JPWO2014115332A1 - Heat exchanger and refrigeration cycle apparatus - Google Patents

Abstract

A pair of inlet header 3 and outlet header 5 that are spaced apart from each other, and are arranged in parallel between the inlet header 3 and the outlet header 5, and both ends of the inlet header 3 and the outlet header 5 enter the header from the through holes. A wave exchanger 4 having a plurality of flat tubes 1 to be inserted and having a corrugation and a corrugated shape in a tube of an inlet header 3 on the refrigerant inflow side when functioning as an evaporator at least. Is provided along the inlet header 3.

Description

  The present invention relates to a heat exchanger or the like used in a refrigeration cycle apparatus such as an air conditioner.

  For example, in a heat exchanger used in a refrigeration cycle apparatus, a condenser has been proposed in which a net-like member is inserted into a header to prevent mist formation of liquid refrigerant that tends to flow out after heat exchange (for example, , See Patent Document 1).

Japanese Patent Laid-Open No. 2002-350,000 (FIG. 1)

  Here, in a refrigeration cycle apparatus such as an air conditioner, for example, the heat exchanger may function not only as a condenser but also as an evaporator. However, the conventional method as described in the above-mentioned Patent Document 1 does not deal with a case where a liquid refrigerant flows in using a heat exchanger as an evaporator. For this reason, when the heat exchanger functions as an evaporator, it has been difficult to evenly distribute the liquid refrigerant to the plurality of heat transfer tubes.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a heat exchanger or the like that can uniformly distribute a refrigerant to a plurality of heat transfer tubes.

  The heat exchanger according to the present invention is disposed between a pair of headers that are spaced apart from each other and through which refrigerant passes, and a plurality of through holes that the pair of headers have in the headers. A heat exchanger having a plurality of heat transfer tubes through which both ends are inserted and through which the refrigerant passes, having at least concave and convex in the header tube on the refrigerant inflow side when functioning as an evaporator The formed corrugated plate is provided along the header.

  Since the corrugated plate is provided in the header tube on the refrigerant inflow side at least when functioning as an evaporator, the liquid refrigerant is evenly distributed and passed through each heat transfer tube without being affected by gravity or the like. Can do.

It is an external view of the heat exchanger of Embodiment 1 of this invention. It is sectional drawing of the header of the heat exchanger of Embodiment 1 of this invention. It is explanatory drawing which shows the state of the gas refrigerant 10 and the liquid refrigerant 11 which concern on Embodiment 1 of this invention. It is an external view of the corrugated board 4 of the heat exchanger of Embodiment 1 of this invention. Explanatory drawing which shows the distance of the flat tube 1 and the corrugated board 4 which concern on Embodiment 1 of this invention. It is an external view of the corrugated board 4 which has the opening hole part 9 which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the refrigerating-cycle apparatus based on this Embodiment 2 of this invention.

Embodiment 1 FIG.
FIG. 1 is an external view of a heat exchanger according to Embodiment 1 of the present invention. Here, the upper side in FIG. 1 will be described as “upper side” and the lower side will be described as “lower side”. In FIG. 1, the direction from the upper side to the lower side is the gravity direction (vertical direction).

  The heat exchanger of the present embodiment is an aluminum (including aluminum alloy) heat exchanger that is used in, for example, an outdoor unit of an air conditioner and uses a flat tube 1 as a heat transfer tube. The flat tube 1 is, for example, a heat transfer tube having a flat cross-sectional outer shape and a wedge shape. Then, the flat tubes 1 are configured by arranging a plurality of rows at intervals along the gravity direction which is the direction of the short axis of the flat shape. For this reason, the long axis in a flat shape is provided along the flow direction of the fluid (air etc.) used as the heat exchange object with a refrigerant | coolant. In the flat tube 1, for example, a plurality of refrigerant channels divided by partition walls are formed.

  A pair of cylindrical headers are attached to both ends of the flat tube 1. The header is a tube (cylinder) for distributing the refrigerant that has flowed into the flat tube 1 that is a heat transfer tube and collecting and flowing out the refrigerant that has passed through the flat tube 1. Each header has a through hole (not shown) for inserting the end of the flat tube 1 into the header. When the heat exchanger is used as an evaporator, the refrigerant passes through the inlet pipe 6, flows into a header (hereinafter referred to as inlet header 3) having a corrugated plate 4 therein, and passes through the flat pipe 1. For example, it passes through a hollow header (hereinafter referred to as an outlet header 5) and flows out from the outlet pipe 7. In addition, although not described in detail in FIG. 1, when the heat exchange target with the refrigerant is air, a plurality of plate-like fins 2 are provided along the same direction as the header in order to promote heat exchange in the flat tube 1. It has been.

