JP2006046773A - Hot water storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage type water heater capable of ensuring the heating value in a hot water storage tank to the maximum at the end of a midnight power time zone with low power cost. <P>SOLUTION: This water heater comprises a circulating passage 19 having a heat exchanger 21, which circulates hot water from the lower part of the hot water storage tank 14 to the upper part thereof, a heat pump unit 13 boiling up the hot water passing in the circulating passage 19 through the heat exchanger 21 to a laminated state from the upper part in the hot water storage tank 14, and an electric heater 18 provided in the lower part in the hot water storage tank. In the midnight power time zone with low power cost, the hot water in the tank 14 is boiled up first by carrying current to the heat pump unit 13, and then re-boiled up by carrying current to the electric heater so that the whole quantity in the tank is uniformly heated to a high temperature at the end of the midnight power time zone, whereby the heating value in the tank is ensured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hot water storage type hot water supply apparatus for boiling hot water in a hot water storage tank to a high temperature.

Conventionally, a hot water storage tank for storing hot water has been provided, and a circulation path for circulating hot water in the hot water storage tank has been provided from the lower part to the upper part of the hot water storage tank. The heat exchanger is heated by the operation, and the hot water in the circulation path heated to the predetermined boiling temperature is sent to the upper part of the hot water storage tank, and the hot water is supplied from the upper side of the hot water storage tank. There is a hot water storage system that stores hot water in layers. (For example, refer to Patent Document 1).
Japanese Patent Laying-Open No. 2003-240349 (second page, FIG. 1)

  In such a hot water storage type hot water supply device, when the heat pump unit is heated in the late-night electricity hours when the electricity rate is cheap, the hot water heated in the middle of the night falls in the morning and cools down to the bottom of the hot water storage tank. Accumulates.

  That is, when the hot water in the hot water storage tank is zero, if the heat pump unit is heated for 8 hours from 23:00 to 7:00 in the morning, the hot water at 90 ° C, for example, heated at 23:00 at night At 7 o'clock, the hot water is stored in the lower part of the hot water storage tank, and the hot water in the lower part of the hot water storage tank has passed 8 hours since entering the hot water storage tank. . In addition, although it depends on the length of the piping in the hot water storage tank and the outdoor unit, even if 90 ° C hot water is flowed from the heat pump unit, it is radiated by about 3 ° C until it accumulates in the hot water storage tank, and accumulates in the hot water storage tank. The hot water temperature becomes 86 ° C. Therefore, the heat radiation until the heat storage tank is accumulated 3 ° C. and the heat radiation after 8 hours is 4 ° C., and the temperature distribution is 87 ° C. in the upper part of the hot water tank and 83 ° C. in the lower part of the hot water tank.

  In addition, when there is residual hot water in the hot water storage tank and the temperature of the hot water in the lower part is lowered to about 50 ° C, the hot water in the lower part of the hot water storage tank is heated to 90 ° C by the heat pump unit. The remaining hot water could only be heated up to about 70 ° C. from the efficiency of the heat pump unit.

  In this way, the hot water boiled in the night dissipates heat in the morning, the temperature of the hot water in the lower part of the hot water storage tank decreases, the amount of heat in the hot water storage tank decreases, and the hot water heated up at midnight power hours only runs out of water. For this reason, it is necessary to increase the daytime boiling with high electricity charges, which is uneconomical. In addition, when the hot water temperature in the hot water storage tank is medium temperature water, even if the medium temperature water is boiled by the heat pump unit, the efficiency is poor and there is a large amount of medium temperature water, and the amount of heat is decreased and the hot water may run out.

  The present invention has been made in view of such points, and at the end of the late-night power hours, the amount of heat in the hot water storage tank is increased to eliminate the risk of running out of hot water. An object of the present invention is to provide a hot water storage type hot water supply device that can be reduced.

  The hot water storage type hot water supply apparatus according to claim 1 includes a hot water storage tank, a circulation path for circulating hot water in the hot water storage tank from the lower part to the upper part of the hot water storage tank, and a heat exchanger provided in the circulation path. A heat pump unit that boils hot water flowing through the circulation path through the exchanger from the upper part of the hot water tank in a stacked state, and an electric heater provided at the lower part of the hot water tank. First, energize the heat pump unit to boil hot water in the hot water tank, then energize the electric heater and reheat the hot water tank so that the entire amount in the hot water tank reaches a uniform high temperature at the end of the midnight power hours It is a thing.

