation mode when the temperature obtained by the outside air temperature sensor satisfies a preset condition.

An ejector-integrated heat exchanger includes multiple tube forming members. The tube forming member includes an ejector, a flow-out side refrigerant passage, and a suction side refrigerant passage. The ejector includes a nozzle portion decompressing a refrigerant, a refrigerant suction port, and a pressure increasing portion in which the refrigerant drawn from the refrigerant suction port and the refrigerant jetted from the nozzle portion are mixed, a pressure of the mixed refrigerant being increased in the pressure increasing portion. In the flow-out side refrigerant passage, the refrigerant flowing out of the pressure increasing portion performs heat exchange while flowing. In the suction side refrigerant passage, the refrigerant that is to be drawn through the refrigerant suction port performs heat exchange while flowing. Multiple tube forming members are arranged such that the refrigerant flows in parallel with each other.

The present invention includes refrigerant composition, including trifluoroiodomethane (CF.sub.3I); 1,1,1,2-tetrafluoropropene (HFO-1234yf); difluoromethane (HFC-32); and pentafluoroethane (HFC-125), for use in a heat exchange system, including refrigeration applications and in particular aspects to the use of such compositions as a replacement of the refrigerant R-404A for heating and cooling applications and to retrofitting heat exchange systems, including systems designed for use with R-404A.

In one general aspect, a converging split-flow microchannel evaporator is disclosed. It includes a conductive contact surface to mate to a surface to be cooled, with a core mounted in thermal connection with the conductive surface that defines at least one layer of microchannels. Within the core, one inlet restriction restricts the flow into each microchannel in a first group of the microchannels, and another restricts the flow into each microchannel in a second group. A centrally located fluid outlet receives the flows from opposite ends of the microchannels in the two groups. A check valve can be provided to help ensure ready startup without reverse flow.

A laminated header according to the present invention includes: a first plate-like body having a plurality of first outlet flow passages formed therein; and a second plate-like body laminated on the first plate-like body, the second plate-like body having a distribution flow passage formed therein, the distribution flow passage being configured to distribute refrigerant, which passes through a first inlet flow passage to flow into the second plate-like body, to the plurality of first outlet flow passages to cause the refrigerant to flow out from the second plate-like body. A branching flow passage of the distribution flow passage includes: a branching portion; an inflow passage extending toward the branching portion; and a plurality of outflow passages extending from the branching portion in directions different from each other. Curvature radii of bending portions of the plurality of outflow passages are different from each other.

The evaporator unit includes an ejector, a discharge-side evaporator, and a suction-side evaporator. The discharge-side evaporator includes discharge-side tubes and a discharge-side tank. The discharge-side tank defines a discharge-side distribution chamber therein which distributes refrigerant to the discharge-side tubes. A partition plate is disposed in the discharge-side distribution chamber and divides the discharge-side distribution chamber into an ejector-side distribution chamber and a tube-side distribution chamber. The partition plate includes a communication hole through which the ejector-side distribution chamber and the tube-side distribution chamber are in fluid communication with each other. The partition plate includes a first portion, a second portion, a third portion, a fourth portion, and a fifth portion. The communication hole has an open area that is larger in each of the first portion, the third portion and the fifth portion than in each of the second portion and the fourth portion.