Abstract:
A heat pump type hot water supply apparatus ( 10 ) for heating water by refrigerant heat and stocking the hot water thus achieved including: a heat pump unit ( 11 ) having a refrigerant circuit using natural refrigerant, the refrigerant circuit including a compressor ( 16 ) for compressing refrigerant, a heat-pump heat exchanger ( 18 ) and a refrigerant-water heat exchanger ( 27 ) for performing the heat exchange between refrigerant and water to achieve hot water; a hot water supply unit ( 12 ) including a hot water supply tank ( 26 ) for stocking the hot water achieved by the refrigerant-water heat exchanger ( 27 ) of the heat pump unit ( 11 ) and supplying the hot water thus stocked; and a water pipe ( 36 ) through which the refrigerant-water heat exchanger ( 27 ) of the heat pump unit ( 11 ) and the hot water supply tank ( 26 ) of the hot water supply unit ( 12 ) are connected to each other to circulate hot-water/water between the refrigerant-water heat exchanger ( 27 ) and said hot water supply tank ( 26 ).

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a heat pump type hot water supply apparatus for heating water by using refrigerant heat and then stocking the hot water thus achieved in a hot-water supply tank.  
           [0003]    2. Description of the Related Art  
           [0004]    There has been hitherto proposed such a heat pump type hot water apparatus that a heat exchanger for hot water supply heats water by using heat of refrigerant and the hot water thus achieved is stocked in a hot-water supply tank. In general, such a type of hot water supply apparatus is equipped with a heat-pump unit containing a compressor, a heat-pump heat exchanger and a pressure-reducing device, and a hot water unit containing a refrigerant-water heat exchanger for performing the heat exchange between refrigerant and water and a hot-water supply tank for stocking hot water achieved through the heat exchange between refrigerant and water in the refrigerant-water heat exchanger, and the hot water unit and the heat pump unit are connected to each other through a refrigerant pipe.  
           [0005]    However, in a case where the heat pump type hot water supply apparatus having the above construction is designed so that the refrigerant pipe through which the hot water unit and the heat pump unit are connected to each other is exposed to the outside, the safety of the heat pump type hot water supply apparatus might be lost if the refrigerant is formed of a refrigerant material containing a large amount of carbon dioxide because the refrigerant pressure of the refrigerant material is higher than that of freon-based refrigerant.  
           [0006]    Further, some of heat pump type hot water supply apparatuses as described above have not only a refrigerant-water heat exchanger for hot water supply, but also a refrigerant-water heat exchanger for reheating of hot water or water in a bath tub. In this case, the heat pump unit must be actuated even when it is sufficient to reheat the hot water or water in the bath tub without supplying hot water into the bath tub.  
           [0007]    Further, in this type of heat pump hot water supply apparatus, the temperature of hot water at the top portion of the hot-water supply tank rises up, and thus there is used such a method that a hot-water outlet pipe is connected to the top portion of the hot water supply tank to take out hot water at the top portion, the hot water supplied through the hot-water outlet pipe is mixed with water to adjust the temperature of the hot water to a proper value, and then the temperature-adjusted hot water is supplied to users. In this case, if the temperature of the hot water in the hot-water supply tank is high, a large amount of water must be mixed with the hot water, and the mixing of a large amount of water reduces the energy efficiency of the heat pump type hot water supply apparatus.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention has been implemented in view of the foregoing situation, and has an object to provide a heat pump type hot water supply apparatus which can prevent a high-pressure refrigerant pipe from being exposed to the outside to enhance the safety of the apparatus and enhance the energy efficiency of the heat pump type hot water supply apparatus.  
