Air Conditioning Equipment

Abstract

This air-conditioning apparatus comprises: an evaporator that exchanges heat between a coolant and air and evaporates the coolant; an outdoor condenser that is provided to an outdoor unit, exchanges heat between the coolant and air, and condenses the coolant; an indoor condenser that is provided to an indoor unit, exchanges heat between the coolant and air, and condenses the coolant; a blowing temperature sensor that, during a dehumidifying operation, detects the blowing temperature of air that is dehumidified by the evaporator and is then reheated by the indoor condenser and blown out of the indoor unit; and a control device that adjusts the condensation heat quantity of the outdoor condenser on the basis of the blowing temperature detected by the blowing temperature sensor.

Description

[Technical field]

[0001] The present disclosure relates to an air conditioner that performs a dehumidifying operation. [Background technology]

[0002] Conventionally, air conditioners that perform dehumidification operation are known. The indoor unit of the air conditioner removes moisture from the sucked air with an evaporator, reheats it with a condenser, and blows it out to reduce the relative humidity in the space to be air-conditioned. The air conditioner also has a condenser provided in the outdoor unit, and adjusts the amount of condensation heat in the condenser of the indoor unit by changing the amount of condensation heat in the condenser of the outdoor unit. Patent Document 1 discloses an air conditioner that performs dehumidification operation. The air conditioner of Patent Document 1 adjusts the rotation speed of the outdoor fan, etc., based on the temperature of the refrigerant flowing through the indoor heat exchanger, with the aim of bringing the indoor temperature closer to a set temperature. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-106706 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in general air conditioners including those in Patent Document 1, dust and the like may adhere to the filters that prevent foreign matter from entering the condenser and evaporator. These effects may cause the volume of air blown out from the indoor unit to become unstable. As a result, even if the air conditioner adjusts the rotation speed of the outdoor fan based on the temperature of the refrigerant flowing through the indoor heat exchanger, it is not possible to bring the temperature of the dry air blown out during dehumidification operation close to the set target temperature, and the target space may be excessively cooled or heated.

[0005] The present disclosure is intended to solve the above-mentioned problems, and has an object to bring the temperature of dry air blown out closer to a set target temperature during dehumidification operation in an air conditioning apparatus. [Means for solving the problem]

[0006] The air conditioning apparatus according to the present disclosure includes an evaporator which exchanges heat between a refrigerant and air to evaporate the refrigerant, an outdoor condenser which is provided in an outdoor unit and exchanges heat between the refrigerant and air to condense the refrigerant, an indoor condenser which is provided in an indoor unit and exchanges heat between the refrigerant and air to condense the refrigerant, a discharge temperature sensor which detects the discharge temperature of air that is dehumidified by the evaporator, reheated by the indoor condenser and blown out of the indoor unit during dehumidification operation, and a control device which adjusts the amount of condensation heat of the outdoor condenser based on the discharge temperature detected by the discharge temperature sensor. An outdoor fan that sends air to the outdoor condenser, a solenoid valve, Equipped with The outdoor condenser has a first condensing section and a second condensing section that exchange heat between a refrigerant and air, the solenoid valve is provided upstream of the second condensing section and has a function of switching between an open state in which the refrigerant flows into the second condensing section and a closed state in which the flow of the refrigerant to the second condensing section is blocked, and the control device increases the output of the outdoor fan when the solenoid valve is closed and the output of the outdoor fan is below a threshold value when the blowing temperature is higher than an upper limit value of the target temperature, and opens the solenoid valve when the solenoid valve is closed and the output of the outdoor fan is equal to or higher than the threshold value when the blowing temperature is higher than the upper limit value of the target temperature. . Effect of the Invention

[0007] The air conditioner of the present disclosure adjusts the amount of condensation heat of the outdoor condenser based on the blowing temperature measured by the temperature sensor during dehumidification operation. The air conditioner directly measures the blowing temperature of the air blown out from the indoor unit and adjusts the amount of condensation heat of the outdoor condenser in accordance with the actual blowing temperature, thereby making it possible to bring the temperature of the blown out dry air closer to the target temperature set during dehumidification operation. [Brief description of the drawings]

[0008] [Figure 1] 1 is a circuit diagram showing an air conditioner according to a first embodiment. [Diagram 2] 1 is a functional block diagram of an air conditioning apparatus according to a first embodiment. [Diagram 3] 1 is a hardware configuration diagram showing an example of the configuration of an outdoor control device according to Embodiment 1. FIG. [Figure 4] 1 is a hardware configuration diagram showing an example of the configuration of an outdoor control device according to Embodiment 1. FIG. [Diagram 5]5 is a flowchart showing the operation of the outdoor control device according to the first embodiment. [Figure 6] FIG. 11 is a circuit diagram showing an air conditioner according to a second embodiment. [Figure 7] FIG. 11 is a functional block diagram of an air conditioning apparatus according to a second embodiment. [Figure 8] 10 is a flowchart showing the operation of the outdoor control device according to the second embodiment. [Figure 9] FIG. 4 is a diagram for explaining the minimum output of the outdoor fan. [Figure 10] FIG. 11 is a diagram for explaining a first control pattern according to the third embodiment. [Figure 11] FIG. 11 is a diagram for explaining a second control pattern according to the third embodiment. [Figure 12] 11 is a flowchart showing the operation of the outdoor control device according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described with reference to the drawings. In each drawing, the same reference numerals are used to denote the same or equivalent parts, and this is common throughout the specification. In addition, the forms of the components shown in the entire specification are merely examples and are not limited to these descriptions. Furthermore, the size relationships of the components in the following drawings may differ from the actual ones.

