JP4647512B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner, and more particularly, to an air conditioner including a finned tube heat exchanger having an improved refrigerant flow path configuration suitable for heating operation and cooling operation.

  Conventionally, the heat exchanger has the same refrigerant flow path for both heating and cooling. Conventionally, the number of flow paths has been selected in consideration of the balance between the performance of the evaporation and condensation processes.

  However, since the refrigerant pressure loss is large in the evaporation process, it is known to use multiple channels, and in the condensation process, it is known to use a single channel because the refrigerant pressure loss is small. In both cases, the optimum flow path could not be set (Patent Document 1).

In addition, the flow rate of refrigerant varies depending on the class of each capacity, so the number of flow paths could not be unified due to the pressure loss in the evaporation process. Furthermore, it is also known to change the refrigerant flow path of the heat exchanger by cooling and heating by switching the valve, but many valves are required and a complicated structure is required, which is fully satisfactory It was not (Patent Document 2).
Japanese Patent Laid-Open No. 10-281574 JP 2002-228273 A

  The present invention has been made in consideration of the above-described circumstances, and an air conditioner in which a heat exchanger is provided with a refrigerant flow path that is optimal during heating operation and cooling operation, and has improved performance during heating operation and cooling operation. The purpose is to provide.

  In order to achieve the above-described object, an air conditioner according to the present invention includes a compressor, a four-way valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, and the refrigerant flow direction is switched by switching the four-way valve. In the air conditioner that switches between the cooling operation and the heating operation by changing the at least one of the indoor heat exchanger and the outdoor heat exchanger is installed in parallel on the refrigerant channel inlet side when acting as an evaporator 1st and 2nd heat exchanger part, 3rd heat exchanger part provided in the downstream of said 1st and 2nd heat exchanger part, said 2nd heat exchanger part, and 3rd The second heat exchanger unit communicates with the third heat exchanger unit when acting as an evaporator, and the second heat when acting as a condenser. Valve means for blocking communication between the exchanger section and the third heat exchanger section, and the first heat exchange Characterized in that the refrigerant channel number of the vessel portion was less than refrigerant passage number of the third heat exchanger unit.

  The air conditioner according to the present invention can provide an air conditioner with improved performance during heating operation and cooling operation.

  An air conditioner according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a refrigeration cycle diagram used in an air conditioner according to an embodiment of the present invention.

  As shown in FIG. 1, the air conditioner according to the present invention includes a refrigeration cycle 1, which includes a compressor 2, a four-way switching valve 4, an outdoor heat exchanger 5, and an electronic automatic as an expansion device. The expansion valve 6 and the indoor heat exchanger 7 are communicated with each other via a refrigerant pipe 8 so as to constitute a heat pump refrigeration cycle.

  The outdoor heat exchanger 5 functions as an evaporator during the heating operation, functions as a condenser during the cooling operation, and is a first outdoor heat exchange installed in parallel on one side that becomes the refrigerant inlet side when functioning as the evaporator. The third outdoor heat provided downstream of the junction p5 where the refrigerant that has passed through the first and second outdoor heat exchangers 5a and 5b merges with the vessel 5a and the second outdoor heat exchanger 5b. And an exchange unit 5c. In addition, an on-off valve 5v is provided between the second outdoor heat exchanger section 5b and the merging section p5, and is set to open when the outdoor heat exchanger 5 functions as an evaporator and to close when functioning as a condenser. The refrigerant flow path of the outdoor heat exchanger 5 is different between the evaporation process and the condensation process.

  On the other hand, the indoor heat exchanger 7 functions as a condenser during the heating operation, functions as an evaporator during the cooling operation, and is installed in parallel on one side that becomes the refrigerant inlet side when functioning as the evaporator. The heat exchanger section 7a and the second indoor heat exchanger section 7b, and a third section provided downstream of the merge section p7 where the refrigerant that has passed through the first and second outdoor heat exchanger sections 7a and 7b merges. It is comprised from the indoor heat exchanger part 7c. Further, an on-off valve 7v is provided between the second indoor heat exchanger section 7b and the junction section p7, and is set to open when the indoor heat exchanger 7 functions as an evaporator and to close when functioning as a condenser. The refrigerant flow path of the indoor heat exchanger 7 is configured to be different between the evaporation process and the condensation process. The on-off valves 5v and 7v are preferably check valves. Thereby, the cost of the on-off valve can be reduced.