           [0009]    In order to attain the above object, according to the present invention, there is provided a heat pump type hot water supply apparatus for heating water by refrigerant heat and stocking the hot water thus achieved, characterized by comprising: a heat pump unit having a refrigerant circuit using natural refrigerant, the refrigerant circuit including a compressor for compressing refrigerant, a heat-pump heat exchanger and a refrigerant-water heat exchanger for performing the heat exchange between refrigerant and water to achieve hot water; a hot water supply unit including a hot water supply tank for stocking the hot water achieved by the refrigerant-water heat exchanger of the heat pump unit and supplying the hot water thus stocked; and a water pipe through which the refrigerant-water heat exchanger of the heat pump unit and the hot water supply tank of the hot water supply unit are connected to each other to circulate hot-water/water between the refrigerant-water heat exchanger and the hot water supply tank.  
           [0010]    In the heat pump type hot water supply apparatus of the present invention, the hot water supply unit further includes hot-water joint control means for controlling the joint of hot water supplied from at least two inner portions of the hot water supply tank which are different in hot-water temperature.  
           [0011]    In the heat pump type hot water supply apparatus of the present invention, the hot-water joint control means comprises at least two hot water outlet pipes that extend from the hot water supply tank and join each other at one ends thereof and through which the hot water is supplied from the hot water supply tank to the outside thereof, each of at least two hot water outlet pipes being equipped with an opening/closing valve for allowing/intercepting flow of the hot water therethrough, and a controller for controlling the opening/closing operation of the opening/closing valves of at least two hot water outlet pipes.  
           [0012]    In the heat pump type hot water supply apparatus of the present invention, the controller controls the opening/closing operation of the opening/closing valves in accordance with the temperature of the hot water in at least one of at least two inner portions of the hot water supply tank so that hot water having a proper temperature is supplied.  
           [0013]    In the heat pump type hot water supply apparatus of the present invention, the hot-water joint control means comprises at least two hot water outlet pipes that extend from the hot water supply tank and join each other at one ends thereof and through which the hot water is supplied from the hot water supply tank to the outside thereof, a mixing valve disposed at the joint position of at least two hot water outlet pipes, the mixing valve controlling the joint degree of the hot water supplied through at least two hot water outlet pipes, and a controller for controlling the mixing operation of the mixing valve.  
           [0014]    In the heat pump type hot water supply apparatus of the present invention, the controller controls the mixing valve to adjust the mixing degree of the hot water supplied through at least two hot water outlet pipes in accordance with the temperature of the hot water in at least one of at least two inner portions of the hot water supply tank so that hot water having a proper temperature is supplied.  
           [0015]    In the heat pump type hot water supply apparatus of the present invention, the mixing valve comprises a wax valve.  
           [0016]    In the heat pump type hot water supply apparatus of the present invention, at least two inner portions of the hot water supply tank includes the top portion of the hot water supply tank and an intermediate portion between the top portion and the bottom portion of the hot water supply tank.  
           [0017]    In the heat pump type hot water supply apparatus of the present invention, the hot water supply unit further includes a water-water heat exchanger for performing the heat exchange between the hot water supplied from the hot water supply tank and hot-water/water circulated in a bath tub to reheat the hot-water/water in the bath tub.  