[0010] Embodiment 1 FIG. 1 is a circuit diagram of an air conditioner 1 according to the first embodiment. The air conditioner 1 of the first embodiment performs a dehumidification operation to blow out dry air into a space to be air-conditioned, such as a living room, to reduce the relative humidity. As shown in FIG. 1, the air conditioner 1 includes an outdoor unit 2 and an indoor unit 3. The outdoor unit 2 is installed, for example, outside the space to be air-conditioned. The indoor unit 3 is installed, for example, in the space to be air-conditioned. Although details will be described later, the air conditioner 1 performs a dehumidification operation by dehumidifying the air drawn into the indoor unit 3 with an evaporator 17, reheating it with an indoor condenser 14, and blowing it out. At this time, the amount of condensation heat in the outdoor condenser 12 of the outdoor unit 2 is changed to adjust the amount of condensation heat in the indoor condenser 14, and thus the blowing temperature To.

[0011] The outdoor unit 2 includes an outdoor condenser 12, an outdoor fan 13, and an outdoor control device 21. The outdoor condenser 12 is, for example, a fin-tube type heat exchanger. The outdoor condenser 12 exchanges heat between the air supplied by the outdoor fan 13 and the refrigerant. The outdoor condenser 12 condenses the gaseous refrigerant discharged from the compressor 11 during dehumidification operation, changing it to a gas-liquid two-phase state.

[0012] The outdoor fan 13 supplies air around the outdoor unit 2 to the outdoor condenser 12. The outdoor fan 13 is, for example, an inverter type, and the output to a motor (not shown) of the outdoor fan 13 is controlled by the outdoor control device 21. Hereinafter, the output to the motor of the outdoor fan 13 may be referred to as the outdoor fan output. By controlling the outdoor fan output, the rotation speed and air volume of the outdoor fan 13 are increased or decreased, and the condensing capacity of the outdoor condenser 12 is adjusted.

[0013] The outdoor control device 21 controls the outdoor fan output. The specific configuration of the outdoor control device 21 and the control content will be described later.

[0014] The indoor unit 3 has a compressor 11, an indoor condenser 14, an indoor fan 15, an expansion valve 16, an evaporator 17, and an indoor control device 22. The compressor 11 sucks in low-temperature, low-pressure gas refrigerant, compresses it, and discharges high-temperature, high-pressure gas refrigerant. The compressor 11 is, for example, an inverter-type compressor 11 whose capacity is controllable.

[0015] The indoor condenser 14 is, for example, a fin-tube type heat exchanger. The indoor condenser 14 exchanges heat between the refrigerant and air supplied by the indoor fan 15. The indoor condenser 14 further condenses and liquefies the refrigerant in a gas-liquid two-phase state that flows out from the outdoor condenser 12 during dehumidification operation.

[0016] The indoor fan 15 supplies air around the indoor unit 3 to the indoor condenser 14. The indoor fan 15 is, for example, a cross-flow fan. The indoor fan 15 is, for example, an inverter type, and the output to a motor (not shown) of the indoor fan 15 is controlled by the indoor control device 22. Hereinafter, the output to the motor of the indoor fan 15 may be referred to as the indoor fan output. By controlling the indoor fan output, the rotation speed and air volume of the indoor fan 15 are increased or decreased, and the condensing capacity of the indoor condenser 14 is adjusted.

[0017] The expansion valve 16 is, for example, an electronic expansion valve whose opening degree is variably controlled. The expansion valve 16 reduces the pressure of the refrigerant flowing out from the indoor condenser 14 to expand it.

[0018] The evaporator 17 is, for example, a fin-tube type heat exchanger. The evaporator 17 exchanges heat between the air drawn into the indoor unit 3 and the refrigerant. The evaporator 17 evaporates and gasifies the refrigerant that flows out from the expansion valve 16.

[0019] The indoor control device 22 controls the operating frequency of the compressor 11, the opening degree of the expansion valve 16, and the indoor fan output. The indoor control device 22 is connected to the outdoor control device 21 via wire or wirelessly so that they can communicate with each other. The specific configuration of the indoor control device 22 and the control contents will be described later.

[0020] A compressor 11, an outdoor condenser 12, an indoor condenser 14, an expansion valve 16, and an evaporator 17 are connected in this order in a circular manner by refrigerant piping 4 to form a refrigerant circuit 5.

[0021] The air conditioner 1 also has a refrigerant temperature sensor 31, a humidity sensor 32, a suction temperature sensor 33, and a discharge temperature sensor 34. The refrigerant temperature sensor 31 is attached to the refrigerant piping 4 at a position downstream of the outdoor condenser 12 inside the outdoor unit 2, that is, at a position between the outdoor condenser 12 and the indoor condenser 14, and detects the condensation temperature CT of the refrigerant flowing through the refrigerant piping 4. The refrigerant temperature sensor 31 transmits the detected condensation temperature CT to the outdoor control device 21.

[0022] The humidity sensor 32 is provided at an inlet (not shown) that draws air into the indoor unit 3, and detects the humidity of the air drawn into the indoor unit 3. Hereinafter, the humidity of the air drawn into the indoor unit 3 is referred to as the intake humidity Rin. The humidity sensor 32 transmits the detected intake humidity Rin to the indoor control device 22.

[0023] The suction temperature sensor 33 is provided at the suction port and detects the temperature of the air sucked into the indoor unit 3. Hereinafter, the temperature of the air sucked into the indoor unit 3 will be referred to as the suction temperature Tin. The suction temperature sensor 33 transmits the detected suction temperature Tin to the indoor control device 22.

[0024] The blowing temperature sensor 34 is provided at an air outlet (not shown) that blows air out of the indoor unit 3, and detects the temperature of the air that is heat exchanged with the refrigerant in the evaporator 17 and the indoor condenser 14 and blown out from the indoor unit 3. Hereinafter, the temperature of the air blown out from the indoor unit 3 is referred to as the blowing temperature To. The blowing temperature sensor 34 transmits the detected blowing temperature To to the indoor control device 22.

