JP2019100620A - Heat pump type water heater - Google Patents

Abstract

To provide a heat pump type water heater capable of suppressing deterioration of energy efficiency when hot water supply water stored in a hot water storage tank is supplied to a hot water supply target while heating the hot water supply water in a heat pump device.SOLUTION: A heat pump type water heater 1 includes a heat pump device 10, a hot water supply circuit 30, a water inflow temperature sensor 121, a hot water supply control section 110 and a heat pump control section 120. A hot water supply water supply pump 38 in the hot water supply circuit 30 is configured to increase a flow rate of hot water supply water flowing in HP piping 36 along with an increase in heating capacity of the heat pump device 10 in a range where the flow rate of the hot water supply water flowing in the HP piping 36 reaches a predetermined HP upper limit flow rate or lower. The heat pump control section 120 calculates a boiling-up temperature when the flow rate of the hot water supply water flowing in the HP piping reaches the HP upper limit flow rate from a water inflow temperature, target heating capacity and an estimated upper limit flow rate, as a lower limit boiling-up temperature. The heat pump control section 120 sets a target boiling-up temperature in a range that is equal to or higher than the lower limit boiling-up temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat pump type water heater.

  Conventionally, when hot water stored in a hot water storage tank is supplied to a bathtub, a heat pump type hot water supply system is known that enables a hot water filling operation with good energy efficiency by operating a heat pump cycle as a supplement. (See, for example, Patent Document 1).

  Here, the HP piping connecting the hot water storage tank and the water refrigerant heat exchanger of the heat pump cycle may be limited so that the flow rate of hot water is equal to or less than a predetermined flow rate in order to suppress corrosion and the like. With such limitations, the flow rate of the hot water flowing through the water refrigerant heat exchanger is insufficient, and the temperature of the hot water flowing out of the water refrigerant heat exchanger tends to exceed the target temperature. It will not be possible to supply hot water.

  As a countermeasure, according to Patent Document 1, when the flow rate of the hot water flowing through the HP piping reaches a predetermined upper limit flow during the above-described hot water filling operation, the temperature of the hot water supplied to the bathtub by the external water supply is adjusted. Is disclosed.

JP, 2012-78023, A

  By the way, in the heat pump apparatus, the pressure loss and the temperature target of the high pressure side refrigerant at the initial stage of operation based on the operating conditions such as the target boiling temperature so as to minimize the start loss at the initial stage of operation and to operate quickly at the highest efficiency point. The values are set to control the operation of various components such as the expansion valve.

  However, for example, when the flow rate of the hot water flowing through the HP piping in a short time reaches the predetermined upper limit flow rate during hot water discharge operation to a bathtub or the like, the boiling temperature of the heat pump apparatus is aimed at the transition period from start to stable state. It will be in the driving | running state which does not become upper temperature, and energy efficiency will deteriorate.

  In view of the above points, the present invention provides a heat pump type water heater capable of suppressing deterioration of energy efficiency when supplying hot water stored in a hot water storage tank to a hot water supply target while heating hot water with a heat pump device. The purpose is to

In order to achieve the above object, the invention according to claim 1 is
A compressor (12), a water refrigerant heat exchanger (14) for heat exchange between the refrigerant discharged from the compressor and the hot water, an expansion valve (16) for decompressing and expanding the refrigerant flowing out of the water refrigerant heat exchanger, expansion A heat pump apparatus (10) comprising an evaporator (18) for evaporating the refrigerant decompressed and expanded by a valve;
A hot water storage tank (32) for storing hot water heated by heat exchange with a refrigerant in a water refrigerant heat exchanger, a hot water supply pipe (34 for supplying hot water stored in the hot water storage tank to a hot water supply target (50) ), HP piping (36) for introducing the hot water stored in the hot water storage tank to the water refrigerant heat exchanger and returning the hot water that has passed through the water refrigerant heat exchanger to the hot water storage tank (36) A hot water supply circuit (30) configured to include a hot water supply pump (38) for supplying stored hot water to the water refrigerant heat exchanger;
An incoming water temperature sensor (121) for detecting the incoming water temperature of the hot water flowing into the water refrigerant heat exchanger in the HP piping;
A target capacity setting unit (110 for setting a target heating capacity of the heat pump apparatus in the hot water discharge mode for supplying hot water stored in the hot water storage tank to a hot water supply target and heating the hot water with the water refrigerant heat exchanger )When,
The target boiling temperature of the heat pump apparatus required to bring the temperature of the hot water supplied to the hot water supply target to the target hot water supply temperature in the hot water mode is set, and the boiling temperature of the hot water in the heat pump apparatus is the target boiling And a heat pump control unit (120) that controls the heat pump device to approach a temperature.

  The hot water supply pump increases the flow rate of hot water flowing through the HP piping as the heating capacity of the heat pump device increases, in the range where the flow rate of hot water flowing through the HP piping is less than or equal to the predetermined HP upper limit flow rate Is configured as. The heat pump control unit controls the boiling temperature of hot water in the heat pump apparatus when the flow rate of hot water flowing through the HP piping reaches the HP upper limit flow rate from the estimated upper flow rate which is the estimated flow rate of the incoming water temperature, target heating capacity, and HP upper limit flow rate. Is calculated as the lower limit boiling temperature, and the target boiling temperature is set in the range which is equal to or higher than the lower boiling temperature.

  Thus, if the boiling temperature of the hot water when the flow rate of the hot water flowing through the HP piping reaches the HP upper limit flow is set as the lower limit of the target boiling temperature, the hot water flowing through the HP piping in the hot water discharge mode Flow rate below the HP upper limit flow rate. For this reason, in the heat pump type hot water supply machine of the present disclosure, an unintentional rise in boiling temperature in the water refrigerant heat exchanger does not occur when the hot water flowing through the HP piping reaches the HP upper limit flow rate in the hot water discharge mode. It is possible to suppress the deterioration of the energy efficiency in the mode.

The invention according to claim 2 is
A compressor (12), a water refrigerant heat exchanger (14) for heat exchange between the refrigerant discharged from the compressor and the hot water, an expansion valve (16) for decompressing and expanding the refrigerant flowing out of the water refrigerant heat exchanger, expansion A heat pump apparatus (10) comprising an evaporator (18) for evaporating the refrigerant decompressed and expanded by a valve;
A hot water storage tank (32) for storing hot water heated by heat exchange with a refrigerant in a water refrigerant heat exchanger, a hot water supply pipe (34 for supplying hot water stored in the hot water storage tank to a hot water supply target (50) ), HP piping (36) for introducing the hot water stored in the hot water storage tank to the water refrigerant heat exchanger and returning the hot water that has passed through the water refrigerant heat exchanger to the hot water storage tank (36) A hot water supply circuit (30) configured to include a hot water supply pump (38) for supplying stored hot water to the water refrigerant heat exchanger;
An incoming water temperature sensor (121) for detecting the incoming water temperature of the hot water flowing into the water refrigerant heat exchanger in the HP piping;
Hot water supply stored in a hot water storage tank is supplied to the hot water supply target, and target temperature setting for setting the target boiling temperature of the hot water supply in the heat pump apparatus at the time of hot water discharge mode in which the hot water supply water is heated by the water refrigerant heat exchanger Part (110),
Set the target heating capacity of the heat pump device required to bring the temperature of the hot water supplied to the hot water supply target to the predetermined target hot water temperature in the hot water discharge mode so that the heating capacity of the heat pump device approaches the target heating capacity And a heat pump control unit (120) for controlling the heat pump device.