  In this configuration, when the remaining hot water in the hot water storage tank is zero during the midnight power hours when the electricity rate is low, the heat pump unit is first energized to boil the water in the hot water storage tank. Next, the electric heater is energized and re-boiled so that the entire amount in the hot water storage tank reaches a uniform high temperature at the end of the midnight power time period. When the hot water temperature in the hot water storage tank is medium hot water, the heat pump unit is first energized to boil the hot water in the hot water storage tank. Thereafter, as in the case where the remaining hot water is zero, the electric heater is energized so that the entire amount in the hot water storage tank reaches a uniform high temperature at the end of the midnight power period, and re-boiling is performed. Therefore, the amount of heat in the hot water storage tank increases at the end of the midnight power time period, and the daytime boiling increase operation for running out of hot water can be eliminated or reduced, which is economical.

  The hot water storage type hot water supply device according to claim 2 is the hot water storage type hot water supply device according to claim 1, wherein a boiling detection sensor is provided at the lower part of the hot water storage tank, and the hot water storage at the end of boiling by the heat pump unit detected by the boiling detection sensor. If the temperature difference between the hot water in the lower part of the tank is large compared to the normal boiling water temperature, the electric heater is energized and the total amount in the hot water storage tank is adjusted to a uniform high temperature at the end of the midnight power hours. When the heater is heated and the temperature difference is small, energization of the electric heater is prohibited.

  In this configuration, if the hot water temperature in the lower part of the hot water storage tank detected by the boiling temperature detection sensor at the end of boiling by the heat pump unit is larger than the normal boiling water temperature, the electric heater Reheating is performed so that the entire amount in the hot water storage tank becomes a uniform high temperature when energized, eliminating the risk of running out of hot water. Further, when the temperature difference is small, energization of the electric heater is prohibited and wasteful power consumption is suppressed.

  The hot water storage type hot water supply apparatus according to claim 3 is the hot water storage type hot water supply apparatus according to claim 1, wherein an outside air temperature detection sensor is provided, and when the outside air temperature detected by the outside air temperature detection sensor is low, after the heating by the heat pump unit is completed. The electric heater is energized and reheated so that the total amount in the hot water storage tank reaches a uniform high temperature at the end of the midnight power hours. When the outside air temperature is high, the electric heater is not energized. is there.

In this configuration, when the outside air temperature detected by the outside air temperature detecting sensor is low, the electric heater is energized after the heating by the heat pump unit is finished, and the entire amount in the hot water storage tank becomes a uniform high temperature at the end of the midnight power period. In this way, re-boiling is performed, and there is no danger of running out of hot water.
In addition, when the outside air temperature is high, energization of the electric heater is prohibited and wasteful power consumption is suppressed.

  According to the hot water supply apparatus of the first aspect, when the remaining hot water in the hot water storage tank is zero in the late-night power hours when the electricity rate is low, the heat pump unit is first energized to boil the hot water in the hot water storage tank. Next, the electric heater is energized and re-boiled so that the entire amount in the hot water storage tank reaches a uniform high temperature at the end of the midnight power period. When the hot water temperature in the hot water storage tank is medium hot water, the heat pump unit is first energized to boil the hot water in the hot water storage tank. Thereafter, as in the case where the remaining hot water is zero, the electric heater is energized so that the entire amount in the hot water storage tank reaches a uniform high temperature at the end of the midnight power period, and re-boiling is performed. Therefore, the amount of heat in the hot water storage tank increases at the end of the midnight power time period, and the daytime boiling-up operation for running out of hot water can be eliminated or reduced, which is economical.

  According to the hot water supply apparatus of claim 2, when the temperature difference between the hot water temperature in the lower part of the hot water storage tank detected by the boiling detection sensor at the end of boiling by the heat pump unit is larger than the normal boiling water temperature. The electric heater is energized and re-boiling is performed so that the entire amount in the hot water storage tank reaches a uniform high temperature, eliminating the risk of running out of hot water. Further, when the temperature difference is small, energization of the electric heater is prohibited and wasteful power consumption is suppressed.

  According to the hot water supply apparatus of claim 3, when the outside air temperature detected by the outside air temperature detecting sensor is low, the electric heater is energized after the heating by the heat pump unit is finished, and the total amount in the hot water storage tank is reached at the end of the midnight power time zone. Re-boiling is performed so as to obtain a uniform high temperature, eliminating the danger of running out of hot water. In addition, when the outside air temperature is high, energization of the electric heater is prohibited and wasteful power consumption is suppressed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  In FIG. 1, a hot water storage type hot water supply apparatus 11 includes a hot water storage unit 12 and a heat pump unit 13 as a boiling means.

