Washing and drying machine

Abstract

To provide a washing and drying machine capable of suppressing reduction in efficiency while securing reliability.SOLUTION: A washing and drying machine comprises: a heat pump unit; a washing tank; an air flowing channel in which air from the washing tank flows sequentially through an evaporator 25 and a condenser 23 and returns to the washing tank; a first temperature sensor 41 to detect a discharged coolant temperature of a compressor 21; a second temperature sensor 42 to detect temperature of the condenser 23; and a control part 50 to control an expansion valve 24 based on a detection value of the first temperature sensor 41 and control the compressor 21 based on a detection value of the second temperature sensor 42.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a washing and drying machine. [Background technology]

[0002] As a technology using a heat pump unit as a heat source for drying operation, for example, the technology described in Patent Document 1 is known. That is, Patent Document 1 describes that "...when the temperature detected by the first detector is equal to or lower than a first predetermined temperature and the temperature detected by the second detector is equal to or higher than a second predetermined temperature, the heat pump device is controlled to stop the operation of the drive unit and to increase the opening of the expansion valve." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-39597 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, when the detected values ​​of the first detector and the second detector are in an abnormal temperature range, the drive unit of the compressor is stopped. However, there is a risk of a significant decrease in efficiency due to the stopping of the drive unit of the compressor, and there is room for improvement.

[0005] In view of the above, an object of the present disclosure is to provide a washer / dryer that is capable of suppressing a decrease in efficiency while ensuring reliability. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the washer / dryer of the present disclosure includes a heat pump unit having a compressor, a condenser, an expansion valve, and an evaporator connected in sequence via refrigerant piping, and also includes a washing tub into which laundry is put, an air passage through which air from the washing tub flows sequentially through the evaporator and the condenser and then back to the washing tub, a first temperature sensor that detects the temperature of refrigerant discharged from the compressor, and a second temperature sensor that detects the temperature of the condenser, and further includes a control unit that controls the expansion valve based on the detection value of the first temperature sensor and controls the compressor based on the detection value of the second temperature sensor. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a washer / dryer that is capable of suppressing a decrease in efficiency while ensuring reliability. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view of a washing / drying machine according to an embodiment; [Diagram 2] 1 is a schematic cross-sectional view showing an internal structure of a washing / drying machine according to an embodiment. [Diagram 3] 1 is a perspective view of the inside of a washer / dryer according to an embodiment, as viewed from the rear side of an outer tub. [Figure 4] FIG. 2 is a perspective view showing an internal structure of a heat pump unit of the washer / dryer according to the embodiment. [Diagram 5] 1 is an explanatory diagram including a refrigerant circuit of a heat pump unit of a washer / dryer according to an embodiment. [Figure 6] 5 is a flowchart relating to control of an expansion valve during a drying operation of the washer / dryer according to the embodiment. [Figure 7] 5 is a flowchart relating to control of a compressor during a drying operation of the washer-dryer according to the embodiment. [Figure 8] 11 is a graph showing an example of changes in the compressor discharge refrigerant temperature, the condenser temperature, the opening degree of the expansion valve, and the compressor drive frequency in a washer / dryer according to an embodiment when the environmental temperature is within a normal range. [Figure 9] 6 is a graph showing an example of changes in the compressor discharge refrigerant temperature, the condenser temperature, the opening degree of the expansion valve, and the compressor drive frequency when the environmental temperature is high in the washer / dryer according to the embodiment. [Figure 10] 6 is a graph showing an example of changes in the compressor discharge refrigerant temperature, the condenser temperature, the opening degree of the expansion valve, and the compressor drive frequency in a washer / dryer according to an embodiment when the environmental temperature is low. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Embodiment> <Washer / dryer configuration> FIG. 1 is a perspective view of a washing / drying machine 100 according to an embodiment. The washer / dryer 100 shown in FIG. 1 is a drum-type washer / dryer that washes, rinses, spins, dries, etc. clothes. The washer / dryer 100 includes a housing 1, an operation unit 2, and a door 3. The housing 1 is a box-shaped body in which components such as an inner tub 4 (see FIG. 2) and an outer tub 8 (see FIG. 2) are installed. An input opening H1 for inserting and removing laundry is provided on the front side of the housing 1. An openable and closable door 3 is also provided at the input opening H1.

[0010] The operation unit 2 receives user operations. For example, a mechanical switch or a capacitance touch panel is used as the operation unit 2. The operation unit 2 may also have a function of displaying the operation state and setting screen of the washer / dryer 100 in addition to the function of receiving user operations. In the example of FIG. 1, the operation unit 2 is provided on a cover panel 1c that is inclined at a predetermined angle between the top cover 1a and the front cover 1b of the housing 1.

[0011] Although not shown, a water supply hose connection port and a water intake hose connection port are provided at the back side of the top cover 1a of the housing 1. A hose for leading tap water from a water faucet is inserted into the water supply hose connection port. A hose for leading remaining bath water is inserted into the water intake hose connection port.

[0012] FIG. 2 is a schematic cross-sectional view showing the internal structure of the washer / dryer 100. As shown in FIG. As shown in Fig. 2, the washer / dryer 100 includes an inner tub 4 (washing tub), a fluid balancer 5, a lifter 6, a motor 7, an outer tub 8, a bellows 9, a circulation pump 10, and a heat pump unit 20. The inner tub 4 is a cylindrical rotating drum with a bottom into which laundry R1 is placed. The inner tub 4 is provided with a plurality of small holes (not shown) used for spin-drying and ventilation. A metal flange 4a is provided at the bottom of the inner tub 4 to connect a drive shaft 7a of the motor 7.