  As shown in FIG. 1, the headers (inlet header 3 and outlet header 5) are usually arranged so as to be parallel (including substantially parallel) to the direction of gravity, and the flat tube 1 is vertical (substantially vertical). Is also included). For this reason, when the liquid refrigerant (liquid refrigerant) and the two-phase refrigerant in which the liquid refrigerant and the gaseous refrigerant (gas refrigerant) are mixed flow into the header in the direction opposite to the gravity direction, the liquid refrigerant And the inertia of the refrigerant. For example, when a mechanism for adjusting distribution is not provided in the header, the inertial force is more effective when the refrigerant flow rate is large (the refrigerant speed is high). For this reason, a lot of liquid refrigerant flows through the flat tube 1 located on the upper side. On the other hand, gravity is more effective when the refrigerant flow rate is small (the refrigerant speed is slow). For this reason, a lot of liquid refrigerant flows through the flat tube 1 located on the lower side. Thus, the amount of refrigerant flowing through each flat tube 1 varies depending on the flow rate of the refrigerant flowing in.

  2 is a cross-sectional view taken along line A-A ′ of FIG. 1 according to the first embodiment of the present invention. In the heat exchanger according to the present embodiment, a curtain-like (wave-like) corrugated plate 4 having irregularities is provided inside the inlet header 3 (in the pipe) so as to be parallel to the flat tube 1. Here, the distance δ between the end of the flat tube 1 in the inlet header 3 and the corrugated plate 4 is 0 ≦ δ ≦ Fp (pitch Fp of the corrugated plate 4).

  FIG. 3 is an explanatory diagram showing states of the gas refrigerant and the liquid refrigerant in the inlet header 3 according to Embodiment 1 of the present invention. The liquid refrigerant 11 is held between plates (valleys) of the corrugated plates 4 by surface tension, and the gas refrigerant 10 flows outside the corrugated plates 4.

  Here, in order for the corrugated plate 4 to effectively hold the liquid refrigerant 11 so that the liquid refrigerant 11 is transmitted upward, the following equation should be satisfied. Here, Bo is the number of bonds, ρL is the density of the liquid refrigerant, Fp is the pitch (interval) of the corrugated plate 4, Ft is the plate thickness, σL is the surface tension of the liquid refrigerant, and r is the liquid radius at the gas-liquid interface.

[Equation 1]
Bo = ρL × (Fp−Ft) / (σL / r) <1

  Since the liquid radius r is considered to be about half of the interval Fp−Ft in the corrugated plate 4, substituting into the equation (1) as r = (Fp−Ft) / 2, and further changing the equation relating to Fp, the following equation: It is represented by Thus, if the corrugated plate 4 is configured to satisfy Fp satisfying the expression (2), the liquid refrigerant 11 can be effectively held.

[Equation 2]
Fp <(2 × σL / ρL) ^0.5 + Ft

  The gas refrigerant 10 flows into the flat tube 1 from the corrugated plate 4 and the gap between the corrugated plate 4 and the flat tube 1. On the other hand, the liquid refrigerant 11 is held by the corrugated plate 4 and sequentially flows into the flat tube 1. As described above, since the inlet header 3 is parallel to the gravity direction (along the gravity direction), the movement of the liquid refrigerant 11 is affected by gravity and the inertial force of the refrigerant. In the heat exchanger of the present embodiment, the liquid refrigerant 11 flows through the inlet header 3 while being held by the corrugated plate 4. For example, when the refrigerant flow rate is large, the held refrigerant is spread to the upper side while weakening the momentum of the liquid refrigerant 11 into which the corrugated plate 4 flows. For example, even when the flow rate of the refrigerant is small, the holding force due to the surface tension applied to the refrigerant is effective in the corrugated plate 4 so that the held refrigerant reaches the upper side. For this reason, the supply of the liquid refrigerant 11 to the flat tube 1 can be leveled and distributed uniformly at any height of the inlet header 3.

  FIG. 4 is an external view of corrugated plate 4 used in the heat exchanger according to Embodiment 1 of the present invention. Since the corrugated plate 4 needs to be fixed in the inlet header 3, the fixing plate 8 for fixing is fixed at regular intervals on the installation side of the flat tube 1 of the corrugated plate 4 and on the opposite side (the side where the wave peaks and valleys). It is attached. By attaching the fixing plate 8 to the corrugated plate 4 at regular intervals in this manner, the corrugated plate 4 can be fixed in the inlet header 3 without hindering the flow of the refrigerant in the inlet header 3.

