EP-4095475-B1 - HEAT EXCHANGER

Inventors

• NAKATA, Shohei
• WATANABE, MASATOSHI
• MAEMA, Yoshinari
• SHIMANO, Daiki
• OKA, KOTARO

Dates

Publication Date

20260506

Application Date

20200930

Claims (4)

1. A heat exchanger (100) (200) comprising: an inlet header (120) in which a plurality of inlet spaces including a first inlet space (2-1) and a second inlet space (2-2) adjacent to and under the first inlet space (2-1) are formed; a plurality of inlet-side heat exchanger tubes (111a) that includes a plurality of first inlet-side heat exchanger tubes that are connected to the first inlet space (2-1) and that are aligned vertically and a plurality of second inlet-side heat exchanger tubes that are connected to the second inlet space (2-2) and that are aligned vertically; a return header (170) in which a plurality of return spaces that are connected to the inlet-side heat exchanger tubes, respectively, are formed, the return spaces including a plurality of first return spaces (5-1) that are connected to the first inlet-side heat exchanger tubes, respectively, and that are aligned vertically and a plurality of second return spaces (5-2) that are connected to the second inlet-side heat exchanger tubes, respectively, and that are aligned vertically; and a plurality of outlet-side heat exchanger tubes (111b) that are connected to the return spaces, respectively, and that are aligned vertically, wherein the second inlet space (2-2) is isolated from the first inlet space (2-1), a communication path (21) that enables a first return space (6) on a bottom side among the first return spaces (5-1) and a second return space (7) on a top side among the second return spaces (5-2) to communicate is further formed in the return header (170), the first return space (6) on the bottom side is isolated from a plurality of third return spaces (5-3) different from the second return space (7) on the top side among the plurality of return spaces, the second return space (7) on the top side is isolated from a plurality of fourth return spaces (5-4) different from the first return space (6) on the bottom side among the plurality of return spaces, and a plurality of fifth return spaces other than the first return space (6) on the bottom side and the second return space (7) on the top side among the plurality of return spaces are isolated from one another.
2. The heat exchanger according to claim 1, wherein a total number of the return spaces (5-1 to 5-4) is equal to a total number of the inlet-side heat exchanger tubes (111a).
3. The heat exchanger according to claim 1, wherein the inlet-side heat exchanger tubes (111a) are arranged along the outlet-side heat exchanger tubes (111b).
4. The heat exchanger according to claim 1, wherein the inlet spaces include a top side inlet space and another inlet space that is arranged under the top side inlet space, and the number of inlet-side heat exchanger tubes that are connected to the top side inlet space among the inlet-side heat exchanger tubes is smaller than the number of inlet-side heat exchanger tubes that are connected to the another inlet space among the inlet-side heat exchanger tubes.

Description

Field The present invention relates to a heat exchanger. Background A heat exchanger is provided in a compressor unit and an indoor equipment of an air conditioner. The heat exchanger functions as an evaporator or a condenser by heat exchange between a coolant that flows inside a heat exchanger tube and the air that flows around fins that are arranged around the heat exchanger tube. Heat exchangers include one in which heat exchanger tubes are multilayered at intervals vertically at the time of setting and one in which a plurality of rows of the multilayered heat exchanger tubes are aligned and coolant is caused to reciprocate through the rows (for example, Patent Literature 1). Specifically, the heat exchanger includes a plurality of first heat exchanger tubes with one ends connected to one header (inlet header) and a plurality of second heat exchanger tubes with one ends connected to another header (outlet header). Furthermore, the heat exchanger includes a return header to which other ends of the first heat exchanger tubes and other ends of the second heat exchanger tubes are connected. The return header includes a condenser space that connects the inside of the first heat exchanger tube and the inside of the second heat exchanger tube that are connected in the same position in the vertical direction. In other words, flow paths that are independent at each level are formed in the return header. The coolant that flows into the inlet header is divided into each of the first heat exchanger tubes in the inlet header. The coolant that flows through the first heat exchanger tubes flows into the second heat exchanger tubes at the same level as that of the first heat exchanger tubes. The coolant that flows through the second heat exchanger tubes joins in the outlet header and flows out of the outlet header. As described above, reciprocating the coolant makes the coolant flow path length long, which enables a lot of coolant to sufficiently evaporate. When the heat exchanger is used as an evaporator, the state of the coolant that flows into the inlet header is preferably a gas-liquid two-phase state. In the above-described heat exchanger, when the coolant is divided into each of the first heat exchanger tubes in the inlet header, the coolant in the liquid-phase state goes down because of the effect of the gravity and the coolant in the gas sate goes up. As a result, there is a problem in that an imbalance occurs in the distribution of the coolant in the inlet header and the coolant in the liquid-phase state and the coolant in the gas state tend not to be divided in the even state. The proportion of the gas phase of the coolant flowing through the heat exchanger tube on an upper side among the layered heat exchanger tubes is higher than the proportion of the gas phase of the coolant flowing through the heat exchanger tube on a lower side. In a coolant with a high proportion of the gas phase (high dryness), the amount of coolant that can be vaporized is small and therefore the amount of latent heat that contributes to heat exchange with a fluid outside the tube (the air) is small. In other words, the amount of heat exchange with the air differs between the heat exchanger tube on the upper side and the heat exchanger tube on the lower side among the layered heat exchanger tubes. As a result, the coolant flowing through the heat exchanger tube on the upper side enters an excessively-heated state before the coolant flowing through the heat exchanger tube on the lower side evaporates completely and an area that does not contribute to heat exchange with the air is caused in the heat exchanger. When a heat exchange area not contributing to heat exchange with the air occurs, the heat exchanger causes a decrease in ability of heat exchange. Thus, the heat exchanger illustrated in FIG. 10 in Patent Literature 2 forms a plurality of spaces that are aligned vertically in the inlet header to cause the coolant to flow into each of the spaces. The vertical length of each of the spaces is smaller than the vertical length of the entire header and therefore the effect of the gravity is reduced and it is possible to cause the coolant to be distributed in an even state and flow into a plurality of flat tubes that are connected to the respective spaces. Citation List Patent Literature Patent Literature 1: Japanese Laid-open Patent Publication No. 2011-214827Patent Literature 2: Japanese Laid-open Patent Publication No. 2015-200497Patent literature 3: WO 2008/064247 A1 Summary Technical Problem In each of the spaces, however, unevenness in the coolant state in the vertical direction because of the effect of the gravity occurs. In the return header, the flow path independent at each level is formed inside and therefore improvement is not made until the unevenness in the coolant state occurring in the inlet header reaches the outlet header. The disclosed technique was made in view of the above-described aspect and an object of the techniq