JPS5853256B2 - Hot water supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot water supply device using an instantaneous water heater with a relatively small amount of hot water storage, which is equipped with a heat source such as a burner that is automatically turned on and off by detecting the hot water temperature. The purpose of the present invention is to eliminate the temperature differential of supplied hot water to O or close to it during intermittent operation, improve hot water supply or heating performance, and provide a safe hot water supply device.

Generally, it detects the hot water temperature of the boiler and automatically turns 0N-O.
In a hot water supply system whose hot water supply source is an instantaneous water heater with a relatively small hot water storage capacity and equipped with an FF-controlled burner, the hot water in the boiler will not rise if hot water is supplied above a certain flow rate, so the temperature will increase. The detector thermostat closes and the burner burns continuously, but when hot water is supplied below a certain flow rate, the temperature of the hot water in the boiler rises and the burner burns intermittently.

If the boundary flow rate between continuous combustion and intermittent combustion in the burner is defined as the critical flow rate, the characteristics of the supplied hot water temperature will be completely different above and below the critical flow rate.

In other words, Figures 3 and 4 show the relationship between the temperature and time of the supplied hot water and the relationship between the temperature and flow rate of the supplied hot water. In the region where the flow rate exceeds the critical flow rate The temperature characteristics are stable at a relatively low temperature like A.

On the other hand, in a region where the flow rate is less than or equal to the critical flow rate X, the burner performs intermittent combustion, and the temperature characteristic of the supplied hot water has a relatively high temperature as shown in B and a temporally sinusoidal change cycle.

This temperature characteristic B has a temperature difference in the temperature of the supplied hot water, that is, a supplied hot water differential having a temperature difference Jθ.

As described above, instantaneous water heaters with a small storage capacity have two typical temperature characteristics of supplied hot water in the upper and lower regions of the critical flow rate of supplied hot water.

In addition, the temperature characteristics of the supplied hot water in the region below the critical flow rate are different from those of a boiler with a large hot water storage capacity.
When θ is large, usually 20'C to 30C, one cycle of temperature difference in lθ is extremely short, about 3 minutes (see FIG. 5).

By the way, the temperature differential Jθ of the supplied hot water is determined by the amount of hot water stored in the boiler, the water inlet, the characteristics (temperature setting and differential) of the can water temperature control thermostat, the mounting position, etc.

For example, if the differential of the thermostat is made extremely small, the temperature differential Aθ of the supplied hot water can also be made small, but if it is made too small, there is a risk that the temperature detection of the thermostat will malfunction.

In addition, the burner starts up too frequently, causing contact problems in the control system and deterioration of the durability of parts due to excessive startup.Simply reducing the thermostat differential will shorten the life of the boiler, and overall This is undesirable, and therefore the design is such that one cycle of the temperature differential of the supplied hot water has to be about three degrees.

This characteristic is the hot water supply performance seen in conventional instantaneous water heaters with a small hot water storage capacity, and although it is relatively unlikely to cause trouble when supplying hot water to a regular bath, it is a problem when used for showers etc. There is.

In other words, it is desirable that the shower conditions satisfy the conditions of hot water supply temperature of 40°C ± 20°C and hot water supply flow rate of 6137 m1yt to 1211 /vtin.On the other hand, if the hot water supply temperature differential Aθ is 200°C to 30°C, it is necessary to use a mixed faucet. Even when using a shower, there is a temperature change of 10°C to 15°C, which exceeds the maximum sensitivity of 20°C when using a shower, and the temperature change cycle time is only about 3 minutes.
If you take a shower for several minutes, you will often feel uncomfortable as it gets hot or lukewarm.

For example, assuming that the thermostat is set to normal, in the case of an instantaneous boiler with a hot water storage capacity of 1511 and an output of 26,000 kal/h, 10137 m1yt corresponds to the critical flow rate at room temperature, and when hot water is supplied at i0A'/mv1 or more, the supply during continuous combustion When hot water is supplied at 10 l/mm or less, the hot water temperature characteristic is the same as that during intermittent combustion when Jθ is 200C to 30C.

When hot water is supplied at 5l7m1yt, the hot water temperature characteristic B, which is closest to a sine waveform, is shown as shown in FIG.

The present invention focuses on the fact that the temperature characteristics of the hot water supplied during intermittent combustion of the burner exhibits alternating current waveform-like changes, and attempts to make this a characteristic without direct current-like changes as shown in FIG. 5C. It is.

That is, by adding the supply hot water temperature characteristic B', which is delayed by 1J2 cycles, to the supply hot water temperature characteristic B shown in FIG. It is.

Examples of implementing the present invention in water heaters are shown in Figures 1 and 2 below.
This will be explained with reference to the figures.

