JP5556403B2 - Water heater - Google Patents

Description

  The present invention relates to a water heater that supplies hot water to a hot water supply terminal.

Conventionally, in this type of water heater, hot water supplied to a hot water supply terminal is generated by mixing high-temperature water in a hot water storage tank and water supplied from a water supply source using a mixing valve.

  In general, the control of the opening of the mixing valve is based on temperature information detected by a thermistor downstream of the mixing valve, and controls the mixing ratio of hot water according to the temperature deviation from the target temperature, Hot water of a target temperature is provided to a hot water supply terminal such as a faucet (see, for example, Patent Document 1).

JP 2000-179880 A

  However, in the conventional configuration, the mixing valve is driven by feedback control from a predetermined flow rate or higher, and the mixing valve is not actively driven below the predetermined flow rate. If a small amount of water below the specified flow rate is discharged due to poor closure of the kitchen faucet or shower in the bathroom, etc., the mixing valve does not drive actively, Water is discharged from the outlet of the mixing valve due to water pressure.

  Therefore, the temperature detected by the thermistor downstream of the mixing valve is lower than the hot water supply temperature set by the remote controller. After that, when the hot water is discharged again at a predetermined flow rate or higher, the temperature detected by the thermistor is lower than the set temperature, and therefore the mixing ratio of the mixing valve is driven further to the hot water side than usual by feedback control. There was a problem that no hot water would come out.

  This invention solves the said conventional subject, and it aims at providing the hot water heater with the high usability which does not discharge hot hot water from a tap tip even if it re-drains with faucet closing failure.

  In order to solve the above-mentioned conventional problems, a water heater of the present invention comprises heating means, a hot water supply pipe for supplying high-temperature water, a water supply pipe for supplying water from a water supply source, the hot water supply pipe and the water supply pipe. Mixing means for mixing hot and cold water, a hot water supply pipe for supplying hot water mixed by the mixing means to a hot water supply terminal, a flow rate detecting device for detecting the flow rate of hot water flowing through the hot water supply pipe, and controlling the operation of the mixing means And a control device, wherein the mixing means is driven only in the water side direction for a predetermined time after the flow rate detection device starts detecting the flow rate.

  As a result, even after reflowing hot water at a predetermined flow rate or higher after hot water discharge due to faucet closing failure, hot water does not come out from the tip of the faucet, and the user does not feel uncomfortable.

  ADVANTAGE OF THE INVENTION According to this invention, the hot water heater with high usability which does not discharge hot hot water from a hot-water supply terminal can be provided even if it discharges hot water again after a very small amount of hot-water supply due to poor closing of a hot-water supply terminal.

The block diagram of the hot water storage type hot water heater in Embodiment 1 of this invention Flow chart when using hot water in the same form Other flowchart when using hot water in the same form Other flowchart when using hot water in the same form Other flowchart when using hot water in the same form The figure which showed the drive speed of the normal temperature control of the electric mixing valve in the same embodiment The figure which showed the drive speed of the electric mixing valve at the time of the start of hot-water in the embodiment

The first invention is a heating means for heating water to generate high temperature water, a hot water storage tank for storing the high temperature water generated by the heating means, and a hot water supply for supplying the high temperature water stored in the hot water storage tank. a tube, a water supply pipe for supplying water from the water source, and mixing means for mixing the water supplied from the water supply pipe and the hot water supplied from the hot water pipe, a hot water mixed by the mixing means and hot water supplied to the hot-water supply terminal tube, a flow rate detection device for detecting the flow rate of the hot water flowing through the hot water supply pipe, a temperature detecting means for detecting the hot water temperature flowing through the hot water supply pipe, supplied to the hot water supply terminal A remote control device for setting the hot water supply set temperature, and a control device for controlling the operation of the mixing means, the control device, when the flow rate of the hot water flowing through the hot water supply pipe is greater than or equal to a predetermined flow rate, Above Temperature of water by driving the mixing means such that the hot water set temperature, the control device, to re-tapping at the predetermined flow rate or more after pouring a small minute flow rate than the predetermined flow rate, the flow rate detection A hot water supply device that drives the mixing means only in the water side direction for a predetermined time after the apparatus detects the predetermined flow rate, and performs re-bathing at a predetermined flow rate or more after hot water discharge due to poor closing of the faucet. However, hot hot water does not come out from the tip of the faucet, and the user is not uncomfortable.

