JP2007147203A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of switching the sensible heat ratio or the dehumidification amount within a cooling capacity according to fluctuation of a sensible heat load even when the sensible heat load out of a cooling load fluctuates, or according to the operation state of other air conditioners. <P>SOLUTION: The air conditioner having a plurality of indoor units B, C, and D for performing heating/cooling operation each having indoor side heat exchangers 5 is equipped with an outdoor temperature detecting device 25 for detecting the temperature of outside air, an evaporation temperature control device 22 for changing the flow rate or pressure of a coolant from the indoor side heat exchangers 5 of the indoor units B, C, and D which are in cooling operation, and an evaporation temperature control part 28 for allowing the evaporation temperature control device 22 to change the pressure of the coolant based on the temperature of outside air and controlling the evaporation temperature of the coolant in the indoor side heat exchangers 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air conditioner. In particular, in a multi-room heat pump air conditioner in which a plurality of indoor units are connected to one heat source unit, air conditioning can be selectively performed for each indoor unit, and indoor units that perform cooling and indoor units that perform heating It is effective for an air conditioner that can be operated simultaneously.

For example, air that can connect a plurality of indoor units (heat exchangers) to one heat source unit, evaporate or condense the refrigerant for each indoor unit, and select a cooling / heating operation for each indoor unit. A harmony device has been proposed (see, for example, Patent Document 1).
JP 2004-324947 A

  In the air conditioner of the above document, for example, when a part of the indoor unit to be cooled is used in a place where the sensible heat ratio (the ratio of the sensible heat load to the cooling load) is large, the valve device is used to increase the evaporation temperature It was possible to perform a setting for selecting an operation for increasing the sensible heat ratio by increasing the sensible heat load among the cooling loads. Here, for example, in summer when the temperature and humidity are high (hereinafter referred to as “summer”), the latent heat load increases in the cooling load. However, if operation with a large sensible heat ratio is set in this state, the latent heat capacity is set. Decreases and the cooling capacity is insufficient. In addition, for example, even when another air conditioner is performing a humidifying operation in the winter season when the temperature and humidity are low (hereinafter, referred to as winter season), the indoor unit dehumidifies and wastes energy. Therefore, it is desirable to be able to perform an operation that can determine switching of the sensible heat ratio or the like depending on the environment in which the cooling operation is performed.

  The present invention has been made in order to solve such problems. In the cooling load, a state in which the sensible heat load fluctuates is determined, and the operation state of another air conditioner is determined according to the fluctuation. Accordingly, the present invention provides an air conditioner that can switch the sensible heat ratio or the amount of dehumidification associated with the cooling operation.

  An air conditioner according to the present invention includes an indoor unit-side heat exchanger, an air conditioner having a plurality of indoor units that perform cooling and heating operations, an outdoor air temperature detection device that detects outdoor outdoor temperature, and cooling The evaporating temperature control device that changes the flow rate of the refrigerant from the indoor unit side heat exchanger of the indoor unit that is in operation, and the evaporating temperature control device changes the flow rate of the refrigerant based on the outdoor outside air temperature, and the indoor unit side An evaporation temperature control unit for controlling the evaporation temperature of the refrigerant in the heat exchanger.

  According to the present invention, the evaporating temperature control changes the flow rate of the refrigerant from the indoor unit side heat exchanger by the evaporating temperature control device based on the outdoor outside air temperature during the cooling operation, and evaporates in the indoor heat exchanger. Since the temperature is controlled, for example, when performing cooling operation when the outside air temperature is high and the humidity is high as in summer, the evaporation temperature is lowered and the sensible heat ratio is low (the latent heat load is high). If the air temperature is low and the air temperature is low, such as in winter, when the cooling operation must be performed, increase the evaporation temperature and perform the operation with a high sensible heat ratio. It is possible to perform an efficient cooling operation with a load corresponding to. Here, the evaporating temperature is controlled based on the outdoor outdoor temperature, but for example, the control is performed based on whether or not there is a device that is performing a heating operation in a humidified state or operation with multiple units. May be.

Embodiment 1 FIG.
FIG. 1 is a refrigerant circuit diagram illustrating the overall configuration of the air-conditioning apparatus according to Embodiment 1. Embodiment 1 of the present invention will be described below in detail with reference to the drawings. In addition, although FIG. 1 demonstrates the case where three indoor units and one relay unit are connected to one heat source unit, even if the number of connection of an indoor unit and a relay unit differs (for example, a single unit or four indoor units) The same effect can be obtained. The air conditioner of FIG. 1 includes a heat source unit A, indoor units B, C, and D connected in parallel to each other, and a relay unit E that connects the heat source unit A and the indoor units B, C, and D.

  The heat source machine A is connected to the compressor 1, the compressor 1, a four-way switching valve 2 that switches the flow direction of the refrigerant, a heat source machine side heat exchanger 3, and an accumulator 4 connected between the four-way switching valve 2 and the compressor 1. Is mainly composed. Furthermore, it has a third check valve 32, a fourth check valve 33, a fifth check valve 34, and a sixth check valve 35. The third check valve 32 is provided between the heat source device side heat exchanger 3 and a second connection pipe 7 described later, and only in the direction from the heat source device side heat exchanger 3 to the second connection pipe 7. Allow refrigerant flow. The fourth check valve 33 is provided between the four-way switching valve 2 and a first connection pipe 6 to be described later, and allows the refrigerant to flow only from the first connection pipe 6 to the four-way switching valve 2. The fifth check valve 34 is provided between the four-way switching valve 2 and the second connection pipe 7 and allows the refrigerant to flow only in the direction from the four-way switching valve 2 to the second connection pipe 7. The sixth check valve 35 is provided between the heat source machine side heat exchanger 3 and the first connection pipe 6, and the refrigerant flows only from the first connection pipe 6 toward the heat source machine side heat exchanger 3. Is acceptable. Further, the outside air temperature detection device 25 detects the outside air temperature outside the room (hereinafter simply referred to as the outside air temperature), and transmits the outside air temperature as a signal to a valve device controller 21 and a throttle device controller 24 described later.

