JP2006003077A - Heat pump type hot water supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type hot water supply apparatus capable of certainly preventing freezing of a circulation path without using hot water inside a hot water storage tank. <P>SOLUTION: This heat pump type hot water supply apparatus has the hot water storage tank 1, and the circulation path 4 connecting an intake 2 provided on a bottom part side of the hot water storage tank 1 and a hot water supply port 3 provided on a top part side of the hot water storage tank 1. A pump 5 and a heat exchange path 6 are interposed in the circulation path 4, and hot water supply operation wherein the heat exchange path 6 is heated by a heat pump type heating source and wherein unheated water from the intake 2 is boiled to a prescribed temperature by the heat exchange path 6 to make hot water of the prescribed temperature flow back to the hot water supply port 3 is performed. The heat pump type hot water supply apparatus has a bypass circuit 17 bypassing the intake 2 and the hot water supply port 3, and a changeover means 19 changing over between state allowing hot water supply operation and a water circulation state through the bypass circuit 17. A control means decides necessity of freeze prevention in time of a hot water supply operation stop. When it is necessary to perform freeze prevention operation, the control means operates the changeover means 19 to bring a state into the water circulation state, and drives the pump 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat pump hot water supply apparatus.

The heat pump type hot water supply apparatus has a hot water storage tank, a circulation path connecting a water intake provided on the bottom side of the hot water storage tank, and a hot water supply opening provided on the top side of the hot water storage tank. The heat exchange path is heated by a heat pump heating source, the unheated water from the water intake is boiled to a predetermined temperature in the heat exchange path, and hot water at a predetermined temperature is supplied to the hot water inlet What was comprised so that the hot-water supply operation which makes it return may be conventionally known (for example, refer patent document 1).
Japanese Patent Laid-Open No. 11-14141

  However, in the heat pump hot water supply apparatus, when the outside air is cold in winter, etc., if the above hot water supply operation is stopped for a long time, the circulation path may be frozen. It was difficult to restart. Therefore, it is necessary not to freeze the circulation path, and conventionally, a method of preventing freezing of the circulation path using hot water in the hot water storage tank has been adopted. However, it is economically problematic to use hot water in the hot water storage tank. In addition, it is conceivable to provide a heating means specially for heating the circulation path, but in this case, the entire apparatus becomes larger and more complicated, which further increases the cost.

  The present invention has been made to solve the above-described conventional drawbacks, and its object is to provide a heat pump type that can reliably prevent freezing of the circulation path without using hot water in the hot water storage tank. The object is to provide a water heater.

Accordingly, the heat pump type hot water supply apparatus according to claim 1 includes a hot water storage tank 1, a circulation path 4 connecting a water intake port 2 provided on the bottom side of the hot water storage tank 1 and a hot water supply port 3 provided on the top side of the hot water storage tank 1. A circulation path 4 with a pump and a heat exchange path 6, the heat exchange path 6 is heated by a heat pump heating source, and unheated water from the water intake 2 is passed to the heat exchange path 6. In the heat pump hot water supply apparatus configured to perform a hot water supply operation in which the hot water is boiled to a predetermined temperature and the hot water at the predetermined temperature is returned to the hot water supply port 3, a bypass circuit 17 that bypasses the intake port 2 and the hot water supply port 3; The switching means 19 for switching between the hot water supply operation state and the water circulation state passing through the bypass circuit 17 and the switching means when it is determined that the freeze prevention operation needs to be performed by determining whether or not the freeze prevention is necessary when the hot water supply operation is stopped. 19 is activated With a water circulation state is characterized by comprising a control means 42 for driving the pump 5.

  In the heat pump type hot water supply apparatus according to the first aspect, when it is determined that it is necessary to perform the freeze prevention operation when the hot water supply operation is stopped, the bypass circuit 17 is opened and the pump 5 is operated so that the inside of the circulation path 4 Since water circulates, the circulation path 4 can be prevented from freezing. In this water circulation state, the hot water stored in the hot water storage tank 1 is not used because the bypass circuit 17 bypasses the intake port 2 and the hot water supply port 3 of the hot water storage tank 1. That is, freezing can be prevented without cooling the hot water stored in the hot water storage tank 1, and the hot water stored in the hot water storage tank 1 can be used without waste in wintertime where a lot of hot water is required.

  In the heat pump hot water supply apparatus according to claim 2, the control means 42 determines that it is necessary to perform the freeze prevention operation when the temperature of the circulation path 4 is lower than a preset freeze prevention judgment temperature. It is characterized by.