The temperature detecting means for detecting the temperature of the hot water flowing through the hot water supply pipe and a remote control device for changing the hot water set temperature of the device, and when the flow rate detection device starts detecting the flow rate, the hot water set temperature of the remote control wherein when the temperature difference of the temperature between the temperature detected by the detecting means is a predetermined value or more and, when driving the mixing means only water side direction, after a minute flow rate hot water by faucet closed defect, again tapping carried out at a predetermined flow rate or more However, hot hot water does not come out from the tip of the faucet, and the user is not uncomfortable.

Note that the flow rate detecting device is within a predetermined time no longer detects the flow rate, when the flow rate detecting device detects the flow rate, the mixing means is driven only water side direction, after a minute flow rate hot water by faucet closed defect Even if the hot water is discharged again at a predetermined flow rate or higher, hot hot water does not come out of the tap and the user is not uncomfortable.

Incidentally, the flow rate detection device a predetermined time from the start of detection of flow rate is carried out when faster than the normal driving speed of said mixing means, after a minute flow rate hot water by faucet closed defect, again tapping at a predetermined flow rate or more However, hot hot water does not come out from the tip of the faucet, and the user is not uncomfortable.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a hot water storage type water heater in the present embodiment. In FIG. 1, a hot water storage type water heater 1 of the present embodiment is composed of a refrigeration cycle 2 and a heating cycle 3 for boiling hot water.

  The refrigeration cycle 2 is configured by sequentially connecting a compressor 5, a refrigerant heat exchanger 6, an expansion valve 7, and an evaporator 8 in an annular manner with refrigerant piping, and the refrigerant circulates in the refrigeration cycle 2. . Carbon dioxide refrigerant is used as the refrigerant. In addition, other refrigerants include CFC refrigerants such as R410a and hydrocarbon refrigerants such as propane.

The heating cycle 3 is configured by sequentially connecting a hot water storage tank 9, a refrigerant heat exchanger 6, and a stacking pump 10 in a ring shape with a hot water supply pipe, and by driving the stacking pump 10, Low temperature water is sent to the refrigerant heat exchanger 6, and the refrigerant heat exchanger 6 receives heat from the high temperature refrigerant to generate high temperature water, and the generated high temperature water is stored in a stacked state from above the hot water storage tank 9. This hot water storage operation is started at a fixed time such as at night or when it is determined from the remaining hot water in the hot water storage tank, and is continued until the hot water storage tank 9 is filled with hot hot water.

  Next, the supply of hot water to the hot water supply terminal 11 such as a currant will be described. In the upper part of the hot water storage tank 9, there are a hot water discharge pipe 12 for discharging hot water, a first water supply pipe 13 for supplying water from the water supply source to the hot water storage tank, and a second water supply branched from the hot water supply pipe 12 and the first water supply pipe 13. The pipe 14 is connected and hot water and water are mixed by the electric mixing valve 15 which is a mixing device. Downstream of the electric mixing valve 15, a thermistor 16 that detects the temperature of the hot water and a flow rate detection device 17 that detects the flow rate of the hot water are provided in the hot water supply pipe 44.

  In addition, a control device (not shown) composed of a microcomputer and electronic parts for controlling the electric mixing valve is provided. Normally, the temperature detected by the thermistor 16 is controlled by the electric mixing valve 15. Then, a control device (not shown) performs feedback control so that the set temperature is set by the user.

  In the hot water storage type hot water heater configured as described above, electric mixing valve control when hot water is used will be described.

  FIG. 2 is a diagram showing the mixing ratio and hot water supply temperature of the electric mixing valve during intermittent hot water. It is assumed that when a user uses the hot water supply terminal 11 to supply hot water from a device and the faucet is opened and closed and a kitchen faucet or a bathroom shower fails to close, a small flow rate flows from the tip of the faucet.

  At this time, the electric mixing valve 15 is driven so that the temperature detected by the thermistor 16 becomes the temperature set by the remote controller until the flow rate detected by the flow rate detection device 17 becomes 2 L / min or less.

  When the hot water supply set temperature is 40 ° C. and the flow rate detected by the flow rate detector 17 is 2 L / min and 10 L / min, the mixing ratio of the electric mixing valve 15 is 60% and 50%, respectively. This is because the lower the flow rate, the greater the pressure loss in the piping, and the less hot water supplied to the electric mixing valve 15.