[0025] Here, the operation of each device constituting the refrigerant circuit 5 and the state of the refrigerant when the air conditioner 1 performs a dehumidification operation will be described. First, the refrigerant sucked into the compressor 11 is compressed by the compressor 11 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas refrigerant discharged from the compressor 11 flows into the outdoor condenser 12. The refrigerant that flows into the outdoor condenser 12 exchanges heat with the outdoor air sent by the outdoor fan 13, condenses, and changes to a two-phase gas-liquid state. The two-phase gas-liquid refrigerant flows into the indoor condenser 14. The two-phase gas-liquid refrigerant that flows into the indoor condenser 14 exchanges heat with the indoor air sent by the indoor fan 15, condenses, and liquefies. At this time, the indoor air that has been dehumidified by heat exchange with the refrigerant in the evaporator 17 is reheated and warmed in the indoor condenser 14 and blown out into the room as dry air, thereby decreasing the relative humidity in the room.

[0026] The liquid refrigerant flows into the expansion valve 16, where it is decompressed and expanded to become a low-temperature, low-pressure, two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant flows into the evaporator 17. The refrigerant that flows into the evaporator 17 exchanges heat with the indoor air drawn into the indoor unit 3, evaporates, and gasifies. At this time, moisture is removed from the indoor air drawn into the room, and the air is dehumidified. The evaporated low-temperature, low-pressure gas refrigerant is then drawn into the compressor 11.

[0027] FIG. 2 is a functional block diagram of the air conditioner 1 according to the first embodiment. As shown in FIG. 2, the indoor control device 22 controls the compressor 11, the indoor fan 15, and the expansion valve 16 based on the suction humidity Rin detected by the humidity sensor 32 and the suction temperature Tin detected by the suction temperature sensor 33. In addition, the outdoor control device 21 and the indoor control device 22 are connected to be able to communicate with each other. This allows the outdoor control device 21 and the indoor control device 22 to share information detected by each sensor, as well as the control states of the outdoor fan 13, the compressor 11, the indoor fan 15, and the expansion valve 16. That is, the outdoor control device 21 can receive information acquired by the indoor control device 22 and control the devices connected to the indoor control device 22 based on the received information. Similarly, the indoor control device 22 can receive information acquired by the outdoor control device 21 and control the devices connected to the outdoor control device 21 based on the received information. In particular, the outdoor control device 21 controls the outdoor fan 13 based on the blowing temperature To received from the indoor control device 22 and the condensation temperature CT detected by the refrigerant temperature sensor 31.

[0028] The control of the outdoor fan 13 will be described in detail. The indoor control device 22 acquires the blowing temperature To measured by the blowing temperature sensor 34 and transmits it to the outdoor control device 21. The indoor control device 22 periodically repeats this operation during dehumidification operation. The outdoor control device 21 sets a target temperature Tm for the blowing temperature To. The target temperature Tm is a temperature set by the user via a remote control (not shown) of the air conditioning device 1. Alternatively, the target temperature Tm is the current indoor temperature. The indoor temperature corresponds to the suction temperature Tin detected by the suction temperature sensor 33.

[0029] The outdoor control device 21 determines the outdoor fan output so that the blowing temperature To approaches the target temperature Tm based on the comparison result between the blowing temperature To and the target temperature Tm received from the indoor control device 22. Specifically, first, the outdoor control device 21 judges whether or not it is necessary to change the outdoor fan output. If the blowing temperature To at the time of control is outside the range of the target temperature Tm [°C] ± a [K], the outdoor control device 21 judges that it is necessary to change the outdoor fan output. a is an allowable range determined for the target temperature Tm. When changing the outdoor fan output, the outdoor control device 21 judges whether to increase or decrease the outdoor fan output. For example, if the blowing temperature To is lower than the lower limit value Tm-a of the target temperature, the amount of condensation heat processed by the indoor condenser 14 is insufficient. For this reason, the outdoor fan output is lowered to reduce the airflow rate of the outdoor fan 13, thereby decreasing the proportion of the condensation heat amount in the outdoor condenser 12 to the total condensation heat amount in the outdoor condenser 12 and the indoor condenser 14, and the blowing temperature To is increased. On the other hand, when the blowing temperature To is higher than the upper limit value Tm+a of the target temperature, the amount of condensation heat processed by the indoor condenser 14 is excessive. For this reason, the outdoor fan output is increased to increase the airflow rate of the outdoor fan 13, thereby increasing the proportion of the condensation heat amount in the outdoor condenser 12 to the total condensation heat amount in the outdoor condenser 12 and the indoor condenser 14, and the blowing temperature To is decreased. Note that it is assumed here that the operating frequency of the compressor 11 and the opening degree of the expansion valve 16 are not changed.

[0030] The outdoor control device 21 determines whether the outdoor fan output can be adjusted in each of the cases of increasing and decreasing the outdoor fan output. Whether the outdoor fan output can be decreased is determined based on whether the condensation temperature CT at the time of control is below an upper allowable value CTmax-b obtained by subtracting a margin b from the upper limit value CTmax of the condensation temperature. Whether the outdoor fan output can be increased is determined based on whether the condensation temperature CT at the time of control exceeds a lower allowable value CTmin+c obtained by adding a margin c to the lower limit value CTmin of the condensation temperature.

[0031] Here, an example of the hardware of the outdoor control device 21 will be described. Note that the hardware of the indoor control device 22 can have the same configuration as the indoor control device 22. Therefore, in the following, illustrations and detailed descriptions of the indoor control device 22 will be omitted. FIG. 3 is a hardware configuration diagram showing an example of the configuration of the outdoor control device 21 according to the first embodiment. When the various functions of the outdoor control device 21 are executed by hardware, the outdoor control device 21 is configured by a processing circuit 41 as shown in FIG. 3. Each function of the outdoor control device 21 shown in FIG. 2 is realized by the processing circuit 41.

[0032] Where the functions are implemented in hardware, the processing circuitry 41 may be, for example, a single circuit, a composite circuit, a programmed processor 42, a parallel programmed processor 42, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof.