  In the heat pump type hot water supply apparatus according to the second aspect, since the necessity determination of the antifreezing operation is performed based on the temperature of the circulation path 4, the determination can be surely performed, and the freezing can be stably prevented. It can be performed.

  Furthermore, when the temperature of the water in the circulation path 4 is lower than the de-icing determination temperature set lower than the anti-freezing determination temperature, the heat pump type hot water supply apparatus according to claim 3 supplies the water in the circulation path 4 to the water. Another heating means 45 for heating is provided.

  In the heat pump type hot water supply apparatus according to the third aspect, the water in the circulation path 4 can be heated by the heating means 45 in a cold region where the circulation path 4 cannot cope with the water in the circulation path 4. Even in a state where the flow rate is extremely lowered, the circulation path 4 can be reliably prevented from freezing.

  The heat pump hot water supply apparatus according to claim 4 is characterized in that the heating means 45 is heat generated from the compressor 20.

  In the heat pump type hot water supply apparatus according to the fourth aspect, heat generated from the compressor 20 provided in the heat pump type hot water supply apparatus, for example, heat generated during the phase loss operation, or heat from the heater for preventing the refrigerant stagnation can be used. For this reason, the entire apparatus can be implemented without any modification to a complicated structure, and the manufacturing cost can be reduced.

  The heat pump type hot water supply apparatus according to claim 5 is characterized in that the heating means 45 is a heat pump heat source of the heat exchange path 6.

  In the heat pump hot water supply apparatus according to the fifth aspect, it is not necessary to use another configuration for heating, and it can be used safely and can be implemented at low cost.

  The heat pump type hot water supply apparatus according to claim 6 is characterized in that the heating means 45 is a heater.

  In the heat pump type hot water supply apparatus of the sixth aspect, since the heater is used as the heating means 45, the water in the circulation path 4 can be heated easily and reliably and cleanly.

  In the heat pump type hot water supply apparatus according to the first aspect, water is circulated in the circulation path when it is determined that the freeze prevention operation is necessary when the hot water supply operation is stopped, so that the circulation path can be prevented from freezing. . In this water circulation state, the hot water in the hot water storage tank does not flow into the circulation path and the hot water stored in the hot water storage tank is not used because the bypass circuit bypasses the intake port and hot water supply port of the hot water storage tank. That is, freezing can be prevented without cooling the hot water stored in the hot water storage tank, and the hot water stored in the hot water storage tank can be used without waste in winter and the like where a lot of hot water is required. Further, it is not necessary to provide a separate heating means, and the entire apparatus is neither enlarged nor complicated, and the cost is not increased.

  In the heat pump type hot water supply apparatus according to the second aspect of the present invention, the necessity of the freeze prevention operation is determined based on the temperature of the circulation path, so that the determination can be made reliably and stable freeze prevention is performed. be able to.

  In the heat pump type hot water supply apparatus according to claim 3, the water in the circulation path can be heated by the heating means in a cold district that cannot be handled by the circulation of the water in the circulation path, and thereby the outside air temperature is extremely reduced. Even in the state, the circulation path can be reliably prevented from freezing.

  In the heat pump type hot water supply apparatus of claim 4, the heat source from the compressor provided in the heat pump type hot water supply apparatus can be used. Therefore, the entire apparatus can be implemented without any modification to any complicated structure, and the production cost can be reduced. Reduction can be achieved.

  In the heat pump hot water supply apparatus according to the fifth aspect, it is not necessary to use another configuration for heating, and it can be used safely and can be implemented at low cost.

  In the heat pump type hot water supply apparatus according to the sixth aspect, since the heater is used as the heating means, the water in the circulation path can be heated easily and reliably and cleanly.