  For example, when a faucet is opened and closed under the conditions of a hot water supply set temperature of 40 ° C. and a hot water supply flow rate of 10 L / min, when a small flow rate (about 0.2 L / min) flows due to a faucet closing failure, an electric mixing valve 15 is driven until the flow rate detected by the flow rate detection device 17 is 2 L / min, and the mixing ratio of the electric mixing valve 15 is 60%.

  When the flow rate detected by the flow rate detection device 17 is a minute flow rate (about 0.2 L / min), the temperature detected by the thermistor 16 is the water supply temperature (about 20 ° C.). Next, when the hot water is re-drained under a hot water supply set temperature of 40 ° C. and a hot water supply flow rate of 10 L / min, the temperature detected by the thermistor 16 is the water supply temperature (about 20 ° C.), so the electric mixing valve 15 is detected by the thermistor 16. The mixing ratio is driven from 60% to 75% by feedback control so that the temperature at which the hot water is supplied is 40 ° C.

  At this time, since the mixing ratio of the electric mixing valve 15 is larger than that at the time of steady tapping, the thermistor 16 detects 60 ° C., and hot water (about 50 ° C.) higher than the set temperature is tapped at the tap. The user feels uncomfortable.

FIG. 3 shows the same intermittent hot water shown in FIG. 2, and at the start of hot water, the driving direction of the electric mixing valve 15 is limited to the water direction only for about 1 second after the flow rate detection device 17 detects 2 L / min. Thereafter, the electric mixing valve 15 is a diagram showing the mixing ratio of the electric mixing valve and the hot water supply temperature when feedback control is performed.

  By making the drive direction of the electric mixing valve 15 only in the water direction for about 1 second from the start of pouring, the mixing ratio of the electric mixing valve 15 does not become larger than 60% (mixing ratio after stopping pouring) The thermistor 16 has a temperature of 43 ° C. and the tap water temperature at the tap end is about 41 ° C., so that hot water that is almost the same as the set temperature is discharged and the user is not uncomfortable.

  FIG. 4 shows the intermittent hot water supply shown in FIG. 2. When the temperature difference between the remote controller set temperature and the thermistor 16 is 10K or more at the start of hot water supply, the driving direction of the electric mixing valve 15 is changed to water for about 1 second from the start of hot water supply. It is the figure which showed the mixing ratio and hot-water supply temperature of an electrically driven mixing valve when it was only made into the side direction. For example, suppose that when the user opens and closes the faucet from a hot water supply flow rate of 10 L / min, a small flow rate (1 L / min) flows from the faucet tip without forgetting to close the faucet.

  At this time, the electric mixing valve 15 is driven so that the temperature detected by the thermistor 16 becomes the hot water supply temperature set by the remote controller until the flow rate detected by the flow rate detection device 17 becomes 2 L / min or less. When the mixing ratio of the electric mixing valve 15 is 60% and the flow rate detected by the flow rate detection device 17 is a minute flow rate (1 L / min), the temperature detected by the thermistor 16 is 30 ° C.

  Next, when the hot water is discharged again at a hot water supply set temperature of 40 ° C. and a hot water supply flow rate of 10 L / min, the temperature difference between the remote controller set temperature and the thermistor 16 is 10 K or more. The driving direction is driven only in the water direction for 2 seconds, and the mixing ratio of the electric mixing valve 15 does not increase further from 60% (mixing ratio after stopping pouring), and the tap water temperature at the tap is higher than the set temperature. The user will not feel uncomfortable.

  If the electric mixing valve 15 performs feedback control from the start of hot water supply, the mixing ratio of the electric mixing valve 15 is changed from 60% to 70%, and the temperature detected by the thermistor 16 is 48 ° C. The temperature at the tip of the faucet is about 45 ° C., which is higher than the set temperature, which causes discomfort to the user.

  In addition, when the user opens and closes the faucet from a hot water supply flow rate of 10 L / min, it is assumed that a minute flow rate (1.5 L / min) flows from the tip of the faucet without forgetting to close the faucet. At this time, the electric mixing valve 15 is driven so that the temperature detected by the thermistor 16 becomes the hot water supply temperature set by the remote controller until the flow rate detected by the flow rate detection device 17 becomes 2 L / min or less. When the mixing ratio of the electric mixing valve 15 is 60% and the flow rate detected by the flow rate detection device 17 is a minute flow rate (1.5 L / min), the temperature detected by the thermistor 16 is 35 ° C.

