Heat exchanger, refrigeration cycle apparatus, and method of manufacturing heat exchanger
A heat exchanger includes a plurality of fins spaced apart from each other such that gas flows therebetween, and a plurality of heat transfer tubes extending through the plurality of fins and joined to the plurality of fins by tube expansion. The heat transfer tubes are arranged in five or more columns along a flow direction of the gas and staggered in a row direction intersecting the flow direction of the gas. Each of the plurality of fins is flat and plate-shaped and continuously extends between the heat transfer tubes in the flow direction of the gas. The plurality of heat transfer tubes satisfy relationships of 1.055D≦Da≦1.068D and 1.56Da≦L≦2.58Da, where D is an unexpanded outside diameter of the heat transfer tubes, Da is an expanded outside diameter thereof, and L is a distance between centers of adjacent two heat transfer tubes.
1. A heat exchanger comprising:
a plurality of fins spaced apart from each other such that gas flows through spaces defined by the plurality of fins; and
a plurality of heat transfer tubes having a plurality of grooves extending axially on an inner surface and a plurality of protrusions, wherein each protrusion is located between two adjacent ones of the grooves, wherein the heat transfer tubes extend through the plurality of fins and are joined to the plurality of fins by tube expansion,
wherein the heat transfer tubes are arranged in five or more columns in a column arrangement direction along a flow direction of the gas and are arranged in a staggered pattern in a row arrangement direction, which intersects the flow direction of the gas,
wherein each of fins of the plurality of fins is flat and plate-shaped and extends continuously between the heat transfer tubes in the column arrangement direction without any cut,
wherein the plurality of heat transfer tubes satisfies relationships of
1.055D≦Da≦1.068D,
1.56Da≦L≦2.58Da, and
6.66D≦N≦10D,
where D is expressed in units of mm,
where D is an unexpanded outside diameter of each of the heat transfer tubes of the plurality of heat transfer tubes, Da is an expanded outside diameter thereof, L is a distance between centers of two adjacent ones of the heat transfer tubes, and N is a number of the protrusions and indicates a sum of the protrusions in the plurality of protrusions, and
wherein the plurality of fins satisfies a relationship of
0.3D≦Fp≦0.58D, and
0.026D≦Ft≦0.037D,
where Fp is a fin pitch that is a distance between two adjacent ones of the fins of the plurality of fins, and Ft is a thickness of each of the fins of the plurality of fins.
2. The heat exchanger of claim 1 , wherein the plurality of fins and the plurality of heat transfer tubes are composed of copper-containing metal.
3. The heat exchanger of claim 1 ,
wherein the heat transfer tubes are arranged in multiple rows in the row arrangement direction intersecting the flow direction of the gas, and
wherein each of the fins is flat and plate-shaped and continuously extends between the plurality of heat transfer tubes in the row arrangement direction.
4. The heat exchanger of claim 1 , wherein the plurality of heat transfer tubes satisfies a relationship of 3 mm≦D≦6 mm.
5. A refrigeration cycle apparatus comprising:
a refrigerant circuit through which refrigerant is circulated, the refrigerant circuit sequentially connecting, by pipes, a compressor, a condensor, an expansion unit, and an evaporator,
at least one of the condensor and the evaporator being the heat exchanger of claim 1 .
6. The refrigeration cycle apparatus of claim 5 , wherein the refrigerant is any of a single-component refrigerant of HC, a refrigerant mixture containing HC, R32, R410A, R407C, carbon dioxide, R1234yf, a refrigerant mixture containing at least R1234yf, R1234ze, and a refrigerant mixture containing at least R1234ze.
7. A method of manufacturing a heat exchanger, the method comprising:
inserting a plurality of heat transfer tubes having a plurality of grooves extending axially on an inner surface and a plurality of protrusions, wherein each protrusion is located between two adjacent ones of the grooves, into a plurality of fins spaced apart from each other; and
expanding the plurality of heat transfer tubes and joining the plurality of heat transfer tubes to the plurality of fins,
wherein the plurality of fins and the plurality of heat transfer tubes are composed of copper-containing metal,
wherein the plurality of heat transfer tubes satisfies relationships of
1.055D≦Da≦1.068D,
1.56Da≦L≦2.58Da, and
6.66D≦N≦10D,
where D is expressed in units of mm,
where D is an unexpanded outside diameter of each of the heat transfer tubes of the plurality of heat transfer tubes, Da is an expanded outside diameter thereof, L is a distance between centers of two adjacent ones of the heat transfer tubes, and N is a number of the protrusions and indicates a sum of the protrusions in the plurality of protrusions,
wherein the plurality of fins satisfies a relationship of
0.3D≦Fp≦0.58D, and
0.026D≦Ft≦0.037D,
where Fp is a fin pitch, which is a distance between two adjacent ones of the fins of the plurality of fins, and Ft is a thickness of each of the fins of the plurality of fins.