           [0018]    In the heat pump type hot water supply apparatus of the present invention, the hot water supply unit includes a mixing control valve for controlling the mixing of tap water and the hot water from the hot water supply tank so that the temperature of the hot water from the hot water supply unit is set to a proper temperature. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 is a refrigerant circuit diagram showing a first embodiment of a heat pump type hot water supply apparatus according to the present invention when water in a hot-water supply tank is heated, and hot water thus achieved is stocked in the hot-water supply tank;  
         [0020]    [0020]FIG. 2 is a refrigerant circuit diagram of the heat pump type hot water supply apparatus shown in FIG. 1 when hot water is supplied to a tap;  
         [0021]    [0021]FIG. 3 is a refrigerant circuit diagram of the heat pump type hot water supply apparatus shown in FIG. 1 when hot water is put into a bath tub;  
         [0022]    [0022]FIG. 4 is a refrigerant circuit diagram of the heat pump type hot water supply apparatus shown in FIG. 1 when water or hot water in the bath tub is heated (reheated) to keep the temperature of the hot water;  
         [0023]    [0023]FIG. 5 is a refrigerant circuit diagram showing a second embodiment of the heat pump type hot water supply apparatus according to the present invention when water in a hot-water supply tank is heated, and hot water thus achieved is stocked in the hot-water supply tank;  
         [0024]    [0024]FIG. 6 is a refrigerant circuit diagram of the heat pump type hot water supply apparatus shown in FIG. 5 when hot water is supplied to a tap;  
         [0025]    [0025]FIG. 7 is a refrigerant circuit diagram of the heat pump type hot water supply apparatus shown in FIG. 5 when hot water is put into a bath tub; and  
         [0026]    [0026]FIG. 8 is a refrigerant circuit diagram of the heat pump type hot water supply apparatus shown in FIG. 5 when water or hot water in the bath tub is heated (reheated) to keep the temperature of the hot water.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0027]    Preferred embodiments according to the present invention will be described hereunder with reference to the accompanying drawings. In the following embodiments, it is assumed that natural refrigerant such as refrigerant containing a large amount of carbon dioxide or the like is used. In the case of refrigerant containing a large amount of carbon dioxide, the pressure of the refrigerant is generally higher than that of freon-based refrigerant.  
         [0028]    [0028]FIG. 1 shows a first embodiment of a heat pump type hot water supply apparatus according to the present invention, and more specifically, FIG. 1 is a refrigerant circuit diagram of the heat pump type hot water supply apparatus when water in a hot-water supply tank is heated and hot water thus achieved is stocked in the hot-water supply tank.  
         [0029]    As shown in FIG. 1, the heat pump type hot water supply apparatus  10  includes a heat pump unit  11 , a hot water unit  12 , a tap (water tap)  13 , a bath tub  14  and controllers  15 A and  15 B.  
         [0030]    The heat pump unit  11  includes a compressor  16 , a heat exchanger for hot water supply (refrigerant-water heat exchanger)  27 , a heat-pump heat exchanger  18  and an accumulator  17 , which are successively connected to one another through a refrigerant pipe  19  in this order. The compressor  16  functions to compress refrigerant. The heat exchanger  27  for hot water supply heats hot water or water by using the heat of refrigerant discharged from the compressor  16 .  
         [0031]    The hot water unit  12  includes a hot-water supply tank  26 , a heat exchanger for bath (water-water heat exchanger)  28 , a tap hot-water supply line  71 , a bath hot-water pouring line  72 , etc.  
         [0032]    The hot-water supply tank  26  is used to stock hot water which is heated by using refrigerant heat in the hot-water heat exchanger  27 . The hot-water supply tank  26  and the hot-water heat exchanger  27  are connected to each other in a loop style through a water pipe  36  for hot water supply which is equipped with a hot-water circulating pump  34 , a flow rate adjusting valve  35  and a first change-over electromagnetic valve  73 , thereby forming a water circulating circuit N for hot water supply through which water is circulated as indicated by a heavy line in FIG. 1 when the first change-over electromagnetic valve  73  is operated to be opened.  
         [0033]    When refrigerant containing a large amount of carbon dioxide is used, the refrigerant pressure thereof is higher than that of freon-based refrigerant as described above. Therefore, the temperature of hot water in the hot water heat exchanger  27  rises up to about 90° C.  
         [0034]    The heat pump unit  11  and the hot water unit  12  are connected to each other in the loop style by the water pipe  36  for hot water supply. Therefore, unlike the conventional heat pump type hot water supply apparatus, the high-pressure refrigerant pipe (for example, refrigerant pipe  19 ) is not exposed to the outside and the safety of the heat pump type hot water supply apparatus can be enhanced.  
         [0035]    A first tap water pipe  38  having a pressure-reduced check valve  37  disposed therein is connected to the bottom portion  26 B of the hot-water supply tank  26  to supply tap water into the hot-water supply tank  26  at all times. Accordingly, the pressure of the tap water acts in the hot-water supply tank  26  at all times.  
