JP4502785B2 - Hot water heater - Google Patents

Description

  The present invention relates to a hot water storage type hot water heater configured to supply hot water via a pipe connected to a hot water storage tank that stores hot water heated by a heating source.

In a hot water storage water heater such as a heat pump hot water supply device and an electric water heater disclosed in Patent Document 1, when hot water is generated by heating water in a hot water storage tank, the water is heated in order from the upper part of the hot water storage tank. Hot water is stored.
Japanese Patent Laid-Open No. 2004-20021

  However, as the temperature of water (hot water) increases, the volume of water expands and the pressure in the hot water storage tank increases. At this time, in order to protect the hot water storage type water heater, when the inside of the hot water storage tank reaches a predetermined pressure, the water corresponding to the expansion is discharged from the overpressure relief valve installed at the upper part of the hot water storage tank. However, since this overpressure relief valve is installed at the upper part of the hot water storage tank, heated high-temperature water is discharged, which is not economical. In addition, in the heat retention performance of the hot water storage tank and the COP of the entire hot water storage type hot water heater, high temperature water is discharged, which causes a decrease in capacity.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to perform pressure relief when the volume of water is expanded due to a high temperature of water during hot water storage operation while improving the hot water storage efficiency of the entire apparatus.

Therefore, the present invention relates to a hot water storage hot water heater that supplies hot water via a pipe connected to a hot water storage tank that stores hot water heated by a heating source, and hot water from the hot water storage tank and the hot water storage tank. A mixing valve for mixing low temperature water from the lower part, an on-off valve for filling hot water mixed by this mixing valve into the bathtub, and an overpressure relief valve between the mixing valve and the on-off valve The overflow pipe, the calculating means for calculating the hot water storage operation time to the hot water storage tank, and the hot water storage operation to the hot water storage tank so that as much low temperature water as possible flows from the lower part of the hot water storage tank through the mixing valve first. And a control device that controls the opening so that high-temperature water from the upper part of the hot water tank flows as much as possible before the hot water storage operation time calculated by the calculating means elapses.
When the hot water storage operation of the hot water storage tank is performed, the volume of the water in the hot water storage tank expands, so that the overpressure relief valve opens and the opening degree is such that the low temperature water from the lower part of the hot water storage tank flows as much as possible first. The low temperature water from the lower part of the hot water storage tank through the controlled mixing valve is discharged out of the apparatus through the overflow pipe, and the high temperature from the upper part of the hot water storage tank is passed before the hot water storage operation time calculated by the calculating means elapses. The mixing valve is controlled to an opening degree at which water flows as much as possible .

  According to the present invention, during hot water storage operation, pressure relief when the volume expands due to high temperature of water can be performed while improving the hot water storage efficiency of the entire apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram showing an overall system of a heat pump type hot water supply apparatus as a hot water storage type hot water heater. In FIG. 1, A is a heat pump unit, B is a tank unit, C is a hot water circulation path for hot water storage, and R is a refrigerant circuit built in the heat pump unit A. In the refrigerant circuit R, a refrigerant such as HFC or CO ₂ can be used, but CO ₂ is used in the present embodiment.

The refrigerant circuit R includes a two-stage compression type compressor 1 capable of adjusting the capacity of suction and compression of CO ₂ refrigerant into high temperature and pressure, and a water refrigerant heat exchanger 2 for hot water storage for exchanging heat between the refrigerant and water. The refrigerant flow path 2A, the air heat exchanger 3 for exchanging heat between the outside air and the refrigerant, and the accumulator 4 are sequentially piped in an annular manner. A blower 5 blows air to the air heat exchanger 3 to perform heat exchange.

  In the hot water circulation path C, the water flow path 2B of the water-refrigerant heat exchanger 2 and the hot water storage tank 8 are annularly connected via a circulation pump 9. Reference numeral 10 denotes a thermistor that detects the temperature of hot water flowing out from the water flow path 2B of the water-refrigerant heat exchanger 2.

  Between the upper part and the middle part of the hot water storage tank 8, a primary flow path 11A of the water heat exchanger 11 and a circulation pump 12 for remedy are connected. A bathtub 14 is connected to the secondary flow path 11 </ b> B of the water heat exchanger 11 via a circulation pump 13. A first mixing valve 15 mixes the hot water in the hot water storage tank 8 with the low-temperature tap water from the water supply pipe 21 via the tap pressure reducing valve 19 and the check valve 20 to obtain hot water of 36 ° C. to 48 ° C., for example. Thus, opening the faucet 17 through the hot water supply pipe 16 enables hot water supply to the kitchen or the like.