  Each of the indoor units B, C, and D includes an indoor unit side heat exchanger 5 and a flow rate control device 9 connected in series to the indoor unit side heat exchanger 5 in proximity to each indoor unit side heat exchanger 5. It consists of The flow rate control device 9 connects the second connection pipes 7b, 7c, and 7d on the indoor unit side according to the degree of superheat on the outlet side of the indoor unit side heat exchanger 5 during cooling and the degree of supercooling on the outlet side during heating. Control the flow rate of refrigerant passing through.

  The relay E is connected to the heat source machine A by a thick first connection pipe 6 connected to the four-way switching valve 2 and a second connection pipe 7 connected to the heat source machine side heat exchanger 3 and narrower than the first connection pipe 6. Connected. Also, connected to the indoor unit side first connection pipes 6b, 6c, 6d connected to the indoor unit side heat exchanger 5 of the indoor units B, C, D and the flow rate control device 9 of the indoor units B, C, D. The indoor unit B, C, D is connected to the indoor unit side second connection pipes 7b, 7c, 7d. And it has an internal structure as described below.

  The first branch section 10 selectively connects the first connection pipes 6b, 6c, 6d on the indoor unit side to the first connection pipe 6 or the second connection pipe 7. Three first valve devices 8a, one end of which is connected to each of the first connection pipes 6b, 6c, 6d on the indoor unit side and the other end of which are connected together and connected to the first connection pipe 6; Are connected to the first connecting pipes 6b, 6c, 6d on the indoor unit side through the throttle device 23 whose valve opening is arbitrarily controlled by the throttle device controller 24, and the other end is connected in a lump. Three second valve devices 20 connected to one connection pipe 6, one end is connected to each of the first connection pipes 6 b, 6 c, 6 d on the indoor unit side, and the other end is collectively connected to the second And three third valve devices 8b connected to the connection pipe 7. By opening the first valve device 8a or the second valve device 20 and closing the third valve device 8b, the first connection pipes 6b, 6c, 6d on the indoor unit side are changed to the first connection pipe 6. By connecting, the first valve device 8a and the second valve device 20 are closed, and the third valve device 8b is opened, whereby the first connection pipes 6b, 6c and 6d on the indoor unit side are connected to the second connection. Connect to pipe 7. Here, in particular, the first valve device 8a, the second valve device 20, and the expansion device 23 are used to control the temperature of the refrigerant in the indoor unit-side heat exchanger 5 during the cooling operation, as will be described later. Therefore, the evaporation temperature control device 22 is assumed.

  The second branch portion 11 includes a first check valve 17 and a second check valve 18 each having one end connected in reverse parallel relation to the second connection pipes 7b, 7c, and 7d on the indoor unit side, The first check valve 17 includes a meeting portion 17A in which the other ends of the check valve 17 are connected together, and a meeting portion 18A in which the other ends of the second check valve 18 are connected together. The gas-liquid separation device 12 is provided in the middle of the second connection pipe 7, the gas phase portion is connected to the third valve device 8 b of the first branch portion 10, and the liquid phase portion is the second branch. Connected to the unit 11.

  The second flow rate control device 13 is connected between the gas-liquid separation device 12 and the second branching portion 11 and can be freely opened and closed. The bypass pipe 14 connects the second branch portion 11 and the first connection pipe 6. The third flow control device 15 is provided in the middle of the bypass pipe 14. The second heat exchange unit 16 exchanges heat between the downstream portion of the third flow control device 15 of the bypass pipe 14 and the pipe from the second flow control device 13 to the meeting part 18A of the second branching unit 11. Is to do. On the other hand, the first heat exchanging part 19 exchanges heat between the downstream part of the second heat exchanging part 16 of the bypass pipe 14 and the pipe connecting the gas-liquid separator 12 and the second flow rate controller 13. Do.

  The first pressure detector 45 is attached to a pipe connecting the second flow rate control device 13 and the gas-liquid separation device 12. The second pressure detector 46 is attached to a pipe connecting the second flow rate control device 13 and the second branch portion 11.

  The valve device control unit 21 controls the opening and closing of the first and second valve devices 8a and 20 used in the cooling operation, particularly among the valve devices. Further, the expansion device control unit 24 can arbitrarily control the valve opening degree of each expansion device 23. In the present embodiment, the valve device controller 21 opens and closes the first valve device 8a and the second valve device 20 based on the temperature of the outside air detected by the outside air temperature detection device 25 and transmitted in the signal. The throttle device control unit 24 controls the valve opening of the throttle device 23. Here, the valve device control unit 21 and the expansion device control unit 24 that control the operation of the evaporation temperature control device 22 are referred to as an evaporation temperature control unit 28.

  By the air conditioning apparatus of Embodiment 1 configured as described above, three types of operation are performed. That is, when all of the indoor units B, C, and D perform a cooling operation, when all the indoor units B, C, and D perform a heating operation, some of the indoor units B, C, and D are cooled. The operation is performed, and the other part is the case of performing the heating operation (simultaneous cooling and heating operation). Furthermore, two forms of operation are performed for the simultaneous cooling and heating operation. That is, when most (two) of the indoor units B, C, and D perform the heating operation (heating operation), most of the indoor units B, C, and D perform the cooling operation. (Cooling-dominated operation). The operation state in each operation will be described below.

  FIG. 2 is a diagram illustrating an operation state of only the cooling or heating of the air conditioner. First, the case of only the cooling operation will be described with reference to FIG. As shown by the solid line arrow in FIG. 2, after the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2 and is condensed by exchanging heat in the heat source unit side heat exchanger 3. , Flows through the third check valve 32 and the second connection pipe 7 and flows into the relay E.

