JP2006275445A - Hot-water supply machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot-water supply machine capable of preventing generated scale from being absorbed into a pump and improving service life of the pump to achieve high reliability. <P>SOLUTION: This hot-water supply machine is constituted by absorbing water from a suction pipe of the pump 7 installed in the vicinity of a bottom part of a hot-water storage tank 8 by the pump 7, circulating water in the hot-water storage tank 8 into a heating source to heat it, and storing hot water having high temperature into the hot-water storage tank 8. A porous plate 27 is provided in an upper part than the suction pipe 10 of the pump 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  FIG. 5 shows a conventional water heater. This will be described with reference to the figure. The pump 7 sucks the water in the hot water storage tank 8 from the suction pipe 10, heats it by the first heating means 30, and returns the hot water to the top of the hot water storage tank 8 by the boil-back pipe 13.

  The pressure reducing valve 20 supplies the city water to an appropriate pressure through the water supply pipe 19 to the hot water storage tank 8.

  The control means 26 detects the temperature of the hot water heated by the first heating means 30 by the tapping temperature sensor 16 and adjusts the flow rate of the pump 7 according to the detected temperature.

  In the conventional invention, the first heating unit 30 or the second heating unit 31 is operated according to the current time and the amount of remaining hot water, that is, the first heating unit 30 is heated with daytime power. The second heating means 31 is switched according to the heating means so that it is heated by night electricity.

Thereby, the boiling frequency by the circulation performed in the 1st heating means 30 can be reduced significantly, the degree that a scale accumulates in piping, and the lifetime of piping can be improved (refer patent document 1). .
JP 2000-130852 A

  However, in the above configuration, the scale generated when water is heated by the first heating means 30 or the second heating means 31 circulates through the first heating means 30. When the scale is sucked into the pump 7, there is a problem that clogging occurs inside the pump 7 and circulation by the pump 7 becomes impossible.

  An object of the present invention is to provide a highly reliable water heater by reducing the suction of the generated scale into the pump 7 and improving the life of the pump 7.

  In order to achieve this object, the water heater of the present invention is heated by sucking water from a pump suction pipe installed near the bottom of a hot water storage tank by a pump and circulating the water in the hot water storage tank to a heating source. And in the hot water supply apparatus which stored hot water in the said hot water storage tank, the perforated plate was installed in the said hot water storage tank.

  As a result, the scale generated by the heating source accumulates on the perforated plate and does not reach the suction pipe. Therefore, the scale is not sucked into the pump, and the clogging of the pump by the scale can be avoided.

  The water heater of the present invention can provide a highly reliable water heater by eliminating the suction of the generated scale into the pump and improving the life of the pump.

  According to a first aspect of the present invention, water is sucked from a suction pipe of the pump installed near the bottom of the hot water storage tank by a pump, and the hot water is heated by circulating the water in the hot water storage tank to a heating source. In a water heater that stores hot water in a tank, a perforated plate was installed in the hot water storage tank.

  As a result, the scale generated by the heating source accumulates on the perforated plate and does not reach the suction pipe. Therefore, the scale is not sucked into the pump, and the pump can be prevented from being clogged by the scale, thereby improving the life of the pump 7. Thus, a highly reliable hot water heater can be provided.

  The second invention is the first invention, in particular, in which the perforated plate is positioned above the suction pipe of the pump and installed horizontally in the hot water storage tank.

  As a result, the scale generated by the heating source accumulates on the perforated plate, and therefore does not reach the suction pipe. Therefore, the scale is not sucked into the pump, and the pump can be prevented from being clogged by the scale, thereby improving the life of the pump 7. Thus, a highly reliable hot water heater can be provided.

  The third invention is the first and second inventions in particular, and the hole formed in the perforated plate is made smaller than the diameter of the suction pipe.

