Hot water generator

Abstract

A warm water generating device is provided that can use a single pump to perform efficient operation or operation that maintains user comfort according to the situation. The warm water generating device (1) can execute air conditioning operation in which a switching valve (45) is switched to circulate water that has undergone heat exchange in a water heat exchanger (11) in an air conditioning water circuit (41), hot water supply and heating operation in which a switching valve (45) is switched to circulate water that has undergone heat exchange in a water heat exchanger (11) in a hot water supply and heating water circuit (42), and a mixed operation mode in which air conditioning operation lasting a first time and hot water supply and heating operation lasting a second time are alternately repeated. In addition, in the mixed operation mode, the warm water generating device (1) changes the second time based on the load state of the air conditioning water circuit (41).

Description

Technical Field

[0001] An embodiment of the present invention relates to a hot water generating device. Background Art

[0002] There is known a hot water supply device that is a hot water generating device including a heat pump refrigeration cycle, an air conditioning water circuit, and a hot water supply and heating water circuit.

[0003] The warm water generating device includes a first circulation pump, a heat pump, a heat exchanger for a hot water supply tank, a radiator for heating (e.g., for floor heating), a switching valve, and water piping for circulating water therethrough. The switching valve switches the destination of water flowing out of the heat pump to either the heat exchanger for the hot water supply tank or the radiator. Furthermore, the warm water generating device includes a second circulation pump, the utilization side of the heat exchanger for the hot water supply tank, a hot water supply tank, and water piping for circulating water therethrough.

[0004] The control unit compares the water temperature in the hot water supply tank with the reboil tank temperature. If the water temperature in the hot water supply tank is lower than the reboil tank temperature, the control unit reboils the water in the hot water supply tank to a target tank temperature. Furthermore, if the per-unit-time variation in the water temperature in the hot water supply tank is less than a reference value, e.g., less than 10 degrees Celsius, the control unit determines that the water temperature has decreased due to heat loss from the hot water supply tank. The control unit operates the second circulation pump at its maximum flow rate, forcing convection of the water in the hot water supply tank and uniformly boiling the water to the target tank temperature. Furthermore, if the per-unit-time variation in the water temperature in the hot water supply tank is greater than a reference value, e.g., greater than 10 degrees Celsius, the control unit determines that the water temperature has decreased due to utilization of the warm water in the hot water supply tank. The control unit operates the second circulation pump at its minimum flow rate to maintain temperature stratification of the water in the hot water supply tank.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-224796 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] Conventional hot water supply devices require multiple circulation pumps, including a first circulation pump and a second circulation pump, to operate efficiently according to conditions or maintain user comfort. Conventional hot water supply devices with such a configuration hinder reduction in power consumption and cost reduction.

[0010] Therefore, an object of the present invention is to provide a hot water generating device that can operate efficiently or maintain user comfort according to the situation using a single pump.

[0011] Means for solving problems

[0012] A warm water generating device according to an embodiment of the present invention includes: a refrigeration circuit for circulating a refrigerant; and a water heat exchange unit having a water heat exchanger for exchanging heat between the refrigerant and first water serving as a heat medium on the utilization side. The water heat exchange unit includes: an air conditioning water circuit for circulating the first water, which has undergone heat exchange in the water heat exchanger, through an external device; a hot water supply and heating water circuit for circulating the first water, which has undergone heat exchange in the water heat exchanger, within a hot water supply tank to heat second water stored in the hot water supply tank; a switching valve for switching the circulation path of the first water to either the air conditioning water circuit or the hot water supply and heating water circuit; and a control unit for controlling the switching valve. The control unit is capable of executing air-conditioning operation by switching the switching valve to allow the first water to circulate in the air-conditioning water circuit, hot water supply and heating operation by switching the switching valve to allow the first water to circulate in the hot water supply and heating water circuit, and a mixed operation mode of alternately repeating the air-conditioning operation for a first time and the hot water supply and heating operation for a second time, and in the mixed operation mode, the second time of the hot water supply and heating operation is changed based on the load state of the air-conditioning water circuit.

[0013] Preferably, in the hot water generating apparatus according to the embodiment of the present invention, the control unit extends the second time when the load of the air-conditioning water circuit is smaller than the minimum capacity of the refrigeration circuit.

[0014] Furthermore, the control unit of the hot water generator according to the embodiment of the present invention preferably determines that the load of the air conditioning water circuit is less than the minimum capacity of the refrigeration circuit when a thermal shutdown occurs during the air conditioning operation in which the compressor of the refrigeration circuit stops.

[0015] Furthermore, it is preferable that the control unit of the hot water generator according to the embodiment of the present invention changes the second time in association with whether the thermal shutdown occurs.

[0016] In addition, preferably, the control unit of the hot water generating device of the embodiment of the present invention extends the second time by the specified extension time when the above-mentioned thermal shutdown occurs in the specified first judgment interval, and cancels the extension of the above-mentioned second time by the above-mentioned extension time when the above-mentioned thermal shutdown does not occur in the specified second judgment interval.

[0017] Furthermore, it is preferable that the control unit of the hot water generator according to the embodiment of the present invention extends the second time when the outside air temperature is higher than a predetermined temperature.

[0018] Effects of the Invention

[0019] According to the present invention, it is possible to provide a hot water generating device that can operate efficiently or maintain user comfort according to circumstances using a single pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a system configuration diagram of a hot water generating device according to an embodiment of the present invention.

[0021] Figure 2 This is a diagram showing the relationship between the load of the air-conditioning water circuit and the capacity of the refrigeration circuit according to the embodiment of the present invention.

[0022] Figure 3 This is an example of a flowchart representing an algorithm for the thermal shutdown execution monitoring control of the hot water generator according to the embodiment of the present invention.

[0023] Figure 4 This is an example of a flowchart representing an algorithm for optimizing control of the hot water generating apparatus according to the embodiment of the present invention.

[0024] Figure 5 This is an example of a time chart of optimization control of the hot water generating apparatus according to the embodiment of the present invention.