A specific embodiment of the heat pump hot water supply apparatus of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a circuit diagram showing a water system and a refrigerant system of a heat pump type hot water supply apparatus. That is, the water system includes a hot water storage tank 1 and a circulation path 4 that connects a water intake port 2 provided on the bottom side of the hot water storage tank 1 and a hot water supply port 3 provided on the top side of the hot water storage tank 1. The circulation path 4 is provided with a pump 5 and a heat exchange path 6, and the water intake port 2 of the hot water storage tank 1 and the pump 5 are connected in communication by a water intake pipe 8. The pump 5 and the heat exchange path 6 are connected to each other. A pipe 11 having a valve 10 is connected in communication. Here, the heat exchange path 6 constitutes a part of the water heat exchanger 9 that functions as a condenser of the refrigerant system circuit described below, and is provided so as to be able to exchange heat with the condensed refrigerant. Furthermore, a pipe 12 connected to a faucet (not shown) such as a kitchen is connected to the hot water supply port 3, and the pipe 12 and the heat exchange path 6 are connected via a pipe 13. Therefore, the circulation path 4 is formed by the intake pipe 8, the pump 5, the heat exchange path 6, the pipe 13, and the like. A water supply port 14 is provided on the bottom side of the hot water storage tank 1, and a water supply pipe 15 is connected to the water supply port 14 for supplying city water to the hot water storage tank 1 while applying a supply water pressure. . A temperature detection thermistor 16 is attached to the lower part of the hot water storage tank 1.

  Further, a bypass circuit 17 that bypasses the water intake port 2 and the hot water supply port 3 is provided, and a three-way valve 18 is disposed at a connection portion between the bypass circuit 17 and the pipe 13. That is, the three-way valve 18 serves as a switching means 19 for switching between a hot water supply operation state and a water circulation state passing through the bypass circuit 17. Here, the hot water supply operation state refers to an operation state in which unheated water from the water intake port 2 is boiled to a predetermined temperature in the heat exchange path 6 and hot water at a predetermined temperature is returned to the hot water supply port 3. The state refers to a state in which hot water circulates in the circulation path 4 using the bypass circuit 17 without returning the hot water to the hot water supply port 3.

  Next, the refrigerant system will be described. These are mainly provided on the outdoor side, and include a compressor 20, an outdoor heat exchanger 21, and a four-way switching valve 22. One primary port of the four-way switching valve 22 and the compressor 20 are connected by a discharge pipe 24 provided with an on-off valve 23, and the other primary port of the four-way switching valve 22 connects the suction pipe 25. To the compressor 20. One secondary port of the four-way switching valve 22 is connected to the indoor heat exchanger 26 via a first gas pipe 27, and the other secondary port of the four-way switching valve 22 is connected to the outdoor heat exchanger 21. To the second gas pipe 28. Furthermore, the outdoor heat exchanger 21 and the indoor heat exchanger 26 are connected via a first liquid pipe 29. Electric expansion valves 30 and 31 are interposed in the first liquid pipe 29 in the vicinity of the outdoor heat exchanger 21 and the indoor heat exchanger 26, respectively.

  A third gas pipe 32 connected to the discharge pipe 24 is connected to one end side of the water heat exchanger 9, and the first liquid pipe 29 is connected to the other end side of the water heat exchanger 9. The 2nd liquid pipe 33 connected with is connected. An electric expansion valve 34 is interposed in the second liquid pipe 33. The refrigerant quantity is controlled by appropriately controlling the opening and closing of the electric expansion valves 30, 31, and 34. Further, this control may be performed by the control means 42 described later or may be performed by other control means using a microcomputer or the like. The compressor 20 is provided with a temperature detection thermistor 35.

  By the way, in this heat pump type hot water supply apparatus, as shown in FIG. 2, the detection means 40 for detecting the temperature of the circulation path 4, and the temperature detected by the detection means 40 and a preset set temperature are compared. And a control means (hot water supply determination controller) 42 for driving the pump 5 as well as operating the switching means 19 constituted by the three-way valve 18 based on the result of the comparison means 41. . The switching means 19 and the control means 42 are configured using a microcomputer having a CPU, a memory, an input / output interface, and the like.

  Specifically, as shown in FIG. 1, the detection means 40 includes a temperature detection thermistor 43 on the intake side that detects the temperature of the intake pipe 8 and a hot water supply that detects the temperature of the pipe 13 on the outlet side of the heat exchange path 6. The temperature detection thermistor 44 on the side is provided, and data (detection temperature) from each thermistor 43, 44 is input to the comparison means 41 (not shown in FIG. 1). In this case, the temperature detected by the temperature detection thermistor 43 is To, and the temperature detected by the temperature detection thermistor 44 is Ti. That is, the comparison means 41 compares the preset antifreezing judgment temperature with at least one of these To and Ti. The control means 42 determines whether or not it is necessary to prevent freezing according to this comparison, and operates (drives) the switching means 19 and the pump 5. Here, the freeze prevention determination temperature can be arbitrarily set, and is a temperature at which the circulation path 4 may freeze when water is not circulating in the circulation path 4. Further, the comparison means 41 is set so as to compare the de-icing determination temperature set in advance with the detected temperature and to input the result to the control means 42. Here, the de-icing determination temperature is a temperature that is lower than the anti-freezing determination temperature, and is a temperature at which the circulation path 4 may be frozen even if water circulates in the circulation path 4. Therefore, a heating means 45 for heating the water in the circulation path 4 is provided in this apparatus. In this case, as the heating unit 45, heat generated from the compressor 20, for example, heat generated during a phase-losing operation or heat from a refrigerant stagnation heater is used.

