JP2007278543A - Water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water heater 11 capable of preventing shortage of hot water caused by reduction of the amount of remaining hot water in an antifreezing operation, preventing unnecessary reheating, and saving electric power. <P>SOLUTION: When conditions of an antifreezing operation for bathtub water in a circulation pipe 23 are satisfied, a circulation pump 28 is driven and the antifreezing operation is performed. The amount of remaining hot water is increased by reheating the hot water in a hot water storage tank 15 by heaters 19, 20 on the basis of conditions of both of execution of the antifreezing operation and detection of reduction of the amount of remaining hot water by a remaining hot water detecting means 51. The unnecessary reheating is prevented to save electric power under conditions excluding both of the control of antifreezing operation and the detection of reduction of the amount of remaining hot water by the remaining hot water detecting means 51. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hot water supply device having a function of raising the temperature of hot water in a bathtub by exchanging heat with hot water in a hot water storage tank.

  Conventionally, in a hot water supply device that stores hot water heated in a hot water storage tank and supplies hot water from the hot water storage tank, the hot water in the hot water storage tank and the hot water in the bathtub are heat-exchanged to keep the hot water in the bathtub warm or retreat. There is a hot water supply device having a function of keeping warm.

  In this hot water supply device, a heat exchanger is disposed on the upper side in the hot water storage tank, a circulation pipe is connected between the heat exchanger and the bathtub, and a circulation pump is disposed in the circulation pipe. The hot water in the bathtub is circulated with respect to the heat exchanger by driving the circulation pump, and the temperature of the hot water in the bathtub being circulated is increased by heat exchange in the heat exchanger.

  By the way, when using this hot water supply device in an environment where the outside air temperature falls below the freezing temperature, such as in a cold district, if hot water is contained in the bathtub, the hot water may freeze in the circulation piping or circulation pump. When the outside air temperature falls below a predetermined temperature or when the hot water temperature in the circulation pipe falls below the predetermined temperature, an antifreeze operation may be performed to drive the circulation pump to circulate hot water in the circulation pipe or circulation pump. It is known (see, for example, Patent Document 1).

  However, by performing anti-freezing operation, the hot water in the hot water storage tank and the hot water in the bathtub are used for heat exchange, so the temperature of the hot water in the hot water storage tank decreases, the remaining hot water volume decreases, and hot water may run out. is there. In particular, repeated freezing prevention operations during daytime hours have reduced the amount of hot water that can be used around the evening when hot water is used most. There is a risk of running out of hot water when used for reheating hot water.

  Therefore, during freezing prevention operation, only the amount of hot water corresponding to the capacity of the circulation pipe is circulated to suppress the decrease in the amount of hot water in the hot water storage tank due to heat exchange between the hot water in the hot water storage tank and the hot water in the bathtub. Yes (see, for example, Patent Document 2).

  However, although it is possible to suppress the decrease in the amount of hot water in the hot water storage tank due to anti-freezing operation, the heat of the hot water in the hot water storage tank decreases and the amount of hot water remaining decreases as long as heat is exchanged between the hot water in the hot water storage tank and the hot water in the bathtub. There is a risk of running out of hot water.

In addition, the hot water supply device monitors the amount of hot water in the hot water storage tank in order to cope with hot water shortage, and when the remaining hot water amount falls below a predetermined amount or when hot water is used above a predetermined amount, It is possible to set a boiling increase function for boiling a predetermined amount or the entire amount.
JP 2003-269787 A (page 3, FIG. 1) JP 2004-150688 A (page 5-6, FIG. 1-2)

  As described above, the amount of remaining hot water in the hot water storage tank decreases due to the freeze prevention operation, and there is a possibility that hot water runs out. In particular, the decrease in the amount of remaining hot water due to the use of hot water by the user is easy for the user to be aware of, but there is a problem that the amount of remaining hot water decreases due to freeze prevention operation without the user's awareness. Otherwise, the hot water may run out.