[0025] Figure 6 A water heat exchange unit of a second example of the hot water generator according to the embodiment of the present invention.

[0026] Figure 7 A water heat exchange unit of a second example of the hot water generator according to the embodiment of the present invention.

[0027] Figure 8 A water heat exchange unit of a second example of the hot water generator according to the embodiment of the present invention.

[0028] Figure 9 A water heat exchange unit of a second example of the hot water generator according to the embodiment of the present invention.

[0029] Figure 10 A water heat exchange unit of a second example of the hot water generator according to the embodiment of the present invention.

[0030] Figure 11 A water heat exchange unit of a second example of the hot water generator according to the embodiment of the present invention. DETAILED DESCRIPTION

[0031] Reference Figures 1 to 11 The embodiment of the hot water generating device of the present invention will be described. In addition, in the plurality of drawings, the same or corresponding components are denoted by the same reference numerals.

[0032] Figure 1 This is a system configuration diagram of a hot water generating device according to an embodiment of the present invention.

[0033] like Figure 1 As shown, the warm water generating device 1 of this embodiment is a heat pump type. The warm water generating device 1 includes: an outdoor unit 2 (Outdoor Unit) serving as a heat source unit that exchanges heat between outdoor air and a refrigerant; a hydro-heat exchange unit 3 (Hydro Unit) that exchanges heat between water (first water) serving as a heat medium on the utilization side and the refrigerant; a remote control 4 serving as an input device for receiving user operations; and a control unit 6 that controls the outdoor unit 2 and the hydro-heat exchange unit 3 based on the operations input to the remote control 4.

[0034] The hot water generating device 1 mainly has the following functions.

[0035] (1) The function of circulating the refrigerant between the outdoor unit 2 and the water heat exchange unit 3 and exchanging heat between the refrigerant and water as the heat medium on the utilization side in the water heat exchanger 11 in the water heat exchange unit 3.

[0036] (2) The function of circulating hot water between the water heat exchange unit 3 and the external device 101 for air conditioning to perform air conditioning in the room where the external device 101 is installed.

[0037] (3) The function of circulating hot water between the water heat exchange unit 3 and the internal heat exchanger 58 housed in the hot water supply tank 13, heating the water supplied from outside the device to the hot water supply tank 13 into hot water and supplying it to the outside of the device.

[0038] Hereinafter, the circulating water flowing through the closed circuit including the water heat exchanger 11 is referred to as first water. The water stored in the hot water supply tank 13 and finally supplied to the outside of the device is referred to as second water.

[0039] The warm water generating device 1 heats the first water and supplies the hot water at the first temperature to an external device 101 for air conditioning, such as a radiator 102 of a floor heating system, i.e., a floor heating panel, or a radiator 102 of an air conditioning system, such as a fan coil unit. The first temperature is affected by the type of refrigerant and the capacity of the outdoor unit 2. When the R410A refrigerant is circulated, the first temperature reaches a maximum of about 60 degrees Celsius (°C). When the R32 refrigerant, which has a higher temperature, is used, the temperature can be increased to about 65 degrees Celsius (°C). The hot water at the first temperature (first water) circulates in the external device 101 and becomes low temperature, and then returns to the water heat exchange unit 3.

[0040] In addition, the warm water generating device 1 can also use the heat exchange between the refrigerant and the first water performed by the water heat exchanger 11 and the heating of the first water performed by the backup heater 12 to generate hot water (first water) at a second temperature higher than the first temperature, for example, around 70 degrees Celsius (°C), and pass it through the hot water supply tank 13.

[0041] Hot water at the first or second temperature, or first water, is used to heat second water in the hot water supply tank 13. The second water is supplied to destinations where the hot water is used, such as restrooms, kitchens, and bathrooms. The hot water supply tank 13 is connected to a municipal water supply. The municipal water supply replenishes the second water to the destination, keeping the hot water supply tank 13 constantly full. Because the municipal water pressure is applied to the second water in the hot water supply tank 13, the second water is released when a faucet is turned on at the destination.

[0042] Typically, the outdoor unit 2 is installed outdoors, and the water heat exchange unit 3 is installed indoors. The outdoor unit 2 and the water heat exchange unit 3 are connected via connecting pipes 17 and 18 of the refrigerant pipe 16 and a communication line (not shown). The warm water generating device 1 does not have any water piping installed outdoors. Therefore, freezing of the water in the water piping can be prevented during winter when the outdoor temperatures are low.

[0043] The hot water generating device 1 includes a heat pump type refrigeration circuit 21. The heat source of the refrigeration circuit 21 is the outdoor air.

[0044] The refrigeration circuit 21 includes a compressor 22 that compresses and discharges refrigerant, a four-way valve 26, an air heat exchanger 23 serving as an evaporator, an expansion valve 25, a water heat exchanger 11 serving as a condenser, a suction cup 27 provided on the suction side of the compressor 22, and refrigerant pipes 16 that sequentially connect these refrigeration cycle components and allow the refrigerant to flow. The refrigeration circuit 21 circulates the refrigerant, transferring heat from the air heat exchanger 23 to the water heat exchanger 11. The refrigeration circuit 21 uses the heat transferred to the water heat exchanger 11 to heat the first water into hot water. The water heat exchanger 11 and a portion of the refrigerant pipes 16 are housed in the water heat exchange unit 3. The remaining components of the refrigeration circuit 21 are housed in the outdoor unit 2.

[0045] When heating water in the refrigeration circuit 21 , the air heat exchanger 23 functions as an evaporator (also called a “heat absorber”), and the water heat exchanger 11 functions as a condenser (also called a “radiator”).

[0046] The compressor 22 is, for example, a rotary compressor. The compressor 22 compresses and pressurizes the refrigerant, then discharges it. The operating frequency of the compressor 22 can be changed using known inverter control. Increasing the speed of the compressor 22 increases the amount of heat transferred to the high-temperature portion, while decreasing the speed of the compressor 22 decreases the amount of heat transferred to the high-temperature portion. This controls the capacity of the outdoor unit 2, i.e., the heating capacity of the first water. Furthermore, increasing the speed of the compressor 22 increases the power consumption of the compressor 22, while decreasing the speed of the compressor 22 decreases the power consumption of the compressor 22.

