JP2011064394A - Hot water storage tank with heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage tank with a heater capable of cutting power transmission to an electric heater in safety even if a temperature of hot-water/water in a hot water storage tank is abnormally increased. <P>SOLUTION: The hot water storage tank with the heater includes a three-phase heater 15a (15b) composed of three heater elements 49a-49c for heating hot-water/water in the hot water storage tank, relays 51a-51c disposed between each of the heater elements and the three-phase power source for switching on/off-operations of power supply to the heater, a main connecting wire 53 for switching on/off-operations of the relays, first to third overtemperature preventing devices 50a-50c disposed between the heater elements and the three-phase power source, a forth overtemperature preventing device 50d disposed on the main connecting wire, and the first to forth overtemperature preventing devices cut power transmission when it is detected that a temperature in the hot water storage tank is a prescribed temperature or higher. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a hot water storage tank having a heater for heating hot water.

  Conventionally, heating equipment using combustion fuels such as oil and gas as the heat source has occupied the majority, but in recent years the heating market using heat pump technology has expanded rapidly. Also, some conventional air conditioners can use both cooling and heating by utilizing heat pump technology.

  However, the conventional air conditioner alone has a problem that the feet are difficult to warm during heating, and a hot water heater using heat pump technology has been developed to solve the problem (see, for example, Patent Document 1). In the hot water heating apparatus described in Patent Document 1, heat exchange is performed between a high-temperature refrigerant and hot water, and the hot water heated by heat exchange is sent to a heating terminal such as a floor heating panel to perform heating.

  FIG. 9 is a configuration diagram of a conventional heat pump hot water heater. As shown in FIG. 9, the conventional heat pump type hot water heating apparatus has a compressor 101, a refrigerant flow path of a water / refrigerant heat exchanger 102, a decompression device 103, and an evaporator 104 that are sequentially annularly formed by a refrigerant pipe 105. The refrigeration cycle 106 was connected to form a boiling cycle by sequentially connecting the water flow path of the water-refrigerant heat exchanger 102, the boiling pump 109, and the hot water storage tank 110 in an annular manner.

  When the heating operation is started, the hot water circulation pump 111 is driven to send the hot water in the hot water storage tank 110 to the heating terminal 108. Further, when performing a hot water supply operation, hot water is exchanged with hot water in the hot water storage tank 110 by a hot water supply heat exchanger 112 provided in the hot water storage tank 110, and the hot water is supplied to the hot water supply terminal.

  The hot water storage tank 110 is provided with an electric heater 115 to heat the hot water in the hot water storage tank 110.

JP 2008-39305 A

  However, in the hot water storage tank equipped with the electric heater of the conventional configuration, the electric heater may break down or some abnormality may occur, and the hot water in the hot water storage tank may become an abnormal temperature. It had the problem of not becoming.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a hot water storage tank with a heater that can safely cut off energization to an electric heater even when hot water in the hot water storage tank becomes abnormally high in temperature. And

In order to solve the above-described conventional problems, a hot water storage tank with a heater according to the present invention includes a hot water storage tank for storing hot water, a three-phase heater composed of three heater elements for heating the hot water in the hot water storage tank, and each heater. Turn on / off the power supply to the heater between the element and the three-phase power supply
FF relay, main connection line for switching ON and OFF of the relay, first to third overheat prevention devices between each heater element and the three-phase power source, and the main connection line 4 and the first to third overheat prevention devices are configured to cut off power to the heater element when the temperature in the hot water storage tank detects a predetermined temperature or higher. The fourth overheat prevention device is characterized in that the energization to the main connection line is cut off when the temperature in the hot water storage tank is detected to be equal to or higher than a predetermined temperature.

  Thereby, when the first to third overheat prevention devices detect an abnormal temperature, not only the power supply to the three heater elements is directly cut off, but also the first to third overheat prevention devices. If the fourth overheat prevention device detects an abnormal temperature by providing the fourth overheat prevention device on the main connection line for sending signals to the three relays even if the Since all the two relays can be turned off, the power supply to the heater can be cut off reliably.

  ADVANTAGE OF THE INVENTION This invention can provide the hot water storage tank with a heater which can interrupt | block the electricity supply to an electric heater safely even if the hot water in a hot water storage tank becomes abnormally high temperature.