  In addition, if the conventional boiling increase operation is set to cope with the decrease in the remaining hot water amount in the hot water storage tank due to the freeze prevention operation, the boiling increase operation is performed even if the remaining hot water amount decreases due to the use of normal hot water, which is unnecessary. There is a problem that it takes up an extra electricity bill by boiling.

  The present invention has been made in view of the above points, and provides a hot water supply device that can prevent hot water shortage due to a decrease in the amount of remaining hot water in the freeze prevention operation, and can prevent unnecessary boiling and save electricity. With the goal.

  The hot water supply apparatus according to claim 1 is a hot water storage tank for storing hot water, a boiling means for boiling the hot water in the hot water storage tank, a remaining hot water amount detecting means for detecting a remaining hot water amount in the hot water storage tank, and the hot water storage tank. A heat exchanger for exchanging heat between the hot water in the bathtub and the hot water in the bathtub, a circulation pipe connecting the heat exchanger and the bathtub, and a circulation pump for circulating the hot water in the bathtub to the heat exchanger through the circulation pipe The heat exchange means, the anti-freezing detecting means for detecting that the anti-freezing operating condition for performing the anti-freezing operation of the circulation pipe, and the anti-freezing operating means are detected by the anti-freezing detecting means. The anti-freezing operation control means for driving the circulation pump to prevent the freezing operation and the anti-freezing operation by the anti-freezing operation control means, and the remaining hot water amount detecting means When detecting a small, but that and a boiling up operation control means for increasing the remaining hot water increases boiling hot water of the hot water storage tank in the heating-up means.

  The hot water supply device according to claim 2 is the hot water supply device according to claim 1, wherein the freezing and boiling increase operation when the remaining hot water amount is reduced by the freeze prevention operation and the normal boiling increase operation when the remaining hot water amount is reduced by other than the freeze prevention operation are performed. A boiling increase setting means is provided, and the boiling increase operation control means is configured to perform the operation other than the freeze prevention operation unless the normal boiling increase operation is set even if the freeze boiling increase operation is set by the boiling increase setting means. Even if a decrease in the amount of remaining hot water is detected, the boiling increase operation is not performed.

  According to the hot water supply apparatus of claim 1, when the decrease in the remaining hot water amount is detected by the remaining hot water amount detecting means by the antifreezing operation by the antifreezing operation control means, the hot water in the hot water storage tank is boiled by the boiling means. In addition, the amount of remaining hot water is increased, so that hot water shortage due to a decrease in the amount of remaining hot water during anti-freezing operation can be prevented, and the anti-freezing operation by the anti-freezing operation control means and the detection of the decrease in remaining hot water amount by the means for detecting remaining hot water. Under both conditions, unnecessary boiling can be prevented and power can be saved.

  According to the hot water supply device of claim 2, in addition to the effect of the hot water supply device of claim 1, even if the freeze boiling increase operation is set, if the normal boiling increase operation is not set, other than the freeze prevention operation Even if a decrease in the amount of remaining hot water is detected, the boiling increase operation is not performed, so unnecessary boiling increases can be prevented and power can be saved.

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

  As shown in FIG. 1, the hot water supply device 11 has a hot water supply function of supplying hot water to a hot water supply place such as a hot water tap, and also has a function of automatically filling hot water in the bathtub 12 or keeping warm and reheating. Yes.

  The hot water supply body 13 provided in the hot water supply device 11 is provided with a hot water storage tank 15 of an electric water heater 14, and the water supply pipe 16 piped to a water supply source such as a water pipe is connected to the lower side of the hot water storage tank 15 via a pressure reducing valve 17. The upper and lower heaters 19 and 20 are connected to the upper side of the hot water storage tank 15, and the upper and lower heaters 19 and 20 as boiling means for boiling the hot water in the hot water storage tank 15 are connected to the upper and lower sides of the hot water storage tank 15. It is arranged. The hot water in the hot water storage tank 15 is heated and stored in the hot water storage tank 15 by the heaters 19 and 20, and the hot water in the hot water storage tank 15 is pushed up by the hot water pressure applied to the lower side of the hot water storage tank 15 by hot water at each hot water supply place. Hot water is supplied from the upper hot water supply pipe 18.