Thereby, the scale generated by the heating source accumulates on the perforated plate and does not reach the suction pipe. Therefore, the scale is not sucked into the pump, and the clogging of the pump by the scale can be avoided. In addition, even if the scale passes through a hole in the perforated plate, the scale becomes finer than the diameter of the suction pipe, so it will not clog in the pump.
Therefore, a reliable hot water heater can be provided by improving the life of the pump 7.

  The fourth invention is the first to third inventions in particular, and the suction pipe is inserted substantially horizontally from the hot water tank side surface.

  This reduces the suction of the scale through the hole in the perforated plate and sinks to the bottom of the hot water storage tank into the pump, thus improving the life of the pump and improving the reliability of the hot water heater. Can be provided.

  In the fifth aspect of the invention, in particular, in the fourth aspect of the invention, a suction hole is formed on the bottom surface side of the hot water storage tank of the suction pipe.

  This reduces the suction of the scale through the hole in the perforated plate and sinks to the bottom of the hot water storage tank into the pump, thus improving the life of the pump and improving the reliability of the hot water heater. Can be provided.

  In the sixth invention, in particular, in the fourth and fifth inventions, a plurality of suction holes are formed.

  As a result, the pressure loss of the pump can be reduced, and the suction of the scale that has settled down to the bottom of the hot water storage tank through the hole in the perforated plate can be reduced, thus improving the pump life. Can provide a highly reliable water heater.

  In the seventh invention, in particular, in the fourth to sixth inventions, the suction hole is made smaller than the diameter of the suction pipe.

  As a result, the suction of the scale can be prevented more reliably, and a highly reliable water heater can be provided by improving the life of the pump.

  Since the eighth invention is a heat pump including a compressor as a heating source in the first to seventh inventions in particular, it can absorb atmospheric heat and boil hot water, thereby improving efficiency.

  In the ninth aspect of the invention, in particular, in the eighth aspect of the invention, a refrigerant whose pressure has been increased to a critical pressure or higher is used for the heat pump.

  As a result, the water is heated by the refrigerant whose pressure has been increased to the critical pressure or higher, so that the refrigerant is pressurized to the critical pressure or higher by the compressor. Even if it does not condense. Therefore, it becomes easy to form a temperature difference between the flow path on the refrigerant side and the flow path on the water side over the entire heat exchanger that heats the water with the refrigerant, so that hot water can be obtained and the heat exchange efficiency can be increased.

(Embodiment 1)
Hereinafter, a water heater according to an embodiment will be described with reference to the drawings. FIG. 1 is a circuit diagram of a heat pump water heater in an embodiment of the present invention.

  FIG. 1 is a configuration diagram of a hot water storage type heat pump hot water supply apparatus according to an embodiment of the present invention.

  The outline of the apparatus includes a hot water storage tank 8 in which low-temperature hot water and high-temperature hot water are stored in a layered state, and a heat pump 6 that is a heating source 1 for heating the hot water. The water is heated and boiled and stored in hot water for use in hot water supply.

  First, the configuration of the heat pump 6 that is the heating source 1 will be described.

  The heat pump 6 includes a compressor 2 that compresses the refrigerant, a radiator 3 that cools the refrigerant, a decompression unit 4 that decompresses the refrigerant, and a heat absorber 5 that evaporates and evaporates the refrigerant.

  The heat pump 6 is connected from the discharge side of the compressor 2 to the decompression means 4 via the radiator 3 and further connected to the suction side of the compressor 2.

  In this heat pump 6, carbon dioxide is used as a refrigerant, and the refrigerant compressed by the compressor 2 enters the radiator 3 as a high-temperature and high-pressure supercritical refrigerant and radiates and cools it here. Thereafter, the pressure is reduced in the pressure reducing means 4 to become low-temperature and low-pressure wet steam, and heat is exchanged with air in the heat absorber 5 to be evaporated and returned to the compressor 2.

