JP4644151B2 - Hot water storage water heater - Google Patents

Description

  The present invention relates to a hot water storage type hot water supply apparatus that boils hot water to be used on the next day at midnight.

Conventionally, in a hot water storage hot water supply apparatus that boils hot water to be used the next day during this midnight time zone, the temperature at the bottom of a hot water storage temperature sensor attached to a hot water storage tank having a heater is monitored. The temperature at the time when the temperature became lowest was used as the feed water temperature to the hot water storage tank, and was used to calculate the peak shift time for starting the boiling operation at midnight.
Japanese Patent Laid-Open No. 01-239343

  However, in this conventional system, when the hot water tank is always filled with hot water even during daytime hours, when there is a large amount of continuous hot water, the bottom hot water temperature sensor detects the water supply temperature. However, if there is only a small amount of hot water, the temperature of the hot water in the lower part of the hot water storage tank will become dull due to the influence of the hot water in the upper part, and the temperature higher than the actual water supply temperature will be the maximum. Since the hot water storage temperature sensor at the bottom detects and uses it for peak shift calculation, the amount of heat required for boiling less than the amount of heat required for boiling is calculated, and hot water may not boil by the next morning. .

  In order to solve the above-mentioned problems, the present invention provides a hot water storage tank in which hot water is stored by connecting a water supply pipe and a hot water discharge pipe, a circulation pump and heating means, and hot water from the lower part of the hot water storage tank is heated. A heating circuit that returns to the upper part of the hot water storage tank, an incoming water temperature sensor that detects the temperature of the hot water entering the heating means, and a plurality of hot water storage temperatures that are provided in the vertical direction of the hot water storage tank and detect the temperature of the hot water storage hot water. A sensor, a water temperature storage unit that stores the minimum temperature of the water temperature detected by the water temperature sensor when the circulating pump is operated, and a lower part that stores the minimum temperature of the hot water temperature detected by the hot water temperature sensor at the bottom. A temperature storage unit, a feed water temperature determining means for comparing the temperature stored in the incoming water temperature storage unit and the temperature stored in the lower temperature storage unit and setting the lower temperature as the feed water temperature, and the feed water temperature It was that a peak shift calculating means for calculating a peak shift time to start boiling with water temperature determined by the constant section.

  According to a second aspect of the present invention, the temperature detected by the incoming water temperature sensor is detected after a predetermined time has elapsed since the operation of the circulation pump was started.

  According to the present invention, the water temperature detected by the water temperature sensor is compared with the hot water temperature detected by the lowermost hot water temperature sensor, and the lower temperature is used for the peak shift calculation as the water temperature. Even when the temperature of the hot water storage tank is low and the temperature of the hot water in the lower part of the hot water tank is dull due to the influence of the hot water in the upper part, it is possible to detect a temperature closer to the actual water supply temperature, improving the accuracy of peak shift calculation and running out of hot water. Can be prevented.

  In addition, it is possible to eliminate the influence of the incoming water temperature detected by the incoming water temperature sensor due to heat radiation or the like in the pipe between the hot water storage tank and the heating means, so that a more accurate water supply temperature can be detected.

  Next, a hot water storage type hot water supply apparatus according to an embodiment of the present invention will be described with reference to the drawings. This hot water storage type hot water supply device boils and stores hot water in the midnight hours when the unit price of contracted power by time is low, and uses the hot water stored for hot water supply. 1 is a hot water storage tank 2 for storing hot water. 3 is a heating unit such as a heat pump unit that heats hot water in the hot water storage tank 2, and 4 is a hot water supply set temperature and various operation modes such as a full tank mode and a forced boiling operation mode. It is a remote controller to do.