  Next, the steady hot water supply operation state of the apparatus configured as described above will be described. First, the open / close valve 23 is closed, the four-way switching valve 22 is switched so that the water heat exchanger 9 functions as a condenser and the outdoor heat exchanger 21 functions as an evaporator. 20 is driven. As a result, the refrigerant flows from the compressor 20 to the water heat exchanger 9 and the outdoor heat exchanger 21. In this case, the three-way valve 18 is operated, the bypass circuit 17 is closed, the pipe 13 and the hot water supply port 3 are communicated, and the water intake 2 of the hot water storage tank 1 is opened, and the pump 5 is operated. Let Then, the stored water flows out from the water intake 2 at the bottom of the hot water storage tank 1 and flows through the heat exchange path 6 via the water intake pipe 8. At this time, this water is heated in the water heat exchanger 9 functioning as a condenser, and returned to the upper part in the hot water storage tank 1 through the pipe 13. By continuously performing such an operation, hot water is gradually stored from the upper end side to the lower end side of the hot water storage tank 1, and the hot water supply operation state continues.

  By the way, in this apparatus, indoor air conditioning can also be performed. First, the heating operation will be described. The third gas pipe 32 and the second liquid pipe 33 are shut off, the open / close valve 23 is opened, and the indoor heat exchanger 26 functions as a condenser. The heat exchanger 21 is set to function as an evaporator. That is, when the compressor 20 is driven, the refrigerant flows from the compressor 20 to the indoor heat exchanger 26 and the outdoor heat exchanger 21, and the outdoor heat exchanger 21 functions as an evaporator and the indoor heat exchanger. 26 functions as a condenser, and thereby heating operation can be performed. In addition, by switching the four-way switching valve 22 so that the outdoor heat exchanger 21 functions as a condenser and the indoor heat exchanger 26 functions as an evaporator, a cooling operation can be performed.

  Next, the operation at the time of stopping the hot water supply operation which is characteristic in this embodiment will be described with reference to the flowchart shown in FIG. When the hot water supply operation is stopped, the control of the bypass valve (three-way valve 18) is started (step S1), and in step S2, the water temperature Ti and To in the circulation path 4 is detected by the detection means 40 and is determined. The data is input to 41. Next, in step S3, the detected Ti and To are compared with the freeze prevention determination temperature. If Ti and To are lower than the freeze prevention determination temperature, the flow proceeds to step S4 and the bypass circuit 17 is opened (3). And the pump 5 is turned on. Thereby, water is circulated through the circulation path 4 to prevent freezing. If the temperature exceeds the freezing prevention determination temperature, the process proceeds to step S5, where the pump 5 is turned off and the three-way valve 18 is directly passed (a hot water supply operation possible state in which the bypass circuit 17 is closed). .

  Next, the process proceeds to step S6, where Ti and To are compared with the de-icing determination temperature. If Ti and To are lower than the de-icing determination temperature, the process proceeds to step S7 and the preheating that is the heating means 45 is performed. The heater (here, the preheating heater is a heat source from the compressor 20) is turned on, and the water in the circulation path 4 is heated by heat transfer from there. On the other hand, when Ti and To exceed the ice melting determination temperature, the preheater heater is turned off as in step S8. Thereafter, the process proceeds to step S1, and thereafter this control is repeated.

  By repeating the control as described above, when the hot water supply operation is stopped, if the temperature falls below the freezing prevention determination temperature, water can flow through the circulation path 4 to prevent freezing, and this circulation is insufficient. Thus, when the water in the circulation path 4 falls below the de-icing determination temperature at which the water may freeze, the heating means 45 heats the water in the circulation path 4. Therefore, it is possible to reliably prevent the circulation path 4 from freezing. Further, when the temperature exceeds the freezing prevention determination temperature, water does not flow into the circulation path 4 and is lower than the freezing prevention determination temperature, but when the temperature exceeds the defrosting determination temperature, the water in the circulation path 4 Although it circulates, the heating means 45 does not heat the water in the circulation path 4. In other words, useless power is not consumed, which is efficient.

