Washing and drying machine

Abstract

To provide a washing and drying machine capable of efficiently performing a drying operation.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; an operation part to receive a selection operation by a user from a plurality of courses including a first course including a drying operation and a second course that performs the drying operation for longer time than the first course and saves energy; a temperature sensor 40 to detect a discharged coolant temperature of a compressor 21; and a control part 50 to adjust opening of an expansion valve 24 so that the discharged coolant temperature of the compressor 21 comes closer to a prescribed target temperature. The opening of the expansion valve is set to be greater in the first course than the second course.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] As a technology that uses 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 "a quick-drying course is executed by increasing the drive frequency of the heat pump compressor" and "a saving course is executed by decreasing the drive frequency of the heat pump compressor" in the drying operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-29275 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, the drive frequency of the compressor is set to be higher in the fast-drying course than in the saving course, but there is room for improvement in terms of efficient drying operation.

[0005] In view of the above, an object of the present disclosure is to provide a washer / dryer that efficiently performs a drying operation. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the washer-dryer of the present disclosure comprises a heat pump unit having a compressor, a condenser, an expansion valve, and an evaporator connected in sequence via refrigerant piping, a washing tub into which laundry is put, and a ventilation path through which air from the washing tub flows sequentially through the evaporator and the condenser and then back to the washing tub, and also comprises an operation unit that accepts a user's selection from among a plurality of courses including a first course including a drying operation and a second course having a longer drying operation time than the first course and being more energy efficient, a temperature sensor that detects the refrigerant discharge temperature of the compressor, and a control unit that adjusts the opening of the expansion valve so as to bring the refrigerant discharge temperature of the compressor closer to a predetermined target temperature, and the opening of the expansion valve is set to be larger in the first course than in the second course. Effect of the Invention

[0007] According to the present disclosure, a washer / dryer that efficiently performs a drying operation can be provided. [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 graph showing an example of changes in discharge refrigerant temperature, the opening degree of an expansion valve, and the rotation speed of a compressor in a washer / dryer according to an embodiment. 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 lower part of the outer tub 8 is provided with a water receiving section 8a having a downwardly recessed shape. The water receiving section 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 installed 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 outline arrows in Fig. 4 indicate the direction in which air flows inside the heat pump unit 20. 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 is for performing gas-liquid separation of the refrigerant, 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) to be dried.

[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, in addition to the components described above, a temperature sensor 40 and a control unit 50 shown in FIG. 5. The temperature sensor 40 detects the temperature of the refrigerant discharged from the compressor 21. In the example of FIG. 5, the temperature sensor 40 is installed in the refrigerant pipe K1 on the discharge side of the compressor 21. The detected value of the temperature sensor 40 is outputted to the control unit 50 from time to time.

[0026] 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 and the expansion valve 24, as well as a blower fan 18 (see FIG. 3) that circulates air and a motor 7 (see FIG. 2) that rotates the inner tank 4 (see FIG. 2). Details of the processing by the control unit 50 will be described later.

[0027] <Time-saving course and energy-saving course> The washer-dryer 100 (see FIG. 1) is provided with a time-saving course (first course) and an energy-saving course (second course) as drying operation courses. In the time-saving course, the drying operation is performed for a shorter period of time than in the energy-saving course. The time-saving course is also sometimes called the standard course or the quick-drying course.

[0028] In addition, the energy saving course has the advantage that the time required for drying operation is longer than the time saving course, but the amount of electricity required for drying operation is less than that of the time saving course. Incidentally, the energy saving course is also called the saving course or the power saving course.

[0029] The type of operation in the time-saving course and the energy-saving course is not limited to the drying operation. For example, a time-saving course or an energy-saving course may be preset for a series of processes when washing, rinsing, spin-drying, and drying are performed in sequence. In this case, the time-saving course is a course in which the time of the drying operation included in the series of processes is shorter than that of the energy-saving course. Also, the energy-saving course is a course in which the time of the drying operation included in the series of processes is longer than that of the time-saving course, but the amount of power consumed for the drying operation is less than that of the time-saving course. In addition to the time-saving course and the energy-saving course, other predetermined courses may be preset.