  FIG. 5 is an explanatory diagram showing the distance between the corrugated plate 4 and the flat tube 1 used in the heat exchanger according to Embodiment 1 of the present invention. The liquid refrigerant 11 and the gas refrigerant 10 are also supplied to the flat tube 1 from between the corrugated plate 4 and the flat tube 1. At this time, in order to hold the liquid refrigerant 11 between the corrugated plate 4 and the flat tube 1, the distance δ between the corrugated plate 4 and the flat tube 1 is about a pitch Fp from the equation (2). Further, if the width of the corrugated plate 4 and the length (width) of the flat tube 1 in the long axis direction are matched, the liquid refrigerant 11 held by the corrugated plate 4 can flow into the flat tube 1 without any spots. .

  FIG. 6 is an external view of corrugated plate 4 having opening hole 9 used in the heat exchanger according to Embodiment 1 of the present invention. As shown in FIG. 3, the liquid refrigerant 11 is held by the corrugated plate 4, but by providing a plurality of minute opening holes 9 in the corrugated plate 4, the liquid refrigerant between all the plates is flattened 1. Will be able to flow to the side. For this reason, even when the flat tube 1 has a plurality of refrigerant channels (microchannels), the refrigerant flowing into each refrigerant channel can be uniformly distributed.

  As described above, according to the heat exchanger of the first embodiment, since the corrugated plate 4 is provided on the inlet header 3 on the refrigerant inflow side when it becomes an evaporator, it is affected by gravity and inertial force. The liquid refrigerant can be uniformly supplied to the flat tube 1 arranged in the direction of gravity (vertical direction) without any problem. Further, since the corrugated plate 4 has only to be inserted into the inlet header 3 and fixed, the manufacture can be easily performed. And the heat exchanger tube of a heat exchanger is comprised by the flat tube 1, and a compact heat exchanger can be obtained.

Embodiment 2. FIG.
FIG. 7 is a diagram showing a configuration of a refrigeration cycle apparatus according to Embodiment 2 of the present invention. In the refrigeration cycle apparatus of FIG. 7, a compressor 33, a condenser 34, a throttling device 35, and an evaporator 36 are connected to form a refrigerant circuit (refrigerant circulation circuit). In addition, the blower 37 forms a flow of air in order to promote heat exchange between the refrigerant passing through the condenser 34 and the evaporator 36 and air by driving the blower motor 38.

  The compressor 33 sucks the refrigerant, compresses it, and discharges it in a high temperature / high pressure state. Here, for example, it may be configured by a compressor of a type that can control the number of revolutions by an inverter circuit or the like and adjust the discharge amount of the refrigerant. The condenser 34 having a heat exchanger, for example, performs heat exchange between the air supplied from the blower 37 and the refrigerant to condense the refrigerant into a liquid refrigerant (condensate liquid).

  The expansion device 35 expands the refrigerant by decompressing it. For example, it is constituted by a flow rate control means such as an electronic expansion valve, but may be constituted by an expansion valve having a temperature sensing cylinder, a refrigerant flow rate adjusting means such as a capillary (capillary), or the like. The evaporator 36 evaporates the refrigerant by heat exchange with air or the like to form a gas (gas) refrigerant (evaporates into gas).

  For example, the heat exchanger described in Embodiment 1 can be used for at least one of the evaporator 36 and the condenser 34. Thereby, in the apparatus of Embodiment 2, heat transfer performance can be improved. By improving the heat transfer performance, an energy-efficient and energy-saving refrigeration cycle apparatus can be obtained.

Here, energy efficiency is comprised by following Formula (1) and (2).
Heating energy efficiency = indoor heat exchanger (condenser) capacity / total input (1)
Cooling energy efficiency = indoor heat exchanger (evaporator) capacity / total input (2)

  Next, operation | movement in each component apparatus of a refrigerating-cycle apparatus is demonstrated based on the flow of the refrigerant | coolant which circulates through a refrigerant circuit. First, the compressor 33 sucks the refrigerant, compresses it, and discharges it in a high temperature / high pressure state. The discharged refrigerant flows into the condenser 34. The condenser 34 performs heat exchange between the air supplied from the blower 37 and the refrigerant, and condenses and liquefies the refrigerant. The condensed and liquefied refrigerant passes through the expansion device 35. The expansion device 35 depressurizes the condensed and liquefied refrigerant passing therethrough. The decompressed refrigerant flows into the evaporator 36. The evaporator 36 exchanges heat between the air supplied from the blower 37 and the refrigerant to evaporate the refrigerant. The compressor 33 sucks the evaporated gas refrigerant.

  Here, the refrigeration cycle apparatus described above includes HCFC (R22) and HFC (R116, R125, R134a, R14, R143a, R152a, R227ea, R23, R236ea, R236fa, R245ca, R245fa, R32, R41, RC318, etc. Several mixed refrigerants such as R407A, R407B, R407C, R407D, R407E, R410A, R410B, R404A, R507A, R508A, R508B, etc.), HC (butane, isobutane, ethane, propane, propylene, etc.) Refrigerant), natural refrigerant (several mixed refrigerants such as air, carbon dioxide, and ammonia), low GWP refrigerant such as HFO1234yf, and several mixed refrigerants of these refrigerants. In particular, the effect can be achieved more efficiently in R410A, R410A, and R32 whose design pressure and physical property values are close.