  The hot water supply pump increases the flow rate of hot water flowing through the HP piping as the heating capacity of the heat pump device increases, in the range where the flow rate of hot water flowing through the HP piping is less than or equal to the predetermined HP upper limit flow rate Is configured as. Then, the heat pump control unit determines the heating capacity of the heat pump apparatus when the flow rate of the hot water flowing through the HP piping reaches the HP upper limit flow rate from the estimated upper limit flow rate which is the estimated flow rate of incoming water temperature, target boiling temperature and HP upper limit flow rate. The target heating capacity is set in the range which is calculated as the upper limit heating capacity and is equal to or less than the upper limit heating capacity.

  As described above, if the heating capacity of the heat pump apparatus when the flow rate of hot water flowing through the HP pipe reaches the HP upper limit flow rate is set as the upper limit of the target heating capacity, the flow rate of hot water flowing through the HP pipe in the hot water discharge mode Becomes less than the HP upper limit flow rate. For this reason, in the heat pump type hot water supply machine of the present disclosure, an unintentional rise in boiling temperature in the water refrigerant heat exchanger does not occur when the hot water flowing through the HP piping reaches the HP upper limit flow rate in the hot water discharge mode. It is possible to suppress the deterioration of the energy efficiency in the mode.

  In addition, the code | symbol in the parenthesis of each means described by this column and the claim shows an example of the correspondence with the specific means as described in embodiment mentioned later.

It is a schematic block diagram of the heat pump type water heater concerning a 1st embodiment. It is a block diagram showing composition of a control device of a heat pump type hot-water supply machine concerning a 1st embodiment. The heat pump type hot water supply machine which concerns on 1st Embodiment WHEREIN: It is a characteristic view which shows the characteristic of the heat pump apparatus at the time of the hot water discharge mode which operates a heat pump apparatus when hot water supply to a hot water supply object terminal. It is a characteristic view which shows the relationship between the heating capacity of the heat pump apparatus in the heat pump type water heater concerning 1st Embodiment, and hot water COP. The heat pump type hot water supply machine which concerns on 1st Embodiment WHEREIN: It is a characteristic view which shows the relationship of the inflow temperature, boiling temperature, and target heating capacity in case the flow volume of the hot water which flows HP piping reaches HP upper limit flow volume. The heat pump type hot water supply machine which concerns on 1st Embodiment WHEREIN: It is explanatory drawing for demonstrating the lower limit of the boiling temperature of a heat pump apparatus when the flow volume of the hot water which flows HP piping reaches HP upper limit flow volume. It is an explanatory view for explaining a relation between HP upper limit flow in a heat pump type hot water supply machine concerning a 1st embodiment, and boiling temperature of a heat pump device. It is a flow chart which shows a flow of control processing which a control device of a heat pump type hot-water supply machine concerning a 1st embodiment performs. The heat pump type hot water supply machine which concerns on 2nd Embodiment WHEREIN: It is a characteristic view which shows the relationship of the incoming water temperature, the target heating capacity, and the target boiling temperature when the flow rate of the hot water which flows HP piping reaches HP upper limit flow rate. The heat pump type hot water supply machine which concerns on 2nd Embodiment WHEREIN: It is explanatory drawing for demonstrating the upper limit of the heating capability of a heat pump apparatus when the flow volume of the hot water which flows HP piping reaches HP upper limit flow volume. It is a flow chart which shows a flow of control processing which a control device of a heat pump type hot-water supply machine concerning a 2nd embodiment performs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same as or equivalent to the items described in the preceding embodiments may be given the same reference numerals, and descriptions thereof may be omitted. In addition, when only a part of the components is described in the embodiment, the components described in the preceding embodiments can be applied to other parts of the components. The following embodiments can be partially combined with each other even if they are not particularly specified as long as there is no problem in particular in the combination.

First Embodiment
The present embodiment will be described with reference to FIGS. 1 to 8. As shown in FIG. 1, the heat pump water heater 1 of the present embodiment includes a heat pump device 10, a hot water supply circuit 30, a control device 100, and the like.

  The heat pump device 10 is a device that heats hot water, and is configured by a vapor compression refrigeration cycle. The heat pump apparatus 10 includes a compressor 12, a water refrigerant heat exchanger 14, an expansion valve 16, and an evaporator 18. The heat pump device 10 is disposed outdoors so as to be capable of taking in outside air.

  Here, in the heat pump device 10 of the present embodiment, carbon dioxide is adopted as the refrigerant, and the pressure of the refrigerant at the portion from the refrigerant discharge side of the compressor 12 to the refrigerant inlet side of the expansion valve 16 is the critical pressure of the refrigerant The above-mentioned supercritical refrigeration cycle is configured.

  Further, in the heat pump device 10 of the present embodiment, the target heating capacity Qtr can be set stepwise in a predetermined range (for example, 4.5 kW to 9 kW) so that the heat management and the like become simple. In the heat pump device 10, the target heating capacity Qtr may be fixed to a predetermined capacity (for example, 4.5 kW).

  The compressor 12 is a device that compresses and discharges the refrigerant to a critical pressure or higher. The compressor 12 of the present embodiment is configured by an electric compressor that drives a fixed displacement type compression mechanism whose discharge displacement is fixed by an electric motor. The refrigerant passage portion 142 of the water refrigerant heat exchanger 14 is connected to the refrigerant discharge side of the compressor 12.

  The water refrigerant heat exchanger 14 has a refrigerant passage portion 142 for circulating the high temperature / high pressure refrigerant discharged from the compressor 12, and a hot water passage portion 144 for circulating hot water flowing through the HP pipe 36 of the hot water supply circuit 30. ing. The water-refrigerant heat exchanger 14 functions as a heat exchanger for heating the hot water, by heat exchange between the refrigerant flowing through the refrigerant passage 142 and the hot water flowing through the hot water passage 144. An expansion valve 16 is connected to the outlet side of the refrigerant passage portion 142 of the water refrigerant heat exchanger 14.

  The expansion valve 16 decompresses and expands the refrigerant flowing out of the refrigerant passage portion 142 of the water refrigerant heat exchanger 14. The expansion valve 16 is configured of a valve mechanism configured to be capable of changing the throttle opening degree, and a variable throttle valve having an actuator for changing the throttle opening degree of the valve mechanism. The operation of the expansion valve 16 of the present embodiment is controlled by a control signal output from the control device 100. An evaporator 18 is connected to the refrigerant outlet side of the expansion valve 16.

  The evaporator 18 is an endothermic heat exchanger that evaporates the refrigerant through heat exchange between the refrigerant decompressed and expanded by the expansion valve 16 and the outside air to exhibit an endothermic effect. Although not shown, the evaporator 18 is additionally provided with a blower fan for supplying the open air to the evaporator 18.

  Subsequently, the hot water supply circuit 30 is a circuit for supplying hot water adjusted to a desired temperature to the hot water supply target terminal 50 including the hot water supply facility and the bathtub of the kitchen. The hot water supply circuit 30 includes a hot water storage tank 32, a hot water supply pipe 34, an HP pipe 36, a hot water supply pump 38, and a water supply pipe 40.

  The hot water storage tank 32 stores hot-water supply water heated by heat exchange with the refrigerant in the water-refrigerant heat exchanger 14. The hot water storage tank 32 has a heat insulating structure which covers the outer periphery of a metal tank portion excellent in corrosion resistance with a heat insulating material, or a vacuum heat insulating structure with a double tank, etc. .