[0013] The fluid balancer 5 is an annular member for suppressing vibrations caused by imbalance during spin-drying of the laundry R1, and is installed on the opening edge of the inner tub 4. The lifter 6 is a member for lifting up the laundry R1, and protrudes radially inward from the inner circumferential surface of the inner tub 4. The motor 7 is a drive source for rotating the inner tub 4, and is connected to a metal flange 4a at the bottom of the inner tub 4 via a drive shaft 7a.

[0014] The outer tub 8 is a cylindrical member with a bottom that contains the inner tub 4. The inner tub 4 and the outer tub 8 have substantially the same central axis (not shown). In the drum-type washer / dryer 100, the central axes of the inner tub 4 and the outer tub 8 are inclined at a predetermined angle so that the front of the tub is raised. As shown in FIG. 2, the outer tub 8 is supported from below by a plurality of suspensions 11 and is suspended by springs 12. The bellows 9 is a rubber ring-shaped member for ensuring watertightness between the outer tub 8 and the door 3, and is installed on the opening edge of the outer tub 8.

[0015] The bottom of the outer tub 8 is provided with a water receiving portion 8a that is recessed downward. The water receiving portion 8a is provided with a drain outlet H2 for draining the wash water. A lint filter 13 for collecting lint mixed in the wash water is provided downstream of the drain outlet H2. When the drain valve 14 is opened, the wash water is drained through the drain outlet H2, the lint filter 13, the drain valve 14, and the drain hose 15 in this order.

[0016] The circulation pump 10 is a pump for pumping the wash water up to the top of the outer tub 8 and spraying it onto the laundry R1 in the inner tub 4, and is disposed below the outer tub 8. The heat pump unit 20 has a function of dehumidifying moist air in a drying operation by an evaporator 25 (see FIG. 4) and further heating the dehumidified air by a condenser 23 (see FIG. 4). The heat pump unit 20 includes a housing 20a for accommodating devices such as a compressor 21 (see FIG. 4). The return duct 17 and the blow-out nozzle 19 shown in FIG. 2 will be described later.

[0017] FIG. 3 is a perspective view of the inside of the washer / dryer as viewed from the rear side of outer tub 8. FIG. The washer / dryer 100 includes, as components used in a drying operation, a hot air duct 16, a return duct 17, a blower fan 18, and a blow-out nozzle 19, as well as the heat pump unit 20 described above. The hot air duct 16 is a duct for guiding hot air (high-temperature, dry air) from the heat pump unit 20 to the blow-out nozzle 19. The blow-out nozzle 19 blows the hot air flowing through the hot air duct 16 into the inner tub 4 (see FIG. 2). In the example of FIG. 3, the downstream end of the hot air duct 16 and the blow-out nozzle 19 are connected via a bellows tube 31.

[0018] The return duct 17 is a duct for guiding the moist air flowing out from the inner tank 4 to the heat pump unit 20. In the example of Fig. 3, the downstream end of the return duct 17 and an inlet (not shown) of the housing 20a of the heat pump unit 20 are connected via a bellows tube 32.

[0019] The blower fan 18 is a fan for circulating air sequentially through the hot air duct 16, the bellows tube 31, the blowing nozzle 19, the inner tank 4 (see FIG. 2), the return duct 17, the bellows tube 32, and the heat pump unit 20. The blower fan 18 includes a fan case 18a, a centrifugal impeller (not shown), and an electric motor (not shown) that rotates the centrifugal impeller.

[0020] FIG. 4 is a perspective view showing the internal structure of the heat pump unit 20. As shown in FIG. The white arrows in Fig. 4 indicate the direction in which air flows. As shown in Fig. 4, the heat pump unit 20 includes a compressor 21, an accumulator 22, a condenser 23, an expansion valve 24, and an evaporator 25. The compressor 21 is a device that compresses a low-temperature, low-pressure gas refrigerant and discharges it as a high-temperature, high-pressure gas refrigerant, and includes a compressor motor 21a (see Fig. 5) that serves as a drive source. The accumulator 22 separates the refrigerant into gas and liquid, and is connected to the suction side of the compressor 21.

[0021] The condenser 23 is a heat exchanger for condensing the high-temperature, high-pressure refrigerant discharged from the compressor 21 through heat exchange with the air. For example, a fin-tube type heat exchanger is used as the condenser 23. The expansion valve 24 is an electronic expansion valve for reducing the pressure of the refrigerant condensed in the condenser 23. For example, a stepping motor is used as a drive source for the expansion valve 24. The evaporator 25 is a heat exchanger for evaporating the low-temperature, low-pressure refrigerant reduced in pressure by the expansion valve 24 through heat exchange with the air. For example, a fin-tube type heat exchanger is used as the evaporator 25.

[0022] As shown in Fig. 4, an evaporator 25 is disposed upstream of the condenser 23 in the air flow direction (white arrow). Air dehumidified by the evaporator 25 flows toward the condenser 23 and is heated by the condenser 23. The air (hot air) dried by the above-mentioned dehumidification and heating is supplied to the inside of the inner tub 4 (see Fig. 2) via the hot air duct 16 (see Fig. 3). This causes the laundry R1 (see Fig. 2) in the inner tub 4 to dry.

