JP3979420B2 - Water heater - Google Patents

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 second heating means 31 heats the water below the suction inlet pipe 10. 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.

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

  In the conventional invention, the suction port pipe 10 is installed slightly above the bottom of the hot water storage tank 8 so that the scale generated by the first heating means 30 and the second heating means 31 is not sucked from the suction pipe port 10.

Furthermore, since the water near the bottom of the suction pipe 10 cannot be heated by the first heating means 30, the water near the bottom of the hot water storage tank 8 is heated by the second heating means 31 (see Patent Document 1).
JP 2000-179941 A

  However, in the above configuration, in order to ensure an effective amount of stored hot water for hot water supply, the water near the bottom of the hot water storage tank 8 at a position lower than the suction pipe 10 must be heated, and the second heating means is newly added. It was necessary to provide in.

  Therefore, since the second heating means 31 is provided in the hot water storage tank 8, the volume of the second heating means 31 and the effective hot water storage amount are reduced.

  An object of the present invention is to provide a hot water supply device with little hot water shortage by securing an effective hot water storage amount without providing new heating means and effectively utilizing a hot water storage tank 8.

  In order to achieve this object, the water heater of the present invention circulates water from the bottom of the hot water storage tank by means of a pump, whereby the hot water is heated to a predetermined temperature in a hot water heater that heats the water in the hot water storage tank by a heating source. When the temperature does not reach, heated hot water is led to the bottom of the hot water storage tank, and when the temperature is higher than a predetermined temperature, the heated hot water is led to the upper part of the hot water storage tank, Heated by a heat source at the time of final boiling operation just before the heating of the hot water in the hot water storage tank is completed, and the suction port of the suction pipe that guides the water in the vicinity of the hot water storage tank located near the bottom to the pump. The water heater is provided with control means for controlling the three-way valve so as to guide the hot water to the bottom of the hot water storage tank.

  This makes it possible to create a flow that draws water at the bottom of the hot water storage tank, which is lower than the suction pipe, which is difficult to be heated during the final boiling operation, into the suction pipe, and draws low-temperature water at the bottom of the hot water storage tank from the suction pipe. And since it can heat with a heat radiator, the amount of effective hot water storage is securable without using a 2nd heating means.

  The hot water supply apparatus of the present invention can provide a hot water supply apparatus with little hot water shortage by securing an effective hot water storage amount without providing new heating means and making effective use of the hot water storage tank.

  In a hot water heater that heats water in a hot water storage tank by a heating source by circulating water from the bottom of the hot water storage tank by a pump, the first invention is heated when the heated hot water does not reach a predetermined temperature. The hot water was led to the bottom of the hot water storage tank, and when the temperature was higher than a predetermined temperature, a three-way valve for controlling the hot water to be led to the upper part of the hot water storage tank and a little above the bottom of the hot water storage tank were installed. The inlet of the inlet pipe for guiding the water near the bottom of the hot water storage tank to the pump, and the hot water heated by the heating source during the final boiling operation just before the heating of the hot water in the hot water tank is completed. The water heater is provided with control means for controlling the three-way valve so as to lead to the bottom.

  This makes it possible to create a flow that draws water at the bottom of the hot water storage tank, which is lower than the suction pipe, which is difficult to be heated during the final boiling operation, into the suction pipe, and draws low-temperature water at the bottom of the hot water storage tank from the suction pipe. Since the effective amount of hot water can be secured without using the second heating means, the hot water storage tank can be used effectively to provide a hot water heater with less hot water.

  The second invention is the first invention, in particular, comprising an incoming water temperature sensor for detecting the water temperature of the suction section of the pump, and when the temperature of the incoming water temperature sensor reaches a predetermined temperature, the three-way valve is placed at the bottom of the hot water storage tank. Control means to control was installed on the lead side.

  As a result, it is possible to reliably detect the boiling end operation, and to create a flow for sucking water at the bottom of the hot water storage tank at a position lower than the suction pipe, which is difficult to be heated at the end of boiling operation, into the suction pipe. Low-temperature water can be sucked from the inlet pipe and heated by a radiator, and the effective hot water storage amount can be secured without using the second heating means. By making effective use of the internal volume of the hot water storage tank, A small number of water heaters can be provided.

  The third invention is the first invention, in particular, comprising a feed water temperature sensor for detecting the temperature near the bottom of the hot water storage tank, and when the temperature of the feed water temperature sensor reaches a predetermined temperature, the three-way valve is installed at the bottom of the hot water storage tank The control means to control was installed on the side leading to.