  Moreover, although air and a refrigerant | coolant were shown as an example as a working fluid, even if it uses other gas, a liquid, and a gas-liquid mixed fluid, there can exist the same effect.

  Further, the same effect can be obtained when the heat exchanger described in the first embodiment is used in an indoor unit.

  Here, the heat exchanger and the refrigeration cycle apparatus described in the first and second embodiments are mixed with refrigerant and oil such as mineral oil, alkylbenzene oil, ester oil, ether oil, and fluorine oil. The effect can be achieved with any refrigeration oil, whether or not it fits.

  As an application example of the present invention, it can be used for a heat pump apparatus that is difficult to be exposed, improves heat exchange performance, and needs to improve energy saving performance.

  DESCRIPTION OF SYMBOLS 1 Flat tube, 2 Fin, 3 Inlet header, 4 Corrugated board, 5 Outlet header, 6 Inlet pipe, 7 Outlet pipe, 8 Fixing plate, 9 Opening hole part, 10 Gas refrigerant, 11 Liquid refrigerant, 12 Air bubbles, 33 Compressor , 34 condenser, 35 throttling device, 36 evaporator, 37 blower, 38 motor for blower.

The heat exchanger according to the present invention is disposed between a pair of headers that are spaced apart from each other and through which refrigerant passes, and a plurality of through holes that the pair of headers have in the headers. A heat exchanger having a plurality of heat transfer tubes through which both ends are inserted and through which the refrigerant passes, having at least concave and convex in the header tube on the refrigerant inflow side when functioning as an evaporator When the formed corrugated plate is provided along the header and the pitch between the corrugated plates is set to Fp, the distance δ between the corrugated plate and the end of the heat transfer tube in the header tube satisfies 0 <δ <Fp. It is configured to satisfy .

The heat exchanger according to the present invention is disposed between a pair of headers that are spaced apart from each other and through which refrigerant passes, and a plurality of through holes that the pair of headers have in the headers. A heat exchanger having a plurality of heat transfer tubes through which both ends are inserted and through which the refrigerant passes, having at least concave and convex in the header tube on the refrigerant inflow side when functioning as an evaporator When the formed corrugated plate is provided along the header and the pitch between the corrugated plates is set to Fp, the distance δ between the corrugated plate and the end of the heat transfer tube in the header tube satisfies 0 <δ <Fp. In order to satisfy , the width of the corrugated plate and the diameter of the heat transfer tube in the header tube are configured to be the same .

Claims (8)

A pair of headers that are spaced apart from each other and through which refrigerant passes through the pipe;
A heat exchanger comprising a plurality of heat transfer tubes disposed between the pair of headers, both ends of which are respectively inserted into the header from a plurality of through holes of the pair of headers, and through which a refrigerant passes. ,
A heat exchanger in which a corrugated plate having a corrugation and formed in a corrugated shape is provided along the header in a pipe of the header serving as a refrigerant inflow side when functioning as an evaporator.   The heat exchanger according to claim 1, wherein the corrugated plate has a plurality of opening holes that allow the refrigerant to flow between the waves. When the corrugated plate has a liquid refrigerant density ρL, a plate thickness Ft, and a liquid refrigerant surface tension σL, the pitch Fp between waves is
Fp <(2 × σL / ρL) ^0.5 + Ft
The heat exchanger according to claim 1 or 2 configured to satisfy the above. The distance δ between the corrugated plate and the end of the heat transfer tube in the header tube when the corrugated pitch Fp of the corrugated plate is
0 <δ <Fp
The heat exchanger as described in any one of Claims 1-3 comprised so that it may satisfy | fill.   The heat exchanger according to claim 4, wherein the width of the corrugated plate and the diameter of the heat transfer tube in the header tube are the same.   The heat exchanger according to claim 5, wherein a fixing plate for fixing the corrugated plate in the header is attached to the corrugated plate on a surface facing the heat transfer tube and an opposite surface thereof.   The heat exchanger according to any one of claims 1 to 6, wherein the heat transfer tube is a flat tube. A compressor that compresses and discharges the refrigerant;
A condenser for condensing the refrigerant by heat exchange;
A throttling device for depressurizing the refrigerant for condensation;
A refrigeration cycle apparatus comprising the heat exchanger according to any one of claims 1 to 7, wherein a refrigerant circuit is configured by pipe connection to an evaporator that evaporates the refrigerant by heat exchange with a refrigerant related to decompression. .

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