  The hot water storage tank 32 is provided with a hot water supply connection portion 322 for connecting the hot water supply pipe 34 and an outlet side connection portion 324 for connecting the outlet side of the HP pipe 36 in the upper side portion. Further, the hot water storage tank 32 is connected to the inlet side connection portion 326 for connecting the inlet side of the HP pipe 36 and the water supply pipe 40 to a portion lower than the hot water supply connection portion 322 and the outlet side connection portion 324. A water supply connection 328 is provided.

  The hot water supply pipe 34 is a pipe for supplying hot water stored in the hot water storage tank 32 to the hot water supply target terminal 50 such as a bathtub. Although not shown, the hot water supply pipe 34 is provided with a temperature control valve for mixing hot water stored in the hot water storage tank 32 with low temperature water such as tap water. By mixing the hot water stored in the hot water storage tank 32 and the low temperature water such as tap water by the temperature control valve, the hot water adjusted to a desired temperature is supplied to the hot water supply target terminal 50 such as a bathtub Be done.

  The HP pipe 36 is a pipe for guiding the hot water stored in the hot water storage tank 32 to the hot water discharge passage 144 of the water refrigerant heat exchanger 14 and returning the hot water passing through the hot water discharge passage 144 to the hot water storage tank 32. is there. A hot water supply pump 38 is provided in the HP pipe 36 between the inlet-side connection part 326 of the hot water storage tank 32 and the hot water passage part 144 of the water refrigerant heat exchanger 14. Note that the hot water supply pump 38 may be provided, for example, between the outlet-side connection portion 324 of the hot water storage tank 32 in the HP pipe 36 and the hot water passage 144 of the water refrigerant heat exchanger 14.

  The hot water supply pump 38 is a pump for supplying the hot water stored in the hot water storage tank 32 to the water refrigerant heat exchanger 14 via the HP pipe 36. The operation of the hot water supply pump 38 is controlled by a control signal from the control device 100.

  Here, in the water-refrigerant heat exchanger 14 of the present embodiment, the hot-water-supplying water passage portion 144 is configured to include copper piping and the like excellent in heat conductivity. Since copper piping and the like cause corrosion when the flow velocity of hot water is high, it is necessary to use copper piping and the like in the range where the flow velocity of hot water becomes equal to or less than a predetermined flow velocity. For this reason, the hot water supply pump 38 according to the present embodiment is configured such that the flow rate of hot water is equal to or lower than a predetermined flow rate (hereinafter, also referred to as HP upper limit flow rate) so that copper pipes and the like are less likely to corrode. Operation is restricted.

  The water supply pipe 40 is a pipe for supplying tap water and the like to the hot water storage tank 32. Although not shown, the water supply pipe 40 is provided with a water supply control valve for adjusting the supply amount of tap water and the like to the hot water storage tank 32.

  Next, the control device 100 that constitutes the electronic control unit of the heat pump type water heater 1 of the present embodiment will be described with reference to FIG. As shown in FIG. 2, the control device 100 of the present embodiment includes a hot water supply control unit 110 and a heat pump control unit 120.

  Each of the control units 110 and 120 is configured by a known microcomputer including a processor and a memory and its peripheral circuit. Each of the control units 110 and 120 performs various arithmetic processing based on the control program stored in the memory, and controls various control target devices connected to the output side. The control units 110 and 120 of the present embodiment are connected to each other so that information acquired by one control unit can be shared with the other control unit.

  The hot water supply control unit 110 is a control unit that mainly acquires acquisition of environmental information on the hot water supply circuit 30 side and controls operations of various devices that constitute the hot water supply circuit 30. On the input side of the hot water supply control unit 110, an in-tank temperature sensor 111 installed in the hot water storage tank 32, a remote controller 112 disposed indoors, and the like are connected.

  The in-tank temperature sensor 111 is a temperature sensor that detects the temperature Twt of the hot water stored in the hot water storage tank 32. The in-tank temperature sensor 111 of the present embodiment has a plurality of sensor units so as to be able to detect temperatures at a plurality of upper and lower locations in the hot water storage tank 32. Thus, the hot water supply control unit 110 can grasp the temperature of the hot water and the temperature distribution in the hot water storage tank 32 according to the water level in the hot water storage tank 32.

  The remote controller 112 is provided with a temperature setting switch 112a, a hot water storage switch 112b, a hot water switch 112c, and the like. The temperature setting switch 112 a is a switch for setting a target outlet temperature Tws of hot water to be output from the hot water supply target terminal 50. The hot water storage switch 112 b is a switch for setting the operation mode of the heat pump device 10 to a hot water storage mode in which the hot water heated by the water refrigerant heat exchanger 14 is stored in the hot water storage tank 32. The hot-dip switch 112 c supplies the hot water stored in the hot water storage tank 32 to the hot water supply target terminal 50 in the operation mode of the heat pump device 10 and sets the hot water to be heated by the water refrigerant heat exchanger 14 in hot water mode. It is a switch for setting. The remote controller 112 is not limited to one fixed to a wall surface in the room, and may be configured to be portable.

  Moreover, the hot water supply control part 110 is connected to the hot water supply pump 38 at the output side. The hot water supply control unit 110 increases the flow rate of the hot water flowing through the HP piping 36 as the heating capacity of the water refrigerant heat exchanger 14 increases in a range where the flow rate of hot water does not exceed the predetermined HP upper limit flow rate. As such, the operation of the hot water supply pump 38 is controlled.

  Here, the hot water supply control unit 110 of the present embodiment sets the target heating capacity Qtr of the heat pump device 10 based on the setting or the like of the remote controller 112 in the hot water discharge mode. Specifically, the hot water supply control unit 110 selects a heating capacity suitable for the target outlet water temperature Tws set by the temperature setting switch 112 a from a plurality of heating capacities set in advance (for example, 4.5 kW to 9 kW), The selected heating capacity is set to the target heating capacity Qtr. In the present embodiment, the hot water supply control unit 110 configures a target capacity setting unit that sets the target heating capacity Qtr of the heat pump device 10 in the hot water discharge mode.

  On the other hand, the heat pump control unit 120 is a control unit that mainly controls acquisition of environment information on the heat pump device 10 side and operations of various devices that constitute the heat pump device 10. The heat pump control unit 120 has, on its input side, an incoming water temperature sensor 121 for detecting the incoming water temperature Twi of the hot water flowing into the water refrigerant heat exchanger 14, and a boiling point for detecting the boiling temperature Two of the hot water in the heat pump device 10. A temperature sensor 122 or the like is connected. The boiling temperature Two is the outflow temperature of the hot water flowing out of the water refrigerant heat exchanger 14.

  The heat pump control unit 120 is connected at its output side to the compressor 12 and the expansion valve 16 that constitute the heat pump device 10. The heat pump control unit 120 sets a target boiling temperature Tw of the heat pump device 10 that is required to bring the temperature of the hot water supplied to the hot water supply target terminal 50 to the predetermined target hot water temperature Tws. Then, the heat pump control unit 120 controls the operation of the compressor 12 and the expansion valve 16 that constitute the heat pump device 10 such that the boiling temperature Two of the hot water in the heat pump device 10 approaches the target boiling temperature Tw.

  Next, the operation of the heat pump type water heater 1 with the above configuration will be described. When the hot water storage switch 112b is turned on in a state where power is supplied from the outside to the heat pump type water heater 1, the control device 100 executes control processing in the hot water storage mode stored in advance in the memory. In addition, when the hot-water switch 112c is turned on in a state where power is supplied to the heat pump type water heater 1 from the outside, the control device 100 executes control processing in the hot water discharge mode stored in advance in the memory.