         [0036]    In this embodiment, a top portion hot-water outlet pipe  40  having a first opening/closing valve  91  is connected to the top portion  26 A of the hot-water supply tank  26 , and an intermediate hot-water outlet pipe  33  having a second opening/closing valve  92  is connected to an intermediate portion (for example, a substantially midpoint portion) and will be referred to as) between the top portion  26 A and the bottom portion  26 B of the hot-water supply tank  26 . The first and second opening/closing valves  91 ,  92  connected to the pipes  40 ,  33  respectively are selectively subjected to opening/closing control by the controller  15 B in accordance with the hot water temperature detected by a temperature sensor  94  disposed at the intermediate portion  26 C of the hot-water supply tank  26 .  
         [0037]    When the hot-water circulating pump  34  is actuated to supply water at the bottom portion  26 B of the hot-water supply tank  26  to the hot-water heat exchanger  27 , the hot-water heat exchanger  27  performs the heat exchange between the water thus supplied and high-temperature refrigerant gas discharged from the compressor  16  of the heat pump unit  11  to heat the water by using the heat of the refrigerant gas. When the first change-over electromagnetic valve  73  is controlled to be opened, the hot water (or water) thus heated is subjected to flow rate adjustment by the flow rate adjusting valve  35  and then fed to the top portion  26 A of the hot-water supply tank  26 , whereby the hot water whose upper limit temperature is equal to about 90° C. can be stocked in the hot-water supply tank  26 .  
         [0038]    The top portion  26 A of the hot-water supply tank  26  is further equipped with a pressure releasing valve  39 . The pressure releasing valve  39  is used to release pressure when hot water or water is excessively heated and the pressure in the hot-water supply tank  26  is excessively increased.  
         [0039]    The bath heat exchanger  28  is a water-water heat exchanger through which the hot water in the hot-water supply tank  26  is circulated to reheat hot water in the bath tub  14 . The hot water in the hot-water supply tank  26  is pumped out by actuating a pump  102  in a circulating pipe  101  extending out from the top portion  26 A. The hot water thus pumped out is passed through the circulating pipe  101 , and led to the bath heat exchanger  28  to heat (reheat) the hot water or water in the bath tub  14 . Thereafter, it is passed through a second change-over electromagnetic valve  74  and a returning pipe  103  and then returned to the intermediate portion  26 C between the top portion  26 A and the bottom portion  26 B of the hot-water supply tank  26 .  
         [0040]    That is, the bath heat exchanger  28  is designed to perform the heat exchange between the hot-water (water) flowing in a water introducing pipe  75  for introducing the hot water in the hot-water supply tank  26  and the hot-water (water) flowing in a first bath water pipe  51  for introducing the hot water or water in the bath tub  14  through the contact between the water introducing pipe  75  and the first bath water pipe  51 . The water introducing pipe  75  and the first bath water pipe  51  are designed in a flat tubular shape to increase the contact area therebetween.  
         [0041]    The first bath water pipe  51  through which the bath heat exchanger  28  and the bath tub  14  intercommunicate with each other is equipped with a circulating pump  46  for bath, a filter  47 , a water level sensor  48 , a thermistor  49  and a flow switch  50 .  
         [0042]    A water circulating circuit P for bath through which hot water or water is circulated between the bath heat exchanger  28  and the bath tub  14  is constructed by the first bath water pipe  51 .  
         [0043]    The water level sensor  48  intercommunicates with the bath tub  14  through the first bath water pipe  51 , and thus it detects the water level of hot water or water in the bath tub  14 . When hot water or water is circulated in the bath water circulating circuit P, the thermistor  49  detects the temperature of the hot water/water to indirectly detect the temperature of the hot water/water in the bath tub  14 . The flow switch  50  detects that hot water or water circulates in the bath water circulating circuit P. Further, the filter  47  filters the circulating hot water/water together with a filter  56  disposed in the bath tub  14 .  