[0033] Another example of hardware of the outdoor control device 21 will now be described. Fig. 4 is a hardware configuration diagram showing an example of the configuration of the outdoor control device 21 according to the first embodiment. When the various functions of the outdoor control device 21 are executed by software, the outdoor control device 21 is composed of a processor 42 such as a CPU and a memory 43, as shown in Fig. 4. Each function of the outdoor control device 21 is realized by the processor 42 and the memory 43. Fig. 4 shows that the processor 42 and the memory 43 are connected to each other via a bus 44 so as to be able to communicate with each other.

[0034] When each function is executed by software, the function of the outdoor control device 21 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the memory 43. The processor 42 realizes the function of the outdoor control device 21 by reading and executing the programs stored in the memory 43.

[0035] For example, non-volatile semiconductor memories such as ROM (Read Only Memory), flash memory, EPROM (Erasable and Programmable ROM), and EEPROM (Electrically Erasable and Programmable ROM) are used as the memory 43. Also, volatile semiconductor memories such as RAM (Random Access Memory) may be used as the memory 43. Furthermore, removable recording media such as magnetic disks, flexible disks, optical disks, CDs (Compact Discs), MDs (Mini Discs), and DVDs (Digital Versatile Discs) may be used as the memory 43.

[0036] Fig. 5 is a flowchart showing the operation of the outdoor control device 21 according to the first embodiment. The procedure for adjusting the amount of condensation heat of the outdoor condenser 12 according to the first embodiment will be described with reference to Fig. 5. The outdoor control device 21 judges whether the blowing temperature To is equal to or higher than the lower limit Tm-a of the target temperature and equal to or lower than the upper limit Tm+a of the target temperature (step S1). If the blowing temperature To at the time of control is equal to or higher than the lower limit Tm-a of the target temperature and equal to or lower than the upper limit Tm+a of the target temperature (step S1: YES), the outdoor control device 21 maintains the current airflow rate of the outdoor fan 13.

[0037] If the blowing temperature To is less than the lower limit value Tm-a of the target temperature or exceeds the upper limit value Tm+a of the target temperature (step S1: NO), the outdoor control device 21 determines whether the blowing temperature To is less than the lower limit value Tm-a of the target temperature (step S2). If the blowing temperature To is less than the lower limit value Tm-a of the target temperature (step S2: YES), the outdoor control device 21 determines whether the condensing temperature CT at the time of control is less than the upper allowable value CTmax-b of the condensing temperature (step S3).

[0038] If the condensation temperature CT at the time of control is less than the upper allowable value CTmax-b of the condensation temperature (step S3: YES), the outdoor control device 21 reduces the outdoor fan output to reduce the air volume of the outdoor fan 13 (step S4). This reduces the proportion of condensation heat in the outdoor condenser 12, and the blowing temperature To increases. Then, the outdoor control device 21 judges whether the elapsed time after the outdoor fan output is reduced is equal to or longer than the adjustment time (step S5). If the elapsed time after the outdoor fan output is reduced is equal to or longer than the adjustment time (step S5: YES), the outdoor control device 21 ends the processing. The adjustment time is set to prevent the refrigerant circuit 5 from becoming unstable due to frequent changes in the air volume of the outdoor fan 13. If the elapsed time after the outdoor fan output is reduced is less than the adjustment time (step S5: NO), the outdoor control device 21 repeats the processing of step S5 until the elapsed time after the outdoor fan output is reduced is equal to or longer than the adjustment time.

[0039] When the condensation temperature CT at the time of control is equal to or higher than the upper allowable condensation temperature CTmax-b (step S3: NO), the outdoor control device 21 maintains the current airflow rate of the outdoor fan 13.

[0040] If the blowing temperature To exceeds the upper limit value Tm+a of the target temperature (step S2: NO), the outdoor control device 21 determines whether the condensation temperature CT at the time of control exceeds the lower allowable value CTmin+c of the condensation temperature (step S6).

[0041] If the condensation temperature CT at the time of control exceeds the allowable value CTmin+c of the condensation temperature CT (step S6: YES), the outdoor control device 21 increases the outdoor fan output to increase the air volume of the outdoor fan 13 (step S7). This increases the proportion of condensation heat in the outdoor condenser 12, and the blowing temperature To decreases. Then, the outdoor control device 21 determines whether the elapsed time after the outdoor fan output is increased is equal to or longer than the adjustment time (step S8). If the elapsed time after the outdoor fan output is increased is equal to or longer than the adjustment time (step S8: YES), the outdoor control device 21 ends the processing. If the elapsed time after the outdoor fan output is increased is less than the adjustment time (step S8: NO), the outdoor control device 21 repeats the processing of step S8 until the elapsed time after the outdoor fan output is increased is equal to or longer than the adjustment time.

[0042] When the condensation temperature CT at the time of control is equal to or lower than the lower allowable value CTmin+c of the condensation temperature (step S6: NO), the outdoor control device 21 maintains the current airflow rate of the outdoor fan 13.

[0043] As described above, according to the first embodiment, during dehumidification operation, the amount of condensation heat of the outdoor condenser 12 is adjusted based on the blowing temperature To measured by the temperature sensor. The air conditioning apparatus 1 directly measures the blowing temperature To of the air blown out from the indoor unit 3, and adjusts the amount of condensation heat of the outdoor condenser 12 in accordance with the actual blowing temperature To, thereby making it possible to bring the temperature of the blown out dry air closer to the set target temperature Tm during dehumidification operation.

[0044] Furthermore, according to the first embodiment, the temperature of the blown dry air is stabilized at a value close to the target temperature Tm. Therefore, when starting and stopping of the compressor 11 is controlled based on the room temperature, the frequency of start-stop operation in which the compressor 11 is repeatedly started and stopped can be reduced, which contributes to energy saving.

[0045] Embodiment 2 The second embodiment differs from the first embodiment in that the amount of condensation heat of the outdoor condenser 12 is adjusted by changing the heat transfer area. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and the differences from the first embodiment will be mainly described.