  Reference numeral 18 denotes a second mixing valve, which mixes the tap water from the water supply pipe 21 via the tap pressure reducing valve 19 and the check valve 20 and the hot water from the hot water storage tank 8 to obtain hot water of about 42 ° C. . Then, the hot water produced by the second mixing valve 18 is opened via the secondary flow path 11B of the water heat exchanger 11 and the circulation pump 13 stopped by opening the on-off valves 24, 25 which are on-off valves. Thus, the hot water filling operation of the bathtub 14 is performed. At this time, the flow rate of the hot water is detected by the flow rate sensor 23A and is controlled by the control device S1 so that a desired amount of hot water filling operation is performed.

  The hot water storage tank 8 has a capacity of, for example, 370 liters. The hot water storage tank 8 has hot water temperature detection sensors T1, T2, T3, T4, T5, T6 and T7 spaced from the bottom to the top of the hot water tank 8. The control device S1 including a microcomputer determines the amount of remaining hot water in the hot water storage tank 8 based on the detected hot water temperature of each detection sensor. At this time, the detection sensor T1 is disposed at a position where the remaining hot water amount is 350 liters, T2 is also 300 liters, T3 is 250 liters, T4 is 200 liters, T5 is 150 liters, T6 is 100 liters, and T7 is 50 liters. . Reference numeral 26 denotes a hot water temperature detection sensor for detecting the hot water temperature near the outlet of the circulation pump 9.

  And the consumer signs a lighting contract according to the time with the electric power company, calculates the amount of water to be heated from the amount of hot water stored at a predetermined time and the time required to boil up the total amount at a predetermined time in the low-night time period when the fee is low, and the heating ends Control is performed by the control device S1 so that the hot water storage operation is started from the time calculated in consideration of the necessary time from the time, and is stopped as soon as the entire amount has been heated up (the temperature detected by the hot water temperature detection sensor 26 is 55 ° C. or higher). At the same time, the control device S1 controls to start the hot water storage operation when the remaining hot water volume is less than 100 liters and to stop the hot water storage operation when it exceeds 150 liters.

Reference numeral 27 denotes an overflow pipe branched from the outlet of the second mixing valve 18. Since the volume expands and the water pressure in the water circuit rises when the water becomes hot, this volume expansion is used as overflow water outside the apparatus (tank unit B An overpressure relief valve 28 is provided for discharge to the outside.

The water pressure reducing valve 19 disposed in the middle of the water supply pipe 21 is set so as to reduce the water supply pressure of the tap water to 170 kPa (about 1.7 kgf / cm ² ), and the overpressure relief valve 28 is It is set to open at 190 kPa (about 1.9 kgf / cm ² ), and when the water supply pressure is sufficient, the internal pressure of the hot water storage tank 8 is normally 170 kPa, and even if the pressure rises, it is always kept below 190 kPa. Be drunk.

  The heat pump unit A is provided with a control device S2 composed of a microcomputer or the like, and the tank unit B is provided with a control device S1 composed of a microcomputer or the like. The control devices S1 and S2 are provided from a bath remote controller (hereinafter referred to as “bath remote controller”) 37 provided in the bathroom, for example, a main remote controller (hereinafter referred to as “main remote controller”) 38 provided in the kitchen. The operation of the compressor 1 and the frequency control, the operation control of the circulation pumps 9, 12, and 13 are performed in accordance with the operation signal and the temperature signal of the hot water temperature detection sensor 26, and the operation will be described below. .

<Hot water storage operation>
In late night hours when the price is low, calculate the amount of water to be heated from the amount of hot water stored at a predetermined time, and the time required to boil up the entire amount, and hot water storage operation starts from the time calculated in reverse from the boiling end time taking into account the required time. Be started. In other time zones, when the remaining hot water volume is less than 100 liters, that is, when the detection sensor T6 detects that the hot water temperature is less than 55 ° C., the hot water storage operation is started.

  That is, hot water is stored in the hot water storage tank 8 based on the detection output from the detection sensor, and the control device S2 operates the circulation pump 9. In the hot water circulation path C, the hot water storage tank 8 → the circulation pump 9 → water refrigerant heat. Hot water for hot water supply flows in the order of the water flow path 2 </ b> B of the exchanger 2 → the hot water storage tank 8, and is stored in the hot water storage tank 8.