[0047] The expansion valve 25 is, for example, an electronic expansion valve (Pulse Motor Valve, PMV) that can adjust the valve opening with fine resolution by being driven by a stepping motor or the like.

[0048] The refrigerant pipe 16 connects the compressor 22, the suction cup 27, the four-way valve 26, the air heat exchanger 23, the expansion valve 25, and the water heat exchanger 11. The refrigerant pipe 16 includes a first refrigerant pipe 16a connecting the discharge side of the compressor 22 to the four-way valve 26, a second refrigerant pipe 16b connecting the suction side of the compressor 22 to the four-way valve 26, a third refrigerant pipe 16c connecting the four-way valve 26 to the water heat exchanger 11, a fourth refrigerant pipe 16d connecting the air heat exchanger 23 to the water heat exchanger 11, and a fifth refrigerant pipe 16e connecting the air heat exchanger 23 to the four-way valve 26.

[0049] The second refrigerant pipe 16b is provided with a suction cup 27. The fourth refrigerant pipe 16d is provided with an expansion valve 25.

[0050] Connecting pipes 17 and 18 of refrigerant pipe 16 allow refrigerant to flow between outdoor unit 2 and water heat exchange unit 3. Connecting pipe 17 is part of the third refrigerant pipe 16c and is laid outside the outdoor unit 2 and outside the water heat exchange unit 3. Connecting pipe 18 is part of the fourth refrigerant pipe 16d and is laid outside the outdoor unit 2 and outside the water heat exchange unit 3. The portion of the third refrigerant pipe 16c disposed within the water heat exchange unit 3 is referred to as the first refrigerant pipe 31 within the water heat exchange unit. The portion of the fourth refrigerant pipe 16d disposed within the water heat exchange unit 3 is referred to as the second refrigerant pipe 32 within the water heat exchange unit.

[0051] The four-way valve 26 switches the direction of flow of the refrigerant in the refrigerant pipe 16. When the first water is heated in the refrigeration circuit 21, the four-way valve 26 allows the refrigerant to flow from the first refrigerant pipe 16a to the third refrigerant pipe 16c, and allows the refrigerant to flow from the fifth refrigerant pipe 16e to the second refrigerant pipe 16b ( Figure 1 , the flow of refrigerant is shown by the solid line).

[0052] The refrigeration circuit 21 discharges compressed, high-temperature, high-pressure refrigerant from the compressor 22 and delivers it to the water heat exchanger 11 via the four-way valve 26. The water heat exchanger 11 exchanges heat with the refrigerant passing through it. This heats the first water and cools the refrigerant, turning it into a high-pressure liquid. In other words, when heating the water to hot water, the water heat exchanger 11 functions as a heat sink. The refrigerant passing through the water heat exchanger 11 is decompressed by the expansion valve 25, becoming a low-pressure gas-liquid two-phase refrigerant. The refrigerant then reaches the air heat exchanger 23. The air heat exchanger 23 exchanges heat with the refrigerant passing through it, cooling the outdoor air. At this point, the air heat exchanger 23 functions as a heat absorber, evaporating the refrigerant and turning it into a gas. The refrigerant passing through the air heat exchanger 23 is then drawn into the compressor 22.

[0053] In addition, in winter, the refrigeration circuit 21 can switch the direction of the refrigerant flow in the refrigerant pipe 16 by the four-way valve 26 to perform a defrosting operation. When performing the defrosting operation, the warm water generator 1 reverses the four-way valve 26 to generate a refrigerant flow in the refrigeration circuit 21 in the opposite direction to the flow of the refrigerant that heats the water into hot water. In the case of the defrosting operation, the four-way valve 26 allows the refrigerant to flow from the first refrigerant pipe 16a to the fifth refrigerant pipe 16e, and allows the refrigerant to flow from the third refrigerant pipe 16c to the second refrigerant pipe 16b ( Figure 1 (The dotted line shows the flow of refrigerant in the figure). During defrosting operation, the air heat exchanger 23 functions as a condenser, and the water heat exchanger 11 functions as an evaporator. As a result, the temperature of the air heat exchanger 23 rises, melting the frost on its surface.

[0054] Alternatively, the refrigeration circuit 21 for warm regions may be a dedicated water heating refrigeration circuit without the four-way valve 26. In this case, the discharge side of the compressor 22 is connected to the water heat exchanger 11 via the refrigerant pipe 16, and the suction side of the compressor 22 is connected to the air heat exchanger 23 via the refrigerant pipe 16.

[0055] Next, the water heat exchange unit 3 includes, in addition to the water heat exchanger 11, an air conditioning water circuit 41 for circulating the first water that has undergone heat exchange in the water heat exchanger 11 to the external device 101, a hot water supply tank 13 for storing hot water, and a hot water supply heating water circuit 42 for circulating the first water that has undergone heat exchange in the water heat exchanger 11 to the hot water supply tank 13 to heat the second water in the hot water supply tank 13.

[0056] The air conditioning water circuit 41 and the hot water supply and heating water circuit 42 share the utilization side of the water heat exchanger 11, the backup heater 12, the pump 43, and the switching valve 45. These components and the water piping 46 connecting them are referred to as the water circuit common section 48. Hot water circulates in one direction within the water circuit common section 48. The switching valve 45 is connected to the discharge side of the pump 43. The downstream side of the switching valve 45 branches into the air conditioning water circuit 41 and the hot water supply and heating water circuit 42, respectively. The switching valve 45 switches the circulation path of the water that has undergone heat exchange in the water heat exchanger 11 to either the air conditioning water circuit 41 or the hot water supply and heating water circuit 42. The air conditioning water circuit 41 and the hot water supply and heating water circuit 42 merge upstream of the water heat exchanger 11. In other words, the water heat exchanger 11 is connected to the downstream side of the air conditioning water circuit 41 and downstream of the hot water supply and heating water circuit 42. The backup heater 12 is connected to the downstream side of the water heat exchanger 11, and the suction side of the pump 43 is connected to the downstream side of the backup heater 12. Alternatively, the pump 43 may be connected to the upstream side of the backup heater 12 .

