JP4966742B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner that forms a refrigeration cycle.

  An air conditioner is a refrigeration system in which a compressor, a condenser that condenses the compressed refrigerant, an expansion valve that decompresses the condensed refrigerant, an evaporator that evaporates the decompressed refrigerant, and the like are connected by refrigerant piping. Forming a cycle.

  In such an air conditioner, it is known that an evaporator is formed by a plurality of distribution passages connected in parallel to exchange heat between the refrigerant flowing through each distribution passage and air.

  For example, in Patent Document 1, indoor heat exchangers (evaporators) of a plurality of refrigeration cycle systems are stacked in an up-down direction inside an indoor unit, and the flow path of each indoor heat exchanger is connected to a shunt. And distributing to a plurality of parallel flow paths. In addition, by performing capacity control for each refrigeration cycle system in such a configuration, it is said that overall operation efficiency can be improved, and water splashing due to mixing of warm air and cold air can be suppressed. .

JP-A-10-132399

  However, although the technique of Patent Document 1 is considered to improve the overall operation efficiency of a plurality of refrigeration cycles, it is considered to improve the heat exchange efficiency of a single indoor heat exchanger of each refrigeration cycle system. I cannot say that.

  That is, in the technique of Patent Document 1, since the indoor heat exchanger is formed by parallel-connected distribution flow paths, the heat exchange conditions are different due to differences in the positions of the distribution flow paths. The appropriate flow rate of the refrigerant for each distribution channel is not controlled, and the heat exchange efficiency may be suppressed as a whole.

  In particular, as disclosed in Patent Document 1, a plurality of distribution channels are arranged at different positions in the vertical direction on the inner side surface of the indoor unit, and the blower fan blows out the air sucked from the side surface of the indoor unit from above. In this case, the distance between each distribution flow path and the blower fan is different, and the amount of air flow per unit time passing through each distribution flow path is different. As a result, the distribution of the refrigerant temperature at the time of heat exchange varies significantly for each distribution channel, and the overall heat exchange efficiency may be suppressed.

  Then, this invention makes it a subject to implement | achieve the air conditioner which improved the heat exchange efficiency of the heat exchanger formed with a some flow path connected in parallel.

  In order to solve the above problems, an air conditioner according to the present invention forms a refrigeration cycle by connecting a compressor, a four-way valve, a condenser, an expansion valve, and an evaporator with a refrigerant circulation pipe. Yes. The evaporator is formed to have a plurality of distribution channels connected in parallel, and an expansion valve is provided in each of the plurality of distribution channels. Furthermore, a control means for controlling the valve opening degree of each expansion valve is provided so that the refrigerant temperature reduced by each expansion valve becomes uniform.

  In other words, an expansion valve is provided for each distribution channel, and the opening of each expansion valve is controlled to adjust the refrigerant flow rate. It is possible to uniformly adjust the refrigerant temperature, that is, the refrigerant evaporation temperature of each distribution flow path, to a desired value. Thereby, suitable heat exchange can be aimed at in all the distribution flow paths, and the heat exchange efficiency of the whole heat exchanger can be improved.

  Further, according to such a configuration, for example, although some of the distribution channels have a large amount of air flow and the refrigerant pressure and temperature are high, the other of the partial distribution channels has a small amount of air flow. It is possible to suppress adverse effects such as dew condensation and water splashing on the heat exchanger due to condensation due to a decrease in pressure and temperature.

  In addition, as described above, instead of the configuration in which the expansion valve is provided in each of the plurality of distribution flow paths connected in parallel, the flow paths adjacent to the arrangement positions of the plurality of distribution flow paths are divided into a plurality of blocks. An expansion valve may be provided for each divided block. Similarly in this case, the valve opening degree of each expansion valve may be controlled so that the refrigerant temperature decompressed by each expansion valve becomes uniform.

  This configuration divides the whole into a plurality of blocks, with the distribution flow channel close to the arrangement position considered to be almost the same blowing condition as one block, and provides an expansion valve for each block. According to this, it is possible to improve the heat exchange efficiency of the entire heat exchanger by suppressing variations in the refrigerant temperature distribution of each distribution flow path, and to suppress the number of parts of the expansion valve.

  Also, a temperature sensor for detecting the temperature of the refrigerant decompressed by each expansion valve is provided, and the control means compares the detected temperature of each temperature sensor with a set reference temperature for each control cycle, It is configured to increase the valve opening degree of the expansion valve corresponding to the temperature sensor in which the high temperature is detected, and to reduce the valve opening degree of the expansion valve corresponding to the temperature sensor in which the temperature lower than the reference temperature is detected. Can do.