  First, the hot water storage mode will be described. The hot water storage mode is an operation mode in which the hot water heated by the water refrigerant heat exchanger 14 is stored in the hot water storage tank 32 during a late-night power period when the power rate is low.

  In the hot water storage mode, the control device 100 operates the heat pump device 10 and the hot water supply pump 38 such that the temperature Twt of the hot water in the hot water storage tank 32 becomes the target boiling temperature Twh (for example, 65 ° C.) for hot water storage. Control. That is, control device 100 controls the operation of compressor 12, expansion valve 16, and hot water supply pump 38 such that the temperature Twt of the hot water in hot water storage tank 32 approaches target boiling temperature Twh for hot water storage. .

  Thus, in the heat pump device 10, the refrigerant discharged from the compressor 12 flows into the refrigerant passage 142 of the water refrigerant heat exchanger 14, and exchanges heat with the hot water flowing through the hot water passage 144. At this time, the hot water flowing through the hot water passage portion 144 is heated so as to approach the target boiling temperature Twh for storing hot water by heat exchange with the refrigerant. The refrigerant that has passed through the water refrigerant heat exchanger 14 is decompressed and expanded by the expansion valve 16 and then flows into the evaporator 18. The refrigerant that has flowed into the evaporator 18 absorbs heat from the outside air and evaporates, and then is drawn into the compressor 12 and compressed again.

  On the other hand, in the hot water supply circuit 30, the low temperature hot water stored on the lower side of the hot water storage tank 32 by the hot water supply pump 38 is supplied to the water refrigerant heat exchanger 14. The hot water supplied to the water-refrigerant heat exchanger 14 is heated by heat exchange with the refrigerant, and is then stored above the hot water storage tank 32.

  Next, the hot water discharge mode will be described. The hot water discharge mode is an operation mode in which the hot water in the hot water storage tank 32 is supplied to the hot water supply target terminal 50 in a state where hot water heated in the hot water storage mode is stored in the hot water storage tank 32.

  The control device 100 of the present embodiment is auxiliary when supplying hot water stored in the hot water storage tank 32 to the hot water supply target terminal 50 in order to improve the energy efficiency of the heat pump water heater 1 in the hot water discharge mode. The heat pump apparatus 10 is operated. That is, when the hot-water supply water stored in the hot-water storage tank 32 is supplied to the hot water supply target terminal 50 in the hot water discharge mode, the control device 100 of the present embodiment operates the heat pump device 10 to supply hot water by the water refrigerant heat exchanger 14 Heat the water.

  Hereinafter, the reason for operating the heat pump apparatus 10 supplementarily when the hot water stored in the hot water storage tank 32 is supplied to the hot water supply target terminal 50 will be described with reference to FIGS. 3 and 4. FIG. 3 is a characteristic diagram showing the relationship between the boiling temperature Two of the hot water and the heating capacity Q in the heat pump device 10 in the hot water mode of the present embodiment. The characteristic diagram shown in FIG. 3 shows that the boiling temperature Two and the heating capacity of the heat pump apparatus 10 under the condition that the incoming water temperature Twi is 9 ° C., the outgoing water temperature is 45 ° C., the pouring amount is 180 liters, and the pouring capacity is 25 kW. It shows the relationship with Q. As shown in FIG. 3, the heat pump device 10 has a characteristic that the heating capacity Q of the heat pump device 10 increases as the boiling temperature Two increases.

  The heat pump water heater 1 of the present embodiment uses the hot water stored in the hot water storage tank 32 in the hot water discharge mode. Therefore, the substantial COP in the hot water discharge mode is not only the COP of the heat pump device 10 in the hot water discharge mode, but also the COP of the heat pump device 10 in the hot water storage mode and the hot water storage tank capacity in the hot water discharge mode and the heating capacity of the heat pump device 10 It is necessary to consider the ratio of

  In the present embodiment, the substantial COP in the hot water tapping mode is referred to as a hot-dip COP, and the hot-dip COP is defined by Equation 1 below.

Hot pot COP = Assist COP × HP ratio + Hot water storage COP × (1-HP ratio) ... (Equation 1)
In addition, the hot water storage COP in Formula 1 has shown COP of the heat pump apparatus 10 in the hot water storage mode (inflow temperature: 9 degreeC, outlet hot water: 65 degreeC, heating capacity: 4.5 kW). The assist COP indicates the COP of the heat pump device 10 in the hot water discharge mode. The HP ratio indicates the ratio of the heating capacity Q of the heat pump device 10 in the hot water filling capacity (hot water storage tank capacity + heating capacity Q).

  FIG. 4 is a characteristic diagram defining the relationship between the heating capacity Q of the heat pump device 10 of the present embodiment and the hot-dip COP in consideration of the characteristics of the heat pump device 10 shown in the above-mentioned equation 1 and FIG. In FIG. 4, the solid line T1 shows the relationship between the heating capacity Q when the boiling temperature is 20 ° C. and the hot water COP, and the solid line T2 shows the relationship between the heating capacity Q when the boiling temperature is 23 ° C. It shows the relationship. Further, in FIG. 4, the solid line T3 indicates the relationship between the heating capacity Q at the boiling temperature of 30 ° C. and the hot water COP, and the solid line T4 indicates the heating capacity Q at the boiling temperature 40 ° C. and the hot water COP. It shows the relationship with Furthermore, in FIG. 4, the broken line HC indicates the upper limit line of the heating capacity required to secure the tapping temperature when the hot water supply target terminal 50 is tapped.

  As shown in FIG. 4, in the hot water discharge mode of the present embodiment, the hot-dip COP is made higher in the case where the heating capacity Q of the heat pump device 10 is exhibited than in the case where the heating capacity Q of the heat pump device 10 is not exhibited. There is a region that can be That is, when supplying hot water from the hot water storage tank 32, the heat pump device 10 is operated at the target boiling temperature Tw lower than that in the hot water storage mode with a predetermined heating capacity (for example, 4.5 kW). Efficiency can be improved.

  For the above reasons, in the present embodiment, when the hot water stored in the hot water storage tank 32 is supplied to the hot water supply target terminal 50 in the hot water discharge mode, the heat pump device 10 is operated supplementally.

  By the way, as described above, the hot water supply pump 38 according to this embodiment is configured to operate in a range in which the flow rate of hot water is equal to or less than the predetermined HP upper limit flow rate. Therefore, simply setting the target boiling temperature Tw from the relationship between the heating capacity Q of the heat pump device 10 and the hot water COP, the flow rate of hot water flowing through the HP pipe 36 may reach the HP upper limit flow rate. When the flow rate of the hot water flowing through the HP piping 36 reaches the HP upper limit flow rate, the boiling temperature Two of the heat pump device rises unintentionally, so that the boiling temperature Two and the target boiling temperature Tw diverge from each other. Energy efficiency may deteriorate.

  On the other hand, the control device 100 according to the present embodiment calculates the lower limit boiling temperature Tw_min of the boiling temperature Two so that the flow rate of the hot water flowing through the HP pipe 36 becomes equal to or lower than the HP upper limit flow rate. The operation of the heat pump device 10 is controlled in the range of the temperature Tw_min or more.

  Specifically, the lower limit boiling temperature Tw_min is calculated using Formula 2 below.