[0046] FIG. 6 is a circuit diagram of an air conditioner 1 according to a second embodiment. As shown in FIG. 6, the outdoor condenser 12A according to the second embodiment is composed of a first condensing section 12a and a second condensing section 12b. The refrigerant pipe 4 branches into a first condensing section 12a side and a second condensing section 12b side at a position upstream of the first condensing section 12a and the second condensing section 12b, and is rejoined at a position downstream of the first condensing section 12a and the second condensing section 12b. An electromagnetic valve 18 is attached to a position upstream of the second condensing section 12b in the branched portion of the refrigerant pipe 4 on the second condensing section 12b side. The electromagnetic valve 18 has a function of switching between an open state in which the refrigerant flows into the second condensing section 12b and a closed state in which the flow of the refrigerant to the second condensing section 12b is blocked. Either the open state or the closed state that the electromagnetic valve 18 is in is called an open / closed state. The outdoor control device 21 switches the open / closed state of the solenoid valve 18, thereby substantially changing the heat transfer area of ​​the outdoor condenser 12A. In the second embodiment, the compressor 11, the outdoor condenser 12A, the first condensing section 12a of the indoor condenser 14 arranged in parallel, the solenoid valve 18, the second condensing section 12b of the indoor condenser 14, the expansion valve 16, and the evaporator 17 are connected in this order in a circular manner by the refrigerant piping 4, thereby forming a refrigerant circuit 5.

[0047] Fig. 7 is a functional block diagram of the air conditioner 1 according to embodiment 2. As shown in Fig. 7, the outdoor control device 21 controls the solenoid valve 18 based on the blowing temperature To detected by the blowing temperature sensor 34 and the condensation temperature CT detected by the refrigerant temperature sensor 31. The outdoor control device 21 controls the outdoor fan 13 based on the condensation temperature CT detected by the refrigerant temperature sensor 31.

[0048] The control of the solenoid valve 18 will be described in detail. In the second embodiment, instead of the control of the outdoor fan output described in the first embodiment, the condensation heat amount of the outdoor unit 2 is adjusted by switching the open / close state of the solenoid valve 18. That is, when the blowing temperature To is lower than the lower limit value Tm-a of the target temperature and the solenoid valve 18 is in the open state, the solenoid valve 18 is closed to block the refrigerant flowing to the second condensing section 12b. As a result, heat exchange is performed only in the first condensing section 12a, and the ratio of the condensation heat amount in the outdoor condenser 12A to the total condensation heat amount in the outdoor condenser 12A and the indoor condenser 14 becomes relatively smaller than when the solenoid valve 18 is in the open state, and the blowing temperature To increases. On the other hand, when the blowing temperature To is higher than the upper limit value Tm+a of the target temperature and the solenoid valve 18 is in the closed state, the outdoor control device 21 opens the solenoid valve 18 to allow the refrigerant to flow to the second condensing section 12b. As a result, heat exchange takes place in both the first condenser section 12a and the second condenser section 12b, and the proportion of the condensation heat in the outdoor condenser 12A to the total condensation heat in the outdoor condenser 12A and the indoor condenser 14 becomes relatively larger than when the solenoid valve 18 is closed, and the blowing temperature To decreases.

[0049] The outdoor control device 21 determines whether or not the outdoor fan output can be adjusted when the solenoid valve 18 is closed and when it is open. Whether or not the solenoid valve 18 can be closed is determined based on whether or not the condensation temperature CT at the time of control is below an upper allowable value CTmax-b of the condensation temperature. Whether or not the solenoid valve 18 can be opened is determined based on whether or not the condensation temperature CT at the time of control is above a lower allowable value CTmin+c of the condensation temperature.

[0050] Fig. 8 is a flowchart showing the operation of the outdoor control device 21 according to the second embodiment. The procedure for adjusting the amount of condensation heat of the outdoor condenser 12A in the second embodiment will be described with reference to Fig. 8. The outdoor control device 21 judges whether the blowing temperature To is equal to or higher than the lower limit Tm-a of the target temperature and equal to or lower than the upper limit Tm+a of the target temperature (step S1). If the blowing temperature To at the time of control is equal to or higher than the lower limit Tm-a of the target temperature and equal to or lower than the upper limit Tm+a of the target temperature (step S1: YES), the outdoor control device 21 maintains the current open / closed state of the solenoid valve 18.

[0051] If the blowing temperature To is less than the lower limit value Tm-a of the target temperature or exceeds the upper limit value Tm+a of the target temperature (step S1: NO), the outdoor control device 21 determines whether the blowing temperature To is less than the lower limit value Tm-a of the target temperature (step S2). If the blowing temperature To is less than the lower limit value Tm-a of the target temperature (step S2: YES), the outdoor control device 21 determines whether the condensing temperature CT at the time of control is less than the upper allowable value CTmax-b of the condensing temperature (step S3).

[0052] If the condensation temperature CT at the time of control is less than the upper allowable value CTmax-b of the condensation temperature (step S3: YES), the outdoor control device 21 judges whether the solenoid valve 18 is in the open state (step S11). If the solenoid valve 18 is in the closed state (step S11: NO), the current open / close state of the solenoid valve 18 is maintained. If the solenoid valve 18 is in the open state (step S11: YES), the outdoor control device 21 closes the solenoid valve 18 to block the refrigerant flowing through the second condensing section 12b (step S12). As a result, the proportion of condensation heat in the outdoor condenser 12A becomes smaller than when the solenoid valve 18 is in the open state, and the blowing temperature To increases.

[0053] If the condensation temperature CT at the time of control is equal to or higher than the upper allowable value CTmax-b of the condensation temperature (step S3: NO), the outdoor control device 21 maintains the current open / closed state of the solenoid valve 18.

[0054] If the blowing temperature To exceeds the upper limit value Tm+a of the target temperature (step S2: NO), the outdoor control device 21 determines whether the condensation temperature CT at the time of control exceeds the lower allowable value CTmin+c of the condensation temperature (step S6).