  As the heating means 45, for example, an electric heater can be used instead of the heat generated from the compressor 20 (the refrigerant stagnation prevention heater shown in FIG. 3 or the heat generation during the phase loss operation). In addition, as a specific arrangement | positioning site | part of this heater, although it can be set as the exit side of the heat exchange path 6, for example, as long as it is a site | part which can heat the water in the circulation path 4, it may be anywhere. Further, as the heating means 45, a heat source of the heat exchange path 6 that is a heat pump type heat source (a heat source from the water heat exchanger 9 functioning as a condenser) may be used.

  By the way, even when other heaters or the heat source of the heat exchange path 6 are used as the heating means 45 without using the heat from the compressor 20, the operation in the hot water supply stop state is shown in the flowchart of FIG. This is the same as shown. That is, instead of the preheating heater ON or OFF in FIG. 3, the heaters that are other heating means may be turned on or off and the heat exchange path 6 may or may not function as a condenser. Therefore, in these cases, it is possible to reliably prevent freezing, and when the temperature exceeds the freezing prevention determination temperature, when water does not flow into the circulation path 4 and further exceeds the defrosting determination temperature, There is no heating of the water in the circulation path 4 by these heating means 45.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. That is, in the present embodiment, as the temperature detection part to be compared with the freeze prevention judgment temperature, the intake pipe 8 and the pipe 13 of the circulation path 4 are used, but in this case, even if the temperature of each pipe 8, 13 itself, It may be the direct temperature of the water in each tube 8,13. Furthermore, the temperature in the atmosphere where this circulation path 4 is arrange | positioned may be sufficient. That is, it suffices if it is possible to determine whether or not it is necessary to prevent freezing when the hot water supply operation is stopped, and the detection part of the detection temperature that is the determination criterion for this necessity is not limited. In this case, of course, the set temperatures for the freeze prevention determination temperature and the de-icing determination temperature are different depending on the detection part, and the determination temperature is based on this detection part.

It is a water system and refrigerant system circuit diagram of a heat pump type hot water supply apparatus which is one embodiment of the present invention. It is a simplified block diagram of a heat pump type hot water supply apparatus. It is a control flowchart figure at the time of hot water supply operation stop.

Explanation of symbols

1. Hot water storage tank, 2. Water intake port, 3. Hot water supply port, 4. Circulation path, 5. Pump, 6. Heat exchange path, 17. Bypass circuit, 19. Switching means, 20. .Compressor 42 ..Control means 45 ..Heating means

Claims (6)

  A circulation path (4) connecting the hot water storage tank (1), a water intake (2) provided on the bottom side of the hot water storage tank (1) and a hot water supply port (3) provided on the top side of the hot water storage tank (1). The circulation path (4) is provided with a pump (5) and a heat exchange path (6), the heat exchange path (6) is heated by a heat pump heating source, and the water intake (2) In a heat pump hot water supply apparatus configured to perform a hot water supply operation in which unheated water from the water is boiled to a predetermined temperature in the heat exchange path (6), and hot water at a predetermined temperature is returned to the hot water supply port (3). A bypass circuit (17) for bypassing the intake port (2) and the hot water supply port (3); a switching means (19) for switching between a hot water supply operation state and a water circulation state passing through the bypass circuit (17); Judged that it is necessary to perform anti-freezing operation by determining whether or not anti-freezing is necessary The heat pump type hot water supply device, characterized in that a control means (42) for driving the pump with come to actuate said switching means (19) for water circulation state.   The control means (42) determines that it is necessary to perform the freeze prevention operation when the temperature of the water in the circulation path (4) is lower than a preset freeze prevention judgment temperature. The heat pump type hot water supply apparatus according to claim 1.   Other heating means that heats the water in the circulation path (4) when the temperature of the water in the circulation path (4) is lower than the de-icing determination temperature set lower than the anti-freezing determination temperature ( 45). The heat pump type hot water supply apparatus according to claim 1 or 2, characterized in that 45) is provided.   The heat pump type hot water supply apparatus according to claim 3, wherein the heating means (45) is heat generated from the compressor (20).   The heat pump type hot water supply device according to claim 3, wherein the heating means (45) is a heat pump heat source of the heat exchange path (6).   The heat pump type hot water supply apparatus according to claim 3, wherein the heating means (45) is a heater.