[0057] In the water circuit common section 48, the first water that has undergone heat exchange in the water heat exchanger 11 is supplied to either the air conditioning water circuit 41 or the hot water supply heating water circuit 42 via the switching valve 45 by the drive of the pump 43. The first water whose temperature has been lowered after being used at the supply destination returns to the water heat exchanger 11 and is heated again by the refrigerant circulating in the refrigeration circuit 21. The first water that has undergone heat exchange in the water heat exchanger 11 is sucked into the pump 43 directly or after being further heated by the standby heater 12. When the standby heater 12 is operated (ON), the first water is heated to 70 degrees Celsius (°C) or above. The standby heater 12 is operated only when the hot water supply heating is in operation and the heat pump does not heat the first water in the water heat exchanger 11 enough, that is, when the water temperature of the first water is low.

[0058] In addition to the water circuit common portion 48, the air conditioning water circuit 41 includes a hot water supply pipe 51 that delivers the first water that has undergone heat exchange in the water heat exchanger 11 to the external device 101, and a hot water return pipe 52 that returns the first water, whose temperature has been lowered by use in the external device 101, from the external device 101 to the water heat exchanger 11. The hot water supply pipe 51 and the hot water return pipe 52 are connected to the external device 101 via an external water piping 103. The air conditioning water circuit 41, the water piping 103, and the external device 101 circulate the first water that has undergone heat exchange in the water heat exchanger 11.

[0059] The hot water supply tank 13 stores the second water (hot water) heated by the hot water supply heating water circuit 42 and discharges the hot water in response to a user's request. The hot water supply tank 13 includes a temperature sensor 55 for measuring the water temperature within the hot water supply tank 13. The output of the temperature sensor 55 is input to the control unit 6.

[0060] The hot water supply heating water circuit 42 includes, in addition to the water circuit common portion 48, a hot water supply pipe 57 for delivering the first water that has undergone heat exchange in the water heat exchanger 11 to the hot water supply tank 13, an in-tank heat exchanger 58 for exchanging heat between the water that has undergone heat exchange in the water heat exchanger 11 and the second water in the hot water supply tank 13, and a hot water return pipe 59 for returning the first water, whose temperature has been lowered after being used in the hot water supply tank 13, to the water heat exchanger 11.

[0061] Connected to the hot water supply tank 13 are a water supply pipe 61 that guides pre-heated municipal water or other water from outside the device as secondary water to the hot water supply tank 13, and a hot water supply pipe 62 that transports the second water, boiled in the hot water supply tank 13, outside the device. The hot water supply pipe 62 supplies warm water to the washroom, kitchen, and bathroom. In the hot water supply tank 13, the second water flowing out of the hot water supply pipe 62 is replenished from the municipal water supply pipe 61. Therefore, when a large amount of warm water is supplied from the hot water supply pipe 62, the proportion of the cooler municipal water increases within the hot water supply tank 13, causing the temperature of the second water to decrease. Furthermore, while the hot water supply tank 13 is insulated with insulation, the temperature of the second water within the hot water supply tank 13 decreases over time due to natural heat dissipation. Therefore, the second water within the hot water supply tank 13 is appropriately heated by the hot water supply heating water circuit 42.

[0062] Hot water generator 1 operates in multiple operating modes, including air conditioning operation, in which water heat exchanged in water heat exchanger 11 circulates through air conditioning water circuit 41; hot water supply and heating operation, in which water heat exchanged in water heat exchanger 11 circulates through hot water supply and heating water circuit 42; and mixed operation (hereinafter also referred to as a mixed operation mode) that switches between air conditioning operation and hot water supply and heating operation as appropriate. Switching between these operating modes is achieved by switching the downstream connection of switching valve 45 to either hot water supply pipe 51 of air conditioning water circuit 41 or hot water supply pipe 57 of hot water supply and heating water circuit 42.

[0063] In the mixed operation mode, air conditioning operation is performed alternately for a first duration and hot water supply and heating operation is performed alternately for a second duration. The first duration of air conditioning operation is, for example, 20 minutes, and the initial value of the second duration of hot water supply and heating operation is, for example, 30 minutes. By switching between the air conditioning operation mode and the hot water supply and heating operation mode, the water in the hot water supply tank 13 is heated (boiled) to the set temperature while maintaining the set temperature requested by the external device 101, or the water in the hot water supply tank 13 is maintained at the requested set temperature.

[0064] The remote controller 4 preferably includes a remote controller (not shown) installed on a wall surface in the room in addition to the remote controller 4 installed in the water heat exchange unit 3 .

[0065] The user can use the remote control 4 to control air conditioning and hot water heating. Furthermore, by simultaneously turning on both air conditioning and hot water heating, a mixed operation mode can be implemented. Furthermore, the remote control 4 can be used to input the set temperature of the room where the external device 101 is located and the set temperature of the second water stored in the hot water tank 13.

[0066] During air conditioning operation, first water is supplied to the external device 101 to maintain the temperature of the room where the external device 101 is installed at the set temperature. Although not shown, a room temperature sensor is installed in the room where the external device 101 is installed to detect the room temperature. During hot water supply and heating operation, first water is supplied to the in-tank heat exchanger 58 to maintain the temperature of the second water in the hot water supply tank 13 at the set temperature. In the mixed operation mode, the air conditioning and hot water supply and heating operations are performed simultaneously or in a time-sharing manner.

[0067] The mixed operation mode occurs when the remote controller 4 is set to both air conditioning and hot water heating modes, i.e., both are turned on simultaneously, and the temperature of the second water in the hot water supply tank 13 is lower than the set temperature. If the temperature of the second water in the hot water supply tank 13 is higher than the set temperature, even if both air conditioning and hot water heating modes are turned on, the hot water heating mode is not activated, and only the air conditioning mode is activated. If the air conditioning mode is turned off, the hot water heating mode is activated when the temperature of the second water in the hot water supply tank 13 is lower than the set temperature. If the temperature of the second water in the hot water supply tank 13 is higher than the set temperature, the compressor remains stopped.