  The hot water storage unit 12 includes a hot water storage tank 14, which employs a first-stop push-up hot water supply method, and a water supply pipe that supplies tap water to the lower portion of the hot water storage tank 14 via a pressure reducing valve 15. 16 is connected, and a hot water supply pipe 17 for supplying hot water to a bathtub or a kitchen is connected to the upper part. Further, an electric heater 18 for re-boiling is provided in the lower part of the hot water storage tank 14, and a boiling detection sensor S1 for detecting the boiling is provided on the lower outer wall of the hot water storage tank 14, respectively.

  The hot water storage tank 14 is connected to a circulation path 19 that exits from the lower part of the hot water storage tank 14 and returns to the upper part of the hot water storage tank 14. A circulation pump 20 that forcibly draws water in the lower part of the hot water storage tank 14 into the circulation path 19 and circulates it in the upper part of the hot water storage tank 14, and a heat exchanger 21 that is arranged in the heat pump unit 13 in the middle of the circulation path 19. Is connected.

  The heat pump unit 13 has a refrigerant circulation path 22 filled with a refrigerant. The refrigerant circulation path 22 functions as a compressor 23 and a condenser, and the water in the heat exchanger 21 and the water flowing in the circulation path 19 are provided. A heat exchanger 21, an expansion valve 24, and an evaporator 25 serving as a heat collector that are heated to a predetermined boiling temperature by exchanging heat with the refrigerant are sequentially connected. Further, the evaporator 25 includes a blower fan 26 and a blower motor 27 that rotationally drives the blower fan 26. S2 is an outside air temperature detection sensor that detects the outside air temperature.

  Next, the operation of the present embodiment will be described.

  First, referring to FIG. 1, an explanation will be given of the action of boiling up the water in the hot water storage tank 14 to a uniform high temperature at the end of the midnight power hours when the electricity charge is cheaper when the amount of hot water in the hot water storage tank 14 is zero.

  The heat pump unit 13 is first energized, for example, at 23:00 in the night power hours. Thereby, the compressor 23 is driven, and the refrigerant flows in the order of the compressor 23, the heat exchanger 21 as a condenser, the expansion valve 24, and the evaporator 25 as indicated by arrows. At the same time, the blower motor 27 is driven to rotate the blower fan 26, collect the atmospheric heat in the evaporator 25, and the vaporized refrigerant is sent to the compressor 23. The high-temperature and high-pressure refrigerant gas compressed by the compressor 23 exchanges heat. Sent to the vessel 21.

  On the other hand, the circulation pump 20 of the circulation path 19 is driven, and as shown by the arrow, the lower water enters the heat exchanger 21 through the circulation path 19 and is heat-exchanged by the refrigerant heat to become hot water and enter the upper part of the hot water storage tank 14. When this is repeated and hot water of a set temperature, for example, 90 ° C. is sequentially stacked from the upper part of the hot water storage tank before 7 o'clock in the morning, when the boiling detection sensor S1 detects the boiling of the total amount of water in the hot water storage tank 14, the boiling is finished. .

  As described in the prior art, the hot water boiled in the night is radiated in the morning, the temperature of the hot water in the lower part of the hot water storage tank is lowered, and the amount of heat in the hot water storage tank is reduced. There is a risk of running out of hot water alone.

  Therefore, following the boiling by the heat pump unit 13, the electric heater 18 is energized and re-boiled so that the entire amount in the hot water storage tank 14 is boiled up to a uniform high temperature at the end of the midnight power period.

  Next, a description will be given of the action of boiling when there is residual hot water in the hot water storage tank and the residual hot water temperature in the lower part of the hot water storage tank is lowered to medium temperature water of about 50 ° C.

  The heat pump unit 13 is first energized at, for example, 2 o'clock in the midnight power time zone. However, in boiling only the heat pump unit 13, even if the heat pump unit 13 is heated to 90 ° C., the remaining hot water of the medium temperature water can be heated only to about 70 ° C. from the efficiency of the heat pump unit. For this reason, after boiling in the heat pump unit 13, the electric heater 18 is energized and re-boiled so that the entire amount in the hot water storage tank 14 becomes a uniform high temperature at the end of the late-night power period. Thereby, the amount of heat in the hot water storage tank 14 is ensured, and there is no fear of running out of hot water, so that it is possible to suppress the boiling increase operation with a high daytime electricity bill.