Tw_min = Qtr / (A × Gw_max × ρ × cp) + Twin (Equation 2)
Qtr in Formula 2 is a target heating capacity of the heat pump device 10, and is set to a predetermined heating capacity (for example, 4.5 kW) based on the target tapping temperature Tws and the like. Gw_max is an estimated upper limit flow rate which is an estimated flow rate of the HP upper limit flow rate, and is preset based on the maximum capacity of the hot water supply pump 38 and the like. A is a correction coefficient for correcting the estimated upper limit flow rate Gw_max. ρ is the density of the hot water supply. cp is the specific heat of hot water. Twin is the incoming water temperature of the hot water flowing into the water refrigerant heat exchanger 14, and can be detected by the incoming water temperature sensor 121.

  According to the above equation 2, the boiling temperature Two when the flow rate of the hot water flowing through the HP pipe 36 reaches the HP upper limit flow from the incoming water temperature Twi, the target heating capacity Qtr, and the estimated upper limit flow Gw_max is the lower limit boiling temperature Tw_min It will be calculated as The boiling temperature Two when the flow rate of the hot water flowing through the HP piping 36 reaches the HP upper limit flow is proportional to the incoming water temperature Twi as shown in FIG. 5 when the target heating capacity Qtr is constant. To grow.

  Here, when the flow rate of the hot water flowing through the HP piping 36 reaches the HP upper limit flow rate, the upper limit line of the heating capacity Q required to secure the hot water outlet temperature when tapping the hot water supply target terminal 50 is shown in FIG. It falls to the line HC2 shown with a dashed dotted line. Therefore, it is also possible to calculate the boiling temperature Two at which the target heating capacity Qtr and the line HC2 cross each other as the lower limit boiling temperature Tw_min in FIG. 6.

  The HP upper limit flow rate changes due to the pressure loss in the HP pipe 36. For example, when the length of the HP pipe 36 is large, the pressure loss in the HP pipe 36 is larger than when the length of the HP pipe 36 is small, so the HP upper limit flow rate is reduced.

  For this reason, even if the estimated upper limit flow rate Gw_max is set before the construction of the heat pump water heater 1, there is a concern that it may deviate from the actual HP upper limit flow rate. If the estimated upper limit flow rate Gw_max set in advance deviates from the actual HP upper limit flow rate, the calculation accuracy of the lower limit boiling temperature Tw_min or the like, which is the lower limit of the target boiling temperature Tw, decreases. This is not preferable because it affects the energy efficiency in the tapping mode.

  Therefore, in the heat pump water heater 1 of the present embodiment, the temperature excess amount ΔTw of the boiling temperature Two with respect to the target boiling temperature Tw when the hot water supply pump 38 is operating at the maximum capacity is calculated. Then, the correction coefficient A is calculated using the following equation 3 so that the estimated upper limit flow rate Gw_min becomes smaller as the temperature excess amount ΔTw becomes larger.

A = (Tw_min-Twi) / (ΔTw + Tw_min-Twi) (Equation 3)
If the estimated upper limit flow rate Gw_max is corrected with the calculated correction coefficient A, the deviation between the estimated upper limit flow rate Gw_max and the actual HP upper limit flow rate when calculating the lower limit boiling temperature T_min or the like is corrected.

  Here, in the configuration in which the pressure loss of the HP piping is large, when the flow rate of the hot water flowing through the HP piping 36 reaches the HP upper limit flow rate, it is necessary to secure the hot water temperature at the time of tapping the hot water supply target terminal 50. The upper limit line of the heating capacity is lowered to the line HC3 indicated by a two-dot chain line in FIG. For this reason, in FIG. 7, it is also possible to calculate the boiling temperature Two at which the target heating capacity Qtr and the line HC3 cross each other as the lower limit boiling temperature Tw_min.

  However, the temperature excess amount ΔTw of the boiling temperature Two with respect to the target boiling temperature Tw flows into the water refrigerant heat exchanger 14 not only when the preset estimated upper limit flow Gw_max and the actual HP upper limit flow diverge. It also occurs when the incoming water temperature Twi of the hot water supply is high.

  For example, when the temperature of the hot water stored in the hot water storage tank 32 is high, the incoming water temperature Twi of the hot water flowing into the water refrigerant heat exchanger 14 may also be high. Under such circumstances, when the boiling temperature Two of the hot water in the heat pump device 10 exceeds the target boiling temperature Tw, the temperature excess amount ΔTw of the boiling temperature Two to the target boiling temperature Tw may increase. .

  Therefore, in the heat pump type water heater 1 of the present embodiment, when the inflow temperature Twi of hot water flowing into the water refrigerant heat exchanger 14 becomes equal to or lower than a predetermined reference temperature, the estimated upper limit flow rate Gw_max is corrected. ing.

  Subsequently, a series of flow of control processing executed by the control device 100 (mainly, the heat pump control unit 120) of the present embodiment in the tapping mode will be described using a flowchart shown in FIG. The control process shown in FIG. 8 is periodically executed by the control device 100 when the hot-water switch 112c is turned on. The control process shown in FIG. 8 ends when the supply of hot water to the hot water supply target terminal 50 is completed.

  As shown in FIG. 8, in step S10, the control device 100 reads output signals from the in-tank temperature sensor 111, the incoming water temperature sensor 121, the boiling water temperature sensor 122, the remote controller 112, and the like connected to the input side.

  Subsequently, in step S20, the control device 100 sets a target heating capacity Qtr of the heat pump device 10 in the hot water outlet mode. For example, the control device 100 selects a heating capacity suitable for the target outlet water temperature Tws set by the temperature setting switch 112 a from a plurality of heating capacities (for example, 4.5 kW to 9 kW) set in advance, and selects the selected heating capacity Set the target heating capacity Qtr.

  Subsequently, in step S30, the control device 100 calculates the lower limit boiling temperature Tw_min, which is the lower limit of the target boiling temperature Tw of the heat pump device 10. Specifically, control device 100 calculates lower limit boiling temperature Tw_min using Equation 2 described above. In the first time, the lower limit boiling temperature Tw_min is calculated after setting the correction coefficient A of the estimated upper limit flow rate Gw_max to "1".

  Then, control device 100 sets up target boiling temperature Tw in the range which becomes more than lower limit boiling temperature Tw_min in Step S40. The control device 100 of the present embodiment sets the lower limit boiling temperature Tw_min to the target boiling temperature Tw. The control device 100 may be configured to set a temperature slightly higher than the lower limit boiling temperature Tw_min to the target boiling temperature Tw.

  Subsequently, in step S50, the control device 100 controls the operation of the compressor 12 and the expansion valve 16 which configure the heat pump device 10 so that the boiling temperature Two approaches the target boiling temperature Tw set in step S40. Do.

  Subsequently, in step S60, the control device 100 determines whether or not the incoming water temperature Twi of the hot water flowing into the water refrigerant heat exchanger 14 is equal to or lower than a predetermined reference temperature Tth. The predetermined reference temperature Tth is set based on, for example, the temperature of tap water (for example, 9 ° C. to 30 °).

  As a result of the determination processing in step S60, when the incoming water temperature Twi is equal to or lower than the reference temperature Tth, the control device 100 calculates the correction coefficient A of the estimated upper limit flow rate Gw_max set in advance in step S70. Specifically, control device 100 calculates correction coefficient A using equation 3 described above.

  On the other hand, when the incoming water temperature Twi exceeds the reference temperature Tth as a result of the determination process of step S70, the control device 100 skips the process of step S70. That is, when the incoming water temperature Twi exceeds the reference temperature Tth, the control device 100 does not correct the correction coefficient A.