         [0044]    When the hot-water pouring into the bath tub  14  as described later is carried out to fill hot water into the bath tub  14  and then the hot water in the bath tub  14  is reheated, the circulating pump  102  and the bath circulating pump  46  are actuated. At this time, as indicated by a heavy line of FIG. 4, both the hot water in the hot-water supply tank  26  and the hot water in the bath tub  14  are made to flow into the bath heat exchanger  28 , and subjected to the heat exchange, whereby the hot water in the bath tub  14  is reheated by the hot water in the hot-water supply tank  26 . The temperature of the hot water working in the bath heat exchanger  28  is reduced to about 50° C. through the heat exchange, and then the hot water flows through the water pipe  103  into the intermediate portion  26 C of the hot water supply tank  26 .  
         [0045]    The tap hot-water supply line  71  comprises a hot-water pipe  59 , a mixing control valve  57  and a flow sensor  58  as indicated by a heavy line Q of FIG. 2. Since the water pressure of the tap water acts on the hot water in the hot water supply tank  26  through the first tap water pipe  38 , the hot water in the hot water supply tank  26  can be supplied to the tap  13  by opening the tap  13 .  
         [0046]    The flow sensor  58  detects the flow rate of the hot water flowing in the hot water pipe  59 . The mixing control valve  57  is connected through a second tap water pipe  62  to the downstream side of the pressure-reduced check valve  37  in the first tap water pipe  38  as indicated by the heavy line of FIG. 2.  
         [0047]    By the opening/closing control operation of the mixing control valve  57 , the hot water from the hot water supply pipe  59  and the tap water from the second tap water pipe  62  are mixed with each other so that the temperature of the hot water to be supplied from the tap is adjusted to about 60° C. or less, for example, to 42° C.  
         [0048]    As indicated by a heavy line S of FIG. 3, a hot-water supply line  72  for bath is constructed by connecting the downstream side of the flow sensor  58  in the hot water supply pipe  59  through the second bath water pipe  68  to the intermediate portion between the bath circulating pump  46  and the flow switch  50 , whereby the hot water in the hot water supply tank  26  can be poured into the bath tub  14 . A flow sensor  64 , a hot water pouring electromagnetic valve  65 , a relief means  66 , a check valve  67  and an electromagnetic valve  54  are successively disposed in this order from the side of the hot water supply pipe  59  in the second bath water pipe  68 .  
         [0049]    The flow sensor  64  detects the flow rate of hot water flowing in the second bath water pipe  68 . When excessively-heated hot water flows into the second bath water pipe  68 , the relief means  66  and the check valve  67  serve to release the pressure of the hot water. The electromagnetic valve  54  is opened when the hot water is poured into the bath tub  14 , and closed when the hot water in the bath tub  14  is reheated.  
         [0050]    When the hot water pouring electromagnetic valves  65 ,  54  are opened under the state that the bath circulating pump  46  is stopped, as indicated by the heavy line S of FIG. 3, the hot water in the hot water supply tank  26  flows through a part of the hot water supply pipe  59  and the second bath water pipe  68  into the first bath water pipe  51 , and then it is passed through the flow switch  50 , the thermistor  49 , the water level sensor  48  and the filter  47  in the first bath water pipe  51  and poured into the bath tub  14 .  
         [0051]    At the stage that it is detected by the water level sensor  48  that a proper amount of hot water is filled from the hot water supply tank  26  into the bath tub  14 , the hot water pouring electromagnetic valves  65 ,  54  are closed. Thereafter, when it is detected by the thermistor  49  that the temperature of the hot water in the bath tub  14  is reduced to a proper temperature or less, the hot water or water in the bath tub  14  is heated (reheated) as described above, so that the temperature of the hot water in the bath tub  14  is kept to the proper value.  
         [0052]    The operation of pouring a proper amount of hot water at a proper temperature from the hot water supply tank  26  into the bath tub  14  and then heating (reheating) the hot water in the bath tub  14  for a required time so that the temperature of the hot water is kept to a proper value is referred to as “bath automatic operation”.  