[0068] The control unit 6 includes a microprocessor (not shown), various control programs executed by the microprocessor, and a storage device (not shown) for storing parameters, etc. The control unit 6 executes the various control programs.

[0069] In addition, the control unit 6 performs operation control of the refrigeration circuit 21, the air-conditioning water circuit 41, and the hot water supply and heating water circuit 42, and operation control of the warm water generating device 1 including switching of the operation circuits of the air-conditioning water circuit 41 and the hot water supply and heating water circuit 42, based on the control signals received from the remote controller 4 and the sensor through a wired or wireless communication line.

[0070] Furthermore, the control unit 6 executes control of air conditioning operation by switching the switching valve 45 so that the water that has undergone heat exchange in the water heat exchanger 11 circulates in the air-conditioning water circuit 41 to perform air-conditioning operation, control of hot water supply and heating operation by switching the switching valve 45 so that the water that has undergone heat exchange in the water heat exchanger 11 circulates in the hot water supply and heating water circuit 42 to heat the water in the hot water supply tank, and control of a mixed operation mode in which air-conditioning operation lasting a first time and hot water supply and heating operation lasting a second time are alternately repeated.

[0071] Here, the relationship between the load of the air-conditioning water circuit 41 (hereinafter also referred to as “air-conditioning load”) and the capacity of the refrigeration circuit 21 will be described.

[0072] Figure 2 This is a line graph showing the relationship between the load on the air conditioning water circuit and the capacity of the refrigeration circuit in an embodiment of the present invention. Here, the load on the air conditioning water circuit 41 refers to the air conditioning load of heating (heating) the room via the external device 101. In this embodiment, the load on the air conditioning water circuit 41 refers to the air conditioning load of the room where the radiator 102 of the floor heating system and the radiator 102 of the air conditioning system are installed.

[0073] exist Figure 2 In FIG. 4 , the relationship between the load of the air-conditioning water circuit 41 and the outside air temperature is represented by a dotted line A, and the relationship between the capacity of the refrigeration circuit 21 and the outside air temperature is represented by a solid line B. FIG.

[0074] like Figure 2 As shown by the dotted line A, the load of the air conditioning water circuit 41 is related to the outside air temperature. As the outside air temperature is higher, the heating capacity of the room is reduced, and thus the load of the air conditioning water circuit 41 is reduced.

[0075] like Figure 2As shown by the solid line B, if the external air temperature is within the range from the first external air temperature t1 to the second external air temperature t2, the capacity of the refrigeration circuit 21 is balanced with the air conditioning load (line segment B2). In addition, the first external air temperature t1 is lower than the second external air temperature t2. Within this range, the hot water generating device 1 changes the capacity of the refrigeration circuit 21 by performing inverter control on the operating frequency of the compressor 22, so that the air conditioning load is balanced with the capacity of the refrigeration circuit 21. The operating frequency of the compressor 22 reaches a maximum value when the external air temperature is the first external air temperature t1. It is set as the maximum capacity balance point Cmax. The operating frequency of the compressor 22 reaches a minimum value when the external air temperature is the second external air temperature t2. It is set as the minimum capacity balance point Cmin.

[0076] Furthermore, when the outside air temperature is lower than the first outside air temperature t1, that is, Figure 2 On the lower side (line segment B1) of the maximum capacity balance point Cmax, the capacity of the refrigeration circuit 21 is less than the air conditioning load, and the set temperature required by the external device 101 cannot be met. Therefore, the compressor 22 continues to operate without stopping. However, the capacity of the refrigeration circuit 21 is typically set to be greater than the air conditioning load at the lowest outdoor temperature within the operating range. Therefore, the system does not operate on the line segment B1 side.

[0077] On the other hand, when the outside air temperature is equal to or higher than the second outside air temperature t2, that is, Figure 2 On the high-temperature side (line segment B3) of the minimum capacity balance point Cmin, the capacity of the refrigeration circuit 21 exceeds the air conditioning load, potentially exceeding the set temperature required by the external device 101. Therefore, if the temperature of the room where the external device 101 is installed exceeds the set temperature as a result of air conditioning operation, the compressor 22 is temporarily stopped to prevent the set temperature required by the external device 101 from exceeding the set temperature. This temporary stop of the compressor 22 is called a thermal shutdown.

[0078] In addition, when the outside air temperature is within the range from the first outside air temperature t1 to the second outside air temperature t2 and the mixed operation mode is executed, the control unit 6 does not change the set value of the first time and the set value of the second time, and alternately repeats the air conditioning operation and the hot water supply heating operation while maintaining the original state, thereby delivering the necessary heat to the external device 101 and boiling the hot water in the hot water supply tank 13.

[0079] On the other hand, when the outside air temperature is above the second outside air temperature t2, the refrigeration circuit 21 has excess capacity. Therefore, when the outside air temperature is above the second outside air temperature t2 and the hybrid operation mode is in effect, a thermal shutdown occurs during the first time of air conditioning operation, and the operation of the compressor 22 continues. Specifically, when the outside air temperature is above the second outside air temperature t2, if the first and second times are not changed and the air conditioning operation and the hot water supply and heating operation are alternately repeated, the time it takes for the hot water in the hot water supply tank 13 to reach the set temperature is unnecessarily delayed.

[0080] Therefore, the controller 6 of the hot water generator 1 of this embodiment changes the second time of the hot water supply and heating operation based on the state of the air conditioning load in the mixed operation mode. This control is called hot water supply capacity optimization control.

[0081] Furthermore, the control unit 6 monitors whether or not a thermo-off occurs during air-conditioning operation in order to perform optimization control. This control is referred to as thermo-off execution monitoring control.