  In addition, the plurality of distribution channels of the evaporator are arranged at different positions in the vertical direction on the side surface inside the housing of at least one of the outdoor unit and the indoor unit of the air conditioner, and the heat from the evaporator A blower fan that blows replacement air may be provided in the upper part of the housing, and the air sucked from the side surface of the housing may be blown upward.

  With such an arrangement configuration of the evaporator and the blower fan, the heat exchange air is passed through the entire evaporator to secure the heat exchange amount, and further, the refrigerant is controlled by the refrigerant flow rate control for each distribution flow path described above. The heat exchange efficiency can be increased by suppressing variations in temperature distribution.

  ADVANTAGE OF THE INVENTION According to this invention, the air conditioner which improved the heat exchange efficiency of the heat exchanger formed with a some flow path connected in parallel is realizable.

  Hereinafter, an embodiment of an air conditioner to which the present invention is applied will be described with reference to FIGS. In the following, a case where a heat exchanger of two refrigeration cycle systems is provided in one indoor unit will be described as an example. However, the present invention is not limited to this, and the present invention is also applicable to a single refrigeration cycle system. Is possible.

  FIG. 1 is a diagram showing a refrigeration cycle configuration of an indoor unit of an air conditioner of the present embodiment, and FIG. 2 is a diagram showing a refrigeration cycle configuration of an outdoor unit of the air conditioner of the present embodiment. The air conditioner of this embodiment is configured by connecting the outdoor unit 20 shown in FIG. 2 to the two refrigerant cycle systems of the indoor unit 1 shown in FIG.

  As shown in FIGS. 1 and 2, the outdoor unit 20 includes a compressor 11 that compresses a refrigerant, a four-way valve 12 that switches a refrigerant flow path between cooling and heating, and an outdoor heat exchange that exchanges heat between the refrigerant and outdoor air. And the like, a condenser 13, an outdoor expansion valve 14 that decompresses the refrigerant, a liquid receiver 15 that stores liquid refrigerant that is no longer necessary in the refrigeration cycle, and the like are connected via a gas refrigerant pipe 16 and a liquid refrigerant pipe 17. Has been.

  The indoor unit 1 is also provided with an indoor expansion valve 6 for reducing the pressure of the refrigerant, indoor heat exchangers 4 and 5 for exchanging heat between the refrigerant and room air, and the like. The refrigerant pipes 17 are connected. The outdoor unit 20 and the indoor unit 1 are connected by a gas refrigerant pipe 16 and a liquid refrigerant pipe 17 to form a two-line refrigeration cycle.

  Here, as shown in FIG. 1, the indoor unit of the present embodiment is branched into three block flow paths 18 in which the liquid refrigerant pipes 17 are arranged in parallel, and these block flow paths 18 are respectively distributed to the distributor 3. It branches into three via. The indoor heat exchangers 4 and 5 are formed with nine distribution passages connected in parallel, and nine passages are gathered into one on the gas refrigerant pipe 16 side of these distribution passages. Then, it is connected to the gas refrigerant pipe 16.

  In other words, each of the indoor heat exchangers 4 and 5 has nine distribution passages connected in parallel, and the liquid refrigerant pipe 17 side of the distribution passage has three adjacent arrangement positions. Each distribution channel is divided into blocks (A block to F block). Then, the three flow paths constituting each block are gathered by the distributor 3 to form a block flow path 18, and further, the three block flow paths 18 are joined together and connected to the liquid refrigerant pipe 17.

  In the present embodiment, the indoor expansion valve 6 is provided for each block flow path 18, and the temperature sensor 2 is provided between each indoor expansion valve 6 and the distributor 3. In addition, a temperature sensor 7 is provided at a collection portion of the nine distribution flow paths on the gas refrigerant pipe 16 side of the indoor heat exchangers 4 and 5. Furthermore, a control means 19 is provided that outputs a control signal of the valve opening degree of each indoor expansion valve 6 by using signals from the temperature sensors 2 and 7 as inputs.