[0023] The "ventilation path" through which air from the inner tub 4 (washing tub: see FIG. 2) flows through the evaporator 25 and the condenser 23 in this order and then returns to the inner tub 4 is configured to include the following components. That is, the "ventilation path" is configured to include the hot air duct 16, the bellows tube 31, the blow-out nozzle 19, the return duct 17, the bellows tube 32, and the housing 20a shown in FIG. 3.

[0024] FIG. 5 is an explanatory diagram including a refrigerant circuit Q1 of the heat pump unit. The white arrows in FIG. 5 indicate the direction in which air flows. Also, the accumulator 22 (see FIG. 4) is not shown in FIG. 5. As shown in FIG. 5, the heat pump unit 20 is configured such that a compressor 21, a condenser 23, an expansion valve 24, and an evaporator 25 are connected in sequence via a refrigerant pipe K1. In the refrigerant circuit Q1, the refrigerant circulates through the compressor 21, the condenser 23, the expansion valve 24, and the evaporator 25 in sequence. In the heat pump unit 20, the latent heat of evaporation in the evaporator 25 is used as energy when the condenser 23 heats the air. Therefore, the drying operation can be performed with high efficiency with little heat radiation loss.

[0025] The washer / dryer 100 (see FIG. 1) includes a first temperature sensor 41, a second temperature sensor 42, and a control unit 50 shown in FIG. 5, in addition to the components described above. The first temperature sensor 41 detects the temperature of refrigerant discharged from the compressor 21. In the example of FIG. 5, the first temperature sensor 41 is installed in the refrigerant pipe K1 on the discharge side of the compressor 21. The detected value of the first temperature sensor 41 is outputted to the control unit 50 from time to time.

[0026] The second temperature sensor 42 detects the temperature of the condenser 23. The momentary detection value of the second temperature sensor 42 is output to the control unit 50. In the example of FIG. 5, the second temperature sensor 42 is installed in the middle of the condenser 23 so as to detect the temperature of the refrigerant in the gas-liquid two-phase region flowing through the condenser 23. For example, the middle part of the refrigerant path of the heat transfer tube of the condenser 23 may be the "middle part" of the condenser 23 when the refrigerant path is divided into three equal parts such as an upstream part, a middle part, and a downstream part. In this way, by installing the second temperature sensor 42 in the middle part of the condenser 23, the temperature of the refrigerant in the condenser 23 can be stably detected. This is because the temperature of the refrigerant is approximately constant in the gas-liquid two-phase region even if the specific enthalpy of the refrigerant changes.

[0027] Although not shown, the control unit 50 is configured to include electronic circuits such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and various interfaces. The CPU reads out a program stored in the ROM and loads it into the RAM, and executes various processes. The control unit 50 controls multiple devices, such as the compressor 21, the expansion valve 24, the blower fan 18 (see FIG. 3) that circulates air, and the motor 7 (see FIG. 2) that rotates the inner tub 4 (see FIG. 2).

[0028] The control unit 50 performs, for example, washing, rinsing, spin-drying in sequence in accordance with a predetermined course selected by the operation unit 2 (see FIG. 1). Below, the processing of the control unit 50 in the drying operation will be described, and the remaining washing, rinsing, and spin-drying operations will not be described since they are well known.

[0029] <Processing of control unit> FIG. 6 is a flowchart relating to control of the expansion valve during drying operation (also see FIG. 5 as appropriate). In step S101 of Fig. 6, the control unit 50 performs origin adjustment of the expansion valve 24. For example, the control unit 50 performs origin adjustment by temporarily closing the expansion valve 24. This is because it is often difficult to grasp the rotation angle (i.e., the opening degree of the expansion valve 24) of the stepping motor that is the drive source of the expansion valve 24 at the time of starting. Therefore, in the origin adjustment, the control unit 50 outputs a predetermined command signal to the expansion valve 24 so as to narrow the number of pulses to a value equal to or greater than the variable range of the opening adjustment. As a result, the expansion valve 24 is temporarily closed (i.e., origin adjustment is performed).

[0030] In step S102, the control unit 50 starts the drying operation. That is, the control unit 50 starts the compressor 21, and also drives the motor 7 (see FIG. 2) that rotates the inner tub 4 (see FIG. 2) and the blower fan 18 (see FIG. 3) that circulates air. For example, the control unit 50 drives the motor 7 (see FIG. 2) so as to rotate the inner tub 4 (see FIG. 2) alternately clockwise and counterclockwise. In addition, the control unit 50 drives the blower fan 18 (see FIG. 3) at a predetermined rotation speed that corresponds to the course selected by the operation unit 2 (see FIG. 1).

[0031] In step S103, the control unit 50 sets the expansion valve 24 to an initial opening. The initial opening is a target opening value when the expansion valve 24 is opened to a predetermined degree after the origin adjustment, and is set in advance. Immediately after the compressor 21 is started, in order to stabilize the heat pump cycle, the opening of the expansion valve 24 is maintained at the initial opening for a predetermined period of time.

[0032] In step S104, the control unit 50 starts counting the elapsed time from the start of the current control interval. E The control interval is repeated at a cycle of 1 (e.g., several tens of seconds or several minutes). For example, immediately after the expansion valve 24 is set to the initial opening, in step S104, counting of the elapsed time from when the initial opening was set is started.