The block diagram of the heat pump type hot water heating apparatus in Embodiment 1 of this invention Partial sectional view of the hot water storage tank in the first embodiment AA sectional view in the first embodiment BB sectional view in the first embodiment Circuit diagram of heater in the first embodiment The principal part enlarged view of the hot water storage tank in Embodiment 1 Driving timing chart of the flow rate adjusting valve in the first embodiment Characteristic diagram of flow regulating valve in embodiment 1 Configuration diagram of conventional heat pump hot water heater

  A hot water storage tank with a heater according to a first aspect of the invention is a hot water storage tank for storing hot water, a three-phase heater composed of three heater elements for heating the hot water in the hot water storage tank, and between each heater element and a three-phase power source. Relays for turning the power supply to the heater ON / OFF, main connection lines for switching the relay ON and OFF, and the first to third temperature overheating between each heater element and the three-phase power source And a fourth overheat prevention device on the main connection line, and the first to third overheat prevention devices are connected to the heater element when the temperature in the hot water storage tank detects a predetermined temperature or higher. The fourth overheat prevention device is configured to cut off the electric power, and is characterized in that the energization to the main connection line is cut off when the temperature in the hot water storage tank detects a predetermined temperature or higher.

  Thereby, when the first to third overheat prevention devices detect an abnormal temperature, not only the power supply to the three heater elements is directly cut off, but also the first to third overheat prevention devices. If the fourth overheat prevention device detects an abnormal temperature by providing the fourth overheat prevention device on the main connection line for sending signals to the three relays even if the Since all the two relays can be turned off, the power supply to the heater can be cut off reliably.

In the hot water storage tank with a heater according to the second invention, in particular, in the first invention, the power to the heater element is interrupted by any one of the first to third overheat prevention devices. Before connecting the safety control device to detect the heat and shutting off the energization to the relay with the fourth overheat prevention device, the power to the heater element was cut off with the overtemperature prevention device connected to the safety control device When the safety control device detects this, the fourth over-temperature prevention device cuts off the power supply to the relay.

  As a result, it is not known which overheat prevention device works first, but if an abnormal temperature is detected, the first to third overheat prevention devices shut off the power to the heater elements in order. The safety control device is connected to only one of the first to third overheat prevention devices, and when the overtemperature prevention device to which the safety control device is connected operates, the fourth Since all three relays can be turned off by cutting off the energization with the overtemperature prevention device, the power to the heater element can be cut off reliably. In addition, since it is not necessary to monitor all three overheating prevention devices, the power supply can be easily routed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a heat pump type hot water heating apparatus according to Embodiment 1 of the present invention. First, the structure of the heat pump type hot water heating apparatus in the present embodiment will be described with reference to FIG. The heat pump type hot water heating apparatus of the present embodiment is composed of three units of a heat pump unit A, a heat exchange unit B, and a tank unit C. The heat pump unit A is installed outdoors, and the heat exchange unit B and the tank unit. C is installed indoors.

  And the heat pump type hot water heating apparatus of the present embodiment includes a compressor 1 that compresses the refrigerant and discharges the high-temperature refrigerant, a water-refrigerant heat exchanger 2 that generates heat by exchanging heat between the water and the high-temperature refrigerant, A decompression device 3 for decompressing the refrigerant, an evaporator 4a for exchanging heat between air and the refrigerant, and a four-way valve 5 for changing the flow path of the refrigerant are provided. And the compressor 1, the water refrigerant | coolant heat exchanger 2, the decompression device 3, the evaporator 4a, and the four-way valve 5 are cyclically connected by the refrigerant | coolant piping 6, and the heat pump cycle is comprised. Furthermore, the ventilation fan 4b which ventilates the evaporator 4a and accelerates | stimulates heat exchange with air and a refrigerant | coolant is provided. In addition, as a form of the water-refrigerant heat exchanger 2, there is no problem even if it is either a plate type or a double pipe type.

  Moreover, the water refrigerant heat exchanger 2 is disposed in the heat exchange unit B, and the compressor 1, the pressure reducing device 3, the evaporator 4a, and the four-way valve 5 are disposed in the heat pump unit A, so that indoors and outdoors are refrigerants. Since it will be connected by piping, even if it is a case where a heat pump type hot water heating apparatus is installed in a cold district, there is little possibility that refrigerant piping will freeze. In this embodiment, the refrigerant is described as R410A. However, the present invention is not limited to this, and for example, a fluorocarbon refrigerant such as R407C can be used.