  The refrigerant that has flowed into the relay E passes through the gas-liquid separator 12 and the second flow rate controller 13 in this order, and then flows into the second branch portion 11. The refrigerant that has flowed into the second branch portion 11 is branched into the second connection pipes 7b, 7c, and 7d on the indoor unit side at the meeting portion 17A, and flows into the indoor units B, C, and D. Based on the degree of superheat at the outlet of each indoor unit side heat exchanger 5, the flow control device 9 depressurizes the refrigerant to a predetermined pressure. The indoor unit side heat exchanger 5 exchanges heat between the indoor air and the refrigerant. The refrigerant evaporates and gasifies in the indoor unit-side heat exchanger 5, thereby depriving the room air of heat and cooling the room.

  Then, the refrigerant in the gas state passes through the first connection pipes 6b, 6c, 6d on the indoor unit side, the first valve device 8a or the second valve device 20 of the first branch portion 10, and passes through the first connection piping 6b, 6c, 6d. A circulation cycle that is sucked into the compressor 1 through the connection pipe 6, the fourth check valve 33, the four-way switching valve 2, and the accumulator 4 is configured to perform a cooling operation. During the cooling operation, the first valve device 8a or the second valve device 20 is opened, and the third valve device 8b is closed.

  At this time, since the first connection pipe 6 is low pressure and the second connection pipe 7 is high pressure, the refrigerant inevitably flows through the third check valve 32 and the fourth check valve 33 side. Further, at the time of this cycle, a part of the refrigerant that has passed through the second flow control device 13 flows into the bypass pipe 14 and is decompressed by the third flow control device 15, and in the second heat exchange unit 16, Heat exchange is performed with the refrigerant flowing into the second branch portion 11 on each indoor unit side. Further, in the first heat exchange unit 19, heat exchange is performed with the refrigerant flowing into the second flow control device 13. The refrigerant evaporated by heat exchange in the first heat exchange section 19 flows into the first connection pipe 6 and is sucked into the compressor 1 through the fourth check valve 33, the four-way switching valve 2, and the accumulator 4. On the other hand, the refrigerant that has been cooled and sufficiently subcooled by heat exchange in the first heat exchange section 19 is the first check valve 17 of the second branch section 11 and the second connection pipe on the indoor side. It flows into indoor units B, C, D via 7b, 7c, 7d.

  When the outside air temperature detected by the outside air temperature detecting device 25 is lower than a preset temperature (for example, 15 ° C.) in the valve device control unit 21, the indoor unit side heat exchanger 5 of the indoor units B, C, and D In order to increase the evaporation temperature, control is performed to open the first valve device 8a and close the second valve device 20. Further, when the outside air temperature detected by the outside air temperature detection device 25 is equal to or higher than a preset temperature, the evaporation temperature of the indoor unit side heat exchanger 5 of the indoor units B, C, D is set to a normal temperature or a low temperature. In order to achieve this, control is performed such that the first valve device 8a is closed and the second valve device 20 is opened. That is, when the first valve device 8a is opened and the second valve device 20 is closed, the refrigerant flows without going through the throttle device 23, so the pressure loss is small and the refrigerant pressure is small. The evaporation temperature of the indoor unit side heat exchanger 5 can be reduced to a normal temperature or a low temperature. On the other hand, when the first valve device 8a is closed and the second valve device 20 is opened, the refrigerant flows through the throttle device 23, so that the pressure loss is large and the refrigerant pressure is increased. It is possible to increase the pressure applied to the refrigerant in the machine-side heat exchanger 5 and increase the evaporation temperature.

  When the refrigerant passes through the expansion device 23, the expansion device control unit 24 arbitrarily controls the valve opening degree of each expansion device 23 so that the refrigerant flows through each expansion device 23. Therefore, the evaporation temperature of each indoor unit side heat exchanger 5 can be individually and arbitrarily set. For example, the lower the outside air temperature obtained by the outside air temperature detection device 25, the smaller the valve opening of the expansion device 23, and the larger the pressure loss when the refrigerant flows, so that the evaporation temperature of the indoor unit side heat exchanger 5 is increased. On the contrary, as the outside air temperature is higher, the valve opening of the expansion device 23 is increased, and the pressure loss when the refrigerant flows is reduced to control the evaporation temperature of the indoor unit-side heat exchanger 5 to be lower. . About the valve opening degree of each expansion device 23, a setting etc. may change with the use environment etc. of each indoor unit. By controlling the evaporation temperature in this way, for example, if the outside air temperature is high, such as in summer, and if the humidity is high and the latent heat load is large, the operation is performed with a low sensible heat ratio. If it is small, the cooling operation according to the air conditioning load (sensible heat load and latent heat load) can be performed throughout the year by performing the operation with a large sensible heat ratio according to the latent heat load.

  FIG. 5 shows the cooling capacity (latent heat capacity and sensible heat capacity) during the cooling operation under a certain air condition (constant dry bulb temperature and wet bulb temperature) when a general indoor heat exchanger is used. It is the figure which showed sensible heat capacity | capacitance and the sensible heat ratio (ratio of sensible heat capacity | capacitance with respect to cooling capacity). The horizontal axis indicates the evaporation temperature, the vertical axis left indicates the cooling capacity and the sensible heat capacity, and the vertical axis right indicates the sensible heat ratio. The relationship between the evaporation temperature and the sensible heat capacity of the indoor unit side heat exchanger during the cooling operation will be described with reference to FIG. As shown in FIG. 5, the cooling capacity decreases as the evaporation temperature rises, but the sensible heat capacity maintains a substantially constant capacity. That is, as the evaporation temperature increases, the sensible heat ratio increases and the latent heat capacity decreases. Therefore, when a cooling load is generated throughout the year, it is desirable to increase the sensible heat ratio by increasing the evaporation temperature when it is better to increase the ratio of the sensible heat load, for example, in winter. For example, when the ratio of the latent heat load increases as in the summer, it is desirable to reduce the sensible heat ratio (increase the latent heat capacity) by lowering the evaporation temperature. By controlling the pressure loss by the expansion device 23 and controlling the evaporation temperature, a cooling operation that matches the state of the sensible heat load is possible. Then, for example, the time (season, climate, etc.) is roughly determined based on the outside air temperature detected by the outside air temperature detection device 25, and the cooling operation with the sensible heat load (latent heat load) corresponding to the time can be performed.