In FIG. 1, reference numeral 1 denotes an instantaneous boiler with a small hot water storage capacity, and water is supplied through a water inlet 2 and heated by, for example, a gun-type burner (not shown), which is controlled ON-OFF by a thermostat 3. ing.

Hot water is supplied from the hot water inlet 4 of the boiler 1 to a faucet 6 via a hot water supply device 5.

As shown in FIG. 2, the hot water supply device 5 has a double structure consisting of an inner shell 7 and an outer shell 8, and the inner shell 7 is provided with a hole 9 for diversion and a hole 10 for mixing. , the inside of the inner shell γ is a first flow path 11, and the inside of the outer shell 8 is a second flow path 12.

The first flow path 11 has a hot water storage amount QA, and the second flow path 12 has a hot water storage amount QB.

Note that the first flow path 11 is provided with a contracted flow path 13 .

In addition, the inner shell 7, upper case 7a, and lower case 7b are integrated, and the outer shell 8 and upper and lower cases 7a>7b are O-rings 1.
3', and is fluid-tightly connected and is slidable, allowing the QB to be changed.

It is assumed that the difference in the amount of hot water stored in the flow path 11 of the combination 1 and the second flow path 12, that is, QBQA=QB-A, and QB-A is set as follows.

In other words, in Figs. 1, 2, and 5, when the amount of hot water supplied at the hot water supply port 4 is 5 l/mv@, one cycle time (burner ON time and OFF time) of the supply hot water temperature characteristic during burner intermittent combustion is If the added time) is 3 minutes, 2.51/mry in the first flow path 11 and 2.51/mry in the second flow path 12.
, 51J/minM If the current is divided so that it flows,
There is no change in the temperature characteristics of the first flow path 11 and the second flow path 12 during one cycle.

If QA=:=O is assumed here, the supply hot water temperature characteristics at the branch point A and the confluence point in Figure 2 are the same in terms of waveform, and there is no period shift, so the temperature in Figure 5 B is the same. It looks like a characteristic waveform.

Next, QB-A=QB-QA=2.5 l/mmx 3
If wX 1/2 = 3.757, the second flow path 12
The waveform of the hot water temperature characteristic at the output donkey position is delayed in cycle from the waveform of the temperature characteristic B by an amount corresponding to 1/2 cycle, as shown by the broken line B' in FIG.

When the waveform of the temperature characteristic B and the waveform of the temperature characteristic B' are superimposed, the flow rate of the flow path 11 and the second flow path 12 in FIG. In other words, the hot water temperature becomes constant.

That is, the temperature differential Jθ of the supplied hot water is adjusted to O at the mixing hole 10.

Then, hot water with no temperature change can be obtained from the faucet 6.

By the way, the critical flow rate may differ depending on the amount of hot water stored in the water heater that is the hot water supply source, the characteristics (temperature setting and differential) and installation position of the thermostat for controlling the temperature of the can water, and changes in the water inlet/hot water inlet, etc. If the critical flow rate changes due to a change in water temperature, and if the cycle characteristics also change, the above characteristic C may not be obtained.

Therefore, I set QB-A = 3.757 so that characteristic C can be obtained when the critical flow rate is 10137 mvt@.
For example, if the critical flow rate changes from 10 l/mtn to 81/mm and the 1 cycle time does not change, flow path 11.
The capacitance difference between 12 is QB A=3.75X8/10=3
By setting the value to 7, characteristic C shown in FIG. 5 can be obtained.

This capacitance difference can be changed by sliding the outer shell 8 with respect to the inner shell 7.

Although the above description has been made regarding an embodiment in which the device of the present invention is applied to a water heater, the present invention can similarly supply hot water without a differential and obtain stable heating in the case of heating.

That is, when a heating load lower than the output of the boiler is applied to the heating device, the temperature of the hot water in the boiler increases and the burner performs intermittent combustion.

The supplied hot water temperature characteristic during intermittent combustion becomes a sine waveform with a differential Jθ, as shown by B in FIG.

Note that B" in FIG. 7 is the return temperature characteristic of hot water, and although the temperature has decreased, the temperature characteristic has a differential synchronized with the characteristic B.

Note that the time per cycle in the supply hot water temperature characteristics during intermittent combustion is the shortest when the heating load is 1/2 of the boiler output, as shown in FIG.

That is, in Fig. 8, B1 is the time-heating load characteristic when the burner is OFF in one cycle, B2 is the time-heating load characteristic when the burner is ON in one cycle, and when the time of both characteristics is added, it becomes the characteristic of B3 shown by the solid line. Become.