[0033] In step S105, the control unit 50 determines whether the elapsed time from the start of the current control interval is a predetermined time t E As described above, it is determined whether the predetermined time t E The period 1 (for example, several tens of seconds or several minutes) is a period of a control interval that is repeated at a predetermined interval and is set in advance.

[0034] In step S105, the elapsed time is a predetermined time t EIf the opening degree of the expansion valve 24 has not reached 1 (S105: Yes), the control unit 50 repeats the process of step S105. For example, immediately after the start of the drying operation, the expansion valve 24 is kept in the state of being narrowed down to the initial opening degree for a predetermined time t E 1. Also, in step S105, when the elapsed time reaches a predetermined time t E If it reaches 1 (S105: No), the process of the control unit 50 proceeds to step S106.

[0035] In step S106, the control unit 50 determines whether the discharge refrigerant temperature of the compressor 21 is equal to a predetermined target temperature. As described above, the discharge refrigerant temperature of the compressor 21 is detected by the first temperature sensor 41. In addition, the target temperature for the discharge refrigerant temperature is set in advance in association with each course of the drying operation. If the discharge refrigerant temperature of the compressor 21 is equal to the target temperature in step S106 (S106: Yes), the process of the control unit 50 proceeds to step S107.

[0036] In step S107, the control unit 50 maintains the opening degree of the expansion valve 24. That is, the control unit 50 sets the opening degree of the expansion valve 24 in the current control interval to be the same as that in the previous control interval. Note that, if the judgment condition in step S106 is satisfied in the first control interval when the opening degree of the expansion valve 24 was set to the initial opening degree (S106: Yes), the opening degree of the expansion valve 24 is maintained at the initial opening degree (S107).

[0037] Furthermore, if the discharge refrigerant temperature of the compressor 21 is not equal to the target temperature in step S106 (S106: No), the process of the control unit 50 proceeds to step S108. In step S108, the control unit 50 determines whether or not the discharge refrigerant temperature of the compressor 21 is higher than the target temperature. If the discharge refrigerant temperature of the compressor 21 is higher than the target temperature in step S108 (S108: Yes), the process of the control unit 50 proceeds to step S109.

[0038] In step S109, the control unit 50 increases the opening of the expansion valve 24. That is, the control unit 50 increases the opening of the expansion valve 24 in the current control interval compared to the previous control interval. When the opening of the expansion valve 24 increases, the flow resistance in the refrigerant circuit Q1 decreases, and the refrigerant circulation flow rate increases. When the opening of the expansion valve 24 increases, the pressure of the refrigerant in the condenser 23 decreases, while the pressure of the refrigerant in the evaporator 25 increases. As a result, the temperature of the refrigerant discharged from the compressor 21 decreases (i.e., approaches the target temperature). In this way, the control unit 50 adjusts the opening of the expansion valve 24 so that the temperature of the refrigerant discharged from the compressor 21 approaches the predetermined target temperature.

[0039] In addition, in step S108, if the discharge refrigerant temperature of the compressor 21 is not higher than the target temperature (S108: No), the process of the control unit 50 proceeds to step S110. In other words, if the discharge refrigerant temperature of the compressor 21 is lower than the target temperature, the process of the control unit 50 proceeds to step S110.

[0040] In step S110, the control unit 50 reduces the opening of the expansion valve 24. When the opening of the expansion valve 24 is reduced, the flow resistance in the refrigerant circuit Q1 increases, and the circulating flow rate of the refrigerant decreases. Furthermore, when the opening of the expansion valve 24 is reduced, the pressure of the refrigerant in the condenser 23 increases, while the pressure of the refrigerant in the evaporator 25 decreases. As a result, the discharge refrigerant temperature of the compressor 21 increases (i.e., approaches the target temperature). In this manner, the control unit 50 controls the expansion valve 24 based on the detection value (discharge refrigerant temperature) of the first temperature sensor 41.

[0041] After performing any one of the processes in steps S107, S109, and S110, the control unit 50 proceeds to step S111. In step S111, the control unit 50 resets the count of the elapsed time from the start of the control interval.

[0042] In step S112, the control unit 50 determines whether the drying operation has ended. That is, the control unit 50 determines whether the execution time of the drying operation has elapsed. The execution time of the drying operation is set in advance. If the drying operation has not ended in step S112 (S112: No), the process of the control unit 50 returns to step S104. Then, the control unit 50 starts counting the control interval again in step S104. Furthermore, if the drying operation is completed in step S112 (S112: Yes), the process of the control unit 50 proceeds to step S113. In step S113, the control unit 50 fully opens the expansion valve 24 and ends the series of processes (END).

[0043] FIG. 7 is a flowchart relating to the control of the compressor during the drying operation (also refer to FIG. 5 as appropriate). It should be noted that the series of processes shown in FIG. 7 (control of the compressor 21) is performed in parallel with the series of processes shown in FIG. 6 (control of the expansion valve 24). In step S201 of FIG. 7, the control unit 50 starts a drying operation. Next, in step S202, the control unit 50 drives the compressor 21 at a predetermined startup frequency. Here, the startup frequency is a target value of the drive frequency (frequency in electrical angle) when starting the compressor 21, and is set in advance. Immediately after starting the compressor 21, in order to stabilize the heat pump cycle, the compressor 21 is driven at the startup frequency for only a predetermined time.