[0030] When washing or the like is performed, a predetermined course is selected from a plurality of courses including a time-saving course and an energy-saving course by the user's operation via the operation unit 2 (see FIG. 1). That is, the user selects from a plurality of courses including a time-saving course (first course) including a drying operation and an energy-saving course (second course) which has a longer drying operation time than the time-saving course and is more energy-efficient, via the operation unit 2 (see FIG. 1).

[0031] Then, the control unit 50 (see FIG. 5) performs control corresponding to the course selected by the user. Specifically, the control unit 50 adjusts the opening of the expansion valve 24 so that the refrigerant temperature discharged from the compressor 21 approaches a predetermined target temperature. Note that the target temperature for the refrigerant discharged from the compressor 21 in the time-saving course is set to be higher than the target temperature in the energy-saving course. The higher the temperature of the refrigerant discharged from the compressor 21, the higher the temperature of the condenser 23 and the easier it is to heat the air, so that the laundry R1 (see FIG. 2) can be dried in a short time.

[0032] Also, the time-saving course (first course) is set to have a larger opening of the expansion valve 24 than the energy-saving course (second course). Although details will be described later, the larger the opening of the expansion valve 24, the greater the refrigerant circulation flow rate in the refrigerant circuit Q1 (see FIG. 5), and thus the heat exchange in the condenser 23 and the evaporator 25 is promoted. As a result, it is possible to perform the drying operation in a short time without significantly increasing the rotation speed of the compressor motor 21a, and therefore the power consumption of the compressor motor 21a can be reduced.

[0033] The control unit 50 sequentially performs, for example, washing, rinsing, spin-drying in accordance with the course selected on the operation unit 2 (see FIG. 1). The following describes the processing of the control unit 50 in the drying operation, and the remaining washing, rinsing, and spin-drying operations are well known and therefore will not be described here.

[0034] <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). At the time of "START" in FIG. 6, it is assumed that a drying operation course (a time-saving course or an energy-saving course) has been selected in advance by a user's operation via the operation unit 2 (see FIG. 1).

[0035] 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).

[0036] 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).

[0037] 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.

[0038] In this embodiment, the initial opening degree of the expansion valve 24 in the time-saving course is set to be larger than the initial opening degree of the expansion valve 24 in the energy-saving course. This ensures a sufficient refrigerant circulation flow rate immediately after the start of the time-saving course, promoting heat exchange in the condenser 23. Also, since the expansion valve 24 is in a throttled state immediately after the start of the energy-saving course, the refrigerant circulation flow rate is suppressed. Therefore, the power consumption of the compressor motor 21a can be reduced.

[0039] 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.

[0040] 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 1 is the period of the control interval which is repeated at a predetermined interval and is set in advance.

[0041] In step S105, the elapsed time is a predetermined time t E If 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.

[0042] In step S106, the control unit 50 judges whether the discharge refrigerant temperature of the compressor 21 is equal to a predetermined target temperature. The target temperature of the discharge refrigerant temperature is set in advance in association with each course of the drying operation. Specifically, the target temperature of the discharge refrigerant temperature is set higher in the time-saving course than in the energy-saving course. As a result, for example, in the time-saving course, the temperature of the refrigerant flowing from the compressor 21 to the condenser 23 becomes higher, and the heat exchange in the condenser 23 promotes the rise in the air temperature. Also, in the energy-saving course, the target temperature of the discharge refrigerant temperature of the compressor 21 is relatively low, so the load when driving the compressor 21 is reduced. This allows the amount of power consumption of the compressor 21 to be reduced.