  A heat exchanger 22 is arranged on the upper side in the hot water storage tank 15, and the heat exchanger 22 and the bathtub 12 are connected by a circulation pipe 23. The circulation pipe 23 has an outward path 24 and a return path 25 with respect to the bathtub 12 as viewed from the heat exchanger 22 side. An outward thermistor 26 is disposed in the outward path 24. On the return path 25, a flow switch 27 for detecting the circulation of hot water in the bathtub 12, a circulation pump 28 for circulating the hot water in the bathtub 12 to the heat exchanger 22, an electric three-way valve 29 as a switching valve for switching the flow path, and detecting the water level A water level sensor 30 and a return thermistor 31 are disposed. In addition, a bypass path 32 is connected between the forward path 24 and the circulation pump 28 and the electric three-way valve 29 in the return path 25, allowing the hot water to flow from the return path 25 to the forward path 24. A check valve 33a that prevents the flow of hot water from the return path 25 to the return path 25 is disposed, allowing the flow of hot water to the bathtub 12 in the forward path 24 between the heat exchanger 22 and the bypass path 32, and the heat exchanger 22 A check valve 33b is provided to block the flow of hot water to the water.

  Further, the downstream side of the pressure reducing valve 17 of the water supply pipe 16 and the hot water supply pipe 18 are connected to the hot water mixing valve 35 and the bathtub mixing valve 36, respectively. These mixing valves 35 and 36 mix the water supplied through the water supply pipe 16 and the hot water supplied through the hot water supply pipe 18 and discharge hot water at a set temperature from the discharge side according to the mixing ratio.

  A hot water supply pipe 37 for connecting hot water to the hot water supply location is connected to the discharge side of the hot water mixing valve 35. A flow sensor 38 for detecting the hot water flow rate and a hot water thermistor 39 for detecting the hot water temperature are provided on the hot water supply pipe 37, respectively. Has been.

  On the discharge side of the bathtub mixing valve 36, a bathtub pipe 41 connected to the electric three-way valve 29 disposed in the return path 25 of the circulation pipe 23 is connected. The bathtub pipe 41 is provided with a simple hopper 42. The simple hopper 42 allows the flow of hot water from the bathtub mixing valve 36 side to the electric three-way valve 29 side to allow the bathtub from the electric three-way valve 29 side. Check valve 43 that prevents backflow of hot water to the mixing valve 36 side, water supply solenoid valve 44 that opens the bathtub piping 41 when hot water is filled, and closes the bathtub piping 41 during standby, and a flow rate that detects the hot water flow rate A sensor 45 and the like are provided.

  The electric three-way valve 29 communicates the bathtub pipe 41 with the bypass path 32 side of the return path 25 of the circulation pipe 23 and closes the bathtub 12 side of the return path 25 of the circulation pipe 23 when hot water is supplied to the bathtub 12. During the circulation of hot water in the bathtub 12, the bathtub pipe 41 side is closed and the return path 25 of the circulation pipe 23 is opened.

  The bathtub mixing water supply valve 36, the bathtub piping 41, the electric three-way valve 29, the circulation piping 23, and the like constitute the hot water supply means 46 for the bathtub that uses the hot water in the hot water storage tank 15 to supply hot water at the set temperature to the bathtub 12. Has been. In addition, heat exchange means 47 that heat-exchanges the hot water in the hot water storage tank 15 and the hot water filled in the bathtub 12 with the heat exchanger 22, the circulation pipe 23, the circulation pump 28, etc., and raises the temperature of the hot water in the bathtub 12 is provided. It is configured.

  The hot water storage tank 15 is provided with a remaining hot water amount detecting means 51 for detecting the remaining hot water amount in the hot water storage tank 15. The remaining hot water amount detecting means 51 is, for example, a hot water temperature sensor 52 at each position where the remaining hot water amounts from the upper part of the hot water storage tank 15 are 20 L, 60 L, 120 L, 180 L, and hot water hot water at a position near the lower heater 20. A temperature sensor 53 is provided.