  The heat pump type water heater 1 of the present embodiment described above is configured such that the heat pump device 10 is controlled such that the boiling temperature Two of the hot water in the heat pump device 10 becomes lower in the hot water discharge mode than in the hot water storage mode. ing. For this reason, the heat pump type hot water supply device 1 can perform the tapping operation with good energy efficiency.

  In particular, the heat pump water heater 1 of the present embodiment sets the boiling temperature Two of hot water supply when the flow rate of hot water flowing through the HP pipe 36 reaches the HP upper limit flow in the hot water discharge mode as the lower limit of the target boiling temperature Tw. It is configured to be set. According to this, the flow rate of the hot water flowing through the HP pipe 36 in the hot water discharge mode becomes equal to or less than the HP upper limit flow rate. For this reason, in the hot water discharge mode, an unintentional rise in the boiling temperature Two in the water refrigerant heat exchanger 14 does not occur when the flow rate of hot water flowing through the HP piping 36 becomes the HP upper limit flow during the hot water discharge mode. The deterioration of the efficiency can be suppressed.

  In the heat pump water heater 1 according to the present embodiment, the estimated upper limit flow rate is based on the temperature excess amount ΔTw of the boiling temperature Two with respect to the target boiling temperature Tw when the hot water supply pump 38 is operating at the HP upper limit flow rate. Gw_max is configured to be corrected.

  According to this, since the deviation between the estimated upper limit flow rate Gw and the actual HP upper limit flow rate is corrected, it is possible to improve the calculation accuracy of the lower limit boiling temperature Tw_min. This greatly contributes to the improvement of the energy efficiency in the tapping mode.

  Furthermore, the heat pump water heater 1 according to the present embodiment corrects the estimated upper limit flow rate Gw_min when the incoming water temperature Twi of the hot water flowing into the water refrigerant heat exchanger 14 becomes equal to or lower than the predetermined reference temperature Tth. The coefficient A is calculated. According to this, it is possible to correct the estimated upper limit flow rate Gw_min to an appropriate flow rate. This greatly contributes to the improvement of the energy efficiency in the tapping mode.

Second Embodiment
Next, a second embodiment will be described with reference to FIGS. 9 to 11. The present embodiment differs from the first embodiment in that the target heating capacity Qtr of the heat pump device 10 is configured to be able to be set to an arbitrary capacity.

  Unlike the first embodiment, the heat pump type water heater 1 of the present embodiment is configured such that the heat pump device 10 can set the target heating capacity Qtr to an arbitrary capacity. As described above, in the configuration in which the target heating capacity Qtr can be set to an arbitrary capacity, there is an advantage such as being able to perform boiling of hot water with good energy efficiency and the like, as compared with the first embodiment.

  Further, the hot water supply control unit 110 of the present embodiment sets the target boiling temperature Tw of the heat pump device 10 based on the setting or the like of the remote controller 112 in the hot water discharge mode. Specifically, the hot water supply control unit 110 sets a heating temperature suitable for the target tapping water temperature Tws set by the temperature setting switch 112 a as the target boiling temperature Tw. In the present embodiment, the hot water supply control unit 110 configures a target temperature setting unit that sets a target boiling temperature Tw of hot water in the heat pump device 10 in the hot water discharge mode.

  On the other hand, the heat pump control unit 120 of the present embodiment sets the target heating capacity Qtr of the heat pump device 10 required to bring the temperature of the hot water supplied to the hot water supply target terminal 50 to the predetermined target hot water temperature Tws. And the heat pump control part 120 controls operation | movement of the compressor 12 which comprises the heat pump apparatus 10, and the expansion valve 16 so that the heating capacity Q of the heat pump apparatus 10 approaches the target heating capacity Qtr.

  The control device 100 according to the present embodiment calculates the upper limit heating capacity Q_max of the heating capacity Q so that the flow rate of the hot water flowing through the HP piping 36 becomes equal to or lower than the HP upper limit flow during the hot water discharge mode. The operation of the heat pump device 10 is controlled within the range of

  Specifically, the upper limit heating capacity Q_max is calculated using Formula 4 below.

Q_max = A × Gw_max × ρ × cp × (Tw−Twin) (Equation 4)
Tw in the equation 4 is a target boiling temperature, and is set to a predetermined boiling temperature (for example, 23 ° C.) based on the target tapping temperature Tws and the like set by the remote controller 112. The other symbols have the same meaning as the symbols described in Formula 2.

  According to the above-mentioned formula 4, the upper limit which makes the target heating capacity Qtr the upper limit when the flow rate of the hot water flowing through the HP piping 36 reaches the HP upper limit flow from the incoming water temperature Twi, the target boiling temperature Tw, and the estimated upper limit flow Gw_max. It will be calculated as the heating capacity Q_max. The target heating capacity Qtr when the flow rate of the hot water flowing through the HP piping 36 reaches the HP upper limit flow is proportional to the incoming water temperature Twi as shown in FIG. 9 when the target boiling temperature Tw is constant. And become smaller.

  Here, when the flow rate of the hot water flowing through the HP piping 36 reaches the HP upper limit flow rate, the upper limit line of the heating capacity Q required to secure the hot water outlet temperature when tapping the hot water supply target terminal 50 is shown in FIG. It falls to the line HC2 shown with a dashed dotted line. Therefore, in FIG. 10, it is also possible to calculate the heating capacity Q at which the target boiling temperature Tw and the line HC2 cross each other as the upper limit heating capacity Tw_max.

  Subsequently, a series of flow of control processing executed by the control device 100 (mainly, the heat pump control unit 120) of the present embodiment in the tapping mode will be described using a flowchart shown in FIG. The control process shown in FIG. 11 is periodically executed by the control device 100 when the hot-water switch 112c is turned on. The control process shown in FIG. 11 ends when the supply of hot water to the hot water supply target terminal 50 is completed.

  As shown in FIG. 11, in step S10, the control device 100 reads output signals from the in-tank temperature sensor 111, the incoming water temperature sensor 121, the boiling temperature sensor 122, the remote controller 112, and the like connected to the input side.

  Subsequently, at step S20A, control device 100 sets target boiling temperature Tw of hot water in heat pump device 10 in the hot water discharge mode. Specifically, the control device 100 calculates the boiling temperature Two suitable for the target tapping water temperature Tws set by the temperature setting switch 112a, and sets the boiling temperature Two to the target boiling temperature Tw.

  Subsequently, in step S30A, the control device 100 calculates the upper limit heating capacity Q_max, which is the upper limit of the target heating capacity Qtr of the heat pump device 10. Specifically, control device 100 calculates upper limit heating capacity Q_max using Equation 4 described above. In the first time, the upper limit heating capacity Q_max is calculated after setting the correction coefficient A of the estimated upper limit flow rate Gw_max to “1”.

  Subsequently, at step S40A, the control device 100 sets the target boiling temperature Tw in a range where the upper heating capability Q_max or less. For example, the control device 100 according to the present embodiment sets the upper limit heating capacity Q_max to the target heating capacity Qth. The control device 100 may be configured to set the target heating capacity Qtr to a capacity slightly lower than the upper limit heating capacity Q_max.

  Subsequently, in step S50A, the control device 100 operates the compressor 12 and the expansion valve 16 that configure the heat pump device 10 so that the heating capacity Q of the heat pump device 10 approaches the target heating capacity Qtr set in step S40A. Control.