[0044] In step S203, the control unit 50 starts counting the elapsed time from the start of the current control interval. In step S204, the control unit 50 determines whether the elapsed time from the start of the current control interval is a predetermined time t E Determine whether the predetermined time t E The control interval period when the control unit 50 controls the compressor 21 is set in advance (predetermined time t E2) and the control interval period when controlling the expansion valve 24 (predetermined time t E 1: see FIG. 6) may be the same length or may be different.

[0045] In step S204, the elapsed time is a predetermined time t E If the elapsed time does not reach the predetermined time t E If it reaches 2 (S204: No), the process of the control unit 50 proceeds to step S205.

[0046] In step S205, the control unit 50 determines whether or not the temperature of the condenser 23 is higher than an upper limit value. Note that an upper limit value and a lower limit value of the temperature of the condenser 23 are set in advance so that the air is appropriately heated in the condenser 23. If the temperature of the condenser 23 is higher than the upper limit value in step S205 (S205: Yes), the process of the control unit 50 proceeds to step S206.

[0047] In step S206, the control unit 50 reduces the drive frequency of the compressor 21. That is, the control unit 50 reduces the drive frequency of the compressor 21 in the current control interval from that in the previous control interval. This reduces the discharge pressure of the compressor 21, and therefore the pressure and temperature of the refrigerant flowing through the condenser 23. Therefore, the temperature of the condenser 23 can be brought closer to a predetermined temperature range (a temperature range specified by an upper limit value and a lower limit value) suitable for the drying operation. In this way, the control unit 50 controls the compressor 21 based on the detection value of the second temperature sensor 42 (the temperature of the condenser 23).

[0048] Furthermore, if the temperature of the condenser 23 is equal to or lower than the upper limit in step S205 (S205: No), the process of the control unit 50 proceeds to step S207. In step S207, the control unit 50 determines whether or not the temperature of the condenser 23 is less than the lower limit value. If the temperature of the condenser 23 is less than the lower limit value in step S207 (S207: Yes), the process of the control unit 50 proceeds to step S208.

[0049] In step S208, the control unit 50 increases the drive frequency of the compressor 21. That is, the control unit 50 increases the drive frequency of the compressor 21 in the current control interval from that in the previous control interval. This increases the discharge pressure of the compressor 21, and therefore increases the pressure and temperature of the refrigerant flowing through the condenser 23. Therefore, the temperature of the condenser 23 can be brought closer to a predetermined temperature range (a temperature range specified by upper and lower limit values) suitable for the drying operation. In this way, the control unit 50 adjusts the drive frequency of the compressor 21 based on the upper and lower limit values ​​of the temperature of the condenser 23.

[0050] Furthermore, if the temperature of the condenser 23 is equal to or higher than the lower limit in step S207 (S207: No), the process of the control unit 50 proceeds to step S209. That is, if the temperature of the condenser 23 is equal to or lower than the upper limit (S205: No) and equal to or higher than the lower limit (S207: No), the process of the control unit 50 proceeds to step S209.

[0051] In step S209, the control unit 50 maintains the drive frequency of the compressor 21. In this case, the temperature of the condenser 23 is within the range defined by the upper limit value and the lower limit value, and the air is appropriately heated in the condenser 23.

[0052] After performing any one of the processes in steps S206, S208, or S209, the control unit 50 proceeds to step S210. In step S210, the control unit 50 resets the count of the elapsed time from the start of the control interval.

[0053] In step S211, the control unit 50 determines whether the drying operation has ended. If the drying operation has not ended in step S112 (S211: No), the process of the control unit 50 returns to step S203. Then, the control unit 50 starts counting the control interval again in step S203. If the drying operation is completed in step S211 (S211: Yes), the process of the control unit 50 proceeds to step S212. In step S212, the control unit 50 stops the compressor 21 and ends the series of processes (END).

[0054] <Influence of environmental temperature and circulating air volume> The environmental temperature around the washer-dryer 100 (see FIG. 1) changes depending on the season, room conditions, etc. Such environmental temperature often affects the refrigerant discharge temperature of the compressor 21 (see FIG. 5) and the temperature of the condenser 23 (see FIG. 5). For example, in summer, the environmental temperature around the washer-dryer 100 can become quite high.

[0055] In the conventional technology, when the drying operation is performed in a high-temperature environment, if the discharge refrigerant temperature or the temperature of the condenser 23 becomes too high, protective control may be performed, such as drastically reducing the rotation speed of the compressor 21 or temporarily stopping the compressor 21. When such protective control is performed, the efficiency of the drying operation is significantly reduced.

[0056] Furthermore, as the filter (not shown) in the ventilation duct through which air circulates during drying operation becomes increasingly clogged, the amount of circulating air decreases when blower fan 18 is driven at a predetermined rotation speed. In this case, the refrigerant is less able to dissipate heat in condenser 23, so the temperature of condenser 23 is more likely to rise. As a result, the rate of change when the temperature of condenser 23 rises increases, making it more likely that a significant overshoot will occur. With conventional technology, when the amount of circulating air decreases due to clogging of the filter (not shown) in the ventilation duct, a significant overshoot in the temperature of condenser 23 could cause a predetermined protective control to be performed.

[0057] Also, for example, in winter, the environmental temperature around the washer / dryer 100 may become considerably low. With the conventional technology, when a drying operation is performed in a low-temperature environment, the temperature of the condenser 23 is unlikely to rise, and the drying of the laundry may not progress easily. Also, there is a possibility that liquid refrigerant that has not completely evaporated in the evaporator 25 may overflow from the accumulator 22, causing liquid compression in the compressor 21.