Since point Y is the heating load at a time equivalent to the boiler output, the 1/2 boiler 1 output point Y is the shortest in terms of time.

From these facts, we created a supply hot water temperature characteristic that is shifted by 1/2 period from the supply hot water sensitivity characteristic during intermittent fuel with a differential of Jθ shown in Fig. 7, and by mixing the supply hot water with both characteristics, the hot water of differential O This can be cycled as .

FIG. 6 shows an example of a heating device implementing the above invention,
In the figure, 14 is a boiler, and a thermostat 15
It is heated by, for example, a gun-type burner (not shown) which is ON-OFF controlled by the heater.

The hot water from the boiler 14 passes from the hot water outlet 16 via the circulation pump 17, through the hot water supply device 18 having the first flow path and the second flow path shown in FIG. The water is returned to the hot water return port 22 of the boiler 14 via the heating return circuit 21 via the hot water return circuit 21 .

Water is supplied to the boiler 14 from the water supply port 23 through a gas tank 24 and a water supply pipe 25, and the expansion water of the boiler 14 is returned to the gas tank 24 via an expansion pipe 26. An overflow pipe 27 is provided.

In the above configuration, as in the case of the water heater described above, there is a difference in the amount of hot water stored in the first flow path and the second flow path of the hot water supply device 18, that is,
With a difference in capacity, the system circulation amount is 10 l/rrw
t, one cycle time of the temperature characteristics of supplied hot water during intermittent combustion of the burner is assumed to be 4 minutes, and 51/mix is supplied to each of the first flow path and the second flow path, and furthermore, the hot water stored in both flow paths is The amount difference is 513 /mrytx4mmX 1/2=1
It is possible to obtain the supply hot water temperature characteristic delayed by 1/2 cycle with the flow rate equivalent to 1/2 cycle as 0 It, and by superimposing this on the supply hot water temperature characteristic during the original intermittent combustion, differential Aθ = 0. By circulating this hot water, stable heating can be achieved at all times.

By the way, as in the case of hot water supply, if the system circulation flow rate changes depending on the number of heating rooms, that is, the heating load, or if the one cycle time during intermittent combustion changes depending on the hot water storage amount of the hot water supply source, the characteristics of the thermostat, etc., the above-mentioned Like Jθ=0
There may be cases where this is not the case.

That is, the system circulation amount is IOl/mB, and the one cycle time is 4 minutes, and the difference in hot water storage amount between both flow paths is 101. For example, the system circulation amount is 611/mvt.

If one cycle time is 3 minutes, the difference in the amount of hot water stored in both channels,
That is, the capacitance difference is 31/mr! tx 377XmX
1/2-4.51, and Jθ=O.

The capacitance difference can be changed by sliding the outer shell 8 with respect to the inner shell 7 and changing QB.

In addition to setting the temperature differential Jθ of hot water for hot water supply and heating to O, the device of the present invention is also effective in improving safety when hot water is tapped.

That is, since a general instantaneous water heater is a water heater with a high output and a small amount of hot water storage, the rate of rise of water in the can in the water heater is high, often reaching 30 degrees per minute.

In such water heaters, if the set temperature of the thermostat for controlling the burner is set to around 70°C, the temperature detection of the can water by the thermostat may not be able to follow the rate of increase in the water temperature of the water heater can, and the thermostat may not operate properly. Due to the delay in heat transfer of the high temperature gas remaining inside the combustion chamber of the latter unit through the combustion chamber wall surface, the can water temperature rises and may approach a boiling state.

On the other hand, if the set temperature of the thermostat is set low, there is a drawback that the temperature at which the hot water falls after tapping becomes too low.

Figure 9 shows the temperature characteristics, and the hot water temperature characteristic of a general instantaneous boiler shown by characteristic curve E is the temperature at boiling (
Starting temperature of hot water) As time passes from point a, the temperature drops as shown at point b.

For example, if you use a bath and the water in the bathtub becomes lukewarm and you add warm water to raise the temperature of the water in the bathtub, it will be difficult to raise the temperature in the bathtub again if the temperature drops to low. However, there is a drawback that the hot water does not get hot again when the hot water supply to the bathtub is actually used.

In addition, the thermostat temperature is set at around 60℃ to prevent boiling at the time of boiling and to prevent the temperature from dropping to low.
Furthermore, even if the arrangement of the water supply and hot water supply piping is taken into account, there is a drawback that hot water at a temperature of around 90° C. comes out at the start of hot water supply, which poses a risk of burns and the like.