[0043] If it is determined in step S106 that the discharge refrigerant temperature of the compressor 21 is equal to the target temperature (S106: Yes), the process of the control unit 50 proceeds to step S107. In step S107, the control unit 50 maintains the opening degree of the expansion valve 24. That is, the control unit 50 makes the opening degree of the expansion valve 24 in the current control interval the same as that in the previous control interval. Note that, if the determination 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).

[0044] 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.

[0045] 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. In addition, 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 (that is, the discharge refrigerant temperature approaches the target temperature). In this way, the control unit 50 adjusts the opening of the expansion valve 24 so that the discharge refrigerant temperature of the compressor 21 approaches the predetermined target temperature.

[0046] 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.

[0047] 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 refrigerant circulation flow rate decreases. Also, the refrigerant pressure in the condenser 23 increases, while the refrigerant pressure in the evaporator 25 decreases. As a result, the refrigerant discharge temperature of the compressor 21 increases (i.e., approaches the target temperature).

[0048] 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.

[0049] 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 preset in association with each of the multiple courses. 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 then ends the series of processes (END).

[0050] FIG. 7 is a graph showing an example of changes in the discharge refrigerant temperature, the opening degree of the expansion valve, and the rotation speed of the compressor (also see FIG. 5 as necessary). The horizontal axis of each graph in Fig. 7 is time. The vertical axis of the graph in the upper part of Fig. 7 is the discharge refrigerant temperature of compressor 21, the vertical axis of the graph in the center is the opening degree of expansion valve 24, and the vertical axis of the graph in the lower part is the rotation speed of compressor 21. The opening degree of expansion valve 24 is represented by the number of pulse signals for exciting each phase winding of a stepping motor (not shown) which is the drive source. In Fig. 7, the graph corresponding to the time-saving course (first course) is shown by a solid line. The graph corresponding to the energy-saving course (second course) is shown by a dashed line.

[0051] 7 is a target value of the discharge refrigerant temperature of the compressor 21 in the time-saving course. Moreover, target temperature T2 is a target value of the discharge refrigerant temperature of the compressor 21 in the energy-saving course. As described above, the target value of the discharge refrigerant temperature is set to be higher in the time-saving course than in the energy-saving course. As a result, for example, in the time-saving course, the refrigerant in the condenser 23 becomes hot, and the air is more likely to be heated in the condenser 23.

[0052] The initial opening degree a1 shown in FIG. 7 is the initial opening degree of the expansion valve 24 in the time-saving course. Another initial opening degree a2 is the initial opening degree of the expansion valve 24 in the energy-saving course. As described above, the initial opening degree of the expansion valve 24 in the time-saving course (first course) is set to be larger than the initial opening degree of the expansion valve 24 in the energy-saving course (second course). As a result, in the time-saving course, the flow resistance of the refrigerant circuit Q1 is reduced when the compressor 21 is started, so that a sufficient refrigerant circulation flow rate is ensured. Therefore, heat exchange through the evaporator 25 and the condenser 23 is promoted. Also, in the energy-saving course, the refrigerant circulation flow rate when the compressor 21 is started is relatively small, so that the rotation speed of the compressor motor 21a can be low. Therefore, the power consumption of the compressor motor 21a can be reduced.

[0053] 7, a first control range A1, which is a control range of the opening degree of the expansion valve 24 in the time-saving course, is set to a range of 50 pulses or more and 120 pulses or less. Also, a second control range A2, which is a control range of the opening degree of the expansion valve 24 in the energy-saving course, is set to a range of 10 pulses or more and 30 pulses or less. In this way, the first control range A1 corresponding to the time-saving course (first course) and the second control range A2 corresponding to the energy-saving course (second course) are set in advance as the control range of the opening degree of the expansion valve 24.

[0054] In addition, the lower limit of the first control range A1 is greater than the upper limit of the second control range A2. In the example of Fig. 7, the lower limit of the first control range A1 is 50 pulses, whereas the upper limit of the second control range A2 is 30 pulses. In other words, the first control range A1 is greater than the second control range A2.