  On the other hand, the structure related to boiling is connected from the lower part of the hot water storage tank 8 to the heat pump 6 through the boiling forward pipe 12 and from the heat pump 6 to the upper part of the hot water storage tank 8 through the boiling up return pipe 13. Then, a bypass pipe 14 bypasses from the middle of the boiling return pipe 13 to the lower part of the hot water storage tank 8. In addition, the lower part of the hot water storage tank 8 to which the boiling forward pipe 12 is connected may be a position where the hot water of the low temperature layer of the hot water storage tank 8 can be acquired.

  A three-way valve 9 is provided at the branch portion of the bypass pipe 14, and the return from the heat pump 6 to the hot water storage tank 8 is returned to the upper part of the hot water storage tank 8 by the boiling return pipe 13 or is returned to the lower part of the hot water storage tank 8 by the bypass pipe 14. It is the structure which can be selected arbitrarily. The upper part of the hot water storage tank to which the boiling return pipe 13 is connected may be a position where hot water returns to the high temperature layer side of the hot water storage tank 8, and the lower part of the hot water storage tank 8 means that hot water is stored in the hot water tank. Any position that returns to the low temperature layer side of the tank may be used.

  In order to send hot water from the hot water storage tank 8 to the heat pump 6 and return it to the hot water storage tank 8, a pump 7 capable of arbitrarily changing the output is provided in the middle of the boiling forward pipe 12. The pump 7 is inserted substantially horizontally near the bottom of the hot water storage tank 8.

  2 shows a view of the suction pipe 10 viewed from the bottom of the hot water storage tank 8, low temperature water near the bottom of the hot water storage tank 8 is sucked from the suction pipe port 10 having a plurality of suction holes 11 formed therein. The suction hole 11 is smaller than the diameter of the suction pipe 10.

  In the hot water storage tank 8, a porous plate 27 is installed substantially horizontally above the suction pipe 10 of the pump 7, and a hole 28 opened in the porous plate 27 is smaller than the diameter of the suction pipe 10.

  A perforated plate 27 is shown in FIG. In this example, the hole 28 is round, but the shape is not limited.

  Further, an incoming water temperature sensor 15 for detecting the temperature of the low hot water before being heated in the heat pump 6 is raised in the vicinity of the inlet side of the heat pump 6 of the boiling pipe 12 and a hot water temperature sensor 16 for detecting the temperature of the heated hot water is raised. The return pipe 13 is provided near the outlet of the heat pump 6. Further, in order to grasp the temperature distribution of the hot water storage tank 8, five hot water storage temperature sensors 17 are provided on the outer wall surface at equal intervals in the vertical direction.

  The hot water temperature sensor 16 and the hot water storage temperature sensor 17 are connected to the control means 26, and the control means 26 can grasp the detected temperatures of the hot water temperature sensor 16 and the hot water temperature sensor 17. The control means 26 controls the switching of the three-way valve 9 based on the detection results of the hot water temperature sensor 16 and the hot water temperature sensor 17.

  As a configuration relating to hot water supply, a water supply pipe 19 for supplying water from a water supply source is connected to the bottom of the hot water storage tank, and a water supply temperature sensor 18 is provided to detect the water supply temperature.

  A hot water supply pipe 21 is connected to the upper part of the hot water storage tank 8 to discharge the hot water stored in the hot water and use it for hot water supply. A water supply bypass pipe 22 from the water supply pipe 21 is connected to the hot water supply pipe 21. Moreover, the mixing valve 23 which can mix the high hot water from the hot water supply pipe 21 and the low hot water from the water supply bypass pipe 22 in arbitrary ratios is provided.

  On the downstream side of the mixing valve 23, a hot water supply temperature sensor 25 is provided to detect the mixed hot water supply temperature, and a hot water supply terminal 24 is connected to the end thereof.