  The hot water storage tank 2 of the hot water storage tank unit 1 has a hot water discharge pipe 5 connected to the upper end, a water supply pipe 6 connected to the lower end, and a forward pipe 7 connected to the heating means 3 so as to be circulated at a lower portion and a return pipe 8. Is connected to the top. A circulation pump 9 for circulating hot water in the hot water storage tank 2 to the heating means 3 is provided in the middle of the outward pipe 7, and the heating circulation circuit 10 is connected by the forward pipe 7, the circulation pump 9, the heating means 3, and the return pipe 8. It is composed. In addition, the incoming pipe temperature sensor 11 and the boiling temperature sensor 12 are provided in the forward pipe 7 and the return pipe 8 before and after the heating unit 3, respectively.

  Next, 13 is a water supply bypass pipe branched from the water supply pipe 6 to bypass the hot water storage tank 2, and 14 is a hot water supply downstream of the hot water supplied from the hot water discharge pipe 5 and water supplied from the water supply bypass pipe 13. A mixing valve for supplying hot water to the pipe 15, 16 is a hot water supply temperature sensor provided in the hot water supply pipe 15 downstream of the mixing valve 15, and 17 is a hot water supply flow rate counter for counting the amount of hot water to be supplied.

  Next, a plurality of hot water storage temperature sensors 18 are arranged in the vertical direction of the hot water storage tank 2. In this embodiment, five hot water storage temperature sensors are arranged and are called 18a, 18b, 18c, 18d, and 18e from the top. The amount of heat remaining in the hot water storage tank 2 is detected based on the temperature information detected by the temperature sensor 18, and the vertical temperature distribution in the hot water storage tank 2 is detected.

  19 calculates the amount of boiling heat and the peak shift time from the amount of heat used and the amount of residual heat in the daytime, and instructs the heating means 3 to start and stop boiling, and also in the daytime time zone, the hot water storage temperature sensor. The hot water storage control unit has a function of starting a predetermined boiling increase operation when the residual heat amount of the hot water storage tank 2 detected at 18 falls below a predetermined amount.

  The heating means 3 includes a compressor 20 for compressing refrigerant, a water-refrigerant heat exchanger 21 as a gas cooler, an electronic expansion valve 22 as decompression means, and a forced air-cooled evaporator 23, A heat pump control unit 25 for controlling the operation thereof, and carbon dioxide is used as a refrigerant in the heat pump circuit 24 to constitute a supercritical heat pump cycle exceeding the critical pressure on the high pressure side. As a result, it is possible to boil low-temperature water to a high temperature of about 90 ° C. without an electric heater.

  When boiling the hot water in the hot water storage tank 2, the circulating pump 9 is operated to boil the hot water in the lower part of the hot water storage tank 2 taken out from the forward pipe 7 by the heating means 3 and from the return pipe 8 to the hot water storage tank. The hot water is stored in the upper part of 2. When the hot water tap (not shown) is opened, hot water in the hot water storage tank 2 is pushed up by the water supply from the water supply pipe 6, and hot water in the upper part of the hot water storage tank 2 is pushed out from the hot water discharge pipe 5. Thus, the hot water is mixed with water from the water supply bypass pipe 13 and supplied.

  Here, when the hot water storage control unit 19 is set to a full tank mode in which the user always fills the hot water storage tank 2 with hot water even in the daytime period via the remote controller 4, a small amount of water is stored in the daytime period. When there is a hot spring, it is heated up and operated. When the start of the reheating operation is instructed, the hot water storage control unit 19 issues a heating operation start command to the heat pump control unit 25, and also starts the operation of the circulation pump 9 to start the hot water storage temperature sensor 18e at the bottom of the hot water storage tank 2. Is heated up to a predetermined temperature or higher to fill up.

  The hot water storage control unit 19 includes an incoming water temperature storage unit 26 that stores the lowest temperature of the incoming water detected by the incoming water temperature sensor 11 when the circulation pump 9 is operated, and a hot water storage temperature that is detected by the lowermost hot water storage temperature sensor 18e. The lower temperature storage unit 27 that stores the lowest temperature of the water, the temperature stored in the incoming water temperature storage unit 26 and the temperature stored in the lower temperature storage unit 27 are compared, and the lower temperature is the water supply temperature. A determining means 28 and a peak shift calculating means 29 for calculating the boiling start time using the feed water temperature determined by the feed water temperature determining means 28 are provided.