  Subsequently, in step S60, the control device 100 determines whether or not the incoming water temperature Twi of the hot water flowing into the water refrigerant heat exchanger 14 is equal to or lower than a predetermined reference temperature Tth. The predetermined reference temperature Tth is set based on, for example, the temperature of tap water (for example, 9 ° C. to 30 °).

  As a result of the determination processing in step S60, when the incoming water temperature Twi is equal to or lower than the reference temperature Tth, the control device 100 calculates the correction coefficient A of the estimated upper limit flow rate Gw_max set in advance in step S70. Specifically, control device 100 calculates correction coefficient A using equation 3 described above.

  On the other hand, when the incoming water temperature Twi exceeds the reference temperature Tth as a result of the determination process of step S70, the control device 100 skips the process of step S70. That is, when the incoming water temperature Twi exceeds the reference temperature Tth, the control device 100 does not correct the correction coefficient A.

  The heat pump type water heater 1 of the present embodiment described above sets the heating capacity Q of hot water supply when the flow rate of hot water flowing through the HP piping 36 reaches the HP upper limit flow rate in the hot water discharge mode as the upper limit of the target heating capacity Qtr. Is configured to According to this, the flow rate of the hot water flowing through the HP pipe 36 in the hot water discharge mode becomes equal to or less than the HP upper limit flow rate. For this reason, in the hot water discharge mode, an unintentional rise in the boiling temperature Two in the water refrigerant heat exchanger 14 does not occur when the flow rate of hot water flowing through the HP piping 36 becomes the HP upper limit flow during the hot water discharge mode. The deterioration of the efficiency can be suppressed.

  Further, since the heat pump type water heater 1 of the present embodiment has the same configuration and operation as the first embodiment, the first embodiment achieves the same effects as those of the first embodiment. It can be obtained as well as the form.

(Other embodiments)
As mentioned above, although the typical embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment, for example, can be variously deformed as follows.

  As in each of the embodiments described above, it is desirable that the estimated upper limit flow rate Gw_max be appropriately corrected with the correction coefficient A, but the present invention is not limited to this. The heat pump water heater 1 may be configured not to correct the estimated upper limit flow rate Gw_max by the correction coefficient A, for example.

  As in each of the above-described embodiments, it is desirable to calculate the correction coefficient A for correcting the estimated upper limit flow rate Gw_max when the incoming water temperature Twi is equal to or lower than the reference temperature Tth, but is not limited thereto. The heat pump water heater 1 may be configured to calculate the correction coefficient A for correcting the estimated upper limit flow rate Gw_max regardless of the incoming water temperature Twi.

  Although the above-mentioned each embodiment demonstrated the example which a carbon dioxide is employ | adopted as a refrigerant | coolant of the heat pump apparatus 10, it is not limited to this. The heat pump apparatus 10 may employ, for example, a fluorocarbon-based refrigerant as a refrigerant.

  Although the thing by which the hot-water supply control part 110 and the heat pump control part 120 were separately provided as the control apparatus 100 was illustrated in each above-mentioned embodiment, it is not limited to this. In the control device 100, for example, the hot water supply control unit 110 and the heat pump control unit 120 may be integrally configured.

  It is needless to say that the elements constituting the embodiment in the above-described embodiment are not necessarily essential except when clearly shown as being essential and when it is considered to be obviously essential in principle.

  In the above embodiment, when numerical values such as the number, numerical value, amount, range and the like of the constituent elements of the embodiment are mentioned, it is clearly indicated that they are particularly essential and clearly limited to a specific number in principle. It is not limited to that particular number except in cases such as, etc.

  In the above embodiment, when referring to the shape, positional relationship, etc. of the component etc., unless otherwise specified or in principle when limited to a specific shape, positional relationship, etc., the shape, positional relationship, etc. It is not limited to etc.

(Summary)
According to a first aspect of the present invention shown in part or all of the above-described embodiments, the heat pump water heater includes a heat pump device, a hot water supply circuit, an incoming water temperature sensor, a target capacity setting unit, and a heat pump control unit. And. The hot water supply pump increases the flow rate of hot water flowing through the HP piping as the heating capacity of the heat pump device increases, in the range where the flow rate of hot water flowing through the HP piping is less than or equal to the predetermined HP upper limit flow rate Is configured as. The heat pump control unit controls the boiling temperature of hot water in the heat pump apparatus when the flow rate of hot water flowing through the HP piping reaches the HP upper limit flow rate from the estimated upper flow rate which is the estimated flow rate of the incoming water temperature, target heating capacity, and HP upper limit flow rate. Is calculated as the lower limit boiling temperature. And a heat pump control part sets up target boiling temperature in the range which becomes more than lower limit boiling temperature.

  Further, according to the second aspect, the heat pump water heater includes the heat pump device, the hot water supply circuit, the incoming water temperature sensor, the target temperature setting unit, and the heat pump control unit. In the hot water supply pump of the hot water supply circuit, the flow rate of hot water flowing through the HP piping as the heating capacity of the heat pump device increases in a range where the flow rate of hot water flowing through the HP piping is less than a predetermined HP upper limit flow rate Is configured to increase. The heat pump control unit heats up the heating capacity of the heat pump apparatus when the flow rate of hot water flowing through the HP piping reaches the HP upper limit flow rate from the estimated upper limit flow rate which is the estimated flow rate of incoming water temperature, target boiling temperature and HP upper limit flow rate. Calculated as ability. And a heat pump control part sets up target heating capacity in the range which becomes below upper limit heating capacity.

  Further, according to the third aspect, the heat pump water heater includes the boiling temperature sensor that detects the boiling temperature of the hot water flowing out of the water refrigerant heat exchanger in the HP pipe. Then, the heat pump control unit calculates the excess temperature of the boiling temperature with respect to the target boiling temperature when the hot water supply pump is operating at the maximum capacity, and the estimated upper limit flow rate decreases as the temperature excess amount increases. Correct the estimated upper limit flow rate to be

  By the way, the HP upper limit flow rate changes depending on the pressure loss in the HP piping. For example, when the length of the HP pipe is large, the pressure loss in the HP pipe is larger than when the length of the HP pipe is small, so the HP upper limit flow rate is reduced.

  For this reason, even if the estimated upper limit flow rate which is the estimated flow rate of the HP upper limit flow rate is set before the construction of the heat pump type water heater, there is a concern that it may deviate from the actual HP upper limit flow rate. Then, if the estimated upper limit flow rate set in advance and the actual HP upper limit flow rate deviate from each other, the calculation accuracy of the lower limit boiling temperature or the like, which is the lower limit of the target boiling temperature, is reduced. This is not preferable because it affects the energy efficiency in the tapping mode.

  On the other hand, in the heat pump type water heater of the present disclosure, the temperature excess amount of the boiling temperature with respect to the target boiling temperature when the hot water supply pump operates at the HP upper limit flow rate is calculated, and the temperature excess amount is large. The estimated upper limit flow rate is corrected so that the estimated upper limit flow rate becomes smaller.

  According to this, since the deviation between the estimated upper limit flow rate used when calculating the lower limit boiling temperature and the like and the actual HP upper limit flow rate is corrected, it is possible to improve the calculation accuracy of the lower limit boiling temperature and the like. This greatly contributes to the improvement of the energy efficiency in the tapping mode.

  Further, according to the fourth aspect, in the heat pump type water heater, the heat pump control unit calculates the correction coefficient for correcting the estimated upper limit flow rate when the incoming water temperature becomes equal to or lower than the predetermined reference temperature.