  As a result, it is possible to reliably detect the boiling end operation, and to create a flow for sucking water at the bottom of the hot water storage tank at a position lower than the suction pipe, which is difficult to be heated at the end of boiling operation, into the suction pipe. Low-temperature water can be sucked from the inlet pipe and heated by a radiator, and the effective hot water storage amount can be secured without using the second heating means. By making effective use of the internal volume of the hot water storage tank, A small number of water heaters can be provided.

  The fourth aspect of the invention is the first to third aspects of the invention, in which the suction pipe is inserted substantially horizontally from the side surface of the hot water storage tank.

  This makes it possible to create a flow that draws water at the bottom of the hot water storage tank, which is lower than the suction pipe, which is difficult to be heated during the final boiling operation, into the suction pipe, and draws low-temperature water at the bottom of the hot water storage tank from the suction pipe. Since the effective amount of hot water can be secured without using the second heating means, the hot water storage tank can be used effectively to provide a hot water heater with less hot water.

  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 port pipe.

  This makes it possible to create a flow that allows the water at the bottom of the hot water storage tank, which is lower than the suction pipe, which is difficult to be heated during the final boiling operation, to be sucked into the suction pipe, and the low temperature water at the bottom of the hot water storage tank is Since the effective amount of stored hot water can be secured without using the second heating means, the hot water storage tank can be used effectively to provide a hot water heater with less hot water.

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

  This makes it possible to create a flow that allows the water at the bottom of the hot water storage tank, which is lower than the suction pipe, which is difficult to be heated during the final boiling operation, to be sucked into the suction pipe, and the low temperature water at the bottom of the hot water storage tank is Since the effective amount of stored hot water can be secured without using the second heating means, the hot water storage tank can be used effectively to provide a hot water heater with less hot water.

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

  As a result, the suction of the scale can be prevented more reliably, and a flow can be made to better suck the water at the bottom of the hot water storage tank located at a lower position than the suction pipe that is difficult to be heated at the end of boiling operation into the suction pipe, Low-temperature water at the bottom of the hot water storage tank can be sucked from the inlet pipe and heated with a radiator, and the effective hot water storage amount can be secured without using the second heating means. A hot water heater with a small amount of water can be provided.

  The eighth invention is a heat pump including a compressor as a heating source in the first to seventh inventions.

  It is possible to create a flow that allows the water at the bottom of the hot water storage tank, which is lower than the suction pipe, which is difficult to be heated at the end of boiling operation, to be sucked into the suction pipe, and the low temperature water at the bottom of the hot water storage tank is sucked from the suction pipe. Therefore, the hot water storage tank can be secured without using the second heating means. Therefore, by making effective use of the hot water storage tank, it is possible to provide a hot water heater with less hot water.

  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, the water heater according to Embodiment 1 will be described with reference to the drawings. FIG. 1 is a circuit diagram of a water heater in 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 for 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.

  Further, in the heat pump 6, carbon dioxide is used as the 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 form low-temperature and low-pressure wet steam, and the heat absorber 5 exchanges heat with air to evaporate and return to the compressor 2.

  On the other hand, the structure related to boiling of hot water is connected to the heat pump 6 from the lower part of the hot water storage tank 8 through the boiling forward pipe 12, and connected 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 suction pipe 10 of the pump 7 is inserted substantially horizontally near the bottom of the hot water storage tank 8. As shown in FIG. 2, when the suction pipe 10 is 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 10 having a plurality of suction holes 11. The suction hole 11 is made smaller than the diameter of the suction port pipe 10.

  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.

  And in order to grasp | ascertain the temperature distribution of the hot water storage tank 8, the hot water storage temperature sensor 17 of 5 points | pieces is provided in the outer wall surface at equal intervals in the orthogonal | 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 the water supply source is decompressed to an appropriate pressure by a pressure reducing valve 20 and enters the water supply pipe 19. In addition, 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 19 is connected to the hot water storage pipe 8. 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 storage tank 8 can be increased by setting the temperature to about 90 ° C.

  In the water heater configured as described above, the operation and action will be described below with reference to 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. 3, 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, the control means for controlling the three-way valve is installed so that the hot water heated by the heating source is guided to the bottom of the hot water storage tank during the boiling end operation when the hot water storage tank is filled with hot water of almost high temperature. It is possible to create a flow that sucks the water at the bottom of the hot water storage tank, which is lower than the suction pipe, which is difficult to be heated during operation, into the suction pipe, and draws low-temperature water at the bottom of the hot water storage tank from the suction pipe to the Since it can heat, the amount of effective hot water storage can be ensured, without using a 2nd heating means.