  Next, when the hot water is re-drained at a hot water set temperature of 40 ° C. and a hot water flow rate of 10 L / min, the temperature deviation between the remote controller set temperature and the thermistor 16 is less than 10K. I do. At the start of hot water supply, the mixing ratio of the electric mixing valve 15 is 60% → 65%, and the temperature detected by the thermistor 16 is 43 ° C. The temperature at the tip of the faucet is about 41 ° C., which is almost the same as the set temperature, so that the user is not uncomfortable.

  If the electric mixing valve 15 is driven only in the water direction for about 1 second from the start of hot water supply, the temperature detected by the thermistor 16 is lower than the set temperature, and the faucet is controlled by feedback control of the electric mixing valve 15 thereafter. The previous temperature fluctuation range becomes large, and the user feels uncomfortable.

  FIG. 5 shows only the hot water within 30 minutes after the hot water supply is stopped by the intermittent hot water shown in FIG. 2, and the drive direction of the electric mixing valve 15 is changed to water for about 1 second after the flow rate detection device 17 detects 2 L / min. It is the figure which showed only the side direction and the mixing ratio and hot-water supply temperature of the electric mixing valve when the electric mixing valve 15 performs feedback control thereafter.

  Within 30 minutes after stopping the hot water supply, the temperature of the hot water in the hot water supply pipe does not drop greatly due to the heat radiation of the hot water supply pipe. When the faucet is changed from open to closed, it is assumed that a minute flow rate (0 L / min to 2 L / min) flows from the tip of the faucet due to forgetting to close the faucet. For example, when the faucet is opened and closed under the conditions of a hot water supply set temperature of 40 ° C., a hot water supply flow rate of 10 L / min, and a mixing ratio of 50%, the flow rate detected by the flow rate detector 17 is 2 L / min. The temperature detected by the thermistor 16 is driven to the hot water supply temperature set by the remote controller until the temperature becomes below.

  At this time, when the mixing ratio of the electric mixing valve 15 is 60% and the flow rate detected by the flow rate detection device 17 is a minute flow rate (0 L / min to 2 L / min), the temperature detected by the thermistor 16 is 20 ° C. to 35 ° C. It becomes ℃. When the hot water is discharged again within 30 minutes after the hot water is stopped, the mixing ratio of the electric mixing valve 15 is driven to be a value larger than 60% by feedback control. The temperature detected by the thermistor 16 is 43 ° C. to 60 ° C., and the temperature at the tip of the faucet is about 43 ° C. to 50 ° C., which is higher than the set temperature, which causes discomfort to the user.

  In addition, only for re-watering within 30 minutes after stopping the hot water supply, the driving direction of the electric mixing valve 15 is set to the water direction only for about 1 second after the flow rate detection device 17 detects 2 L / min. The mixing valve 15 performs feedback control. The mixing ratio of the electric mixing valve 15 does not become larger than the mixing ratio when the hot water is stopped, the temperature of the faucet tip does not become higher than the set temperature, and the user does not feel uncomfortable.

  In the hot water 30 minutes after the hot water is stopped, the hot water in the pipe becomes close to the water temperature due to heat dissipation loss of the hot water supply pipe. In re-watering after 30 minutes from the end of the hot water supply, hot water lower than the hot water supply set temperature is always discharged, so the electric mixing valve 15 is driven only in the water direction for 1 second after the start of hot water supply. As a result, the time until the temperature at the faucet reaches the set temperature becomes longer, which causes discomfort to the user.

  FIG. 6 is a diagram showing the driving speed of the electric mixing valve 15 based on the flow rate and temperature deviation detected by the flow rate detection device 17. The temperature deviation in FIG. 6 is an absolute value of the set temperature of the hot water supply terminal and the temperature actually detected by the thermistor 16. For example, the set temperature is 40 ° C. and the temperature detected by the thermistor 16 is At 35 ° C, the temperature deviation is 5 ° C. Moreover, PPS shown in FIG. 6 represents Pulse / Second, and indicates the driving speed per second.

  As shown in FIG. 6, in the normal control of the electric mixing valve 15, when the flow rate detected by the flow rate detection device 17 is 7.0 L / min or more, it is determined that the flow rate is high, and the high flow rate mode is set. By selecting and further calculating the current temperature deviation, one stage is selected from a plurality of stages, and the electric mixing valve 15 is controlled at the corresponding driving speed.