  The tank unit C has a hot water storage tank 7 for storing hot water, and the interior of the hot water storage tank 7 is divided into upper and lower portions by a partition plate 8. In the hot water storage tank 7, the hot water supply hot water part 7 a is above the partition plate 8, and the hot water hot part 7 b is below the partition plate 8. By dividing the interior of the hot water storage tank 7 in this way, the hot water in the hot water supply hot water section 7a can be used for heat exchange during hot water supply, and the hot water in the hot water supply section 7b is used during heating. Can be used to circulate to the heating terminal.

  Furthermore, a boiling pump 9 for sending low-temperature water from the lower part of the hot water storage tank 7 to the water-refrigerant heat exchanger 2 is provided. Then, by driving the boiling pump 9, low temperature water is sent from the water outlet 10 below the hot water storage tank 7 to the water refrigerant heat exchanger 2, and the water refrigerant heat exchanger 2 generates heat from the refrigerant to generate hot water. ing.

  Further, the hot water generated by the water-refrigerant heat exchanger 2 is returned to the hot water inlet 11 below the partition plate 8 and at a substantially intermediate portion of the hot water storage tank 7. Thus, in this Embodiment, the hot water storage tank 7, the water outlet 10, the boiling pump 9, the water refrigerant | coolant heat exchanger 2, and the hot water inlet 11 are connected with piping, and the boiling cycle is comprised. The boiling pump 9 is an AC pump with a constant circulation flow rate.

  FIG. 2 is a partial cross-sectional view of the hot water storage tank 7, and FIG. 3 is a cross-sectional view taken along AA in FIG. As shown in FIGS. 2 and 3, a partition plate 8 is disposed at a substantially intermediate portion of the hot water storage tank 7. Moreover, as shown in FIG. 3, the partition plate 8 is provided with a plurality of openings 8a. When the hot water heated in the heat pump cycle returns to the heating hot water section 7b, the opening 8a passes through the openings 8a. Hot water flows into the hot water supply hot water section 7a. Although four openings 8a are provided in the present embodiment, the present invention is not limited to this.

  Further, the periphery of the partition plate 8 and the inner wall of the hot water storage tank 7 are welded at four welding points 8b, and there is a gap between the periphery of the partition plate 8 other than the welded portion and the hot water storage tank 7. . The hot water returned from the hot water inlet 11 passes through the gap formed between the periphery of the partition plate 8 and the inner wall of the hot water storage tank 7 and flows into the hot water supply hot water section 7a. In this embodiment, four welding points 8b are provided, but the present invention is not limited to this.

  4 is a cross-sectional view taken along the line BB in FIG. As shown in FIG. 4, the partition plate 8 is welded via the hot water storage tank 7 and the arm 8c. The arm 8c is configured to form an angle θ so as to be separated from the inner wall of the hot water storage tank 7, and is welded to the hot water storage tank 7 at a welding point 8d. Further, the partition plate 8 and the arm 8c are welded at a welding point 8b.

  Stainless steel is used for the hot water storage tank 7 and the partition plate 8 from the viewpoint of corrosion resistance. However, if the gap between the stainless steels is narrow, gap corrosion occurs, and as a result, water leakage may occur. Therefore, in the present embodiment, a predetermined gap La is provided between the partition plate 8 and the inner wall of the hot water storage tank 7, and a predetermined gap Lb is provided between the partition plate 8 and the arm 8c. In this embodiment, a gap of 50 μm or more is taken. Since the gap corrosion occurs when the gap between the stainless steels is less than 40 μm, the predetermined gaps La and Lb can be reliably prevented by setting the gaps La and Lb to 40 μm or more.

  FIG. 5 is a circuit diagram of the upper heater 15a (or the lower heater 15b). Each of the upper heater 15a and the lower heater 15b includes three heater elements 49a to 49c. Further, between the three-phase power source 52 and each of the heater elements 49a to 49c, when detecting that the temperature has risen abnormally, the internal contacts are released and the first to third overtemperatures are cut off. Ascending prevention devices 50a to 50c and relays 51a to 51c which are ON / OFF means for turning ON / OFF the power supply to the heater are provided. Furthermore, the main connection line 53 for switching ON and OFF of the relays 51 a to 51 c is provided, and the main connection line 53 is also provided with an overtemperature preventing device 50 d. In addition, a safety control device 54 is connected to the third overheat prevention device.