[0055] If the condensation temperature CT at the time of control is greater than the lower allowable condensation temperature CTmin+c (step S6: YES), the outdoor control device 21 judges whether the solenoid valve 18 is closed or not (step S13). If the solenoid valve 18 is open (step S13: NO), the current open / closed state of the solenoid valve 18 is maintained. If the solenoid valve 18 is closed (step S13: YES), the outdoor control device 21 opens the solenoid valve 18 to allow the refrigerant to flow through the second condensing section 12b (step S14). As a result, the proportion of condensation heat in the outdoor condenser 12A becomes greater than when the solenoid valve 18 is closed, and the blowing temperature To decreases.

[0056] When the condensation temperature CT at the time of control is equal to or lower than the lower allowable value CTmin+c of the condensation temperature (step S6: NO), the outdoor control device 21 maintains the current open / closed state of the solenoid valve 18.

[0057] As described above, also in the second embodiment, the amount of condensation heat of the outdoor condenser 12A is adjusted based on the blowing temperature To measured by the temperature sensor during dehumidification operation. The air conditioning apparatus 1 directly measures the blowing temperature To of the air blown out from the indoor unit 3, and adjusts the amount of condensation heat of the outdoor condenser 12A in accordance with the actual blowing temperature To, thereby making it possible to stabilize the temperature of the dry air blown out during dehumidification operation.

[0058] Embodiment 3 The third embodiment combines both the adjustment of the amount of condensation heat of the outdoor condenser 12 by the outdoor fan 13 described in the first embodiment, and the adjustment of the amount of condensation heat of the outdoor condenser 12A by changing the heat transfer area described in the second embodiment. In the third embodiment, the same parts as those in the first and second embodiments are given the same reference numerals and the description will be omitted, and the differences from the first and second embodiments will be mainly described.

[0059] The configuration itself of the refrigerant circuit 5 of the air conditioning apparatus 1A of embodiment 3 is the same as that of embodiment 2, so a circuit diagram is omitted. The outdoor control device 21 controls the outdoor fan 13 and the solenoid valve 18 based on the blowing temperature To detected by the blowing temperature sensor 34 and the condensation temperature CT detected by the refrigerant temperature sensor 31.

[0060] The control of the outdoor fan 13 and the solenoid valve 18 will be described in detail. In the third embodiment, the amount of condensation heat of the outdoor unit 2 is adjusted by controlling the outdoor fan output described in the first embodiment and switching the open / closed state of the solenoid valve 18 described in the second embodiment. The outdoor control device 21 performs a first control pattern and a second control pattern for the control of the outdoor fan 13 and the solenoid valve 18. First, the first control pattern will be described. When the blowing temperature To is lower than the lower limit value Tm-a of the target temperature, if the solenoid valve 18 is open and the outdoor fan output is not minimum, the outdoor fan output is lowered to reduce the air volume of the outdoor fan 13 (from point A to point B in FIG. 10). Also, when the blowing temperature To is lower than the lower limit value Tm-a of the target temperature, if the solenoid valve 18 is open and the outdoor fan output is minimum, the solenoid valve 18 is closed to block the refrigerant flowing through the second condenser section 12b (from point B to point C in FIG. 10). In this way, when the blowing temperature To is lower than the lower limit value Tm-a of the target temperature, first the outdoor fan output is reduced, and if the outdoor fan output cannot be reduced, the solenoid valve 18 is closed. This reduces the proportion of the condensation heat amount in the outdoor condenser 12A to the total condensation heat amount in the outdoor condenser 12A and the indoor condenser 14, and the blowing temperature To increases.

[0061] A supplementary explanation of the minimum outdoor fan output will be given. FIG. 9 is a diagram for explaining the minimum output of the outdoor fan. As shown in FIG. 9, the outdoor fan output cannot be set arbitrarily in the entire range between 0 and 100%. Specifically, in the range between 0% and less than a predetermined output value, the condensation capacity of the outdoor condenser 12A cannot be adjusted, and therefore a value included in this range cannot be set as the set value of the outdoor fan output. The minimum outdoor fan output value refers to this predetermined output value. When the outdoor fan output is reduced to increase the blowing temperature, once the outdoor fan output reaches the minimum output, the blowing temperature cannot be adjusted any further by the outdoor fan 13 alone. Particularly in winter when the outdoor air temperature is low, the condensation capacity increases even with a small air volume, and the range in which adjustment is not possible becomes large.

[0062] On the other hand, when the blowing temperature To is higher than the upper limit value Tm+a of the target temperature, if the solenoid valve 18 is closed and the outdoor fan output is less than the threshold value, the outdoor fan output is increased to increase the air volume of the outdoor fan 13 (from point C to point D in FIG. 10). At this time, the adjusted outdoor fan output represented by point D is set so as to obtain a condensation capacity equivalent to the condensation capacity at point B. Also, when the blowing temperature To is higher than the upper limit value Tm+a of the target temperature, if the solenoid valve 18 is closed and the outdoor fan output is equal to or greater than the threshold value, the solenoid valve 18 is opened to allow the refrigerant to flow through the second condenser section 12b (from point D to point E in FIG. 10). The threshold value of the outdoor fan output is an arbitrary outdoor fan output value at which a condensation capacity greater than the condensation capacity at point B in FIG. 10 is obtained when the solenoid valve 18 is closed, and is, for example, a value indicating an output at which the outdoor fan 13 operates at the maximum rotation speed taking into consideration a tolerance for ensuring stable operation. In this way, when the blowing temperature To is higher than the upper limit value Tm+a of the target temperature, the outdoor fan output is first increased, and when the outdoor fan output cannot be increased, the solenoid valve 18 is opened. As a result, the proportion of the condensation heat amount in the outdoor condenser 12A to the total condensation heat amount in the outdoor condenser 12A and the indoor condenser 14 increases, and the blowing temperature To decreases.