On the other hand, in the present invention, even if water at 90°C is boiled in the boiler 1 in the configurations shown in FIGS.
In order to prevent the hot water in the first flow path 11 and the second flow path 12 from rising due to convection with the can water in the boiler 1, the diameter of the branch part of the hot water supply port 4 is made small, for example. If the hot water in the flow path 11 and the second flow path 12 is set to rise only to around 40°C, the hot water from the hot water supply port 4 to the 9
Even when hot water at 0°C begins to flow, it is mixed with the hot water of around 40°C in the first flow path 11 and the second flow path 12, and the temperature of the hot water gradually increases from around 50°C as shown in the temperature characteristics shown in Figure 9C. This allows for safe hot water to be drawn without sagging.

In addition, in the temperature characteristic C in FIG. 9, the temperature drops once during the rise in the first flow path 11 and the second flow path 1.
This is because a mixing delay occurs due to the difference in capacity between the two.

The device of the present invention has the following effects due to the above configuration and operation.

(1) Even if the boiler is not a boiler with a zenith hot water capacity, it is possible to supply hot water during intermittent combustion by simply attaching a hot water supply device of about 31 to the hot water outlet in an instantaneous boiler with a small hot water storage capacity and an 0N-OFF burner without proportional control. It is possible to provide stability in the hot water temperature characteristics without differentials due to height differences.

(2) Since the temperature differential during hot water supply can be set to 0, discomfort will not be caused when using the shower.

(3) When installed at the hot water inlet of a heating circuit, the temperature flowing out of the heating circuit remains uniform and does not change.With a convection type fan convector, there is no change in the temperature of the hot air, making it possible to provide high-grade heating and at the same time provide floor heating. When used on the floor, temperature changes do not occur on the floor surface, so the heating effect is doubled.

(4) Since repeated thermal stress due to hot water temperature differences is not applied to hot water supply or heating piping, damage to piping materials due to repeated thermal stress can be prevented.

(5) Since the hot water supply device is small, with only about 31 boilers, a boiler including a hot water supply device has a much greater cost advantage than a boiler with a zenith hot water capacity.

(6) It is possible to prevent high-temperature hot water at the start of hot water dispensing and to prevent the temperature from dropping during hot water supply, which improves safety and allows smooth heating during reheating hot water supply when used in a bathtub or the like.

(7) Since the hot water supply device is composed of double cylinders, the hot water supply device is compact and has a simple structure, so it is easy to install, and the hot water is heated through the heat transfer surface of the inner body. This has the effect of reducing Jθ due to heat exchange.

(8) When used for hot water supply, the critical flow rate and 1 cycle time may change in response to differences in hot water storage capacity of the hot water supply source, changes in water temperature, changes in thermostat characteristics, and changes in the output of the hot water supply source. However, the difference in capacity between both flow paths can be adjusted arbitrarily.
lθ=0 can be set in any case.

Similarly, in the case of heating, changes in system circulation amount,
The difference in capacity between the two flow paths can be arbitrarily adjusted in response to a change in one cycle time, and Jθ=O can be achieved in any case.

In the above embodiment, only the case of a one-end type boiler was explained, but it is possible to obtain the same effect by incorporating the device of the present invention in a two-can type boiler with a built-in hot water heat exchanger. Needless to say.

Further, the boiler heat source may be gas, kerosene, electricity, or the like.

Furthermore, if the hot water supply outlet is subdivided into two or more separate flows, performance with a temperature differential lθ-〇 of the supplied hot water can be achieved over a wider range.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a hot water supply system embodying the present invention, Fig. 2 is a sectional view of the same hot water supply system, Figs. 3 and 4 are temperature characteristics of hot water supplied to an instantaneous boiler, and Fig. 5 is the same A detailed explanatory diagram of supply hot water temperature characteristics, FIG. 6 is a configuration diagram of a heating device implementing the present invention, FIG. 7 is a hot water temperature characteristic diagram during heating, and FIG. 8 is an ON-OFF cycle-heating load characteristic diagram. FIG. 9 is a diagram showing the outlet temperature characteristics. 1...Boiler, 4...Hot water inlet, 5...Hot water supply device, 7...Inner shell, 8...Outer shell, 9...Diversion hole, 10...Mixing hole, 11...First channel, 12...Second channel.

Claims (1)

[Claims] 1 The heat source of the boiler is 0N-O at the set temperature of hot water.
A hot water supply source is an instantaneous water heater with a small hot water storage capacity that is controlled by FF, and the hot water supply path is branched to provide at least two flow paths having a capacity difference, and the flow path having the above capacity difference is used as a hot water supply source. A hot water supply device that shifts the cycle of hot water temperature change when the heat source is interrupted and mixes the hot water with the shifted temperature change cycle, characterized in that the capacity difference between the flow channels is configured to be variable. Feeding device.