  The hot water supply device body 13 is provided with an outside air temperature detection sensor 55 that detects the outside air temperature.

  As shown in FIG. 2, the hot water supply device 11 includes a control unit 61 that controls the hot water supply device 11. The control unit 61 includes an anti-freezing operation and a boiling increase operation, a remaining hot water amount detection means 51, an anti-freezing detection means 62 for detecting that the anti-freezing operation condition for performing the anti-freezing operation of the circulation pipe 23 is satisfied, The boiling increase setting means 63 for setting the operation, the circulation pump 28, the heaters 19, 20 and the like are connected.

  The freeze prevention detection means 62 includes a return-side thermistor 31, an outside air temperature detection sensor 55, and the like. For example, when the detection temperature of the outside-air temperature detection sensor 55 is 3 ° C. or less and the detection temperature of the return-side thermistor 31 is less than 7 ° C. In addition, it is detected that the anti-freezing operation condition for performing the anti-freezing operation of the circulation pipe 23 is satisfied.

  The boiling increase setting means 63 is composed of a remote control or the like, and is used for freezing and boiling increase operation when the remaining hot water amount is reduced by freeze prevention operation, and for other than freeze prevention operation, hot water for the bathtub, hot water supply to the shower, etc. Set normal boiling-up operation when the amount of normal remaining hot water is reduced due to the use of hot water. For normal boiling increase operation, small boiling increase operation in which only a small amount is boiled to reach 60 L when the remaining hot water volume is less than 60 L, full boiling increase operation in which the entire amount is boiled only once on the setting day, for example, from 7:00 to 17:00 When 60L is used during the daytime period, the total amount is boiled any number of times, and when the remaining hot water volume is less than 60L from 17:00 to the start time of the nighttime period, only a small amount is increased so that it becomes 60L. It is possible to select operation.

  Then, the control unit 61 functions as the anti-freezing operation control unit 64 for driving the circulation pump 28 to perform the anti-freezing operation when the anti-freezing detecting unit 62 detects that the anti-freezing operation condition is satisfied, When the decrease in the remaining hot water amount is detected by the remaining hot water amount detecting means 51 by causing the freeze prevention operation control means 64 to perform the antifreezing operation, the heaters 19 and 20 boil the hot water in the hot water storage tank 15 to increase the remaining hot water amount. It has the function of the boiling increase operation control means 65. The detection of the decrease in the remaining hot water amount by the remaining hot water amount detecting means 51 is performed when the remaining hot water amount is 120L or more and less than 180L, or the detection temperatures of the 120L and 180L hot water temperature sensors 52 and the hot water temperature sensor 53 are all 75 ° C. or lower. And when. The freeze boiling increase operation is performed at least in the daytime period from, for example, 7 o'clock to 17 o'clock, and at least the decrease in the amount of remaining hot water due to the freeze prevention operation is increased.

  Regarding the boiling increase operation control means 65, in particular, even if the freezing and boiling increase operation is set by the boiling increase setting means 63, if the normal boiling increase operation is not set, a decrease in the remaining hot water amount is detected by means other than the freeze prevention operation. Even if it has a function not to increase boiling operation.

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

  In the electric water heater 14, the heaters 19 and 20 are energized in a specific time zone such as a night time zone when the electricity rate is low in the hourly lighting system, and the water and the remaining hot water supplied to the hot water storage tank 15 are heated to a predetermined temperature. Boil and store hot water.

  Hot water is supplied through the hot water supply pipe 37 by mixing hot water supplied through the hot water supply pipe 16 and hot water supplied through the hot water supply pipe 18 by the hot water mixing valve 35 with a set temperature.