[0055] The opening degree of the expansion valve 24 is set to be larger in the time-saving course (first course) than in the energy-saving course (second course). For example, even if the values ​​of a plurality of parameters, such as the rotation speed of the compressor 21, the ambient temperature, and the rotation speed of the blower fan 18 (see FIG. 3), are different from one another, the opening degree of the expansion valve 24 in the time-saving course may be set to be larger than the opening degree of the expansion valve 24 in the energy-saving course.

[0056] In this way, by opening the expansion valve 24 more in the time-saving course than in the energy-saving course, the refrigerant circulation flow rate is increased, and heat exchange in the condenser 23 and the evaporator 25 is promoted. As a result, high-temperature, dry air is easily supplied to the inner tank 4 (see FIG. 2), so that the drying operation can be performed in a short time. In addition, the expansion valve 24 can adjust the temperature and expansion rate of the refrigerant discharged from the compressor 21.

[0057] In addition, in the energy saving course, the opening of the expansion valve 24 is smaller than in the time saving course, so the flow resistance of the refrigerant circuit Q1 is larger, and as a result, the circulation flow rate of the refrigerant is smaller. Therefore, the rotation speed of the compressor 21 can be reduced, so that the power consumption of the compressor 21 can be reduced. In addition, by appropriately throttling the expansion valve 24 in the second control range A2, the discharge refrigerant temperature increases, promoting heat exchange in the condenser 23, and enabling the drying operation to be performed in a relatively short time while saving energy.

[0058] 7, a predetermined startup rotation speed N0 is set in advance for control of the compressor 21. After starting the compressor 21 at time t0, the control unit 50 controls the rotation speed of the compressor motor 21a to increase to the startup rotation speed N0. After the rotation speed of the compressor motor 21a reaches the startup rotation speed N0, the control unit 50 controls the rotation speed of the compressor motor 21a to approach a predetermined target rotation speed.

[0059] In the example of Fig. 7, the target rotation speed N1 of the compressor motor 21a in the time-saving course is set to be higher than another target rotation speed N2 corresponding to the energy-saving course. This increases the circulation flow rate of the refrigerant in the time-saving course, promoting heat exchange in the condenser 23. Also, in the energy-saving course, the rotation speed of the compressor motor 21a is relatively low, making it possible to achieve energy conservation.

[0060] In the example of Fig. 7, in the time-saving course (solid line graph), after the start of the drying operation (time t0), the control unit 50 increases the rotation speed of the compressor 21 while appropriately throttling the expansion valve 24 to increase the discharge refrigerant temperature. At time t1 in Fig. 7, the discharge refrigerant temperature has reached the target temperature T1 (S108 in Fig. 6: Yes), so the control unit 50 increases the opening of the expansion valve 24 within the first control range A1 (S109). As a result, the discharge refrigerant temperature changes from increasing to decreasing.

[0061] Also, in the time-saving course (solid line graph), since the discharge refrigerant temperature is lower than the target temperature T1 at time t2 (S108: No in FIG. 6), the control unit 50 reduces the opening of the expansion valve 24 within the first control range A1 (S110). As a result, the discharge refrigerant temperature changes from decreasing to increasing. The same applies to the control of the expansion valve 24 in the energy-saving course (dashed line graph). In the example of FIG. 7, the timings of times t1, t2, and t3 are set to be the same between the time-saving course and the energy-saving course for the sake of convenience, but these timings are usually different.

[0062] <Effects> According to this embodiment, the control unit 50 controls the expansion valve 24 based on the discharge refrigerant temperature of the compressor 21. This allows the expansion valve 24 to adjust the discharge refrigerant temperature of the compressor 21, and also adjusts the circulation flow rate and expansion rate of the refrigerant. As a result, when the discharge refrigerant temperature is set to a predetermined target temperature, it is not necessary to increase the rotation speed of the compressor motor 21a that much, thereby making it possible to achieve energy conservation in each course.