         [0053]    Since this embodiment has the refrigerant circuit using natural refrigerant, the temperature of hot water stocked in the hot water supply tank  26  rises up to a higher temperature (about 90° C.) than that in the refrigerant circuit using freon-based refrigerant. Accordingly, by circulating the hot water in the hot water supply tank  26 , the hot water in the bath tub  14  can be reheated by the hot water thus circulated. Therefore, when the hot water or water in the bath tub is reheated without supplying hot water, the heat pump unit  11  is not needed to be actuated, so that the energy efficiency can be enhanced.  
         [0054]    The controller  15 A is disposed in the heat pump unit  11  to control the operation (containing the capacity control) and stop of the compressor  16 . The controller  15 B is disposed in the hot water supply unit  12  to control the actuation or stop of the circulating pump  34  for hot water supply and the circulating pump  46  for bath, the opening/closing operation of the first change-over electromagnetic valve  73 , the second change-over electromagnetic valve  74  and the hot water pouring electromagnetic valves  65 ,  54 , the opening degrees of the flow rate adjusting valve  35  and the mixing control valve  57 , etc. The controller  15 B is connected to the controller  15 A of the heat pump unit  11  through a communication line (not shown) to perform interactive communications with the controller  15 A, and also connected to remote controllers (kitchen remote controller KR and bath remote controller BR) in a wired or wireless style.  
         [0055]    In this embodiment, the top portion hot-water outlet pipe  40  having the first opening/closing valve  91  is connected to the top portion  26 A of the hot water supply tank  26 , and the intermediate portion hot-water outlet pipe  33  having the second opening/closing valve  92  is connected to the substantially intermediate portion  26 C between the top portion  26 A and the bottom portion  26 B of the hot water supply tank  26 . The first and second opening/closing valves  91 ,  92  connected to the pipes  40 ,  33  respectively are subjected to the opening/closing control through the controller  15 B in accordance with the hot-water temperature detected by the temperature sensor  94  disposed at the intermediate portion  26 C of the hot water supply tank  26 .  
         [0056]    For example, if the hot-water temperature detected by the temperature sensor  94  is equal to about 50° C., the hot-water temperature is approximately near to the required temperature at the tap  13 . In this case, the first opening/closing valve  91  is closed and the second opening/closing valve  92  is opened, so that the hot water at the intermediate portion  26 C can be taken out from the tap  13 .  
         [0057]    In this case, by controlling the opening degree of the mixing control valve  57 , the hot water from the hot water pipe  59  and the tap water from the second tap water pipe  62  are mixed with each other so that the temperature of the hot water to be supplied from the tap  13  is adjusted to a proper value (for example, 42° C.). An electric valve using a stepping motor or the like is used as the mixing control valve  57  to maintain high mixing precision.  
         [0058]    When the temperature of the hot water at the intermediate portion  26   c  is lower than that required for the tap  13 , the second opening/closing valve  92  is closed, and the first opening/closing valve  91  is opened, whereby the hot water at the top portion  26 A is taken out. In this case, by controlling the opening degree of the mixing control valve  57 , the hot water from the hot water pipe  59  and the tap water from the second tap water pipe  62  are also mixed with each other so that the temperature of the hot water to be supplied from the tap  13  is adjusted to a proper value (for example, 42° C.).  
         [0059]    According to this embodiment, when the hot water in the hot water supply tank  26  is used, the opening/closing operation of the first and second opening/closing valves  91 ,  92  is controlled in accordance with the temperature of the hot water at the intermediate portion  26 C of the hot water supply tank  26 , so that hot water whose temperature is near to the hot-water temperature required for the tap  13 , the bath tub  14  or the like can be taken out. Therefore, waste of energy can be prevented and the energy efficiency of the hot water supply apparatus  10  can be enhanced.  