[0058] Therefore, in this embodiment, the control unit 50 controls the expansion valve 24 based on the detection value of the first temperature sensor 41, and controls the compressor 21 based on the detection value of the second temperature sensor 42. Although details will be described later, by performing such control, it is possible to suppress a decrease in efficiency while ensuring the reliability of the washer / dryer 100.

[0059] FIG. 8 is a graph showing an example of changes in the compressor discharge refrigerant temperature, the condenser temperature, the opening degree of the expansion valve, and the compressor drive frequency when the environmental temperature is within a normal range (also see FIG. 5 as appropriate). In Fig. 8, it is assumed that the environmental temperature during drying operation is within a normal range (e.g., 20°C) and that the circulating air volume is also within a normal range. From the top of the page in Fig. 8, changes in the discharge refrigerant temperature, the temperature of condenser 23, the opening degree of expansion valve 24, and the drive frequency of compressor 21 are shown. The horizontal axis of each graph in Fig. 8 represents time.

[0060] When the drying operation is started at time t0, the expansion valve 24 is set to an initial opening degree a1 (S103 in FIG. 6), and the compressor 21 is started with a predetermined startup frequency N0 as a target value (S202 in FIG. 7). The control unit 50 drives the compressor 21 at the startup frequency N0 for a predetermined time, and then increases the drive frequency of the compressor 21 until the temperature of the condenser 23 becomes equal to or higher than the lower limit value Tc2. In addition, the control unit 50 gradually reduces the opening degree of the expansion valve 24. As a result, the discharge refrigerant temperature of the compressor 21 and the temperature of the condenser 23 rise.

[0061] In the example of Fig. 8, since the temperature of the condenser 23 reaches the lower limit value Tc2 at time t1 (S207: No in Fig. 7), the drive frequency of the compressor 21 is maintained at the value at time t1 for a while thereafter (S209 in Fig. 7). Also, since the discharge refrigerant temperature becomes higher than the target temperature T1 at time t2 (S108: Yes in Fig. 6), the opening degree of the expansion valve 24 changes from a decrease to an increase (S109 in Fig. 6). As a result, some time after time t2, the discharge refrigerant temperature of the compressor 21 changes from an increase to a decrease.

[0062] In addition, when the discharge refrigerant temperature of compressor 21 is higher than the target temperature, it is preferable to increase the opening degree by which control unit 50 increases the opening degree of expansion valve 24 as the rate of change (positive value) of the discharge refrigerant temperature of compressor 21 increases. This makes it possible to prevent the discharge refrigerant temperature from rising suddenly and becoming much higher than the target temperature. Therefore, it is possible to prevent compressor 21 from entering an overheating operation state, thereby improving the reliability of the washer / dryer 100.

[0063] Furthermore, when the discharge refrigerant temperature of the compressor 21 is lower than the target temperature, the control unit 50 may increase the reduction in the opening of the expansion valve 24 as the absolute value of the rate of change (negative value) of the discharge refrigerant temperature of the compressor 21 increases. This makes it possible to prevent the discharge refrigerant temperature from suddenly decreasing to be significantly lower than the target temperature. This makes it possible to prevent the temperature of the condenser 23 from becoming extremely low, and ultimately prevents liquid compression in the compressor 21.

[0064] Incidentally, a change in the opening degree of the expansion valve 24 affects not only the temperature of the refrigerant discharged from the compressor 21 but also the temperature of the condenser 23. For example, when the opening degree of the expansion valve 24 increases while the drive frequency of the compressor 21 is constant, the temperature of the refrigerant in the condenser 23 decreases. Furthermore, a change in the drive frequency of the compressor 21 affects not only the temperature of the condenser 23 but also the temperature of the refrigerant discharged from the compressor 21. For example, when the drive frequency of the compressor 21 increases while the opening degree of the expansion valve 24 is constant, the discharge refrigerant temperature increases.

[0065] However, in this embodiment, the control unit 50 controls the expansion valve 24 based on the discharge refrigerant temperature, and controls the compressor 21 based on the temperature of the condenser 23. Even with this type of control, it is possible to appropriately adjust the discharge refrigerant temperature and the temperature of the condenser 23. Furthermore, because this is a simple method, it is possible to reduce the processing load on the control unit 50.

[0066] Although not specifically shown in the flowchart of Fig. 6, the control unit 50 may control the expansion valve 24 as follows. That is, when the absolute value of the difference between the discharge refrigerant temperature of the compressor 21 and the target temperature is equal to or less than a first predetermined value, and further, when the absolute value of the rate of change of the discharge refrigerant temperature of the compressor 21 is equal to or less than a second predetermined value, the control unit 50 may maintain the opening degree of the expansion valve 24. This makes it possible to prevent the opening degree of the expansion valve 24 from being frequently increased and decreased repeatedly at every predetermined control interval (e.g., several tens of seconds or several minutes). Also, the discharge refrigerant temperature can be maintained close to the target temperature.

[0067] 8, the discharge refrigerant temperature is maintained at a value close to the target temperature T1, and the temperature of the condenser 23 is generally within a range of not more than the upper limit Tc1 and not less than the lower limit Tc2. This allows the air to be appropriately heated by the condenser 23 while ensuring the reliability of the compressor 21 and the like.