[0082] like Figure 3 As shown, the thermal shutdown execution monitoring control of the hot water generator 1 of this embodiment monitors whether a thermal shutdown occurs at a predetermined first determination interval, for example, every 20 minutes, during air conditioning operation. If a thermal shutdown occurs within the first determination interval, a counter F, which counts the number of thermal shutdowns, is incremented by 1 (so-called increment). Furthermore, if no thermal shutdown occurs within a predetermined second determination interval, for example, 30 minutes, the thermal shutdown execution monitoring control decrements the counter F by 1 (so-called decrement). The thermal shutdown execution monitoring control is executed during air conditioning operation and mixed operation mode.

[0083] Specifically, the control unit 6 monitors whether the remote controller 4 has received an instruction to start air conditioning operation ("No" in step S1). Each step is executed by the control unit 6, so the "step" designation is omitted below. If the remote controller 4 has received an instruction to start air conditioning operation mode ("Yes" in S1), the control unit 6 starts a first timer for counting the first determination interval and a second timer for counting the second determination interval (S2).

[0084] Next, the control unit 6 monitors whether a heat shutdown has occurred due to the room temperature rising above the set temperature due to the air conditioning operation in the external device 101 (S3). When the first timer reaches the first determination interval ("YES" in S4), the control unit 6 initializes the first timer to zero and restarts the first timer (S5).

[0085] Next, the control unit 6 checks whether a thermal shutdown has occurred during the immediately preceding counting by the first timer ( S6 ).

[0086] If a heat shutoff occurs during the immediately preceding first timer count ("YES" in S6), the control unit 6 increments the counter F by 1 (S7). This counter F is preferably set to a maximum value. For example, the maximum value of the counter F is set to 8 (S8, S9). If the heat shutoff execution monitoring control does not receive a stop instruction for the air conditioning operation mode ("YES" in S10), the process returns to S3 and repeats.

[0087] On the other hand, if heat off does not occur during the immediately preceding first timer count, the control unit 6 maintains the count F (No in S6). Then, if the control unit 6 does not receive an instruction to stop the air conditioning operation (Yes in S10), it returns to S3 and repeats the process.

[0088] Next, when the second timer reaches the second determination interval (No in S4 , Yes in S11 ), the control unit 6 initializes the second timer to zero and restarts the timing of the second timer ( S12 ).

[0089] Next, the control unit 6 checks whether a thermal shutdown has occurred during the immediately preceding timing of the second timer ( S13 ).

[0090] If heat OFF is executed during the immediately preceding first timer count, the value of the counter F is maintained (YES in S13 ). If no instruction to stop the air-conditioning operation is received (YES in S10 ), the process returns to S3 and repeats.

[0091] On the other hand, if no heat shutoff has occurred during the immediately preceding second timer count ("No" in S13), the count F is decremented by 1 (S14). The count F is preferably set to a minimum value. For example, the minimum value of the count F is set to 0 (S15, S16). If the heat shutoff execution monitoring control does not receive an instruction to stop the air conditioning operation ("Yes" in S10), the process returns to S3 and repeats.

[0092] like Figure 4 As shown, the controller 6 of the hot water generator 1 of this embodiment extends the second time when the air conditioning load is less than the minimum capacity of the refrigeration circuit 21. The controller 6 determines that the air conditioning load is less than the minimum capacity of the refrigeration circuit 21 when a thermal shutdown occurs during air conditioning operation, in which the compressor 22 of the refrigeration circuit 21 stops.

[0093] Furthermore, the control unit 6 varies the second time depending on whether a thermal shutdown occurs. Specifically, if a thermal shutdown occurs within a predetermined first determination interval, the control unit 6 extends the second time by a predetermined extension time. If a thermal shutdown does not occur within the predetermined second determination interval, the control unit 6 cancels the extension of the second time.

[0094] Specifically, the control unit 6 monitors whether the remote controller 4 has received an instruction to start the hot water supply and heating operation ("No" in S31). If the remote controller 4 has received an instruction to start the hot water supply and heating operation ("Yes" in S31), the control unit 6 monitors whether the value measured by the temperature sensor 55 of the hot water supply tank 13 is below the set temperature (S32, "No" in S32).

[0095] If the value measured by the temperature sensor 55 of the hot water supply tank 13 is lower than the set temperature (Yes in S32), the control unit 6 starts the hot water supply and heating operation (S33). At this time, the execution time of the hot water supply and heating operation is started.

[0096] Then, the control unit 6 determines whether or not the air-conditioning operation is being performed simultaneously with the hot water supply and heating operation ( S34 ).

[0097] When the air conditioning operation is not performed ("No" in S34), the control unit 6 monitors whether the measurement value of the temperature sensor 55 reaches the set temperature (S35, "No" in S35). When the measurement value of the temperature sensor 55 reaches the set temperature ("Yes" in S35), the hot water supply heating operation is ended (S36) and returns to S32.

[0098] Next, when the air-conditioning operation is being performed (YES in S34 ), the control unit 6 determines whether the count F added and subtracted in the thermo-off execution monitoring control is greater than 0 ( S37 ).

[0099] When the count F is 0 (No in S37 ), the control unit 6 sets the second time to an initial value, for example, 30 minutes ( S38 ).

[0100] On the other hand, if the count F is greater than 0 ("YES" in S37), the control unit 6 increases the second time of the continuous hot water supply and heating operation. The product of the count F value and a predetermined extension time, for example, 5 minutes, is added to the second time (S39). If the count F is 0, the extension of the second time is canceled and the second time is returned to the initial value.

[0101] Next, the control unit 6 monitors whether the measured value of the temperature sensor 55 reaches the set temperature while the second time set in S38 or the second time extended in S39 continues (No in S41) (S40).

[0102] When the second time set in S38 or the second time extended in S39 has passed ("YES" in S41), or when the measured value of the temperature sensor 55 reaches the set temperature ("YES" in S40), the control unit 6 ends the hot water supply heating operation (S36) and returns to S32.