  Next, the case of only heating operation will be described with reference to FIG. In this case, the four-way switching valve 2 is switched, and the refrigerant flow is as shown by broken-line arrows in FIG. That is, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, passes through the fifth check valve 34 and the second connection pipe 7, and flows into the relay machine E. The refrigerant that has flowed into the relay E flows into the gas-liquid separator 12 and the first branch portion 10. The refrigerant that has flowed into the first branching section 10 passes through the third valve device 8b and the first connection pipes 6b, 6c, and 6d on the indoor unit side, and flows into the indoor units B, C, and D. The side heat exchanger 5 exchanges heat with room air to condense and liquefy it, thereby heating the room. And the refrigerant | coolant which became the liquid state passes through the flow control apparatus 9 controlled by the subcooling degree of the exit of each indoor unit side heat exchanger 5, and passes from the 2nd connection piping 7b, 7c, 7d by the indoor unit side. After flowing into the second branch portion 11 and passing through the second check valve 18, they merge at the meeting portion 18 </ b> A, and flow into the third flow rate control device 15 from here to the low pressure gas-liquid two-phase state. Depressurized. The refrigerant depressurized to a low pressure passes through the bypass pipe 14, the second heat exchange unit 16, and the first heat exchange unit 19, and then passes through the first connection pipe 6, the sixth check valve 35, and the heat source unit. The refrigerant that flows into the side heat exchanger 3 and exchanges heat to evaporate into a gas state constitutes a circulation cycle that is sucked into the compressor 1 through the four-way switching valve 2 and the accumulator 4, and performs a heating operation. At this time, the first and second valve devices 8a and 20 are closed, and the third valve device 8b is opened. In addition, since the first connection pipe 6 is low pressure and the second connection pipe 7 is high pressure, the refrigerant inevitably flows to the fifth check valve 34 and the sixth check valve 35.

  FIG. 3 is a diagram illustrating a driving operation state of the air-conditioning apparatus that is mainly heating. Next, the case of heating mainly in the simultaneous cooling and heating operation will be described with reference to FIG. Here, two indoor units B and C will be described as performing heating operation, and the indoor unit D performing cooling operation. That is, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, the fifth check valve 34, and the second connection pipe 7 as shown by broken line arrows in FIG. Inflow. The refrigerant that has flowed into the relay machine E flows into the first branch section 10 through the gas-liquid separator 12. The refrigerant that has flowed into the first branch section 10 passes through the third valve device 8b connected to the indoor units B and C and the first connection pipes 6b and 6c on the indoor unit side in this order, and the indoor unit that is going to be heated It flows into B and C, heat-exchanges with indoor air with the indoor unit side heat exchanger 5, is condensed and liquefied, and the room is heated. The refrigerant in the liquid state is controlled by the degree of supercooling at the outlet of the indoor unit-side heat exchanger 5 and is slightly depressurized through the flow control device 9 in a substantially fully open state, so that the intermediate pressure between the high pressure and the low pressure ( Intermediate pressure), the second connection pipes 7b and 7c on the indoor unit side pass through the second check valve 18 and merge at the meeting portion 18A.

  The refrigerant flowing to the indoor unit D that is going to be cooled has a second branching portion in which a part of the refrigerant joined at the meeting portion 18A of the second branching portion 11 of the relay E passes through the second heat exchanging portion 16. 11 passes through the first check valve 17 connected to the indoor unit D and the second connection pipe 7d on the indoor side, enters the indoor unit side heat exchanger 5 and exchanges heat to evaporate. It becomes a gas state, cools the room, and flows into the first connection pipe 6 via the first valve device 8a or the second valve device 20 connected to the indoor unit D of the first branching section 10.

  On the other hand, the other part of the refrigerant for heating the indoor units B and C that has flowed from the indoor units B and C into the meeting portion 18A of the second branching unit 11 of the relay device E is the high pressure of the second connection pipe 7. And the third flow control device 15 that can be opened and closed that is controlled so as to make the difference between the intermediate pressure of the second branch portion 11 constant, flows into the bypass pipe 14, and enters the first connection pipe 6. Therefore, the indoor unit D joins with the cooled refrigerant and flows into the thick first connection pipe 6 and flows into the sixth check valve 35 and the heat source unit side heat exchanger 3 to exchange heat and evaporate. The refrigerant in the gas state constitutes a circulation cycle that is sucked into the compressor 1 through the four-way switching valve 2 and the accumulator 4 and performs heating-main operation.

  At this time, the first valve device 8a and the second valve device 20 connected to the indoor units B and C to be heated are closed, the third valve device 8b is opened, and the indoor unit D to be cooled is The first valve device 8a or the second valve device 20 to be connected is opened, and the third valve device 8b is closed. In addition, since the first connection pipe 6 is low pressure and the second connection pipe 7 is high pressure, the refrigerant inevitably flows to the fifth check valve 34 and the sixth check valve 35.

  Further, during this cycle, the refrigerant that has entered the bypass pipe 14 is decompressed to a low pressure by the third flow control device 15, and the refrigerant that flows into the second branch portion 11 by the second heat exchange unit 16. Then, the refrigerant that has evaporated by the heat exchange with the refrigerant flowing into the second flow rate control device 13 in the first heat exchanging unit 19 enters the first connection pipe 6 and enters the sixth check After passing through the valve 35, it flows into the heat source unit side heat exchanger 3 and exchanges heat to evaporate into a gas state. The refrigerant is sucked into the compressor 1 through the four-way switching valve 2 and the accumulator 4. On the other hand, the refrigerant that has been cooled by exchanging heat in the first and second heat exchanging units 19 and 16 and having a sufficient degree of supercooling flows into the indoor unit D that is going to be cooled.