  The lower temperature storage unit 27 stores the lowest temperature of the hot water storage detected by the lowermost hot water storage temperature sensor 18e. Therefore, when a hot water is supplied and a sufficient amount of water flows into the lower portion of the hot water storage tank 2. An accurate feed water temperature can be detected and stored.

  Further, the incoming water temperature storage unit 26 is configured to start monitoring the incoming water temperature and stop the circulating pump 9 after a predetermined time from when the boiling operation or the additional heating operation is started and the circulation pump 9 is activated. Therefore, the temperature of the water at the bottom of the hot water storage tank 2 lower than that of the lowermost hot water storage temperature sensor 18e can be detected. At this time, since the temperature of the water remaining in the heating circuit 10 between the hot water tank unit 1 and the heating means 3 is not detected, a more accurate water supply temperature can be detected and stored. .

  Then, the water supply temperature determination means 28 compares the water temperature of the incoming water temperature storage unit 26 with the water temperature of the lower temperature storage unit 27 and sets the lower temperature as the supply water temperature, so that the full tank mode is set. When a sufficient amount of water is not contained in the lower part of the hot water storage tank 2 and the temperature detected by the hot water storage temperature sensor 18e at the bottom is dull and raised due to the influence of the hot water existing above the hot water storage tank 2 In this case, the incoming water temperature sensor 11 can detect the incoming water temperature when the water supply existing further below the lowermost hot water storage temperature sensor 18e is heated, and the detected water temperature is detected by the incoming water temperature sensor 11. The water temperature stored in the unit 26 is lower than the water temperature stored in the lower temperature storage unit 27, and a temperature closer to the actual water supply temperature is adopted as the water supply temperature.

  Therefore, the peak shift calculation means 29 uses the temperature close to the actual water supply temperature to calculate the peak shift time for shifting the start of the boiling operation from the midnight time zone start time, so that the accuracy of the peak shift calculation is improved. In the morning, the situation that boiling is not completed is eliminated, and the occurrence of hot water can be prevented.

  In addition, this invention is not limited to this one Embodiment, It does not prevent changing in the range which does not change a summary.

The schematic block diagram of the hot water storage type hot water supply apparatus of one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Hot water storage tank 3 Heating means 5 Hot water discharge pipe 6 Water supply pipe 9 Circulation pump 10 Heating circulation circuit 11 Incoming water temperature sensor 18 Hot water storage temperature sensor 26 Incoming water temperature memory | storage part 27 Lower temperature memory | storage part 28 Feed water temperature determination means 29 Peak shift calculation means

Claims (2)

  A hot water storage tank connected to a hot water supply pipe and a hot water discharge pipe for storing hot water, a heating circuit having a circulation pump and a heating means, heating the hot water from the lower part of the hot water storage tank and returning it to the upper part of the hot water storage tank, and the heating means Detected by an incoming water temperature sensor that detects the temperature of hot water entering the water, a plurality of hot water temperature sensors that are provided in the vertical direction of the hot water storage tank to detect the temperature of the hot water stored in the hot water tank, and the incoming water temperature sensor when the circulation pump is operating An incoming water temperature storage unit that stores a minimum temperature of the incoming water temperature, a lower temperature storage unit that stores a minimum temperature of the hot water temperature detected by the hot water storage temperature sensor at the bottom, and a temperature stored in the incoming water temperature storage unit Is compared with the temperature stored in the lower temperature storage unit, and the boiling water is opened using the feed water temperature determining means that uses the lower temperature as the feed water temperature and the feed water temperature determined by the feed water temperature determining means. Hot water storage type water heater, characterized in that a peak shift calculating means for calculating a peak shift time to.   The hot water storage type hot water supply apparatus according to claim 1, wherein the temperature detected by the incoming water temperature sensor is detected after a predetermined time has elapsed since the operation of the circulating pump.

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