  In addition, the higher the flow rate, the shorter the time that is supplied to the user from the hot water storage tank 9, so it is necessary to operate the mixing valve at a higher drive speed than when the flow rate is low, and if the temperature deviation is large The larger the value, the faster the difference between the set temperature and the value detected by the thermistor 16 must be reduced. Therefore, it is necessary to operate the mixing valve at a higher driving speed than when the temperature deviation is small. The driving speed shown in FIG. 6 is a predetermined experimental value, and can be changed according to the situation.

For example, when the faucet is opened and closed under the conditions of a hot water supply set temperature of 40 ° C., a hot water supply flow rate of 10 L / min, and a mixing ratio of 50%, the flow rate detected by the flow rate detector 17 is 2 L / min. The temperature detected by the thermistor 16 is set to the hot water supply temperature set by the remote controller until the temperature becomes below. At this time, when the mixing ratio of the electric mixing valve 15 is 60% and the flow rate detected by the flow rate detection device 17 is a minute flow rate (0 L / min to 2 L / min), the temperature detected by the thermistor 16 is 20 ° C. to 3 ° C.
5 ° C. When re-bathing is performed, the mixing ratio of the electric mixing valve 15 is driven to be a value larger than 60% by feedback control.

  The temperature detected by the thermistor 16 is 43 ° C. to 60 ° C., and the temperature at the tip of the faucet is about 43 ° C. to 50 ° C., which is higher than the set temperature. Therefore, when the temperature difference between the thermistor 16 and the set temperature is large at the start of hot water supply, it is necessary to increase the drive speed of the electric mixing valve 15. Unless the mixing ratio of the electric mixing valve 15 is driven quickly, the temperature fluctuation range at the tip of the faucet becomes large, and the user is uncomfortable.

  Therefore, at the normal mixing valve driving speed shown in FIG. 6, the temperature fluctuation width of the faucet tip is increased, so that a matrix of driving speeds higher than normal for 1 second from the start of hot water supply as shown in FIG. Is newly prepared, and more comfortable hot water temperature control is performed so as not to make the user uncomfortable. The driving speeds shown in FIGS. 6 and 7 are experimental values determined in advance, and can be changed according to the situation.

  As described above, the water heater according to the present invention can reduce the temperature fluctuation width at the start of the hot water, thereby making it uncomfortable for the user, and is not limited to a heat pump hot water storage water heater, It can be used for electricity, gas, oil, fuel cells, etc.

DESCRIPTION OF SYMBOLS 1 Hot water storage type hot water supply device 2 Refrigeration cycle 3 Heating cycle 5 Compressor 6 Refrigerant heat exchanger 7 Expansion valve 8 Evaporator 9 Hot water storage tank 10 Laminated pump 11 Hot water supply terminal 12 Hot water supply pipe 13 1st water supply pipe 14 2nd water supply pipe 15 Electric type Mixing valve 16 Thermistor 17 Flow rate detector

Claims (1)

Heating means for heating the water to produce hot water ;
A hot water storage tank for storing the high-temperature water generated by the heating means;
A hot water supply pipe for supplying the high temperature water stored in the hot water storage tank ;
A water supply pipe for supplying water from a water supply source;
Mixing means for mixing the high temperature water supplied from the hot water pipe and the water supplied from the water supply pipe;
A hot water supply pipe for supplying hot water mixed by the mixing means to a hot water supply terminal;
A flow rate detector for detecting the flow rate of the hot water flowing through the hot water supply pipe,
Temperature detecting means for detecting the temperature of the hot water flowing through the hot water supply pipe;
A remote control device for setting a hot water supply set temperature of the hot water supplied to the hot water supply terminal;
And a controller for controlling the operation of said mixing means,
The control device drives the mixing means so that the temperature of the hot water becomes the hot water supply set temperature when the flow rate of the hot water flowing through the hot water supply pipe is equal to or higher than a predetermined flow rate,
In the case where the control device discharges hot water at a minute flow rate smaller than the predetermined flow rate and then re-charges hot water at the predetermined flow rate or higher, the control device sets the mixing means to the water side for a predetermined time after detecting the predetermined flow rate. A water heater that is driven only in the direction.

Images