  When the outside air temperature detected by the outside air temperature detection device 25 is lower than the preset temperature in the valve device controller 21 during the heating main operation, the indoor unit side heat exchanger 5 of the indoor unit D to be cooled is used. In order to increase the evaporation temperature of the air, the first valve device 8a corresponding to the indoor unit is closed and the second valve device 20 is opened, and the outside air temperature detected by the outside air temperature detecting device 25 is controlled. Is higher than a preset temperature, in order to reduce the evaporation temperature of the indoor unit-side heat exchanger 5 of the indoor unit D that is going to be cooled to a normal temperature or a low temperature, the first corresponding to the indoor unit Control is performed to open the valve device 8a and close the second valve device 20. That is, when the first valve device 8a is opened and the second valve device 20 is closed, the refrigerant flows without passing through the expansion device 23, so the pressure loss is small and the evaporation of the indoor unit side heat exchanger 5 is performed. The temperature can be normal or lower. On the other hand, when the first valve device 8a is closed and the second valve device 20 is opened, the refrigerant flows through the expansion device 23, so that the pressure loss is large and the indoor unit-side heat exchanger 5 evaporates. The temperature can be increased. At this time, by arbitrarily controlling the valve opening degree of the expansion device 23 by the expansion device control unit 24, the pressure loss when the refrigerant flows through the expansion device 23 can be arbitrarily controlled. It becomes possible to raise the evaporation temperature of the heat exchanger 5 individually and arbitrarily. Thus, since the effect of individually controlling the evaporation temperature of the indoor unit D to be cooled is the same as the effect during the cooling operation by all the indoor units described above, the description thereof is omitted here.

  FIG. 4 is a diagram showing a cooling operation state of the air conditioner. Next, the case of the cooling main in the simultaneous cooling and heating operation will be described with reference to FIG. Here, the explanation will be made assuming that the two indoor units B and C perform the cooling operation and the indoor unit D performs the heating operation. That is, as shown by the solid arrows in FIG. 4, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2 and exchanges an arbitrary amount of heat with the heat source unit side heat exchanger 3. It becomes a gas-liquid two-phase high-temperature and high-pressure refrigerant and flows into the relay E through the third check valve 32 and the second connection pipe 7. The refrigerant that has flowed into the relay E is sent to the gas-liquid separator 12 where the refrigerant is separated into a gas refrigerant and a liquid refrigerant, and the separated gas refrigerant passes through the second connection pipe 7 to the first of the relay E. Through the third valve device 8b of the branching section 10 and the first connecting pipe 6d on the indoor unit side, and flows into the indoor unit D to be heated, and exchanges heat with indoor air in the indoor unit side heat exchanger 5 The liquid is condensed and heated.

  Furthermore, it is controlled by the degree of supercooling at the outlet of the indoor unit-side heat exchanger 5 and is slightly depressurized through the flow control device 9 which is in a fully open state, resulting in an intermediate pressure between the high pressure and the low pressure (intermediate pressure). 2 through the second connection pipe 7d, through the second check valve 18 of the second branching section 11 and into the bypass pipe 14 from the meeting section 18A, the pressure is reduced to a low pressure by the third flow control device 15, Heat exchange with the refrigerant flowing into the second branching section 11 at the second heat exchanging section 16 and between the refrigerant flowing into the second flow control device 13 at the first heat exchanging section 19 The refrigerant that has evaporated and exchanged heat reaches the first connection pipe 6. On the other hand, the remaining liquid refrigerant separated by the gas-liquid separation device 12 of the relay E is cooled by exchanging heat at the first heat exchanging unit 19 and sufficiently subcooled, and then the difference between the high pressure and the intermediate pressure. Flows into the meeting part 17A of the second branch part 11 through the second flow rate control device 13 that is controlled to be constant.

  The refrigerant flow to the indoor units B and C to be cooled is the first check valve 17 connected to the indoor units B and C from the meeting part 17A of the second branching unit 11 of the relay machine E, the indoor unit It passes through the second connection pipes 7b and 7c on the side and flows into the indoor units B and C. And this refrigerant | coolant is pressure-reduced to low pressure by the flow control device 9 controlled by the superheat degree of the exit of the indoor unit side heat exchanger 5 of the indoor units B and C, and indoor air and heat in the indoor unit side heat exchanger 5 It is exchanged and evaporated to gasify, and the room is cooled. Then, the refrigerant in the gas state passes through the first connection pipes 6b and 6c on the indoor unit side, the first valve device 8a or the second valve device 20 of the first branching section 10, and the first The fourth check valve 33, the four-way switching valve 2, and the accumulator 4 are flown into the connection pipe 6, merged with the above-described indoor unit D heating refrigerant flowing into the first connection pipe 6 through the bypass pipe 14. After that, a circulation cycle that is sucked into the compressor 1 is configured, and the cooling main operation is performed.

  At this time, the first valve device 8a or the second valve device 20 connected to the indoor units B and C to be cooled is opened, the third valve device 8b is closed, and the indoor unit D to be heated is connected. The connected first and second valve devices 8a and 20 are closed, and the third valve device 8b is opened. Further, since the first connection pipe 6 is low pressure and the second connection pipe 7 is high pressure, the refrigerant inevitably flows to the third check valve 32 and the fourth check valve 33.