  In the heat pump unit A, when the compressor 1 is operated by the control device S2, in the refrigerant circuit R, the compressor 1 → the refrigerant flow path 2A of the water refrigerant heat exchanger 2 → the air heat exchanger 3 → the accumulator 4 → the compressor 1 in this order. The refrigerant flows.

  The temperature of the hot water supplied to the hot water storage tank 8 is 85 ° C., but the frequency of the compressor 1 is controlled by the control device S2 so that the temperature detected by the hot water temperature detection sensor 26 becomes this temperature.

As shown in the flowchart of FIG. 3, when heat treatment is started for hot water storage in the hot water storage tank 8, the control device S <b> 1 opens the second mixing valve 18 with low-temperature tap water from the water supply pipe 21. Control to change to the side (all on the tap water side, but may be on the tap water side as much as possible). Therefore, in this hot water storage operation, for example, in the process where the water at 20 ° C. becomes 85 ° C., the volume of water expands by about 3%, but this expansion causes the overpressure relief valve 28 to be set to 190 kPa (about 1.9 kgf). / cm ²⁾ open, the low-temperature expansion water from the lower hot water storage tank 8 is discharged out of the apparatus (outside tank unit B) from the overflow pipe 27 via a second mixing valve 18 and over-pressure relief valve 28.

  And when the heat processing of the water in the hot water storage tank 8, ie, a hot water storage driving | operation, is complete | finished, control apparatus S1 controls so that the opening degree of the 2nd mixing valve 18 may be returned.

  Therefore, conventionally, the pressure relief when the volume of the hot water storage tank 8 is expanded due to the high temperature of the hot water during the hot water storage operation is performed by draining the high temperature water from the upper part of the hot water storage tank 8. According to this, it is possible to perform the pressure relief while improving the hot water storage efficiency by performing the operation of discharging the low temperature water below the hot water storage tank 8.

  Conventionally, the pressure relief is performed by an overpressure relief valve connected to the upper part of the hot water storage tank 8 and also serves as an air vent for the hot water storage tank 8. However, in the embodiment shown in the flowchart of FIG. The second mixing valve 18 is set to the high temperature water side (all on the high temperature water side, but may be on the high temperature water side as much as possible), so that when the pressure rises due to heating, expansion occurs. Water and air are discharged from the overflow pipe 27 (tank unit B) through a pipe connected to the upper part of the hot water storage tank 8 through a second mixing valve 18 and an overpressure relief valve 28 whose opening degree is set on the high temperature water side. When the heat treatment of the water in the hot water storage tank 8 is completed, the control device S1 controls to return the opening of the second mixing valve 18 to the original. Thereby, the air pool of the hot water storage tank 8 upper part can be suppressed as much as possible.

  Further, as shown in the flowchart shown in FIG. 5, the opening of the second mixing valve 18 is not particularly set to the extremely high temperature water side and the low temperature water side, but a large amount of the high temperature water side is opened to provide a hot water storage tank. 8. Mix high temperature water from the upper part with low temperature water from the lower part and discharge it from the overflow pipe 27 to the outside of the apparatus (outside the tank unit B) via the second mixing valve 18 and the overpressure relief valve 28. Thus, by mixing the low temperature water, the discharge of the high temperature water can be prevented as much as possible, and the upper part of the hot water storage tank 8 can be vented at the same time. Then, when the heat treatment in the hot water storage tank 8 is completed, the control device S1 performs control so that the opening degree of the second mixing valve 18 is restored.

  When the heating time of the water in the hot water storage tank 8 is clear in advance, when the heating is started, the opening of the second mixing valve 18 is set to the low temperature water side (all on the tap water side, but may be on the tap water side as much as possible). )), The expanded water is drained from the overflow pipe 27 to the outside of the apparatus (outside of the tank unit B), and when heating is about to end, the hot water side (all hot water side is used, but the hot water side may be used as much as possible. ), The air pool at the upper part of the hot water storage tank 8 can be discharged from the overflow pipe 27 to the outside of the apparatus (outside of the tank unit B). More specifically, when the heat treatment for hot water storage in the hot water storage tank 8 is started, the control device S1 calculates the heating time T1, sets the opening degree of the second mixing valve 18 to the low temperature water side, and the heating time. Control is performed so that the temperature is set to the high temperature water side before the end of T1 before time T2. Then, when the heat treatment in the hot water storage tank 8 is completed, the control device S1 performs control so that the opening degree of the second mixing valve 18 is restored. Thereby, the expansion water can be discharged and the air pool can also be discharged.