  FIG. 6 is a perspective view of a main part of the hot water storage tank 7. As shown in FIG. 6, the hot water storage tank 7 is provided with temperature rise prevention devices 50a to 50d in the vicinity of the upper heater 15a or the lower heater 15b so as to detect the temperature of the hot water.

  Further, a temperature sensor 12 a that detects the incoming water temperature is provided at the water side inlet of the water refrigerant heat exchanger 2, and a temperature sensor 12 b that detects the tapping temperature is provided at the water side outlet of the water refrigerant heat exchanger 2. Moreover, the flow switch 13 for detecting that hot water is flowing in the boiling cycle is provided.

  7A is a configuration front view of the heat exchange unit B, and FIG. 7B is a configuration perspective view of the heat exchange unit B. As shown in FIGS. 7A and 7B, the flow switch 13 is arranged above the boiling pump 9 in the heat exchange unit B. By arranging the flow switch 13 above the boiling pump 9 in this way, it is possible to detect that the boiling pump 9 is not operating normally unless the flow switch 13 detects the flow of hot water. it can.

  Further, an overpressure relief valve 14 for adjusting the pressure in the boiling cycle is provided. When an abnormality occurs in the boiling cycle and the internal pressure rises and becomes higher than the set pressure of the overpressure relief valve 14, The expanded hot water from the overpressure relief valve 14 can be drained.

  Further, an upper heater 15a and a lower heater 15b are disposed in each of the hot water supply hot water section 7a and the heating hot water section 7b of the hot water storage tank 7. The upper heater 15a is used for heating the hot water in the hot water supply hot water section 7a, and the lower heater 15b is used for heating the hot water in the heating hot water section 7b.

  Further, temperature sensors 16 a to 16 d are arranged on the side wall of the hot water storage tank 7 to detect the temperature of the hot water in the hot water storage tank 7. The temperature sensor 16a is disposed above the upper heater 15a, and the temperature sensor 16b is disposed at substantially the same height as the upper heater 15a. The temperature sensor 16c is disposed below the partition plate 8 and above the lower heater 15b, and the temperature sensor 16d is disposed at substantially the same height as the lower heater 15b.

  A hot water supply heat exchanger 18 that generates hot water to be sent to the hot water supply terminal 17 is also provided. And the high temperature water in the hot water storage tank 7 is sent to the primary side flow path of the hot water supply heat exchanger 18, and the low temperature water is sent from the water supply source to the secondary side flow path of the hot water supply heat exchanger 18. It has become.

  In addition, a hot water supply pump 19 is provided to send the high temperature water in the hot water storage tank 7 to the hot water supply heat exchanger 18. Then, by driving the hot water supply pump 19, high temperature water is sent from the hot water outlet 20 provided above the hot water storage tank 7 to the flow path on the primary side of the hot water supply heat exchanger 18.

  Then, the hot water after heat exchange by the hot water supply heat exchanger 18 is returned to the hot water storage tank 7 from a water inlet 21 provided in a lower portion of the hot water storage tank 7. Thus, in this Embodiment, the hot water storage tank 7, the hot water outlet 20, the hot water supply heat exchanger 18, the hot water supply pump 19, and the water inlet 21 are connected with piping, and the hot water supply cycle is comprised. Note that an AC pump having a constant circulating flow rate is used as the hot water supply pump 19.

  Between the hot water supply pump 19 and the water inlet 21, a flow rate adjusting valve 22 for adjusting the circulating flow rate of hot water in the boiling cycle and a check valve 23 are provided. The check valve 23 is provided to prevent convection of hot water in the hot water supply cycle. This is because even when the hot water supply pump 19 is not driven, high temperature water at the upper part of the hot water storage tank 7 may enter the lower part of the hot water storage tank 7 through the hot water supply heat exchanger 18. If high temperature water flows into the lower part of the tank 7, the temperature of the hot water sent to the water-refrigerant heat exchanger 2 will become high, and boiling efficiency will fall.

  Therefore, in the present embodiment, the check valve 23 is provided so that the hot water circulates in the forward direction in the hot water supply cycle only when the flow rate exceeds a predetermined load. In the present embodiment, hot water flows in the forward direction only when a load of 20 g is applied to the forward direction of the check valve 23. Note that the value of the load is not limited to 20 g.