  During this cooling main operation, when the outside air temperature detected by the outside air temperature detecting device 25 is lower than a preset temperature in the valve device control unit 21, the indoor unit side heat exchange of the indoor units B and C to be cooled is performed. In order to increase the evaporation temperature of the vessel 5, the first valve device 8 a corresponding to the indoor unit is closed and the second valve device 20 is opened, and the outside air temperature detection device 25 detects the temperature. When the outside air temperature is higher than a preset temperature, it corresponds to the indoor unit in order to lower the evaporation temperature of the indoor unit side heat exchanger 5 of the indoor units B and C to be cooled to a normal temperature or lower. The first valve device 8a is opened and the second valve device 20 is closed. That is, when the first valve device 8a is opened and the second valve device 20 is closed, the refrigerant flows without passing through the expansion device 23, so the pressure loss is small and the evaporation of the indoor unit side heat exchanger 5 is performed. The temperature can be normal or lower. On the other hand, when the first valve device 8a is closed and the second valve device 20 is opened, the refrigerant flows through the expansion device 23, so the pressure loss is large and the evaporation temperature of the indoor unit side heat exchanger 5 is large. Can be increased. At this time, by arbitrarily controlling the valve opening degree of the expansion device 23 by the expansion device control unit 24, the pressure loss when the refrigerant flows through the expansion device 23 can be arbitrarily controlled. It becomes possible to raise the evaporation temperature of the heat exchanger 5 individually and arbitrarily. Thus, since the effect of individually controlling the evaporation temperatures of the indoor units B and C that are in the cooling operation is the same as the effect during the cooling operation described above, the description thereof is omitted here.

  As described above, according to the first embodiment, particularly during the cooling operation, the valve device control unit 21 determines whether or not the temperature is, for example, a predetermined temperature or more based on the outside air temperature detected by the outside air temperature detecting device 25. The switching control of opening and closing of the first valve device 8a and the second valve device 20 is performed, and when it is determined that the temperature is lower than a predetermined temperature, the indoor unit side heat is passed through the expansion device 23. The exchanger 5 is controlled so that the evaporation temperature of the refrigerant becomes high. For example, when the outside air temperature is judged and the cooling operation is performed when the outside air temperature is high and the humidity is high, such as in summer, it is obvious. Operate at a low heat ratio (high latent heat load), and operate at a high sensible heat ratio when cooling operation must be performed even when the outside air temperature is low and the humidity is low, such as in winter. By the load according to the environment It is possible to perform the rate good cooling operation. In addition, since the expansion device 23 is provided independently for each indoor unit, the expansion device control unit 24 can control the valve opening degree according to the environment of each indoor unit and control the evaporation temperature. it can. In this embodiment, the present invention is applied to an air conditioner that can be operated simultaneously with cooling and heating with a plurality of indoor units. However, the present invention can also be applied to an air conditioner with one indoor unit. In addition, the refrigeration cycle is configured by the heat source unit A, the plurality of indoor units B, C, D and the relay unit E, and the evaporating temperature control device 22 is provided in each indoor unit. Therefore, the present invention can be applied even if there is only one indoor unit that is in cooling operation. Further, since the evaporating temperature control device 22 is constituted by the valve devices of the first valve device 8a and the second valve device 20 and the throttle device 23, there is no pipe having a small pressure loss without the throttle device 23, and the throttle device 23. A large switching of the cooling load can be performed by switching a pipe having a considerable pressure loss with a valve device. Further, fine control by the diaphragm device 23 can be performed.

Embodiment 2. FIG.
FIG. 6 is a refrigerant circuit diagram illustrating the overall configuration of the air-conditioning apparatus according to Embodiment 2. Next, the air conditioner of Embodiment 2 will be described based on FIG. In this figure, the same or corresponding parts as in FIG. In FIG. 6, the humidifier 26 is mounted on the indoor unit D, and a humidifying operation can be performed. Further, the valve device control unit 21 determines whether or not the humidifying device 26 is performing a humidifying operation. Here, since the refrigerant flow during the cooling operation, the heating operation, and the simultaneous cooling / heating operation (cooling main operation and heating main operation) is the same as that in the first embodiment, description thereof is omitted in the present embodiment. .

  In the second embodiment, the valve device control unit 21 and the expansion device control unit 24 will be described. Here, the case where the indoor units B and C perform the cooling operation and the indoor unit D performs the humidification operation will be described. In Embodiment 1, the valve device controller 21 closes the valve device 8a and opens the second valve device 20, or opens the valve device 8a and closes the second valve device 20. The determination was made based on the outside air temperature detected by the outside air temperature detection device 25. In the present embodiment, the determination is made based on whether or not the humidifying device 26 is performing a humidifying operation. The fact that the humidifying operation is performed by the humidifying device 26 basically means that the necessity of performing a cooling operation with a high latent heat load such as dehumidification is not recognized in other indoor units. Because.

  Therefore, the valve device control unit 21 determines whether or not the humidifying device 26 of the indoor unit D is performing a humidifying operation, and if it is determined that the humidifying device 26 is performing a humidifying operation, Control is performed such that the first valve device 8a connected to the first connection pipes 6b and 6c is closed and the second valve device 20 is opened, and the indoor units of the indoor units B and C are passed through the expansion device 23. It controls so that the evaporation temperature in the side heat exchanger 5 becomes high. On the other hand, when it is determined that the humidifying device 26 is not performing the humidifying operation, the first valve device 8a connected to the first connection pipes 6b and 6c on the indoor unit side is opened, and the second valve device 20 is opened. Is closed, and the evaporation temperature in the indoor unit side heat exchanger 5 of the indoor units B and C is controlled without passing through the expansion device 23.

  FIG. 7 is a diagram showing the relationship between the evaporation temperature of the indoor unit side heat exchanger 5 and the dehumidification amount during the cooling operation. As shown in FIG. 7, by increasing the evaporation temperature, the sensible heat ratio increases and the dehumidification amount decreases. For this reason, when there is a device performing a humidifying operation, when performing a cooling operation, it is possible to prevent wasteful consumption of energy by controlling the evaporation temperature so that dehumidification is not performed.