  As shown in FIG. 2, the outdoor heat exchanger 5 will be described in detail. The outdoor heat exchanger 5 is formed by laminating heat transfer fins 5f having the same shape with a predetermined pitch interval, and having the same length on the heat transfer fins 5f. And a plurality of pipes 5p1, 5p2, and 5p3 having a diameter, and the first outdoor heat exchanger section 5a, the second outdoor heat exchanger section 5b, and the third outdoor heat exchanger section 5c. Connect to configure.

  As shown in FIG. 3, for example, the first outdoor heat exchanger section 5a has two refrigerant channels, that is, two channels, and includes two pipes 5p1 per channel. Consists of four pipes, the second outdoor heat exchanger section 5b has two flow paths, is composed of 6 pipes and 8 pipes 5p2 per flow path, is composed of a total of 14 pipes, The third outdoor heat exchanger section 5c (divided vertically in FIG. 2) has four flow paths, is composed of six pipes 5p3 per flow path, and is composed of a total of 24 pipes.

  As shown in FIG. 4, the indoor heat exchanger 7 will be described in detail. The indoor heat exchanger 7 is formed of first to third indoor heat exchanger portions 7a, 7b, and 7c. The fins 7f1 of the first and second indoor heat exchanger units 7a and 7b are integrally formed, and the fins 7f2 and 7f3 of the third indoor heat exchanger unit 7c are formed separately. As shown in FIG. 5, for example, the first indoor heat exchanger section 7a has one flow path and is configured by a total of twelve pipes 7p1, and the second indoor heat exchanger section 7b has three flows. It consists of two pipes 7p2 per flow path and is composed of a total of six pipes. The third indoor heat exchanger section 7c (divided vertically in FIG. 4) has four flow paths. And it consists of six pipes 7p3 per one flow path, and is composed of a total of 24 pipes.

  The first outdoor heat exchanger section 5a has a refrigerant flow path number (2) smaller than the refrigerant flow path number (4) of the third outdoor heat exchanger section 5c, and the first indoor heat exchanger section. 7a is set so that the number of refrigerant channels (1) is smaller than the number of refrigerant channels (4) of the third indoor heat exchanger section 7c. Thereby, it becomes possible to increase the flow velocity of the portion where the liquid ratio of the refrigerant during condensation is large (the portion where the pressure loss in the pipe is small), and the heat exchange efficiency is improved.

  The first outdoor heat exchanger section 5a is composed of 6 and 8 pipes per flow path, and the second outdoor heat exchanger section 5b is composed of 2 pipes per flow path. It is longer than the length of one refrigerant flow path of the outdoor heat exchanger section 5b. Furthermore, the first outdoor heat exchanger section 5a has a total number of 14 pipes, and the second outdoor heat exchanger section 5b has a total pipe number. Therefore, the total refrigerant flow volume of the first indoor heat exchanger section 5a is set to be twice or more that of the second outdoor heat exchanger section 5b.

  The first indoor heat exchanger section 7a is composed of 12 pipes per flow path, and the second indoor heat exchanger section 7b is composed of 2 pipes per flow path. It becomes longer than the flow path length of one refrigerant flow path of the heat exchanger section 7b. Furthermore, the first indoor heat exchanger section 7a has 12 total pipes, and the second indoor heat exchanger section 7b has a total number of pipes. Therefore, the total refrigerant flow volume of the first indoor heat exchanger section 7a is set to be twice or more that of the second indoor heat exchanger section 7b.

  Thereby, at the time of a condensation function, the loss of the number of pipes by the non-use of the 2nd outdoor heat exchanger part 5b and the 2nd indoor heat exchanger part 7b can be reduced, and performance can be improved.

  The first outdoor heat exchanger section is preferably a single flow path, but is not necessarily limited to a single flow path, and may be, for example, two or more flow paths.

  Next, the operation of the refrigeration cycle used in the air conditioner according to the present invention will be described.

  First, the heating operation will be described.

  As shown in FIG. 6, the indoor heat exchanger 7 functions as a condenser, and the on-off valve 7v is closed. By closing the on-off valve 7v, as shown in FIG. 5, the refrigerant flows only in the first indoor heat exchanger section 7a having the number of flow paths 1, and a single flow path is formed downstream of the indoor heat exchanger 7. It is formed.