Further, an overpressure relief valve 24 for adjusting the pressure in the hot water supply cycle is provided. When the pressure in the hot water supply cycle becomes higher than the set pressure of the overpressure relief valve 24, hot water is drained from the overpressure relief valve 24. I can do it. Further, a drain plug 25 is provided in the lower part of the hot water storage tank 7 so that the hot water in the hot water storage tank 7 can be discharged to the outside.

  A water pipe extending from a water supply source is connected to the water supply pipe 26, and the water supply pipe 26 is connected to the bottom of the hot water storage tank 7 and the secondary side flow path of the hot water supply heat exchanger 18 through a three-way valve 27. ing. Further, an overpressure relief valve 28 is provided between the three-way valve 27 and the hot water storage tank 7 so that the expansion water can be drained.

  Then, when installing the tank unit C, the three-way valve 27 is switched to a flow path connected to the hot water storage tank 7 to perform water filling, and after the hot water storage tank 7 is full, the three-way valve 27 is connected to the hot water supply heat exchanger. The flow path is connected to the flow path connected to 18. Thus, after entering the hot water storage tank 7, the water circuit including the hot water storage tank 7 becomes a closed circuit by switching the three-way valve 27 to a flow path connected to the hot water supply heat exchanger 18. Therefore, even in a hard water area containing a large amount of minerals, the precipitation of scale can be limited to the amount of water initially put in the hot water storage tank 7.

  An overpressure relief valve 29 is provided between the three-way valve 27 and the hot water supply heat exchanger 18. This is because the hot water supply pressure is directly applied to the hot water supply heat exchanger 18 from the water supply source. When the water supply pressure is high, if the water enters the hot water supply heat exchanger 18 directly from the water supply source, the hot water supply heat exchanger 18 is destroyed. There is a possibility of failure. Therefore, by providing the overpressure relief valve 29, when hot water having a certain supply water pressure or more enters, it is drained to the outside through the overpressure relief valve 29, thereby preventing a failure of the hot water heat exchanger 18.

  When the temperature of the low-temperature water supplied from the water supply source rises in the hot water supply heat exchanger 18, the low temperature water is supplied to the hot water supply terminal 17 through the hot water supply pipe 30. Further, the hot water supply pipe 30 is provided with a temperature sensor 31 that is a hot water supply temperature detecting means for detecting the temperature of hot water and a preliminary temperature sensor 32, and a flow rate sensor 33 that is a flow rate detecting means for detecting a flow rate.

  Moreover, the heating terminal 34 which heats the inside of a living room is provided, and the inside of a heating terminal 34 can be heated by circulating the hot water in the hot water storage tank 7 inside. Therefore, a heating pump 35 is provided for sending hot water from the heating hot water section 7 b of the hot water storage tank 7 to the heating terminal 34. The hot water sent to the heating terminal 34 is taken out from a hot water outlet 36 provided in the vicinity of the hot water inlet 11, and the hot water in the heating hot water section 7 b is supplied to the heating terminal 34. The hot water after heat exchange at the heating terminal 34 is returned to the bottom of the hot water storage tank 7. The heating pump 35 is an AC pump having a constant circulation flow rate.

  The heat exchange unit B and the tank unit C are provided with remote control devices 37 and 38 for setting. Furthermore, the heat pump unit A, the heat exchange unit B, and the tank unit C are provided with control devices 39a to 39c that give instructions to driving devices arranged in the respective units. The control device 39c may also function as the safety control device 54.

  In the heat pump type hot water heating apparatus configured as described above, the operation of the heat pump type hot water heating apparatus will be described below.

First, the boiling operation will be described. First, the user sets a boiling temperature Th of hot water in the water / refrigerant heat exchanger 2 by using a remote control device 37 provided in the heat exchange unit B. When the boiling operation is started, the boiling pump 9 is driven and the hot water in the hot water storage tank 7 is supplied to the water / refrigerant heat exchanger 2. Then, the heating operation by the heat pump cycle is continued until the temperature detected by the temperature sensor 12b exceeds the boiling temperature Th. When the hot water in the hot water storage tank 7 is boiled up in a heat pump cycle, the four-way valve 5 is switched so that a high-temperature refrigerant discharged from the compressor 1 becomes a flow path into the water-refrigerant heat exchanger 2.