[0063] In this embodiment, the opening degree of the expansion valve 24 in the time-saving course is set to be larger than the opening degree of the expansion valve 24 in the energy-saving course. This ensures a sufficient refrigerant circulation flow rate in the time-saving course and promotes heating of the air in the condenser 23, so that the drying operation can be performed in a short time. In the energy-saving course, the expansion valve 24 is throttled to reduce the refrigerant circulation flow rate, so that the power consumption of the compressor 21 can be reduced. In this way, the washer-dryer 100 according to this embodiment can perform the drying operation efficiently.

[0064] <<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, the control unit 50 may adjust the change width when changing the opening degree of the expansion valve 24 based on the change speed of the discharge refrigerant temperature. Specifically, when the discharge refrigerant temperature of the compressor 21 is higher than the target temperature, the control unit 50 increases the increase width of the opening degree when increasing the opening degree of the expansion valve 24 as the change speed (positive value) of the discharge refrigerant temperature of the compressor 21 increases. This makes it possible to prevent the discharge refrigerant temperature from rising suddenly and becoming much higher than the target temperature. This makes it possible to prevent the compressor 21 from entering an overheating operation state, thereby improving the reliability of the washer / dryer 100.

[0065] 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.

[0066] In the embodiment, the first control range A1 (see FIG. 7) of the expansion valve 24 in the time-saving course is larger than the second control range A2 (see FIG. 7) of the expansion valve 24 in the energy-saving course, but the present invention is not limited to this. For example, the first control range A1 and the second control range A2 may partially overlap. In this case, the upper limit value of the opening degree of the expansion valve 24 in the first control range A1 may be larger than the upper limit value of the opening degree of the expansion valve 24 in the second control range A2. Also, the lower limit value of the opening degree of the expansion valve 24 in the first control range A1 may be larger than the lower limit value of the opening degree of the expansion valve 24 in the second control range A2. Even with such settings, the same effects as those of the embodiment are achieved.

[0067] In the embodiment, a case has been described in which when the rotation speed of the compressor 21 reaches a predetermined target rotation speed, the rotation speed thereafter is kept constant (see FIG. 7), but the present invention is not limited to this. For example, in addition to controlling the expansion valve 24, the control unit 50 may adjust the rotation speed (driving frequency) of the compressor 21 so that the temperature of the intermediate portion of the condenser 23 falls within a range not exceeding a predetermined upper limit value and not less than a predetermined lower limit value. This makes it easier to maintain the discharge refrigerant temperature and the temperature of the condenser 23 within an appropriate range, regardless of external factors such as the environmental temperature. 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.

[0068] 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]

[0069] 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 40 Temperature Sensor 50 Control section K1 Refrigerant piping Q1 Refrigerant circuit R1 Laundry

Claims

1. a heat pump unit including 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; The washing machine includes an air passage through which air from the washing tub passes through the evaporator and the condenser in sequence and returns to the washing tub, an operation unit that accepts a user's selection operation from among a plurality of courses including a first course including a drying operation and a second course having a longer drying operation time than the first course and being more energy-efficient; a temperature sensor for detecting a temperature of a refrigerant discharged from the compressor; a control unit that adjusts an opening degree of the expansion valve so that a discharge refrigerant temperature of the compressor approaches a predetermined target temperature, The opening degree of the expansion valve is set to be larger in the first course than in the second course.

2. an initial opening degree of the expansion valve in the first course is set to be larger than an initial opening degree of the expansion valve in the second course; The washing and drying machine according to claim 1 .

3. A first control range corresponding to the first course and a second control range corresponding to the second course are set as a control range of the opening degree of the expansion valve, The lower limit of the first control range is greater than the upper limit of the second control range. 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 1 .

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 1 .

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