  Further, regarding hot water supply using hot water in the hot water storage tank 8, when the hot water supply terminal 24 is opened for hot water supply, hot water in the hot water storage tank 8 is discharged from the hot water supply pipe 21 and from the water supply pipe 19 to the hot water storage tank 8. Water is supplied. With respect to the hot water supply temperature, the water supply is branched by the water supply bypass pipe 22, and high hot water from the hot water storage tank 8 and low hot water from the water supply are mixed at the mixing valve 23 by changing the mixing ratio, thereby changing the hot water supply temperature. Hot water is supplied to 24. The mixing ratio at this time is controlled in accordance with the hot water temperature detected by the hot water temperature sensor 25 and is kept at a predetermined hot water temperature. Since hot water is supplied by mixing the hot water and water in the hot water storage tank 8 and lowering the temperature, the hot water temperature in the hot water storage tank is significantly higher than the hot water temperature of 40 ° C. to about 50 ° C. The heat storage density of the hot water tank 21 can be increased by setting the temperature to about 90 ° C.

  In the hot water storage type heat pump hot water supply apparatus configured as described above, its operation and action will be described below.

  Hereinafter, a description will be given based on FIG.

  In the heat pump 6, the refrigerant compressed by the compressor 2 enters the radiator 3 as a high-temperature and high-pressure refrigerant in a supercritical state, where it dissipates heat and cools it. Thereafter, the pressure is reduced in the pressure reducing means 4 to become low-temperature and low-pressure wet steam, and heat is exchanged with air in the heat absorber 5 to be evaporated and returned to the compressor 2. At this time, the hot water in the low temperature layer under the hot water storage tank 8 is heated by absorbing the heat of the radiator 3.

  On the other hand, in the hot water storage operation in which the low temperature hot water in the lower part of the hot water storage tank is heated by the heat pump 6 and returned to the hot water storage tank 8, the three-way valve 9 is switched to the bypass pipe 14 side when the heat pump 6 is stopped. And the heat pump 6 is started, the pump 7 is driven, and the low hot water from the hot water storage tank 8 is heated.

  The temperature of the water heated by the heat pump 6 is detected by the tapping temperature sensor 16 and the output of the pump 7 is changed to control the tapping temperature from the heat pump 6 so as to achieve the target temperature.

  The detected hot water temperature detected by the hot water temperature sensor 16 and the detected temperature detected by the incoming water temperature sensor 15 installed at the inlet of the radiator 3 and the feed water temperature sensor 18 on the outer surface of the hot water storage tank 8 are sent to the control means 26. Is output. And the control means 26 determines and controls the switching timing to the boiling return pipe | tube 24 side of the three-way valve 16 based on the hot water temperature and the temperature of the hot water of the hot water storage tank lower part.

  Although the water supply temperature sensor 18 is attached to the lower part of the hot water tank 1 as shown in FIG. 1, the temperature of the hot water in the low temperature layer of the high temperature and low temperature layers formed in the hot water tank 1 can be measured. Any position is acceptable.

  When the temperature detected by the tapping temperature sensor 16 is higher than the predetermined temperature and the temperature detected by the feed water temperature sensor 18 is lower than the predetermined temperature, the control means 26 moves the three-way valve 9 to the boiling return pipe 13 side. When the detected temperature is higher than the predetermined temperature, the three-way valve 9 is switched to the bypass pipe 14 side.

  When the temperature detected by the hot water temperature sensor 16 is lower than the predetermined temperature, the hot water temperature sensor 18 detects the hot water temperature of the low hot water layer below the hot water storage tank 8, and the detected temperature is higher than a predetermined temperature. If it is lower, the control means 26 sets the three-way valve 9 to the bypass pipe 14 side, and switches the three-way valve 9 to the boiling return pipe 13 side if the detected temperature is higher than a predetermined temperature set in advance.

  The processing procedure of the control means 26 is represented by the flowchart shown in FIG. In FIG. 4, the detected temperature of the hot water temperature sensor 16 is X, and the detected temperature of the feed water temperature sensor 18 is Y.