  As a result, the high-temperature water discharged from the compressor 1 flows into the water-refrigerant heat exchanger 2 and radiates heat to the hot water, thereby generating high-temperature water. In the water / refrigerant heat exchanger 2, water and the refrigerant are counterflowed to improve heat exchange efficiency.

  When the temperature of the hot water discharged from the water / refrigerant heat exchanger 2 detected by the temperature sensor 12b approaches the boiling temperature Th, the rotation speed of the compressor 1 is reduced to lower the capacity. When the temperature detected by the temperature sensor 12b is higher than the boiling temperature Th by a predetermined temperature Ta (for example, 2 ° C.), the operation of the compressor 1 is stopped and the boiling operation is terminated. The hot water storage tank 7 is filled with hot water having a boiling temperature Th.

  The high-temperature water generated in the water-refrigerant heat exchanger 2 is returned to the heating hot water section 7b, but passes through a gap formed between the partition plate 8 and the hot water storage tank 7 to pass through the hot water hot water section. 7a is also filled with hot water at the boiling temperature Th. At this time, the control device 39b stores the incoming water temperature Ti detected by the temperature sensor 12a when the operation of the compressor 1 is stopped.

  Further, even after the boiling operation by the heat pump cycle is completed, the boiling pump 9 is driven to circulate the hot water in the hot water storage tank 7 to the water refrigerant heat exchanger 2. Even when the boiling operation is stopped, it is necessary to detect the temperature of the hot water in the hot water storage tank 7 with the temperature sensor 12a and the temperature sensor 12b, and as soon as the temperature of the hot water in the hot water storage tank 7 decreases. This is because the heating operation by the heat pump cycle must be resumed.

  And while the hot water supply operation is stopped, the boiling pump 9 is driven and the temperature sensor 12a constantly detects the hot water in the hot water storage tank 7, and the temperature detected by the temperature sensor 12b stops the operation of the compressor 1. When the stored water temperature Ti becomes lower than the stored temperature Ti by a predetermined temperature Tb (for example, 5 ° C.), the operation of the compressor 1 is resumed and the boiling operation is started.

  For example, when 55 ° C. is set as the boiling temperature Th, the operation of the compressor 1 is stopped when the temperature detected by the temperature sensor 12b exceeds 57 ° C. (= 55 ° C. + 2 ° C.). Then, if the temperature when the operation of the compressor 1 is stopped is 53 ° C., the incoming water temperature Ti is stored as 53 ° C. The boiling pump 9 is driven even after the operation of the compressor 1 is stopped, and the compressor 1 is detected when the temperature detected by the temperature sensor 12b is lower than the incoming water temperature Ti by a predetermined temperature Tb (for example, 5 ° C.). Resume driving. Further, the predetermined temperatures Ta and Tb shown in the present embodiment are one example, and are not limited to the present embodiment.

  Further, the remote control device 38 provided in the tank unit C can set the boiling temperature in the upper heater 15a. FIG. 8 is a front view of the remote control device 38. As shown in FIG. 8, the remote control device 38 has an operation unit 38a and a display unit 38b, and the temperature can be set by operating the operation unit 38a. In the present embodiment, the heating temperature Tu of the upper heater 15a, the boiling temperature Tbo of the lower heater 15b, and the hot water supply temperature Tk to the hot water supply terminal 17 can be set by operating the operation unit 38a.

In this embodiment, the hot water in the hot water supply hot water section 7a is boiled by setting the boiling temperature Tu of the upper heater 15a to a temperature higher than the boiling temperature Th set by the remote control device 37. It can be boiled up to the temperature Tu. For example, when the boiling temperature Th is set to 55 ° C. by the remote control device 37 and the boiling temperature Tu is set to 75 ° C. by the remote control device 38, the water refrigerant heat exchanger 2 is heated to the boiling temperature Th (55 ° C.). Further, the boiling operation is performed to 75 ° C. with the upper heater 15a.

  In this way, since different boiling temperatures can be set on the upper and lower sides of the partition plate 8, it is possible to boil up to an optimum temperature according to each terminal, and to improve usability.

  Next, the heating operation in the upper heater 15a will be described. When the operation of the upper heater 15a is started, the temperature detected by the temperature sensor 16a provided at a position higher than the upper heater 15a is lower than the boiling temperature Tu by a predetermined temperature Tc (for example, 5 ° C.). When detected, the output of the upper heater 15a is turned ON. The hot water in the hot water supply hot water section 7a is heated by the upper heater 15a, and the temperature detected by the temperature sensor 16b provided at the same position as the upper heater 15a is a predetermined temperature Td (for example, 2 ° C.) rather than the boiling temperature Tu. The output of the upper heater 15a is turned off when a high temperature is detected.