  At this time, by arbitrarily controlling the valve opening degree of the expansion device 23 by the expansion control unit 24, the pressure loss when the refrigerant flows through the expansion device 23 can be arbitrarily controlled. The evaporating temperature of the heat exchanger 5 can be set individually and arbitrarily, and the amount of dehumidification can be arbitrarily controlled.

  As described above, according to the second embodiment, the valve device control unit 21 determines whether the humidifying device 26 is performing a humidifying operation, and opens and closes the first valve device 8a and the second valve device 20. For example, when the humidifying operation is being performed, the evaporating temperature is controlled via the expansion device 23 so that the dehumidification is not necessary. Efficient cooling operation with a high sensible heat ratio can be performed under a certain environment.

Embodiment 3 FIG.
FIG. 8 is a refrigerant circuit diagram illustrating the overall configuration of the air-conditioning apparatus according to Embodiment 3. Next, Embodiment 3 of the present invention will be described with reference to FIG. In FIG. 8, the same or corresponding parts as in FIG. In addition, since the refrigerant flow during the cooling and heating simultaneous operation (cooling main operation and heating main operation) is the same as that in the first embodiment, description thereof is omitted.

  In the third embodiment, the valve device control unit 21 and the expansion device control unit 24 will be described. Here, in the present embodiment, a case where the indoor units B and C perform the cooling operation and the indoor unit D performs the heating operation will be described. The valve device control unit 21 determines whether or not at least one indoor unit is performing the heating operation. For example, if there is at least one first connection pipe on the indoor unit side that closes the first valve device 8a and the second valve device 20, it is determined that the heating operation is being performed. For example, when the indoor unit D performs the heating operation, the first valve device 8a connected to the first connection pipes 6b and 6c on the indoor unit side is closed, and the second valve device 20 is opened. The evaporating temperature in the indoor unit side heat exchanger 5 of the indoor units B and C is controlled to be higher through the expansion device 23. On the other hand, when none of the indoor units is performing the heating operation, the first valve device 8a connected to the first connection pipes 6b and 6c on the indoor unit side is opened, and the second valve device 20 is closed. The evaporating temperature in the indoor unit side heat exchanger 5 of the indoor units B and C is lowered without passing through the expansion device 23.

  It can be said that winter is when at least one indoor unit is in heating operation. Therefore, when the other indoor unit performs a cooling operation in this state, an operation with a high sensible heat ratio is performed by controlling the evaporation temperature to be high, and an operation that matches the air conditioning load with a large sensible load ratio in winter can be performed. . At this time, by arbitrarily controlling the valve opening degree of the expansion device 23 by the expansion device control unit 24, the pressure loss when the refrigerant flows through the expansion device 23 can be arbitrarily controlled. It is possible to control the evaporation temperature of the heat exchanger 5 individually and arbitrarily to an arbitrary temperature.

  As described above, according to the third embodiment, the valve device control unit 21 determines whether the indoor unit is in a heating operation, and switches between opening and closing of the first valve device 8a and the second valve device 20. For example, when heating operation is performed in at least one indoor unit, when cooling operation is performed in another indoor unit, it is connected to the first connection pipe on the indoor unit side The first valve device 8a thus closed is closed and the second valve device 20 is opened to control the evaporating temperature through the expansion device 23. For example, in the winter season In an environment with a large sensible heat load, when performing a cooling operation in another indoor unit, it is possible to perform an efficient cooling operation with a high sensible heat ratio.

Embodiment 4 FIG.
FIG. 9 is a refrigerant circuit diagram illustrating an overall configuration of the air-conditioning apparatus according to Embodiment 4. Next, a fourth embodiment of the present invention will be described with reference to FIG. In FIG. 9, the same or corresponding parts as in FIG. In FIG. 9, the outside air introduction port 27 is provided for introducing outside air into the indoor unit D. Here, the flow of the refrigerant during the simultaneous cooling and heating operation (cooling main operation and heating main operation) is the same as that in the above-described first embodiment, and thus description thereof is omitted.

  In the fourth embodiment, the valve device control unit 21 and the expansion device control unit 24 will be described. Here, in the present embodiment, a case where the indoor units B and C perform the cooling operation and the indoor unit D performs the heating operation will be described. The valve device control unit 21 determines whether or not the indoor unit D is performing a heating operation. For example, if the first valve device 8a and the second valve device 20 connected to the first connection pipe 6d on the indoor unit side are closed, it is determined that the indoor unit D is in the heating operation. When the indoor unit D performs a heating operation, the first valve device 8a connected to the first connection pipes 6b and 6c on the indoor unit side is closed and the second valve device 20 is opened. And the evaporating temperature in the indoor unit side heat exchanger 5 of the indoor units B and C is controlled to be high. On the other hand, when the indoor unit D is not performing the heating operation, the first valve device 8a connected to the first connection pipes 6b and 6c on the indoor unit side is opened, and the second valve device 20 is closed. The evaporating temperature in the indoor unit side heat exchanger 5 of the indoor units B and C is lowered without passing through the expansion device 23.

  This is because the indoor unit D that introduces outside air is in a heating operation because the outside air temperature is low and it is considered to be in winter. Therefore, when other indoor units perform cooling operation in this state, the evaporating temperature is controlled to be high, the cooling operation with a large sensible heat ratio is performed, and the cooling load with a large ratio of the sensible heat load as in the winter season. Can be operated in accordance with. Conversely, the fact that the indoor unit D that introduces outside air is not in a heating operation is a state in which the outside air temperature is high and is considered to be summer. Therefore, when other indoor units perform cooling operation in this state, cooling operation with a low sensible heat ratio is performed so that the evaporation temperature is low, and a cooling load with a large latent heat load ratio such as in summer is performed. Can be operated in accordance with. At this time, by arbitrarily controlling the valve opening degree of the expansion device 23 by the expansion device control unit 24, the pressure loss when the refrigerant flows through the expansion device 23 can be arbitrarily controlled. It is possible to control the evaporation temperature of the heat exchanger 5 individually and arbitrarily to an arbitrary temperature.