[0068] FIG. 9 is a graph showing an example of changes in the refrigerant discharge temperature of the compressor, the temperature of the condenser, the opening degree of the expansion valve, and the drive frequency of the compressor when the environmental temperature is high. In FIG. 9, the environmental temperature is high (for example, 30° C.), while the circulating air volume is within a normal range. In the example of FIG. 9, the discharge refrigerant temperature exceeds the target temperature T1 at time t1 (S108: Yes in FIG. 6). In such a case, the control unit 50 increases the opening degree of the expansion valve 24 (S109 in FIG. 6). In addition, since the washer-dryer 100 is in a high-temperature environment, the temperature of the condenser 23 exceeds the upper limit value Tc1 at time t2 (S205: Yes in FIG. 7). In such a case, the control unit 50 reduces the drive frequency of the compressor 21 (S206 in FIG. 7). This, combined with the increase in the opening degree of the expansion valve 24, causes the temperature of the condenser 23 to change from rising to falling early, and therefore it is possible to prevent the temperature of the condenser 23 from becoming extremely high.

[0069] When the circulating air volume is small due to clogging of a filter (not shown), the rate at which the temperature of condenser 23 rises will be higher than normal (when the circulating air volume is within the normal range), but the method of controlling compressor 21 and expansion valve 24 will be the same as in the case of Figure 9.

[0070] FIG. 10 is a graph showing an example of changes in the refrigerant discharge temperature of the compressor, the temperature of the condenser, the opening degree of the expansion valve, and the drive frequency of the compressor when the environmental temperature is low. In Fig. 10, the ambient temperature is low (e.g., 0°C), while the circulating air volume is within a normal range. In the example of Fig. 10, because the ambient temperature is low, the timing (time t1) when the discharge refrigerant temperature of the compressor 21 reaches the target temperature T1 and the timing (time t2) when the temperature of the condenser 23 reaches the lower limit Tc2 are delayed compared to normal times (see Fig. 8) and high temperatures (see Fig. 9). As a result, at time t1 when the discharge refrigerant temperature reaches the target temperature T1, the expansion valve 24 is considerably throttled and the flow resistance of the refrigerant circuit Q1 is large, and the compressor 21 is driven at high speed.

[0071] Then, when the discharge refrigerant temperature reaches the target temperature T1 and the opening degree of the expansion valve 24 changes from decreasing to increasing (time t1), the flow path resistance of the refrigerant circuit Q1 decreases, and coupled with the high-speed drive of the compressor 21, the high-temperature refrigerant flows into the condenser 23 all at once. This promotes the rise in temperature of the condenser 23. In this way, in a low-temperature environment, the control unit 50 drives the compressor 21 at high speed while finely adjusting the opening degree of the expansion valve 24, thereby adjusting the discharge refrigerant temperature and the temperature of the condenser 23.

[0072] <Effects> According to this embodiment, the control unit 50 controls the expansion valve 24 based on the detection value (discharge refrigerant temperature) of the first temperature sensor 41, while controlling the compressor 21 based on the detection value (temperature of the condenser 23) of the second temperature sensor 42. This makes it possible to prevent the discharge refrigerant temperature and the temperature of the condenser 23 from becoming extremely high or low. Therefore, it is possible to prevent the compressor 21 from being temporarily stopped due to a predetermined protection control.

[0073] Moreover, since the discharge refrigerant temperature and the condenser temperature can be kept stable regardless of external factors such as the ambient temperature, the temperature of the hot air sent into the inner tub 4 can be kept substantially constant. Even if the temperature deviates from the target temperature, the temperature can be quickly returned to a normal state. Thus, according to this embodiment, the reliability of the washer / dryer 100 can be ensured while a decrease in efficiency can be suppressed.

[0074] Also, the drive frequency of the compressor 21 is adjusted so that the temperature of the condenser 23 falls within a temperature range specified by upper and lower limits, rather than a predetermined target temperature. This makes it possible to suppress frequent repetition of increases and decreases in the drive frequency of the compressor 21 (hunting). As a result, noise due to vibration of the compressor 21 can be suppressed. In particular, changes in the rotation speed of the compressor 21 are often more sensitively reflected in changes in the temperature of the condenser 23 than in the control of the opening degree of the expansion valve 24. Therefore, it is effective in suppressing noise to make the temperature of the condenser 23 fall within a temperature range specified by upper and lower limits. On the other hand, the expansion valve 24 can adjust the discharge refrigerant temperature of the compressor 21 by adjusting its opening degree, as well as the circulation flow rate and expansion rate of the refrigerant.

[0075] <<Variations>> Although the washer / dryer 100 according to the present disclosure has been described in the embodiment above, the washer / dryer 100 is not limited to the embodiment described above and may be modified in various ways. For example, when the control unit 50 repeats the control interval of the expansion valve 24 in a first cycle and the control interval of the compressor 21 in a second cycle, the timing at which the control interval of the expansion valve 24 is switched and the timing at which the control interval of the compressor 21 is switched may be set to be offset from each other. This allows the influence of the change in the opening degree of the expansion valve 24 to be reflected in the subsequent control of the compressor 21, thereby suppressing a sudden change in the temperature of the condenser 23. In addition, the influence of the change in the drive frequency of the compressor 21 to be reflected in the subsequent control of the expansion valve 24, thereby suppressing a sudden change in the discharge refrigerant temperature. Note that the first cycle (control cycle of the expansion valve 24) and the second cycle (control cycle of the compressor 21) may be equal to each other, or one may be longer than the other.