  Thus, the temperature sensor that is determined when the upper heater 15a is turned on and the temperature sensor that is determined when the upper heater 15a is turned off are not frequently switched on and off of the upper heater 15a. Thus, the durability of the upper heater 15a is improved. Further, the predetermined temperatures Tc and Td shown in the present embodiment are one example, and are not limited to the present embodiment.

  Next, the boiling operation in the lower heater 15b will be described. The lower heater 15b can be prevented from being lowered in temperature of the hot water in the heating hot water section 7b by turning on the lower heater 15b when the heat pump unit A cannot perform the boiling operation.

  For example, if the heating operation is continued, the evaporator 4a is frosted and the defrosting operation must be performed. At that time, the refrigerant flow path is switched by the four-way valve 5 so that the high-temperature refrigerant discharged from the compressor 1 flows into the evaporator 4a and defrosting is performed at the refrigerant temperature.

  However, since the water refrigerant heat exchanger 2 cannot dissipate heat during the defrosting operation, hot water cannot be generated in the water refrigerant heat exchanger 2. As a result, the hot water in the heating hot water section 7b is lowered, and the temperature of the hot water supplied to the heating terminal 34 is lowered. In order to prevent this, by turning on the lower heater 15b, it is possible to prevent the warm water in the heating hot water section 7b from being lowered and maintain comfort at the heating terminal 34. Not only the defrosting operation but also when the heat pump unit A fails, the hot water in the heating hot water section 7b can be heated by the lower heater 15b.

  In this embodiment, the remote controller 38 can set the boiling temperature Tbo in the lower heater 15b. On the other hand, the boiling temperature Tbo is often set to the same temperature as the boiling temperature Th. Further, in the heating hot water section 7b, there is a temperature distribution in which the upper temperature is high and the lower temperature is low.

  Therefore, even if the temperature of the warm water returning from the water-refrigerant heat exchanger 2 is the boiling temperature Th (= Tbo), the temperature detected by the temperature sensor 16d is lower than the boiling temperature Th (= Tbo). End up. This is because the hot water radiated by the heating terminal 34 and the hot water radiated by the hot water supply heat exchanger 18 are returned to the lower part of the hot water storage tank 7.

As a result, if the lower heater 15b is controlled so that the temperature detected by the temperature sensor 16d is maintained at the boiling temperature Tbo, the lower heater 15b is turned on if the temperature detected by the temperature sensor 16d is slightly below the boiling temperature Tbo. The lower heater 15 frequently
The boiling operation is performed at b.

  However, it is generally more efficient that the hot water in the heating hot water section 7b is heated using the heat pump unit A as much as possible without using the lower heater 15b. Therefore, in the present embodiment, the lower heater 15b is turned on only when it is detected that the temperature detected by the temperature sensor 16d is lower than the boiling temperature Tbo by a predetermined temperature Te (for example, 10 ° C.). Is controlled.

  As a result, when the boiling temperature Tbo is set to the boiling temperature Th, the heating hot water section 7b is heated to the boiling temperature Th by the heat pump unit A, and the temperature detected by the temperature sensor 16d. However, unless it is detected that the temperature is lower than the boiling temperature Tbo by the predetermined temperature Te, the lower heater 15b is not turned on.

  Further, only when it is detected that the temperature detected by the temperature sensor 16d is lower than the boiling temperature Tbo by a predetermined temperature Te during the defrosting operation of the evaporator 4a or when the capacity of the heat pump unit A is not achieved. The lower heater 15b can be turned on, and a very efficient boiling operation can be performed.

  When the lower heater 15b is stopped when the lower heater 15b is heated, the temperature detected by the temperature sensor 16d is a predetermined temperature Tf (for example, 2 ° C.) rather than the boiling temperature Tbo. When it is detected that the temperature is higher, the boiling operation is performed so that the lower heater 15b is turned off.

  As described above, by using the boiling operation by the heat pump unit A and the boiling operation by the lower heater 15b together, the boiling operation by the heat pump unit A is not performed by the defrosting operation of the evaporator 4a. Even if it exists, the warm water in the warm water part 7b for heating is maintained in the state of the boiling temperature Tbo, warm water can be stably sent to the heating terminal 34, and comfort is not impaired. Further, the predetermined temperatures Te and Tf shown in the present embodiment are one example, and are not limited to the present embodiment.