[0063] FIG. 11 is a diagram for explaining a second control pattern according to the third embodiment. In the second control pattern, when the outdoor fan output is minimized while the solenoid valve 18 is in the open state, the solenoid valve 18 is closed and the outdoor fan output is increased at the same time (from point B to point D in FIG. 11). At this time, the outdoor fan output after adjustment represented by point D is set so as to obtain a condensation capacity equivalent to the condensation capacity at point B. When the solenoid valve 18 is closed and the blowing temperature is increased, the outdoor fan output is reduced to the minimum output and the condensation capacity is reduced (from point D to point C in FIG. 11). When the solenoid valve 18 is closed and the blowing temperature is reduced, the outdoor fan output is increased and the condensation capacity is increased (from point D to point F in FIG. 11). Then, when the solenoid valve 18 is closed and the outdoor fan output is increased, if the outdoor fan output reaches a threshold value, the solenoid valve 18 is opened and the outdoor fan output is reduced at the same time (from point F to point G in FIG. 11). At this time, the outdoor fan output after adjustment represented by point G is set so that a condensation capacity equivalent to the condensation capacity at point F is obtained.

[0064] In the first control pattern, the timing of switching the solenoid valve 18 and the change in output of the outdoor fan 13 are not linked, and therefore control is easy. On the other hand, there is waste compared to the second control pattern, since the change in condensation capacity is discontinuous at the transition from point B to point C and the transition from point D to point E when the solenoid valve 18 is switched. Also, although the control is more complex in the second control pattern, the change in condensation capacity is continuous at the transition from point B to point C and the transition from point F to point G when the solenoid valve 18 is switched, and therefore adjustment can be made without waste. For this reason, in the second control pattern, the time until the stable point is reached is short, even if the surrounding environment changes.

[0065] Fig. 12 is a flowchart showing the operation of the outdoor control device 21 according to the third embodiment. The procedure for adjusting the amount of condensation heat of the outdoor condenser 12A in the third embodiment will be described with reference to Fig. 12. Here, the first control pattern will be described. The outdoor control device 21 judges whether the blowing temperature To is equal to or higher than the lower limit Tm-a of the target temperature and equal to or lower than the upper limit Tm+a of the target temperature (step S1). If the blowing temperature To at the time of control is equal to or higher than the lower limit Tm-a of the target temperature and equal to or lower than the upper limit Tm+a of the target temperature (step S1: YES), the outdoor control device 21 maintains the current outdoor fan output and the open / closed state of the solenoid valve 18.

[0066] If the blowing temperature To is less than the lower limit value Tm-a of the target temperature or exceeds the upper limit value Tm+a of the target temperature (step S1: NO), the outdoor control device 21 determines whether the blowing temperature To is less than the lower limit value Tm-a of the target temperature (step S2). If the blowing temperature To is less than the lower limit value Tm-a of the target temperature (step S2: YES), the outdoor control device 21 determines whether the condensing temperature CT at the time of control is less than the upper allowable value CTmax-b of the condensing temperature (step S3).

[0067] If the condensation temperature CT at the time of control is less than the upper allowable value CTmax-b of the condensation temperature (step S3: YES), the outdoor control device 21 judges whether the solenoid valve 18 is in an open state and the outdoor fan output is at a minimum (step S21). If the solenoid valve 18 is in a closed state or the outdoor fan output is not at a minimum (step S21: NO), the outdoor control device 21 reduces the outdoor fan output (step S22). Then, the outdoor control device 21 judges whether the elapsed time after the outdoor fan output is reduced is equal to or greater than the adjustment time (step S23). If the elapsed time after the outdoor fan output is reduced is equal to or greater than the adjustment time (step S23: YES), the outdoor control device 21 ends the process. If the elapsed time after the open / closed state of the solenoid valve 18 is switched is less than the adjustment time (step S23: NO), the outdoor control device 21 repeats the process of step S23 until the elapsed time after the open / closed state of the solenoid valve 18 is switched is equal to or greater than the adjustment time.

[0068] If the solenoid valve 18 is open and the outdoor fan output is minimum (step S21: YES), the outdoor control device 21 closes the solenoid valve 18 to block the refrigerant flowing through the second condenser section 12b (step S24). By the above processes of steps S21 to S24, the proportion of condensation heat in the outdoor condenser 12A decreases, and the blowing temperature To increases.

[0069] If the condensation temperature CT at the time of control is equal to or higher than the upper allowable condensation temperature CTmax-b (step S3: NO), the outdoor control device 21 maintains the current outdoor fan output and the open / closed state of the solenoid valve 18.

[0070] If the blowing temperature To exceeds the upper limit value Tm+a of the target temperature (step S2: NO), the outdoor control device 21 determines whether the condensation temperature CT at the time of control exceeds the lower allowable value CTmin+c of the condensation temperature (step S6).

[0071] If the condensation temperature CT at the time of control is greater than the lower allowable condensation temperature CTmin+c (step S6: YES), the outdoor control device 21 judges whether the solenoid valve 18 is in a closed state and the outdoor fan output is equal to or greater than a threshold value (step S25). If the solenoid valve 18 is in an open state or the outdoor fan output is less than a threshold value (step S25: NO), the outdoor control device 21 increases the outdoor fan output (step S26). Then, the outdoor control device 21 judges whether the elapsed time after the outdoor fan output is increased is equal to or greater than the adjustment time (step S27). If the elapsed time after the outdoor fan output is increased is equal to or greater than the adjustment time (step S27: YES), the outdoor control device 21 ends the processing. If the elapsed time after the outdoor fan output is increased is less than the adjustment time (step S27: NO), the outdoor control device 21 repeats the processing of step S27 until the elapsed time after the outdoor fan output is increased is equal to or greater than the adjustment time.

[0072] When the solenoid valve 18 is closed and the outdoor fan output is equal to or greater than the threshold (step S25: YES), the outdoor control device 21 opens the solenoid valve 18 to allow the refrigerant to flow through the second condenser section 12b (step S28). By the processes of steps S25 to S28, the proportion of the condensation heat in the outdoor condenser 12A increases, and the blowing temperature To decreases.

[0073] If the condensation temperature CT at the time of control is equal to or lower than the lower allowable condensation temperature CTmin+c (step S6: NO), the outdoor control device 21 maintains the current outdoor fan output and the open / closed state of the solenoid valve 18.