[0103] exist Figure 5 In the mixed operation mode, the first time of continuous air conditioning operation is set to 20 minutes, the initial value of the second time of continuous hot water supply heating operation is set to 30 minutes, and the extension time is set to 5 minutes (C in the figure).

[0104] exist Figure 5 In the interval A shown, the air conditioning load is small, the counter F (x in the figure) is 0, and the control unit 6 alternately repeats the air conditioning operation for 20 minutes (α in the figure) and the hot water supply and heating operation for 30 minutes (β in the figure).

[0105] exist Figure 5 In the illustrated interval B, heat shutoffs did not occur more than once during air conditioning operation. Therefore, counter F increments every first determination interval, for example, every 20 minutes. Each time the controller 6 switches from 20 minutes of air conditioning operation to hot water supply and heating operation, it extends the second time, alternating between air conditioning operation and hot water supply and heating operation.

[0106] In addition, Figure 5 In the illustrated interval C, no heat shutoff occurs during air conditioning operation. Therefore, the counter F is decremented every second determination interval, for example, every 30 minutes. Each time the controller 6 switches from a 20-minute air conditioning operation to a hot water supply and heating operation, it shortens the second time, alternating between air conditioning operation and hot water supply and heating operation.

[0107] Furthermore, since the thermal shutdown execution monitoring control and the optimization control are executed asynchronously, the second time does not necessarily change by one unit of extension time (5 minutes), but may change by multiple units, for example, two units of extension time (10 minutes in total).

[0108] Furthermore, the controller 6 may extend the second time period regardless of the count F if the outside air temperature exceeds a predetermined temperature at which the air conditioning load is estimated to be less than the minimum capacity of the refrigeration circuit 21. In this case, the warm water generator 1 preferably includes a temperature sensor for measuring the outside air temperature. Optimal control based on the outside air temperature is suitable, for example, for a warm water generator 1 equipped with a compressor 22 whose operating frequency cannot be changed.

[0109] As described above, the hot water generator 1 of this embodiment varies the second time period based on the air conditioning load during hybrid operation mode control. Consequently, the hot water generator 1 can allocate excess capacity in the refrigeration circuit 21 during air conditioning operation to the hot water supply and heating operation. For example, when the air conditioning load is low, the hot water generator 1 can allocate a longer time period to the hot water supply and heating operation. Compared to conventional hot water supply devices equipped with multiple pumps, this operational control of the hot water generator 1 provides efficient operation of the hot water generator 1 tailored to the situation, or operation that maintains user comfort.

[0110] Furthermore, in the hybrid operation mode, the hot water generator 1 of this embodiment extends the second time when the air conditioning load is less than the minimum capacity of the refrigeration circuit 21. Therefore, the hot water generator 1 can reliably allocate the excess capacity of the refrigeration circuit 21 during air conditioning operation to the hot water supply and heating operation. As a result, the hot water generator 1 can bring the temperature of the second water in the hot water supply tank 13 to the set temperature earlier.

[0111] Furthermore, when thermal shutdown occurs during air conditioning operation, the hot water generator 1 of this embodiment determines that the air conditioning load is less than the minimum capacity of the refrigeration circuit 21. Therefore, the hot water generator 1 can reliably determine whether the refrigeration circuit 21 has sufficient capacity during air conditioning operation.

[0112] The hot water generator 1 of this embodiment changes the second time depending on whether or not heat generation is shut down. Therefore, the hot water generator 1 can reliably allocate excess capacity of the refrigeration circuit 21 during air conditioning operation to hot water supply and heating operation.

[0113] Furthermore, the hot water generator 1 of this embodiment extends the second time by a predetermined extension time if a thermal shutdown occurs within the predetermined first judgment interval, and cancels the extension of the second time by the predetermined extension time if a thermal shutdown does not occur within the predetermined second judgment interval. Thus, the hot water generator 1 can timely reflect the remaining capacity of the refrigeration circuit 21 during air conditioning operation.

[0114] Furthermore, the hot water generating device 1 of this embodiment can also extend the second time when the outside air temperature is higher than a predetermined temperature. Even when the hot water generating device 1 includes a compressor 22 whose operating frequency cannot be changed, it is possible to provide efficient operation of the hot water generating device 1 according to the situation or operation of the hot water generating device 1 that maintains user comfort.

[0115] Next, another example of the hot water generator 1 of this embodiment will be described. In the hot water generator 1A and the hot water generator 1B described in each example, the same components as those of the hot water generator 1 are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0116] like Figures 6 to 8 As shown, a hot water generator 1A according to a second example of the present embodiment includes a water heat exchange unit 3A.

[0117] The water heat exchange unit 3A includes a second switching valve 65A that bypasses the air-conditioning water circuit 41 and the hot water supply and heating water circuit 42 .

[0118] Second switching valve 65A switches the connection destination of hot water return pipe 52 of air-conditioning water circuit 41 to either water heat exchanger 11 or hot water supply pipe 57 of hot water supply and heating water circuit 42. The water heat exchanger 11 side of second switching valve 65A merges with hot water return pipe 59 of hot water supply and heating water circuit 42.

[0119] In addition, the switching valve 45 and the second switching valve 65A are shown with blanks to indicate the path that allows the flow of water, and are shown with black to indicate the path that blocks the flow of water.

[0120] like Figure 6 As shown, when the discharge side of pump 43 is switched to air conditioning water circuit 41 via switching valve 45 and the downstream connection of second switching valve 65A is switched to hot water supply pipe 57 of hot water supply and heating water circuit 42, the first water used in air conditioning water circuit 41 is reused to heat or maintain the temperature of the second water in hot water supply tank 13. In other words, hot water generator 1A can prioritize air conditioning operation and simultaneously perform both air conditioning and hot water supply and heating operations. Hot water generator 1A can prevent the temperature of external device 101 from dropping during hot water supply and heating operation.

[0121] In addition, if Figure 7 As shown, by switching the discharge side of the pump 43 to the air-conditioning water circuit 41 via the switching valve 45 and switching the downstream connection destination of the second switching valve 65A to the water heat exchanger 11, the first water can be circulated solely in the air-conditioning water circuit 41. In other words, the hot water generating device 1A can independently perform the air-conditioning operation mode.