  By the way, when the hot water storage tank 14 is heated from zero with only the heat pump unit 13, if the upper part of the hot water storage tank 14 is 87 ° C, the lower part of the hot water storage tank 14 is 83 ° C and the tank capacity is 460L, the amount of heat in the tank is If it is roughly 38250K calories and the inside of the tank is uniform, it will be 40500K calories, and the amount of heat in the tank at the end of the midnight power hours will be as much as 2250K calories. Moreover, in the case of a heat pump, since the medium temperature water is not boiled up to 90 degreeC, the difference in calorie | heat amount will be more than 2250K calories. Since 2250 K calories are converted to 42 ° C. hot water and become 54 L, the amount of 54 L hot water used is increased, and the boiling increase operation with high daytime electricity charges can be suppressed.

  In addition, since the electricity charge for boiling with an electric heater in the midnight power hours and boiling with a heat pump in the daytime are only about 1 liter per minute, hot water can be continuously poured by filling the bathtub or taking a shower when taking a bath. If used, the boiling operation may not catch up and there is a risk of running out of hot water. However, the method of storing more heat in the midnight power time zone as in the present invention, even if a lot of hot water is used instantaneously, the hot water runs out. There is an advantage that does not become.

  In addition, when boiling only with a heat pump, if there is a large amount of hot water in the hot water storage tank, a large amount of heat cannot be stored in the hot water storage tank 14, but the hot water can also be heated to 90 ° C. with an electric heater. So there is less risk of running out of hot water.

  Further, for example, when the temperature of tap water supplied into the hot water storage tank 14 is low, the hot water temperature in the lower part of the hot water storage tank at the end of boiling by the heat pump unit detected by the boiling detection sensor S1 is the normal boiling temperature. The temperature difference may be larger than the rising hot water temperature. In such a case, the electric heater 18 is energized and reheated so that the entire amount in the hot water storage tank 14 becomes a uniform high temperature at the end of the midnight power time period, thereby ensuring the maximum amount of heat in the hot water storage tank 14. Therefore, there is no risk of running out of hot water. Further, when the temperature difference is small, energization of the electric heater 18 is prohibited, and wasteful power consumption is suppressed.

  Further, for example, when the outside air temperature detected by the outside air temperature detection sensor S2 is low as in winter, the electric heater 18 is energized after the heating by the heat pump unit 13 is finished, and the total amount in the hot water storage tank 14 is reached at the end of the midnight power period. Reheating is performed so as to obtain a uniform high temperature to ensure the maximum amount of heat in the hot water storage tank 14. Therefore, there is no risk of running out of hot water. In addition, when the temperature difference is small as in summer, the electric heater 18 is prohibited from being energized to suppress wasteful power consumption.

It is a block diagram which shows one Embodiment of the hot water storage type hot-water supply apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Hot water storage type hot water supply device 12 Hot water storage unit 13 Heat pump unit 14 Hot water storage tank 16 Water supply pipe 18 Electric heater
19 Circulation path 20 Circulation pump 21 Heat exchanger S1 Boiling detection sensor S2 Outside air temperature detection sensor

Claims (3)

  There is a hot water storage tank, a circulation path for circulating hot water in the hot water storage tank from the lower part to the upper part of the hot water storage tank, and a heat exchanger provided in the circulation path, and the hot water flowing through the circulation path through the heat exchanger A heat pump unit that heats up in a stacked state from the upper part of the hot water tank and an electric heater provided in the lower part of the hot water tank. The hot water storage water heater is characterized in that the hot water is boiled, then the electric heater is energized and reheated so that the entire amount in the hot water storage tank reaches a uniform high temperature at the end of the midnight power hours .   2. The hot water storage type hot water supply apparatus according to claim 1, wherein a boiling detection sensor is provided at a lower part of the hot water storage tank, and the hot water temperature in the lower part of the hot water storage tank at the end of boiling by the heat pump unit detected by the boiling detection sensor If the temperature difference is large compared to the rising hot water temperature, the electric heater is energized and reheated so that the entire amount in the hot water storage tank reaches a uniform high temperature at the end of the midnight power hours. A hot water storage type hot water supply apparatus characterized in that energization of an electric heater is prohibited.   The hot water storage type hot water supply apparatus according to claim 1, wherein an outside air temperature detection sensor is provided, and when the outside air temperature detected by the outside air temperature detection sensor is low, the electric heater is energized after the heating by the heat pump unit is completed, and the midnight electric power time zone A hot water storage type hot water supply apparatus, wherein reheating is performed so that the entire amount in the hot water storage tank becomes a uniform high temperature at the end, and the electric heater is not energized when the outside air temperature is high.

Images