  The basic operation of such an air conditioner will be described. In the case of the cooling operation, as indicated by solid arrows in FIGS. 1 and 2, the high-temperature and high-pressure gas refrigerant compressed by the compressor 11 is discharged from the compressor 11, and the gas refrigerant passes through the four-way valve 12 and then the outdoor heat exchanger. It flows in into 13 and heat-exchanges here, and is condensed and liquefied. The condensed and liquefied refrigerant passes through the outdoor expansion valve 14, the surplus refrigerant is stored in the liquid receiver 15, and the remainder passes through the liquid refrigerant pipe 17 and is sent to the indoor unit 1.

  The sent liquid refrigerant branches into each block flow path 18 and then flows into the indoor expansion valve 6 where it is depressurized to a low pressure to be in a low-pressure two-phase state. Replace and evaporate and gasify. Thereafter, the gas refrigerant flows into the outdoor unit 20 through the gas refrigerant pipe 16 and returns to the compressor 11 through the four-way valve 12.

  In the case of heating operation, as indicated by the broken-line arrows in FIGS. 1 and 2, the high-temperature and high-pressure gas refrigerant compressed by the compressor 11 is discharged from the compressor 11, passes through the four-way valve 12 and the gas refrigerant pipe 16, and is heated indoors. It flows into the exchangers 4 and 5 and exchanges heat with room air in each distribution flow path to be condensed and liquefied. The condensed and liquefied refrigerant flows into the outdoor unit 20 through each indoor expansion valve 6, and after the surplus refrigerant is collected by the liquid receiver 15, the refrigerant is decompressed by the outdoor expansion valve 14, and the outdoor air is exchanged by the outdoor heat exchanger 13. It evaporates by heat exchange and gasifies. The gasified refrigerant returns to the compressor 11 through the four-way valve 12.

  By the way, the indoor unit of the air conditioner of this embodiment has a structure as shown to Fig.3 (a), (b). FIG. 3A is a front structural diagram of the indoor unit, and FIG. 3B is a side structural diagram of the indoor unit 1. As shown in the figure, the indoor heat exchangers 4 and 5 are vertically stacked along the side surface in the casing of the indoor unit 1, and the blocks A to F for each indoor heat exchanger are also arranged in the vertical direction. They are arranged at different positions. A blower fan 8 is provided in the upper part of the housing, and the blower fan 8 is driven by a motor 9 via a belt 10. As a result, the indoor air that has been sucked in from the side surface of the housing and has passed through the indoor heat exchangers 4 and 5 is blown out from above the housing.

  The flow of indoor air in the indoor unit having such a structure will be described with reference to FIG. As shown in FIG. 4, each of the blocks A to F of the indoor heat exchangers 4 and 5 has a higher wind speed as it passes through the heat exchanger from A to F due to the positional relationship with the blower fan 8. Become. For this reason, the blast volume per unit time is different for each block, and the heat exchange conditions vary. If the same refrigerant flow is flowing in each of the blocks A to F, the refrigerant temperature distribution varies for each block, thereby suppressing the heat exchange efficiency of the entire heat exchanger.

  Therefore, the control means 19 which is a characteristic part of the present embodiment performs the following control during cooling operation, for example. First, as basic control, the detected temperature of each of the temperature sensors 2 and 7 is input, and the degree of superheat on the suction side of the compressor 11 is within an appropriate range based on the temperature difference between the temperature sensors 2 and 7. Thus, the valve opening degree of the indoor expansion valve 6 is adjusted.

  In addition to this, in the present embodiment, the control means 19, for each control cycle, the refrigerant temperature (t) decompressed by the indoor expansion valve 6 detected by each temperature sensor 2 and a preset reference temperature ( and t ′). When the refrigerant temperature is higher than the reference temperature (when t> t ′), a signal for increasing the valve opening degree of the indoor expansion valve 6 corresponding to the temperature sensor 2 where the refrigerant temperature is detected is output. When the refrigerant temperature is lower than the reference temperature (t <t ′), a signal for reducing the valve opening degree of the indoor expansion valve 6 corresponding to the temperature sensor 2 where the refrigerant temperature is detected is output.

  In this way, the control means 19 adjusts the refrigerant flow rate by controlling the valve opening degree of each indoor expansion valve 6 so that the refrigerant temperature decompressed by each indoor expansion valve 6 becomes uniform. According to this, even if the heat exchange conditions for each distribution channel or block of the heat exchanger arranged in one indoor unit are different, the refrigerant temperature reduced by each indoor expansion valve, that is, each distribution It becomes possible to uniformly adjust the refrigerant evaporation temperature of the flow path to a desired value. Thereby, optimization of heat exchange can be aimed at in all the distribution channels, and the heat exchange efficiency of the whole heat exchanger can be improved.