  On the other hand, as shown in FIG. 7, the outdoor heat exchanger 5 functions as an evaporator, and the on-off valve 5v is opened. By opening the on-off valve 7v, as shown in FIG. 3, a first outdoor heat exchanger section 5a having two flow paths and a second outdoor heat exchanger section having two flow paths are arranged in parallel. A heat exchanger section with four flow paths is formed at 5b, and the number of flow paths is the same as that of the third outdoor heat exchanger section 5c with four flow paths, and a multi-flow path is formed.

  The refrigerant, which has been compressed by the compressor 2 shown in FIG. 1 and has become high temperature and pressure, flows into the indoor heat exchanger section 7 in the state shown in FIG. 6 through the four-way switching valve 4.

  The refrigerant flowing into the indoor heat exchanger 7 increases the flow rate of the refrigerant and efficiently exchanges heat in the first indoor heat exchanger section 7a formed with a single flow path suitable for the condensation process. And flows to the electronic automatic expansion valve 6. The liquid refrigerant flowing into the electronic automatic expansion valve 6 is decompressed and flows into the outdoor heat exchanger 5.

  The refrigerant that has flowed into the outdoor heat exchanger 5 in the state shown in FIG. 7 is efficiently heat-exchanged with the refrigerant pressure loss suppressed by the outdoor heat exchanger 5 in which a multi-flow path suitable for the evaporation process is formed, It becomes a gas refrigerant and returns to the compressor 2 through the four-way switching valve 4.

  Next, the cooling operation will be described.

  As shown in FIG. 8, the indoor heat exchanger 7 functions as an evaporator, and the on-off valve 7v is opened. By opening this on-off valve 7v, as shown in FIG. 3, a first indoor heat exchanger section 7a having a flow path number of 1 and a second indoor heat exchanger section having a flow path number of 3 are arranged in parallel. 7b forms a four-channel heat exchanger section, which has the same number of channels as the third indoor heat exchanger section 7c having four channels, thereby forming a multi-channel.

  On the other hand, as shown in FIG. 9, the outdoor heat exchanger 5 functions as a condenser, and the on-off valve 5v is closed. By closing the on-off valve 5v, as shown in FIG. 3, only the first outdoor heat exchanger section 5a having two flow paths is opened, and a small flow path is formed. In the condensation process, the number of pipes of the refrigerant channels effective for heat transfer performance decreases, but this can be covered by an increase in the refrigerant mass velocity accompanying the decrease in the number of refrigerant channels. In addition, the cost of parts can be reduced because the parts can be added with an on-off valve and a junction.

  As shown in FIG. 1, the refrigerant that has been compressed by the compressor 2 to become a high temperature and high pressure flows into the outdoor heat exchanger 5 in the state shown in FIG. 9 through the four-way switching valve 4.

  As shown in FIG. 9, the refrigerant flowing into the outdoor heat exchanger 5 has an increased flow rate of the refrigerant in the first outdoor heat exchanger section 5a having two flow paths close to the single flow path suitable for the condensation process. Then, the heat is efficiently exchanged to become a liquid refrigerant and flow to the electronic automatic expansion valve 6. The liquid refrigerant flowing into the electronic automatic expansion valve 6 is decompressed and flows into the indoor heat exchanger 7.

  The refrigerant that has flowed into the indoor heat exchanger 7 in the state shown in FIG. 8 is efficiently heated with the refrigerant pressure loss suppressed by the indoor heat exchanger 7 in which a multi-channel of four channels suitable for the evaporation process is formed. The gas refrigerant is exchanged and returns to the compressor 2 through the four-way switching valve 4.

  According to the air conditioner according to the present embodiment including the refrigeration cycle, the refrigerant flow paths of the outdoor heat exchanger and the indoor heat exchanger are different in the evaporation process and the condensation process, and the number of flow paths is increased in the evaporation process. As a result, the refrigerant pressure loss is reduced, and in the condensation process, it is possible to increase the refrigerant flow rate by reducing the flow path, thereby realizing high efficiency.

  Moreover, other embodiment of the refrigerating cycle used for the air conditioner which concerns on this invention is described.