  First, the outputs of the hot water temperature sensor 16 and the feed water temperature sensor 18 are received (step S201).

  Next, the temperature detected by the tapping temperature sensor 16 is compared with a preset first predetermined temperature (step S202).

  As a result, if the first predetermined temperature is higher than the detected temperature of the hot water temperature sensor 16, the detected temperature of the hot water supply temperature sensor 18 is compared with a preset second predetermined temperature (step S203).

  Next, if the temperature detected by the hot water supply temperature sensor 18 is higher than the second predetermined temperature, the three-way valve 9 is switched to the boiling return pipe 13 side (step S204).

  If the second predetermined temperature is higher than the detected temperature of the hot water supply temperature sensor 18, the three-way valve 9 is switched to the bypass pipe 14 side (step S205).

  If the detected temperature of the tapping temperature sensor 16 is higher than the first predetermined temperature as a result of step 202, the detected temperature of the hot water supply temperature sensor 18 is compared with a preset third predetermined temperature (step). S206).

  Next, if the third predetermined temperature is higher than the temperature detected by the hot water supply temperature sensor 18, the three-way valve 9 is switched to the bypass pipe 14 side (step S207).

  If the temperature detected by the hot water supply temperature sensor 18 is higher than the third predetermined temperature, the three-way valve 9 is switched to the boiling return pipe 13 side (step S208).

  In this way, during the hot water storage operation in which hot water is stored in the hot water storage tank 8, if the hot water temperature detected by the radiator 3 with the tapping temperature sensor is heated to about 80 ° C. or higher, the heating part of the radiator 3 is charged with water. The melted impurities are deposited as scale, peeled off, and sent through the boiling return pipe 13 into the hot water storage tank 8. At this time, the scale settling in the hot water storage tank is deposited on the porous plate 27 and is not sucked into the pump from the suction pipe.

  In addition, even if the scale passes through the hole in the perforated plate and settles to the bottom of the hot water storage tank, the suction of the scale into the pump can be reduced, and further, the pump pressure loss can be reduced, so the life of the pump Can be improved.

  As described above, the hot water supply apparatus according to the present invention is useful as a highly reliable hot water heater by eliminating the suction of the generated scale into the pump 7 and improving the life of the pump 7.

Circuit diagram of a water heater in an embodiment of the present invention Drawing of the suction pipe in the embodiment of the present invention Diagram of a perforated plate in an embodiment of the present invention Control flow diagram in the embodiment of the present invention Circuit diagram of a conventional water heater

Explanation of symbols

1 Heating Source 2 Compressor 6 Heat Pump 7 Pump 8 Hot Water Storage Tank 10 Suction Pipe 11 Suction Hole 27 Perforated Plate 28 Hole

Claims (9)

The pump draws water from the suction pipe of the pump installed near the bottom of the hot water storage tank, heats the hot water storage tank by circulating it through a heating source, and stores hot hot water in the hot water storage tank. A hot water heater according to claim 1, wherein a perforated plate is installed in the hot water storage tank. The hot water heater according to claim 1, wherein the perforated plate is located above the suction pipe of the pump and is installed substantially horizontally in the hot water storage tank. The water heater according to claim 1 or 2, wherein the hole formed in the perforated plate is smaller than the diameter of the suction pipe. The hot water supply device according to any one of claims 1 to 3, wherein the suction pipe is inserted substantially horizontally from a side surface of the hot water storage tank. The water heater according to any one of claims 1 to 4, wherein a suction hole is formed on a bottom surface side of the hot water storage tank of the suction pipe. The water heater according to claim 5, wherein a plurality of suction holes are formed. The water heater according to claim 6, wherein the suction hole is smaller than the diameter of the suction pipe. The hot water supply device according to any one of claims 1 to 7, wherein the heating source is a heat pump including a compressor. The heat pump water heater according to claim 8, wherein a refrigerant whose pressure is raised to a critical pressure or higher is used for the heat pump.

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