  In addition, this makes it possible to suppress dew and water splashing caused by variations in temperature distribution in the heat exchanger regardless of adjustment of the length of the refrigerant pipe, the pipe diameter, and the like. In particular, the indoor heat exchanger of an air conditioner with a large output horsepower is large, and variations in heat exchange conditions due to the arrangement conditions in the indoor unit and the positional relationship with the blower fan are significant. By applying this control, it is possible to optimize the heat exchange for each distribution channel and improve the heat exchange efficiency.

  In the present embodiment, a case has been described in which a plurality of distribution channels are divided into blocks A to F to make the refrigerant temperature uniform in each block. This is because the adjacent distribution channels are regarded as having substantially the same heat exchange conditions. Therefore, the number of channels in one block may be changed as appropriate in consideration of the arrangement conditions of the distribution channels. For example, without dividing into blocks, it is possible to provide an indoor expansion valve for each distribution flow path and perform the same control as described above. Further, the valve opening degree is controlled based on the temperature detected by the temperature sensor 2, but instead of this, for example, a refrigerant pressure or the like may be applied.

  Further, in the present embodiment, a case has been described in which the refrigerant flow rate control is performed by each indoor expansion valve for the indoor heat exchanger that acts as an evaporator during cooling operation, but outdoor heat exchange that acts as an evaporator during heating operation. It is also possible to apply a similar configuration and control to the vessel.

It is a figure which shows the refrigerating cycle structure of the indoor unit of the air conditioner of this embodiment. It is a figure which shows the refrigerating cycle structure of the outdoor unit of the air conditioner of this embodiment. It is the front and side structure figure of the indoor unit of the air conditioner of this embodiment. It is a figure explaining the wind speed distribution for every distribution channel of an indoor heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Indoor unit 2, 7 Temperature sensor 3 Distributor 4, 5 Indoor heat exchanger 6 Indoor expansion valve 8 Blower fan 9 Motor 10 Belt 11 Compressor 12 Four-way valve 13 Outdoor heat exchanger 14 Outdoor expansion valve 15 Receiver 16 Gas refrigerant Piping 17 Liquid refrigerant piping 18 Block flow path 19 Control means 20 Outdoor unit

Claims (3)

A compressor, a four-way valve, a condenser and, evaporator and the air conditioner by forming a refrigerating cycle by connecting a pipe for circulating the refrigerant,
The evaporator has a plurality of distribution channels connected in parallel, with bulging expansion valve is provided on the inlet side of each of the refrigerant distribution passage of said plurality of,
A temperature sensor for detecting the temperature of the refrigerant decompressed by each expansion valve is provided between each of the plurality of distribution passages and each of the expansion valves, and the detection temperature of the temperature sensor is set. When the temperature of the expansion valve is higher than the reference temperature, the opening degree of the corresponding expansion valve is increased, and when the temperature is lower than the reference temperature, the opening degree of the corresponding expansion valve is decreased. An air conditioner comprising control means for controlling the valve opening of each expansion valve so that the refrigerant temperature becomes uniform. A compressor, a four-way valve, a condenser and, evaporator and the air conditioner by forming a refrigerating cycle by connecting a pipe for circulating the refrigerant,
The evaporator has a plurality of distribution channels connected in parallel, is divided into blocks to multiple flow paths positions of the distribution channel of said plurality of proximity as a block by block, No, respectively Re its with Rise expansion valve is provided on the inlet side of the refrigerant for each block,
A temperature sensor for detecting the temperature of the refrigerant decompressed by each expansion valve is provided between each of the plurality of blocks and each of the expansion valves, and the detected temperature of the temperature sensor is a set reference temperature. The refrigerant temperature reduced by each expansion valve by increasing the valve opening degree of the corresponding expansion valve when higher, and decreasing the opening degree of the corresponding expansion valve when lower than the reference temperature. An air conditioner comprising control means for controlling the valve opening degree of each expansion valve so as to be uniform. The plurality of distribution channels of the evaporator are arranged at different positions in the vertical direction on the side surface inside the housing of at least one of the outdoor unit and the indoor unit of the air conditioner, and exchange heat with the evaporator. The air conditioner according to claim 1 or 2 , wherein a blower fan that blows air is provided at an upper portion of the casing and is configured to blow upward the air sucked from a side surface of the casing. Machine.

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