(Embodiment 2)
In the first embodiment, the three-way valve 9 is controlled based on the temperature detected by the water supply temperature sensor 18 at the lower part of the hot water storage tank 8. Is used to control the three-way valve 9.

  Hereinafter, the operation will be described, but the description of the same operation as that of the first embodiment will be omitted. FIG. 1 is a configuration diagram showing the second embodiment.

  The processing procedure of the control means 26 is represented by the flowchart shown in FIG.

  When the temperature detected by the hot water temperature sensor 16 is higher than the predetermined temperature and the temperature detected by the incoming water temperature sensor 15 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 incoming water temperature sensor 15 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 the predetermined temperature set in advance. 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.

  In FIG. 4, the detected temperature of the hot water temperature sensor 16 is X, and the detected temperature of the incoming water temperature sensor 15 is Z.

  First, the outputs of the hot water temperature sensor 16 and the incoming water temperature sensor 15 are received (step S301). Next, the temperature detected by the tapping temperature sensor 16 is compared with a preset first predetermined temperature (step S302). 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 incoming water temperature sensor 15 is compared with a preset second predetermined temperature (step S303).

  Next, if the temperature detected by the incoming water temperature sensor 15 is higher than the second predetermined temperature, the three-way valve 9 is switched to the boiling return pipe 13 side (step S304). If the second predetermined temperature is higher than the detected temperature of the incoming water temperature sensor 15, the three-way valve 9 is switched to the bypass pipe 14 side (step S305). If the detected temperature of the hot water temperature sensor 16 is higher than the first predetermined temperature as a result of step 302, the detected temperature of the incoming water temperature sensor 15 is compared with a preset third predetermined temperature (step). S306).

  Next, if the third predetermined temperature is higher than the detected temperature of the incoming water temperature sensor 15, the three-way valve 9 is switched to the bypass pipe 14 side (step S307). If the detected temperature of the incoming water temperature sensor 15 is higher than the third predetermined temperature, the three-way valve 9 is switched to the boiling return pipe 13 side (step S308).

  In this way, the control means for controlling the three-way valve is installed so that the hot water heated by the heating source is guided to the bottom of the hot water storage tank during the boiling end operation when the hot water storage tank is filled with hot water of almost high temperature. It is possible to create a flow that sucks the water at the bottom of the hot water storage tank, which is lower than the suction pipe, which is difficult to be heated during operation, into the suction pipe, and draws low-temperature water at the bottom of the hot water storage tank from the suction pipe to the Since it can heat, the amount of effective hot water storage can be ensured, without using a 2nd heating means.

  As described above, the hot water supply apparatus according to the present invention is useful as a hot water supply device with less hot water shortage by ensuring the effective hot water storage amount without providing new heating means and effectively utilizing the internal volume of the hot water storage tank. It is.

Circuit diagram of a water heater in an embodiment of the present invention The figure of the suction inlet pipe in embodiment of this invention Control flow diagram in Embodiment 1 of the present invention Control flow diagram in Embodiment 2 of the present invention Circuit diagram of a conventional water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating source 2 Compressor 6 Heat pump 7 Pump 8 Hot water storage tank 9 Three-way valve 10 Suction port pipe 11 Suction hole 15 Incoming water temperature sensor 18 Supply water temperature sensor 26 Control means

Claims (9)

In a water heater that heats water in a hot water storage tank by a heating source by circulating water from the bottom of the hot water storage tank using a pump, if the heated hot water does not reach a predetermined temperature, the heated hot water is A three-way valve that controls the hot water to be led to the upper part of the hot water storage tank and a hot water tank located near the bottom of the hot water storage tank. The inlet of the inlet pipe for guiding water to the pump, and the hot water heated by the heating source during the final boiling operation just before the hot water in the hot water tank is completed is guided to the bottom of the hot water tank. A water heater provided with a control means for controlling the three-way valve. 2. A water inlet temperature sensor for detecting the water temperature of the suction part of the pump, and the control means controls the three-way valve to a side leading to the bottom of the hot water storage tank when the temperature of the water inlet temperature sensor reaches a predetermined temperature. Water heater. A water supply temperature sensor for detecting a temperature in the vicinity of the bottom of the hot water storage tank is provided, and the control means controls the three-way valve to the side leading to the bottom of the hot water storage tank when the temperature of the water supply temperature sensor reaches a predetermined temperature. 1. The water heater according to 1. 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 claim 4, wherein a suction hole is formed in the 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 any one of claims 4 to 6, wherein the suction hole is made 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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