         [0060]    Next, a second embodiment of the hot water supply apparatus in which the temperature of hot water to be supplied to the tap  13 , the bath tub  14 , etc. can be more finely controlled with no tap water will be described with reference to FIGS.  5  to  8 . The hot water supply apparatus of the second embodiment has substantially the same construction and operation as the first embodiment shown in FIGS.  1  to  4  except that a mixing valve  100  is used in place of the first and second opening/closing valves  91 ,  92  of the first embodiment. Accordingly, the same elements as those of FIGS.  1  to  4  are represented by the same reference numerals, and only the differences between the first and second embodiments will be described with omitting the duplicative description.  
         [0061]    In the second embodiment, an automatically-adjustable mixing valve  100  mixes the hot water from the top portion  26 A with the hot water from the intermediate portion  26 C of the hot water supply tank  26  (the mixing ratio of the hot water from the top portion  26 A and the hot water from the intermediate portion  26 C may be freely and automatically adjustable) is disposed at the joint portion between the intermediate portion hot-water outlet pipe  33  and the top portion hot-water outlet pipe  40  as shown in FIGS.  5  to  8 . Therefore, when the temperature of the hot water at the intermediate portion  26 C approximately approaches to the required temperature for the tap  13 , the bath tub  14  or the like, the mixing valve  100  is controlled to stop the mixing of the hot water from the top portion  26 A so that the hot water at the intermediate portion  26 C can be directly taken out from the tap  13  through the mixing valve  100 .  
         [0062]    When the temperature of the hot water at the intermediate portion  26 C is low, the mixing valve  100  mixes a larger amount of high-temperature hot water from the top portion  26 A with the hot water from the intermediate portion  26 C and then feeds out the mixed hot water to the joint pipe  59 . On the other hand, when the temperature of the hot water at the intermediate portion  26 C is high, the mixing valve  100  feeds the hot water from the intermediate portion  26 C to the joint pipe  59  while the hot water from the top portion  26 A is hardly mixed with the hot water from the intermediate portion  26 C.  
         [0063]    If the temperature of the hot water fed out from the mixing valve  100  is above the required temperature of the hot water at the tap  13 , the bath tub  14  or the like, the hot water from the hot water supply pipe  59  is mixed with the tap water from the second tap water pipe  62  by controlling the opening degree of the mixing control valve  57  so that the temperature of the hot water to be supplied from the tap  13 , the bath tub  14  is adjusted to a proper value (for example, 42° C.) as shown in FIGS. 6, 7.  
         [0064]    Accordingly, the hot water in the hot water supply tank  26  can be directly fed out to the tap  13 , the bath tub  14 , etc. without lowering the temperature of the hot water from the hot water supply tank  26  with tap water, so that waste of energy can be prevented and the energy efficiency of the hot water supply apparatus  10  can be enhanced.  
         [0065]    In this case, a wax valve may be used as the mixing valve  100 , and in this case the cost can be reduced.  
         [0066]    If the mixing ratio of the hot water from the top portion  26 A and the hot water from the intermediate portion  26 C is more finely adjusted in accordance with the temperature of the intermediate portion  26 C detected by the temperature sensor  94 , the temperature of the hot water to be supplied to the tap  13 , the bath tub  14 , etc. can be more finely adjusted. Further, if the mixing ratio of the hot water fed through the hot water supply pipe  59  and the tap water from the second tap water pipe  62  is more finely adjustable, the temperature of the hot water to be supplied to the tap  13 , the bath tub  14 , etc. can be further more finely adjusted. Further, as described above, if an electric valve using a stepping motor or the like is used as the mixing control valve  57 , the mixing precision can be kept high.  
         [0067]    Further, when the hot water in the bath tub  14  is reheated, the mixing valve  100  may be controlled to stop the supply of the hot water from both the top portion  26 A and the intermediate portion  26 C as shown in FIG. 8.  
         [0068]    The present invention is not limited to the above first and second embodiments, and various modifications may be made to the first and second embodiments without departing from the subject matter of the present invention.  
         [0069]    As described above, the above-described embodiments have the following effect.  