  Here, the excess temperature of the boiling temperature with respect to the target boiling temperature is not limited to the case where the estimated upper limit flow rate set beforehand and the actual HP upper limit flow rate diverge, and the incoming water of hot water flowing into the water refrigerant heat exchanger It also occurs when the temperature rises.

  For example, when the temperature of the hot water stored in the hot water storage tank is high, the incoming water temperature of the hot water flowing into the water refrigerant heat exchanger may also be high. Under such circumstances, when the boiling temperature of the hot water in the heat pump apparatus exceeds the target boiling temperature, the excess temperature of the boiling temperature with respect to the target boiling temperature may increase.

  Therefore, in the heat pump type hot water supply machine of the present disclosure, when the incoming water temperature of the hot water flowing into the water refrigerant heat exchanger becomes equal to or lower than a predetermined reference temperature, a correction coefficient for correcting the estimated upper limit flow rate is calculated. It has become. According to this, the estimated upper limit flow rate can be corrected to an appropriate flow rate. This greatly contributes to the improvement of the energy efficiency in the tapping mode.

  Further, according to the fifth aspect, the heat pump type water heater controls the heat pump device such that the heat pump control unit makes the boiling temperature of the hot water in the heat pump device lower in the hot water discharge mode than in the hot water storage mode. . As described above, when the heat pump apparatus is operated at the boiling temperature lower than that in the hot water storage mode, the hot water discharge operation with good energy efficiency becomes possible. The hot water storage mode is an operation mode in which the hot water supplied by the water refrigerant heat exchanger is stored in a hot water storage tank.

DESCRIPTION OF SYMBOLS 1 heat pump type water heater 10 heat pump apparatus 16 water refrigerant heat exchanger 30 hot water supply circuit 32 hot water storage tank 36 HP piping 110 hot water supply control part (target capability setting part, target temperature setting part)
120 heat pump control unit 121 water temperature sensor

Claims (5)

A compressor (12), a water refrigerant heat exchanger (14) for heat exchange between the refrigerant discharged from the compressor and the hot water, an expansion valve (16) for decompressing and expanding the refrigerant flowing out of the water refrigerant heat exchanger A heat pump apparatus (10) including an evaporator (18) for evaporating the refrigerant decompressed and expanded by the expansion valve;
A hot water storage tank (32) for storing hot water heated by heat exchange with a refrigerant in the water refrigerant heat exchanger, a hot water supply pipe for supplying hot water stored in the hot water storage tank to a hot water supply target (50) (34), HP piping (36) for guiding hot water stored in the hot water storage tank to the water refrigerant heat exchanger and returning hot water having passed through the water refrigerant heat exchanger to the hot water storage tank, the HP A hot water supply circuit (30) including a hot water supply pump (38) for supplying hot water stored in the hot water storage tank via the piping to the water refrigerant heat exchanger;
An incoming water temperature sensor (121) for detecting an incoming water temperature of hot water flowing into the water refrigerant heat exchanger in the HP pipe;
A target capacity for setting a target heating capacity of the heat pump apparatus in a hot water discharge mode in which hot water stored in the hot water storage tank is supplied to the hot water supply target and the hot water is heated by the water refrigerant heat exchanger A setting unit (110),
The target boiling temperature of the heat pump apparatus required to bring the temperature of the hot water supplied to the hot water supply target to the predetermined target hot water temperature in the hot water discharge mode is set, and the boiling temperature of the hot water in the heat pump apparatus A heat pump control unit (120) for controlling the heat pump device so that the temperature approaches the target boiling temperature;
In the hot water supply pump, the hot water flowing through the HP piping is increased as the heating capacity of the heat pump device increases in a range where the flow rate of hot water flowing through the HP piping is equal to or less than a predetermined HP upper limit flow rate. Configured to increase the flow rate,
The heat pump control unit performs the heat pump when the flow rate of hot water flowing through the HP pipe reaches the HP upper limit flow rate from the estimated incoming flow rate from the incoming water temperature, the target heating capacity, and the estimated flow rate of the HP upper limit flow rate. A heat pump type hot water supply apparatus which calculates the boiling temperature of the hot water in the apparatus as the lower limit boiling temperature and sets the target boiling temperature within the range of the lower boiling temperature or more. A compressor (12), a water refrigerant heat exchanger (14) for heat exchange between the refrigerant discharged from the compressor and the hot water, an expansion valve (16) for decompressing and expanding the refrigerant flowing out of the water refrigerant heat exchanger A heat pump apparatus (10) including an evaporator (18) for evaporating the refrigerant decompressed and expanded by the expansion valve;
A hot water storage tank (32) for storing hot water heated by heat exchange with a refrigerant in the water refrigerant heat exchanger, a hot water supply pipe for supplying hot water stored in the hot water storage tank to a hot water supply target (50) (34), HP piping (36) for guiding hot water stored in the hot water storage tank to the water refrigerant heat exchanger and returning hot water having passed through the water refrigerant heat exchanger to the hot water storage tank, the HP A hot water supply circuit (30) including a hot water supply pump (38) for supplying hot water stored in the hot water storage tank via the piping to the water refrigerant heat exchanger;
An incoming water temperature sensor (121) for detecting an incoming water temperature of hot water flowing into the water refrigerant heat exchanger in the HP pipe;
In order to supply hot water stored in the hot water storage tank to the hot water supply target, and to set a target boiling temperature of hot water in the heat pump apparatus in a hot water mode in which the hot water is heated by the water refrigerant heat exchanger Target temperature setting unit (110),
The target heating capacity of the heat pump apparatus, which is required to bring the temperature of the hot water supplied to the hot water supply target to a predetermined target tapping temperature, is set during the tapping mode, and the heating capacity of the heat pump unit is the target heating A heat pump control unit (120) for controlling the heat pump device to approach the capacity;
In the hot water supply pump, the hot water flowing through the HP piping is increased as the heating capacity of the heat pump device increases in a range where the flow rate of hot water flowing through the HP piping is equal to or less than a predetermined HP upper limit flow rate. Configured to increase the flow rate,
The heat pump control unit is configured to allow the flow rate of hot water flowing through the HP pipe to reach the HP upper limit flow rate from the estimated upper limit flow rate which is the estimated flow rate of the incoming water temperature, the target boiling temperature and the HP upper limit flow rate. A heat pump type hot water supply which calculates the heating capacity of a heat pump device as upper limit heating capacity, and sets the target heating capacity in the range which becomes less than the upper limit heating capacity. A boiling temperature sensor (122) for detecting a boiling temperature of hot water flowing out of the water refrigerant heat exchanger in the HP pipe;
The heat pump control unit calculates a temperature excess amount of boiling temperature of hot water to the target boiling temperature when the hot water supply pump is operating at maximum capacity, and the estimation is performed as the temperature excess amount is larger. The heat pump water heater according to claim 1 or 2, wherein the estimated upper limit flow rate is corrected so that the upper limit flow rate becomes a small flow rate.   The heat pump water heater according to claim 3, wherein the heat pump control unit calculates a correction coefficient for correcting the estimated upper limit flow rate when the incoming water temperature becomes equal to or lower than a predetermined reference temperature.   The heat pump control unit causes the boiling temperature of the hot water in the heat pump apparatus to be lower than that in the hot water storage mode in which the hot water heated by the water refrigerant heat exchanger is stored in the hot water storage tank in the hot water discharge mode. The heat pump water heater according to any one of claims 1 to 4, wherein the heat pump apparatus is controlled as described above.

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