[0076] Also, the manner in which the expansion valve 24 and the compressor 21 are controlled may be different between a time-saving course (first course) including a drying operation and an energy-saving course (second course) in which the drying operation time is longer than that of the time-saving course and energy is saved. For example, the opening degree of the expansion valve 24 may be made larger in the time-saving course than in the energy-saving course. This ensures a refrigerant circulation flow rate in the time-saving course, promoting the heating of air in the condenser 23. Therefore, the time required for the drying operation can be shortened. Also, in the energy-saving course, the expansion valve 24 is narrowed to suppress the refrigerant circulation flow rate, thereby reducing the amount of power consumed by the compressor 21.

[0077] The target value of the rotation speed of the compressor 21 may be set higher in the time-saving course than in the energy-saving course. This makes it easier for the temperature of the condenser 23 to rise in the time-saving course, so that the laundry tends to dry more quickly. Also, in the energy-saving course, the rotation speed of the compressor 21 is relatively low, so that the amount of power consumed by the compressor 21 can be reduced.

[0078] In addition, in the embodiment, a case has been described in which a target temperature is set for the discharge refrigerant temperature, while an upper limit value and a lower limit value are set for the temperature of the condenser 23, but this is not limited thereto. For example, an upper limit value and a lower limit value may be set for the discharge refrigerant temperature, while a target temperature may be set for the temperature of the condenser 23. Also, a target temperature may be set for each of the discharge refrigerant temperature and the temperature of the condenser 23, or an upper limit value and a lower limit value may be set. Either is acceptable.

[0079] In addition, in the embodiment, the case where the second temperature sensor 42 is installed in the middle part of the condenser 23 has been described, but the installation position of the second temperature sensor 42 can be changed as appropriate. In addition, in the embodiment, the washing / drying machine 100 is of a drum type, but the present invention can also be applied to other types of machines, such as a vertical washing / drying machine.

[0080] Furthermore, the program executed by the control unit 50 can be provided via a communication line, or can be written onto a recording medium such as a CD-ROM and distributed. In addition, the embodiments are described in detail to clearly explain the present disclosure, and are not necessarily limited to those having all the configurations described. In addition, it is possible to add, delete, or replace a part of the configuration of the embodiment with another configuration. In addition, the above-mentioned mechanisms and configurations are shown as being necessary for the explanation, and do not necessarily show all the mechanisms and configurations in the product. In addition, the control lines and information lines are shown as being necessary for the explanation, and do not necessarily show all the control lines and information lines in the product. In reality, it may be considered that almost all the configurations are connected to each other. [Explanation of symbols]

[0081] 1 Case 2 Control section 3 Door 4 Inner tub (washing tub) 8 Outer tank 16 Warm air duct (ventilation duct) 17 Return duct (ventilation passage) 18 Blower fan 19 Blowout nozzle (ventilation duct) 20 Heat pump unit 20a Housing (ventilation passage) 21 Compressor 22 Accumulator 23 Condenser 24 Expansion valve 25 Evaporator 31, 32 Bellows tube (ventilation passage) 100 Washer / dryer 41 First temperature sensor 42 Second temperature sensor 50 Control section K1 Refrigerant piping Q1 Refrigerant circuit R1 Laundry

Claims

1. The heat pump unit includes a compressor, a condenser, an expansion valve, and an evaporator connected in sequence via a refrigerant pipe. A washing tub into which laundry is put; an air passage through which air from the washing tub passes through the evaporator and the condenser in sequence and then returns to the washing tub; a first temperature sensor for detecting a temperature of a refrigerant discharged from the compressor; a second temperature sensor that detects a temperature of the condenser; The washer / dryer further includes a control unit that controls the expansion valve based on a detection value of the first temperature sensor, and controls the compressor based on a detection value of the second temperature sensor.

2. The second temperature sensor is disposed in a middle portion of the condenser. The washing and drying machine according to claim 1 .

3. The control unit adjusts an opening degree of the expansion valve so as to bring a discharge refrigerant temperature of the compressor closer to a predetermined target temperature, and adjusts a drive frequency of the compressor based on an upper limit value and a lower limit value of a temperature of the condenser. The washing and drying machine according to claim 1 .

4. The control unit increases an increase in the opening degree of the expansion valve when the opening degree of the expansion valve is increased as a rate of change in the discharge refrigerant temperature of the compressor is higher than the target temperature. The washing and drying machine according to claim 3 .

5. The control unit, when a discharge refrigerant temperature of the compressor is lower than the target temperature, increases a reduction amount of the opening degree when reducing the opening degree of the expansion valve as an absolute value of a change rate of the discharge refrigerant temperature of the compressor increases. The washing and drying machine according to claim 3 .

6. The control unit maintains the opening degree of the expansion valve when an absolute value of a difference between a discharge refrigerant temperature of the compressor and the target temperature is equal to or less than a first predetermined value, and further, when an absolute value of a rate of change of the discharge refrigerant temperature of the compressor is equal to or less than a second predetermined value. The washing and drying machine according to claim 3 .

7. the control unit repeats a control interval of the expansion valve in a first cycle and repeats a control interval of the compressor in a second cycle; The timing at which the control interval of the expansion valve is switched and the timing at which the control interval of the compressor is switched are set to be offset from each other. The washing and drying machine according to claim 1 .

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