  In addition, when filling the bathtub 12, the electric three-way valve 29 closes the bathtub 12 side of the return path 25 of the circulation pipe 23 and connects the bathtub pipe 41 and the bypass path 32 side of the return path 25 of the circulation pipe 23, Open the water supply solenoid valve 44, mix the water supplied through the water supply pipe 16 and the hot water supplied through the hot water supply pipe 18 at the mixing valve 36 for the bathtub with the hot water set at the set temperature, the pipe 41 for the bathtub, the electric three-way valve 29. Hot water is supplied to the bathtub 12 through the return path 25, the bypass path 32, and the forward path 24 of the circulation pipe 23, and the hot water is filled.

  The flow rate sensor 45 disposed in the simple hopper 42 detects that the amount of hot water supplied to the bathtub 12 has reached the set amount, or the water level sensor 30 disposed in the return path 25 sets the water level filled in the bathtub 12 When it is detected that the water level has been reached, the water supply solenoid valve 44 is closed to stop the hot water supply.

  In addition, after filling the bathtub 12, the hot water in the bathtub 12 is kept at a set temperature by the heat exchanging means 47 by automatic warming operation every predetermined time or by setting the reheating with a remote controller (not shown), Alternatively, the temperature is raised to about 1 to 1.5 ° C. higher than the set temperature.

  In the heat exchanging means 47, after closing the bathtub pipe 41 side with the electric three-way valve 29 and opening the return path 25 of the circulation pipe 23, the circulation pump 28 is operated, whereby the hot water in the bathtub 12 is supplied to the circulation pipe 23. The return path 25, the electric three-way valve 29, the circulation pump 28, the heat exchanger 22, and the forward path 24 are circulated back to the bathtub 12. Heat is exchanged between the hot water flowing in the heat exchanger 22 and the hot water in the hot water storage tank 15, and the hot water heated is returned to the bathtub 12 to raise the hot water temperature of the bathtub 12.

  The heat exchange means 47 is stopped if the hot water in the bathtub 12 reaches a set temperature during automatic warming or reaches a temperature about 1 to 1.5 ° C. higher than the set temperature during reheating.

  Next, the freeze prevention operation by the control unit 61 will be described with reference to the flowchart of FIG.

  For example, in the daytime period from 7:00 to 17:00, when the water level sensor 30 detects that there is hot water in the bathtub 12, for example, the detection temperature of the outside air temperature detection sensor 55 is 3 ° C. or less and the return side thermistor When the detected temperature of 31 is less than 7 ° C., it is detected that the freeze prevention detection means 62 satisfies the freeze prevention operation condition for performing the freeze prevention operation of the circulation pipe 23 (step 1).

  By satisfying the anti-freezing operation condition, the anti-freezing operation for driving the circulation pump 28 and circulating the bath water in the circulation pipe 23 is performed (step 2). In this freeze prevention operation, for example, if the circulating pump 28 is driven for 1 minute to circulate the bath water in the circulation pipe 23, and the detected temperature of the return side thermistor 31 becomes 8 ° C. or more after 1 minute, the freeze prevention operation condition Therefore, the circulation pump 28 is stopped and the freeze prevention operation is stopped. If the detected temperature of the return side thermistor 31 is less than 8 ° C., the circulation pump 28 is driven until the detected temperature of the return side thermistor 31 becomes 8 ° C. or higher. When hot water in the bathtub 12 is drained during the freeze prevention operation, the flow switch 27 is turned off. If the flow switch 27 is turned off for a predetermined time, it is determined that the hot water in the bathtub 12 has been drained, and the circulation pump Stop 28 and stop the freeze prevention operation.

  When the freezing and boiling increase operation is set by the boiling increase setting means 63 (step 3), the remaining hot water amount is monitored by the remaining hot water amount detecting means 51 simultaneously with the freeze prevention operation (step 4). For example, it is monitored whether the remaining hot water amount is 120 L or more and less than 180 L, or whether the detection temperatures of the 120 L and 180 L hot water temperature sensors 52 and the hot water temperature sensor 53 are all 75 ° C. or less.

  If a decrease in the amount of remaining hot water is confirmed, the hot water in the hot water storage tank 15 is heated by the heaters 19 and 20 to increase the amount of remaining hot water (step 5). At this time, the decrease in the remaining hot water amount due to the freeze prevention operation may be increased or the total amount in the hot water storage tank 15 may be increased.