Embodiment 5. FIG.
In the above-described embodiment, at the time of cooling, the indoor unit side first connection pipe connected to each indoor unit and the first connection pipe 6 is made into two systems, and pressure loss does not occur in one pipe as much as possible. I am doing so. However, for example, even when only one system can be used due to the circumstances of piping or the like, although pressure loss occurs, it can be substituted by fully opening the throttling device 23.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the air conditioning apparatus which shows Embodiment 1 of this invention. It is a driving | running operation state figure of only air_conditioning | cooling or heating of the air conditioning apparatus shown in FIG. It is a driving | running operation state figure of the heating main body of the air conditioning apparatus shown in FIG. It is a driving | running operation state figure of the cooling main body of the air conditioning apparatus shown in FIG. It is a figure which shows the relationship between the evaporation temperature of the indoor unit side heat exchanger at the time of air_conditionaing | cooling operation, and sensible heat capability. It is a whole block diagram of the air conditioning apparatus which shows Embodiment 2 of this invention. It is a figure which shows the relationship between the evaporation temperature of the indoor unit side heat exchanger at the time of air_conditionaing | cooling operation, and dehumidification amount. It is a whole block diagram of the air conditioning apparatus which shows Embodiment 3 of this invention. It is a whole block diagram of the air conditioning apparatus which shows Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor, 2 way switching valve, 3 Heat source machine side heat exchanger, 4 Accumulator, 5 Indoor unit side heat exchanger, 6 1st connection piping, 6a, 6b, 6c 1st connection piping on the indoor unit side, 7 Second connection piping, 7a, 7b, 7c Second connection piping on the indoor unit side, 8a First valve device, 8b Third valve device, 9 Flow control device, 10 First branch, 11th 2 branch portions, 12 gas-liquid separator, 13 second flow control device, 14 bypass piping, 15 third flow control device, 16 second heat exchange portion, 17 first check valve, 17A, 18A Meeting unit, 18 Second check valve, 19 First heat exchange unit, 20 Second valve device, 21 Valve device control unit, 22 Evaporation temperature control device, 23 Throttle device, 24 Throttle device control unit, 25 Outside air Temperature detection device, 26 humidification device, 27 outside air inlet, 28 evaporation temperature control unit, 32 third Check valve, 33 fourth check valve, 34 fifth check valve, 35 sixth check valve, 45 first pressure detector, 46 second pressure detector, A heat source machine, B, C, D Indoor unit, E Repeater.

Claims (6)

In the air conditioner having a plurality of indoor units each having an indoor unit side heat exchanger and performing air conditioning operation,
An outdoor temperature detection device for detecting outdoor outdoor temperature,
An evaporation temperature control device that changes the flow rate or pressure of the refrigerant from the indoor unit-side heat exchanger of the indoor unit that is performing cooling operation;
An evaporating temperature control unit that controls the evaporating temperature of the refrigerant in the indoor unit heat exchanger by changing the flow rate or pressure of the refrigerant in the evaporating temperature control device based on the outdoor outside air temperature. An air conditioner characterized. Among the plurality of indoor units each having an indoor unit side heat exchanger, in an air conditioner including at least one indoor unit having a humidifying device that performs a humidifying operation,
An evaporation temperature control device that changes the flow rate or pressure of the refrigerant from the indoor unit-side heat exchanger of the indoor unit that is performing cooling operation;
The refrigerant in the indoor unit-side heat exchanger of the indoor unit that is performing the cooling operation by changing the flow rate or pressure in the evaporation temperature control device based on whether or not the humidifying operation by the humidifier is performed. An air conditioning apparatus comprising: an evaporation temperature control unit that controls the evaporation temperature of the air. In the air conditioner having a plurality of indoor units each having an indoor unit side heat exchanger and performing air conditioning operation,
An evaporation temperature control device that changes the flow rate or pressure of the refrigerant in the indoor unit-side heat exchanger of the indoor unit that is performing cooling operation;
Based on whether or not at least one indoor unit of the plurality of indoor units is performing a heating operation, the flow rate or pressure of the refrigerant is changed in the evaporation temperature control device, and the indoor unit is performing a cooling operation. An air conditioner comprising: an evaporation temperature control unit that controls an evaporation temperature of the refrigerant in the machine-side heat exchanger.   An indoor unit side heat exchanger that performs heat exchange between outdoor air and refrigerant out of the plurality of indoor units, instead of based on whether or not at least one of the plurality of indoor units is performing a heating operation. The air conditioning according to claim 3, wherein the evaporating temperature control unit causes the evaporating temperature control device to change the flow rate or pressure of the refrigerant based on whether or not the indoor unit having a heating operation is performed. apparatus. The air conditioner is
One heat source machine having a compressor, a switching valve for switching the flow path of the refrigerant discharged from the compressor, and a heat source machine side heat exchanger connected to the switching valve,
A plurality of indoor units having the indoor unit side heat exchanger and a flow rate control device connected to the indoor unit side heat exchanger, and the first and second connecting pipes connecting the heat source unit and the indoor units. A first branch section having the evaporating temperature control device provided on the refrigerant flow path on the first connection pipe side in accordance with each indoor unit, and each indoor unit side heat exchanger The air conditioning apparatus according to any one of claims 1 to 4, wherein a refrigeration cycle is configured by a relay machine including a second branch portion that can be connected to the second connection pipe. The evaporation temperature control device includes:
A throttle device capable of changing the flow rate of the refrigerant;
6. The air according to claim 5, wherein the first connecting pipe is constituted by a valve device that switches a flow path of the refrigerant between a pipe provided with the throttle device and a pipe not provided with the throttle device. Harmony device.

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