  In the embodiment as described above, as shown in FIG. 1, the overflow pipe 27 is branched from the second mixing valve 18, and the overpressure relief valve 28 is provided in this branching path. An overflow pipe may be branched from the valve 15 and an overpressure relief valve 28 may be provided in the branch path. Thereby, it becomes the structure which can utilize the 1st mixing valve 15 provided in the hot water supply circuit, and control by the control apparatus S1 of this 1st mixing valve 15 is the same by controlling similarly to the control which concerns on the 2nd mixing valve 18. An effect is obtained.

<Water supply operation, hot water filling operation and memorial operation>
The hot water stored in the hot water storage tank 8 is mixed with the tap water from the water supply pipe 21 via the tap pressure reducing valve 19 and the check valve 20 by the first mixing valve 15 to supply hot water as 36 ° C. to 48 ° C. hot water. Opening the faucet 17 through the pipe 16 enables hot water supply to the kitchen or the like. When this hot water supply is performed, water is supplied from the water supply pipe 21 to the lower part of the hot water storage tank 8.

  Further, the hot water stored in the hot water storage tank 8 by the second mixing valve 18 and the tap water from the water supply pipe 21 are mixed and heated to about 42 ° C. by opening the on-off valves 24 and 25, The hot water filling operation of the bathtub 14 is performed through the secondary circulation path 11 </ b> B of the water heat exchanger 11 through the circulation pump 13 that is stopped and not through the circulation pump 13.

  In addition, the control device S1 operates the circulation pumps 12 and 13, thereby exchanging heat between the hot water in the hot water storage tank 8 and the hot water in the bathtub 14 with the water heat exchanger 11 to replenish the hot water in the bathtub 14. You can also.

  When the boiling of the whole amount is completed in the midnight time zone (when the hot water temperature detection sensor 26 detects 55 ° C. or more), and when the remaining hot water amount becomes 150 liters or more in other time zones, that is, the detection sensor When T5 detects 55 ° C. or higher, the control devices S1 and S2 control the hot water storage operation to be stopped.

  Although the embodiments of the present invention have been described above, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the various alternatives and modifications described above are within the scope of the present invention. Or a modification is included.

It is a whole system diagram of a heat pump type hot water supply apparatus. It is a control block diagram. It is a figure which shows a control flowchart. It is a figure which shows the control flowchart which concerns on other embodiment. It is a figure which shows the control flowchart which concerns on other embodiment. It is a figure which shows the control flowchart which concerns on other embodiment.

Explanation of symbols

8 Hot Water Storage Tank 14 Bath 18 Second Mixing Valve 21 Water Supply Pipe 27 Overflow Pipe 28 Overpressure Relief Valve A Heat Pump Unit B Tank Unit C Hot Water Circulation Path R Refrigerant Circuit S1 Controller

Claims (1)

In a hot water storage hot water heater configured to supply hot water via a pipe connected to a hot water storage tank that stores hot water heated by a heating source, hot water from the hot water storage tank and low temperature water from the lower part of the hot water storage tank A mixing valve, an on-off valve for filling hot water mixed by the mixing valve into the bathtub, an overflow pipe having an overpressure relief valve interposed between the mixing valve and the on-off valve, The calculation means for calculating the hot water storage operation time to the hot water storage tank, and the opening of the mixing valve at the time of the hot water storage operation to the hot water storage tank are controlled to an opening degree at which low temperature water from the lower part of the hot water storage tank flows as much as possible. And a control device for controlling the opening degree so that high-temperature water from the upper part of the hot water storage tank flows as much as possible before the hot water storage operation time calculated by the calculating means elapses,
When the hot water storage operation of the hot water storage tank is performed, the volume of the water in the hot water storage tank expands, so that the overpressure relief valve opens and the opening degree is such that the low temperature water from the lower part of the hot water storage tank flows as much as possible first. The low temperature water from the lower part of the hot water storage tank through the controlled mixing valve is discharged out of the apparatus through the overflow pipe, and the high temperature from the upper part of the hot water storage tank is passed before the hot water storage operation time calculated by the calculating means elapses. A hot water storage water heater , wherein the mixing valve is controlled to an opening degree at which water flows as much as possible .

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