[0122] Furthermore, if Figure 8As shown, by switching the discharge side of pump 43 to hot water supply and heating water circuit 42 via switching valve 45 and switching the downstream connection of second switching valve 65A to water heat exchanger 11, the first water can be circulated solely in hot water supply and heating water circuit 42. In other words, hot water generator 1A can operate solely in hot water supply and heating mode. Furthermore, while second switching valve 65A connects hot water return pipe 52 to water heat exchanger 11, the air conditioning water circuit 41 side of switching valve 45 is closed, preventing the circulation of the first water in air conditioning water circuit 41.

[0123] like Figures 9 to 11 As shown in FIG. 1 , a hot water generator 1B according to a third example of the present embodiment includes a water heat exchange unit 3B.

[0124] The water heat exchange unit 3B includes a second switching valve 65B that bypasses the air-conditioning water circuit 41 and the hot water supply and heating water circuit 42 .

[0125] Second switching valve 65B switches the connection destination of hot water return pipe 59, which supplies hot water to heating water circuit 42, to either water heat exchanger 11 or hot water supply pipe 51 of air conditioning water circuit 41. The water heat exchanger 11 side of second switching valve 65B merges with hot water return pipe 52 of air conditioning water circuit 41.

[0126] In addition, the switching valve 45 and the second switching valve 65B are shown with blanks to indicate the path that allows the flow of water, and are shown with black to indicate the path that blocks the flow of water.

[0127] like Figure 9 As shown, when the discharge side of pump 43 is switched to hot water supply and heating water circuit 42 by switching valve 45, and the downstream connection destination of second switching valve 65A is switched to hot water supply pipe 51 of air conditioning water circuit 41, the water used in hot water supply and heating water circuit 42 is reused in external device 101. In other words, hot water generator 1B can prioritize hot water supply and heating operation while simultaneously performing air conditioning and hot water supply and heating operations. Hot water generator 1B can circulate water from hot water supply and heating water circuit 42, which has a higher set temperature than the general set temperature, to air conditioning water circuit 41, which has a lower set temperature. This allows simultaneous air conditioning and hot water supply and heating operations even when the set temperature of external device 101 is lower than the boiling set temperature.

[0128] In addition, if Figure 10 As shown, by switching the discharge side of the pump 43 to the hot water supply and heating water circuit 42 via the switching valve 45 and switching the downstream connection destination of the second switching valve 65B to the water heat exchanger 11, water can be circulated solely in the hot water supply and heating water circuit 42. In other words, the hot water generating device 1B can perform the hot water supply and heating operation independently.

[0129] Furthermore, if Figure 11 As shown, by switching the discharge side of pump 43 to air conditioning water circuit 41 via switching valve 45 and switching the downstream connection of second switching valve 65B to hot water supply pipe 51 of air conditioning water circuit 41, water can circulate solely through air conditioning water circuit 41. In other words, hot water generator 1B can independently perform air conditioning operation. Furthermore, while second switching valve 65B connects hot water return pipe 59 to hot water supply pipe 51, the hot water supply heating water circuit 42 side of switching valve 45 is closed, preventing water from circulating in hot water supply heating water circuit 42.

[0130] Therefore, according to the hot water generating device 1 of the present embodiment, it is possible to perform efficient operation or operation while maintaining user comfort according to the situation without using a plurality of pumps.

[0131] While several embodiments of the present invention have been described, these embodiments are provided as examples and are not intended to limit the scope of the invention. These novel embodiments may be implemented in various other ways, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their variations are intended to be included within the scope and spirit of the invention, and are also intended to be included in the invention described in the technical claims and their equivalents.

[0132] Explanation of symbols

[0133] 1, 1A, 1B: Warm water generating device; 2: Outdoor unit; 3, 3A, 3B: Water heat exchange unit; 4: Remote control; 6: Control unit; 11: Water heat exchanger; 12: Backup heater; 13: Hot water supply tank; 21: Refrigeration circuit; 22: Compressor; 23: Air heat exchanger; 41: Air conditioning water circuit; 42: Hot water supply and heating water circuit; 43: Pump; 45: Switching valve; 48: Common part of the water circuit; 58: In-tank heat exchanger; 65A, 65B: Second switching valve; 101: External device.

Claims

1. A warm water generating device comprising: a refrigeration circuit to circulate a refrigerant; and The water heat exchange unit includes a water heat exchanger for exchanging heat between the refrigerant and first water as a heat medium on the utilization side. The water heat exchange unit comprises: an air conditioning water circuit for circulating the first water that has undergone heat exchange in the water heat exchanger in an external device; a hot water supply heating water circuit for circulating the first water heat-exchanged in the water heat exchanger in the hot water supply tank to heat the second water stored in the hot water supply tank; a switching valve for switching the circulation path of the first water to either the air conditioning water circuit or the hot water supply and heating water circuit; and The control unit controls the switching valve. The control unit is: The switching valve is switched to allow the first water to circulate in the air-conditioning water circuit, the switching valve is switched to allow the first water to circulate in the hot water supply and heating water circuit, and a mixed operation mode is performed in which the air-conditioning operation is alternately repeated for a first period of time and the hot water supply and heating operation is alternately repeated for a second period of time. In the mixed operation mode, the second time is changed based on the load state of the air-conditioning water circuit. When a heat shutdown occurs during the operation of the air conditioner, in which the compressor of the refrigeration circuit stops, the control unit determines that the load of the air conditioning water circuit is less than the minimum capacity of the refrigeration circuit, and extends the second time. The control unit extends the second time by a predetermined extension time when the thermal shutdown occurs within a predetermined first determination interval, and cancels the extension of the second time by the predetermined extension time when the thermal shutdown does not occur within the predetermined second determination interval.

2. The hot water generating device according to claim 1, wherein The control unit extends the second time when the outside air temperature is higher than a predetermined temperature.

Images