         [0070]    The heat exchanger  27  for hot water supply which can heat water by using refrigerant heat and stock the water thus heated (hot water) into the hot water supply tank  26  is disposed in the heat pump unit  11  having the compressor  16  for compressing refrigerant, the hot water supply tank  26  is disposed in the hot water supply unit  12 , and the heat exchanger  28  for bath heats the hot water or water in the bath tub  14  by using the heat of the hot water from the heat exchanger  27  for hot water supply to keep the temperature of the hot water. Therefore, the refrigerant pipe  19  in which high-pressure refrigerant flows is disposed only in the heat pump unit  11 , and it is not disposed between the heat pump unit  11  and the hot water supply unit  12 , so that the high-pressure refrigerant pipe can be prevented from being exposed to the outside, and the safety of the heat pump type hot water supply apparatus  10  can be enhanced.  
         [0071]    The heat exchanger  28  for bath can perform the heat exchange of hot water (or water) flowing in both the water introducing pipe  75  for introducing the hot water in the hot water supply tank  26  and the first water pipe  51  for bath for introducing the hot water (or water) in the bath tub  14  through the contact between the contact portions thereof in the heat exchanger  28  for bath. Therefore, the heat pump unit  11  is not needed to be actuated when the hot water in the bath tub is reheated, so that the energy efficiency can be enhanced. Further, even when one of the pipes (the water introducing pipe  75  and the first water pipe  51  for bath) is damaged, the other pipe is not influenced by the damage of the former pipe. For example, even when the first water pipe  51  for bath is damaged, for example, polluted hot water or water in the first water pipe  51  for bath is not contaminated into hot water or water in the water introducing pipe  75 . Accordingly, since the polluted hot water is prevented from flowing through the first water pipe  51  for bath into the hot water supply tank  26 , the hot water or water in the hot water supply tank  26  can be kept clean at all times.  
         [0072]    Since the refrigerant circuit using natural refrigerant is equipped, the temperature of the hot water stocked in the hot water supply tank  26  rises up to a higher temperature (about 90° C.) as compared with that in the refrigerant circuit using freon-based refrigerant. Accordingly, the temperature of the hot water at the substantially intermediate portion  26 C of the hot water supply tank  26  is also frequently kept to about 50° C. If so, the hot water at the intermediate portion  26 C can be directly used because the temperature of the hot water required for the tap  13  is frequently equal to about 42 to 43° C.  
         [0073]    In the above embodiments, the hot water to be joined to the hot water supplied from the top portion  26 A of the hot water supply tank  26  is supplied from only one position (the intermediate portion  26 C of the hot water supply tank  26 ) through only one outlet pipe (the intermediate portion hot-water outlet pipe  33 ). However, the hot water to be joined may be supplied from any number of intermediate positions between the top portion  26 A and the bottom portion  26 C through any number of intermediate portion hot-water outlet pipes. If plural outlet pipes are provided, each pipe is equipped with an opening/closing valve connected to the controller  15 B (in the first embodiment), or connected to the mixing valve  100 . According to the position from which the hot water to be joined is supplied, the temperature of the hot water to be supplied to the tap  13 , the bath tub  14 , etc. can be more finely adjusted.  
         [0074]    According to the present invention, the refrigerant circuit using natural refrigerant is equipped, and thus the temperature of hot water stocked in the hot water supply tank rises up to a higher temperature than the refrigerant circuit using freon-based refrigerant. Accordingly, the temperature of hot water to be supplied through the intermediate hot water outlet pipe is very high. However, the opening/closing operation of the first and second opening valves or the mixing operation of the mixing valve is controlled in accordance with the temperature of hot water at the intermediate portion of the hot water supply tank to select one of the hot water supplied through the intermediate portion hot water outlet pipe and the hot water supplied through the top portion hot water outlet pile or to adjust the mixing ratio of the former hot water and the latter hot water, so that it is avoided to mix unnecessary tap water with hot water and thus the energy efficiency of the hot water supply apparatus can be enhanced.