  As shown in FIG.10 and FIG.11, the indoor heat exchanger 7 of the refrigerating cycle 11 of other embodiment provides the throttle mechanism 12 in the junction part p7. During the cooling and heating operation, the throttle mechanism 12 is fully opened, the refrigerant is throttled by the electronic automatic expansion valve 6, and during the dehumidifying operation, the refrigerant is fully opened by the electronic automatic expansion valve 6, and the throttle mechanism 12 is throttled. The indoor heat exchanger section 7a and the second indoor heat exchanger section 7b are condensed (air heated) and evaporated (air cooled) in the third indoor heat exchanger section 7c, thereby having a reheat dehumidifying function. A highly efficient refrigeration cycle is realized. In addition, by providing the throttle mechanism 12 at the junction p7, the number of components at the junction can be reduced.

  In each of the above-described embodiments, an example in which a heat exchanger having an improved refrigerant flow path configuration is used for both the outdoor heat exchanger and the indoor heat exchanger has been described. However, the outdoor heat exchanger or the indoor heat exchanger You may make it employ | adopt only to one side.

The conceptual diagram of the refrigerating cycle used for the air conditioner which concerns on one Embodiment of this invention. The conceptual diagram of the outdoor heat exchanger of the refrigerating cycle used for the air conditioner which concerns on one Embodiment of this invention. Explanatory drawing of the number of flow paths and the number of pipes of the outdoor heat exchanger of the refrigerating cycle used for the air conditioner which concerns on one Embodiment of this invention. The conceptual diagram of the indoor heat exchanger of the refrigerating cycle used for the air conditioner which concerns on one Embodiment of this invention. Explanatory drawing of the number of flow paths and the number of pipes of the indoor heat exchanger of the refrigerating cycle used for the air conditioner which concerns on one Embodiment of this invention. The conceptual diagram at the time of the condensation process of the indoor heat exchanger of the refrigerating cycle used for the air conditioner which concerns on one Embodiment of this invention. The conceptual diagram at the time of the evaporation process of the outdoor heat exchanger of the refrigerating cycle used for the air conditioner which concerns on one Embodiment of this invention. The conceptual diagram at the time of the evaporation process of the indoor heat exchanger of the refrigerating cycle used for the air conditioner which concerns on one Embodiment of this invention. The conceptual diagram at the time of the condensation process of the outdoor heat exchanger of the refrigerating cycle used for the air conditioner which concerns on one Embodiment of this invention. The conceptual diagram of the refrigerating cycle used for the air conditioner which concerns on other embodiment of this invention. The conceptual diagram of the indoor heat exchanger of the refrigerating cycle used for the air conditioner which concerns on other embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Refrigeration cycle, 2 ... Compressor, 4 ... Four way switching valve, 5 ... Outdoor heat exchanger, 5a ... Outdoor heat exchanger part, 5b ... Outdoor heat exchanger part, p5 ... Merging part, 5p1, 5p2, 5p3 ... Pipe, 5v ... Open / close valve, 6 ... Electronic automatic expansion valve, 7 ... Indoor heat exchanger, 7a ... First indoor heat exchanger section, 7b ... Second indoor heat exchanger section, p7 ... Junction section, 7v ... open / close valves, 7f1, 7f2, 7f3 ... fins, 7p1, 7p2, 7p3 ... pipes, 8 ... refrigerant pipes.

Claims (3)

In an air conditioner having a compressor, a four-way valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, changing the flow direction of the refrigerant by switching the four-way valve, and switching between a cooling operation and a heating operation.
At least one of the indoor heat exchanger and the outdoor heat exchanger includes first and second heat exchanger units installed in parallel on the refrigerant flow path inlet side when acting as an evaporator,
A third heat exchanger section provided downstream of the first and second heat exchanger sections;
It is provided between the second heat exchanger part and the third heat exchanger part, and communicates with the second heat exchanger part and the third heat exchanger part when acting as an evaporator to condense Valve means for blocking communication between the second heat exchanger part and the third heat exchanger part when acting as a heat exchanger;
An air conditioner characterized in that the number of refrigerant channels in the first heat exchanger section is smaller than the number of refrigerant channels in the third heat exchanger section. The flow path length of one refrigerant flow path in the first heat exchanger section is longer than the flow path length of one refrigerant flow path in the second heat exchanger section, and the first heat exchanger section 2. The air conditioner according to claim 1, wherein the total refrigerant flow volume is at least twice the total refrigerant flow volume of the second heat exchanger section. The indoor heat exchanger includes first to third heat exchangers and valve means, and a confluence portion is provided between the first and second heat exchanger portions and the third heat exchanger, and this confluence portion 2. The air conditioner according to claim 1, further comprising a throttle means.

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