  Next, safety control of the upper heater 15a (or the lower heater 15b) will be described. First, when any one of the first to fourth temperature rise prevention devices attached to the side surface of the hot water storage tank 7 detects that the hot water in the hot water storage tank 7 is at an abnormally high temperature, the detected temperature The contact in the over-rise prevention device is turned off to cut off the energization. The first to fourth over-temperature prevention devices 50a to 50d are configured to shut off energization by turning off the internal contacts when an abnormally high temperature is detected.

  For example, when the first overheat prevention device 50a detects an abnormal temperature, the contact in the first overheat prevention device 50a is turned off and the energization to the heater element 49a is cut off. Next, when the third overheat prevention device 50c detects an abnormal temperature, the contact in the third overheat prevention device 50a is turned off, and the energization to the heater element 49c is interrupted.

  Since the safety control device 54 is connected to the third overheat prevention device, when it is detected that the third overheat prevention device has worked, the fourth overheat prevention device 50d works. Even if not, by turning off the contacts in the fourth overheat prevention device 50d, the energization to all the relays is cut off, and all the relays are turned off to cut off the energization to the heater element 49b.

Thus, since the 1st-4th overheat prevention device 50a-50d interrupts | blocks electricity supply from the location which detected abnormal temperature, the 1st-3rd overheat prevention device 50a-50c Before the operation, the fourth overheat prevention device 50d may operate. In addition, it is possible to make a double safety configuration by simply connecting a safety control device to any one of the first to third overheat prevention devices 50a to 50c, such as lead wiring. It can be simplified. In addition, because of the simple structure, the connection workability can be improved and erroneous connection can be prevented.

  As described above, the heater-equipped hot water storage tank of the present invention not only cuts off the power supply to each heater element, but also can cut off the power supply to the relay that is turning on and off the heater, Safety can be improved.

  As mentioned above, the hot water storage tank with a heater of the present invention can be applied to an electric water heater or a heat pump hot water heater.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Water refrigerant | coolant heat exchanger 3 Pressure reducing device 4a Evaporator 4b Blower fan 5 Four way valve 6 Refrigerant pipe 7 Hot water storage tank 8 Partition plate 9 Boiling pump 10 Water outlet 11 Hot water inlet 12a, b Temperature sensor 13 Flow switch 14 Excess Pressure relief valve 15a Upper heater 15b Lower heater 16a-d Temperature sensor 17 Hot water supply terminal 18 Hot water supply heat exchanger 19 Hot water supply pump 20 Hot water outlet 21 Water inlet 22 Flow rate adjustment valve 23 Check valve 24 Overpressure relief valve 25 Drain plug 26 Water supply pipe 27 Three-way valve 28 Overpressure relief valve 29 Overpressure relief valve 30 Hot water supply pipe 31 Temperature sensor 32 Preliminary temperature sensor 33 Flow rate sensor 34 Heating terminal 35 Heating pump 36 Hot water outlet 37 Remote control device 38 Remote control device 39a-c Control device A Heat pump unit B Heat exchange unit C Tank unit

Claims (2)

A hot water storage tank for storing hot water, a three-phase heater composed of three heater elements for heating the hot water in the hot water storage tank, and the power supply to the heater between each of the heater elements and the three-phase power supply are turned on. A relay to be turned off, a main connection line for switching between ON and OFF of the relay, first to third overheat prevention devices between the respective heater elements and a three-phase power source, and the main connection The wire is provided with a fourth overheat prevention device, and the first to third overheat prevention devices cut off the electric power to the heater element when the temperature in the hot water storage tank detects a predetermined temperature or higher. The fourth overheat prevention device is configured to cut off energization to the main connection line when the temperature in the hot water storage tank detects a temperature equal to or higher than a predetermined temperature. . A safety control device that detects that power to the heater element is cut off is connected to any one of the first to third overheat prevention devices, and the fourth overtemperature prevention device is connected. When the safety control device detects that the power to the heater element is cut off by the temperature rise prevention device connected to the safety control device before turning off the energization to the relay by the rise prevention device, 4. The hot water storage tank with a heater according to claim 1, wherein energization of the relay is interrupted by an overheat prevention device of 4.