[0074] As described above, also in the third embodiment, the amount of condensation heat of the outdoor condenser 12A is adjusted based on the blowing temperature To measured by the temperature sensor during dehumidification operation. The air conditioning apparatus 1 directly measures the blowing temperature To of the air blown out from the indoor unit 3, and adjusts the amount of condensation heat of the outdoor condenser 12A in accordance with the actual blowing temperature To, thereby making it possible to stabilize the temperature of the dry air blown out during dehumidification operation.

[0075] Generally, under conditions where the ambient temperature of the outdoor unit 2 is low, such as in winter, a large amount of heat is dissipated even with a small amount of airflow, so that it may be difficult to adjust the amount of condensation heat only by controlling the outdoor fan output. Therefore, according to the third embodiment, the adjustment of the amount of condensation heat of the outdoor condenser 12 by the outdoor fan 13 described in the first embodiment and the adjustment of the amount of condensation heat of the outdoor condenser 12A by changing the heat transfer area described in the second embodiment are combined. This expands the adjustment range of the amount of condensation heat, and enables more accurate control of the blowing temperature To.

[0076] The above is an explanation of the embodiment of the present disclosure, but the present disclosure is not limited to the configuration of the above embodiment, and various modifications or combinations are possible within the scope of the technical concept. For example, the air conditioner 1 may perform cooling operation. In this case, the indoor unit 3 performs cooling operation by supplying cold heat to the air-conditioned space by heat exchange between the refrigerant supplied from the outdoor unit 2 and the air. In addition, the air conditioner 1 may perform heating operation by providing a flow path switching device that switches the flow path in the opposite direction to the flow path described in the embodiment.

[0077] In the first embodiment, in the procedure for adjusting the amount of condensation heat of the outdoor condenser 12, if step S3: NO in Fig. 5 is performed, the outdoor condenser 12 is in a low-capacity state and is therefore maintained in operation. However, if step S3: NO is performed, the output of the indoor fan 15 may be adjusted. In this case, the output of the indoor fan 15 is adjusted so as to enable control so as to bring the target temperature set in the outdoor fan 13 and the temperature of the dry air blown out closer to each other, while allowing for the possibility that the dehumidification capacity of the evaporator 17 may decrease.

[0078] Moreover, in the third embodiment, a case has been described in which control of the outdoor fan output is given priority over switching the open / closed state of the solenoid valve 18. However, switching the open / closed state of the solenoid valve 18 may be given priority over control of the outdoor fan output. In this case as well, the same effects as those of the third embodiment can be obtained.

[0079] Also, a case has been described in which the outdoor control device 21 is provided in the outdoor unit 2, and the indoor control device 22 is provided in the indoor unit 3. However, the outdoor control device 21 and the indoor control device 22 may be provided outside the outdoor unit 2 and the indoor unit 3. Also, one of the outdoor control device 21 and the indoor control device 22 may be omitted, and the function of one may be realized by the other. Both the outdoor control device 21 and the indoor control device 22 correspond to the "control device" in this disclosure.

[0080] Further, in the first to third embodiments, the compressor 11 is provided in the indoor unit 3, but it may be provided in the outdoor unit 2. [Explanation of symbols]

[0081] 1, 1A air conditioning device, 2 outdoor unit, 3 indoor unit, 4 refrigerant piping, 5 refrigerant circuit, 11 compressor, 12, 12A outdoor condenser, 12a first condensation section, 12b second condensation section, 13 outdoor fan, 14 indoor condenser, 15 indoor fan, 16 expansion valve, 17 evaporator, 18 solenoid valve, 21 outdoor control device, 22 indoor control device, 31 refrigerant temperature sensor, 32 humidity sensor, 33 suction temperature sensor, 34 discharge temperature sensor, 41 processing circuit, 42 processor, 43 memory, 44 bus.

Claims

1. an evaporator that exchanges heat between the refrigerant and air to evaporate the refrigerant; an outdoor condenser provided in the outdoor unit, which exchanges heat between a refrigerant and air and condenses the refrigerant; an indoor condenser provided in the indoor unit, which exchanges heat between a refrigerant and air and condenses the refrigerant; a blowout temperature sensor that detects a blowout temperature of air that has been dehumidified by the evaporator, reheated by the indoor condenser, and blown out from the indoor unit during a dehumidification operation; a control device that adjusts a condensation heat amount of the outdoor condenser based on the blowing temperature detected by the blowing temperature sensor; an outdoor fan for blowing air to the outdoor condenser; A solenoid valve; The outdoor condenser is The condenser includes a first condenser section and a second condenser section that exchange heat between the refrigerant and the air, The solenoid valve is the second condensation section is provided upstream of the second condensation section, and has a function of switching between an open state in which the refrigerant flows into the second condensation section and a closed state in which the refrigerant is blocked from flowing into the second condensation section; The control device includes: When the blowing temperature is higher than the upper limit value of the target temperature, if the solenoid valve is in the closed state and the output of the outdoor fan is less than a threshold value, increasing the output of the outdoor fan, When the blowing temperature is higher than the upper limit value of the target temperature, if the solenoid valve is in the closed state and the output of the outdoor fan is equal to or higher than the threshold value, the solenoid valve is in the open state. Air conditioning equipment.

2. The control device reduces an air volume of the outdoor fan when the blowing temperature is lower than a lower limit value of the target temperature. The air conditioning apparatus according to claim 1.

3. The control device increases an air volume of the outdoor fan when the blowing temperature is higher than an upper limit value of the target temperature.

3. An air conditioning apparatus according to claim 1 or 2.

4. The control device includes: When the blowing temperature is lower than the lower limit value of the target temperature, if the solenoid valve is in the open state and the output of the outdoor fan is not at a minimum, the output of the outdoor fan is reduced, When the blowing temperature is lower than the lower limit of the target temperature, if the solenoid valve is in the open state and the output of the outdoor fan is at a minimum, the solenoid valve is in the closed state. The air conditioning apparatus according to claim 1.

Images