  When no decrease in the amount of remaining hot water is confirmed, the boiling increase operation is not performed.

  In addition, even if the freezing and boiling increase operation is set by the boiling increase setting means 63, if the normal boiling increase operation is not set, the hot water supply to the bathtub 12 and the hot water supply to the shower or the reheating of the hot water of the bathtub 12 are performed. Even if it detects a decrease in the amount of remaining hot water due to other than anti-freezing operation, the boiling increase operation is not performed.

  In addition, when normal boiling increase operation is set in the boiling increase setting means 63, the amount of remaining hot water is reduced by other than anti-freezing operation such as filling the bathtub 12 with hot water, supplying hot water to the shower, or reheating hot water in the bathtub 12, etc. When this is detected, boiling increase operation is performed.

  In this way, when the decrease in the remaining hot water amount is detected by the remaining hot water amount detecting means 51 by causing the freezing prevention operation control means 64 to perform the antifreezing operation, the heaters 19 and 20 boil the hot water in the hot water storage tank 15 to increase the remaining hot water amount. Therefore, it is possible to prevent hot water shortage due to a decrease in the amount of remaining hot water in the freeze prevention operation, and also to control the freeze prevention operation by the freeze prevention operation control means 64 and to detect the decrease in the remaining hot water amount by the remaining hot water amount detection means 51. Under both conditions, unnecessary boiling can be prevented and power can be saved. In other words, even if the freeze boiling increase operation is set, if the normal boiling increase operation is not set, the boiling increase operation is not performed even if a decrease in the amount of remaining hot water is detected except for the freeze prevention operation. Can be prevented and power can be saved.

  In order to boil hot water in the hot water storage tank 15, not only the heaters 19 and 20, but also a heat pump unit that collects heat in the atmosphere may be used.

It is a lineblock diagram of a hot-water supply device showing one embodiment of the present invention. It is a block diagram of a hot-water supply apparatus same as the above. It is a flowchart of a freezing prevention operation and a boiling increase operation same as the above.

Explanation of symbols

11 Water heater
12 Bathtub
15 Hot water storage tank
19, 20 Heater as boiling means
22 Heat exchanger
23 Circulation piping
28 Circulation pump
47 Heat exchange means
51 Means for detecting remaining hot water
62 Freezing prevention detection means
63 Boiling increase setting means
64 Freezing prevention operation control means
65 Boiling increase operation control means

Claims (2)

A hot water storage tank for storing hot water,
A boiling means for boiling the hot water in the hot water storage tank;
A remaining hot water amount detecting means for detecting a remaining hot water amount in the hot water storage tank;
A heat exchanger that exchanges heat between the hot water in the hot water storage tank and the hot water in the bathtub, a circulation pipe that connects the heat exchanger and the bathtub, and a circulation that circulates the hot water in the bathtub to the heat exchanger through the circulation pipe A heat exchange means having a pump;
Anti-freezing detection means for detecting that the anti-freezing operation condition for performing the anti-freezing operation of the circulation pipe is satisfied,
Antifreeze operation control means for driving the circulation pump to prevent freeze operation when detecting that the freeze prevention operation condition is satisfied by the freeze prevention detection means,
When the anti-freezing operation is controlled by the anti-freezing operation control means, when the decrease in the remaining hot water amount is detected by the remaining hot water amount detecting means, the boiling means increases the remaining hot water amount by boiling the hot water in the hot water storage tank by the boiling means. And a hot water supply device. Boiling increase setting means for setting freezing boiling increase operation when the remaining hot water amount is reduced by the freeze prevention operation, and normal boiling increase operation when the remaining hot water amount is reduced by other than the freeze prevention operation,
Even if the boiling increase operation is set by the boiling increase setting means, or if the normal boiling increase operation is not set, the boiling increase operation control means can detect the decrease in the amount of remaining hot water except for the freeze prevention operation. The hot water supply device according to claim 1, wherein no additional operation is performed.

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