JPS6336528B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot water temperature control device for a hot water supply system that supplies hot water by installing an instant heating type auxiliary heater on a hot water heat source heated by a solar collector or waste heat recovery device. The main idea is to arbitrarily control the temperature of the water sent to the faucet or shower by controlling the flow rate ratio to mix the hot water that passes through the hot water supply heat source with the water that does not pass through the hot water heat source, and by controlling the capacity of the auxiliary heater.

The purpose of the present invention is to eliminate the troublesome operation of selecting the temperature and amount using a mixing valve on a faucet or shower, and the inconvenience caused by changes in the temperature of the hot water heat source depending on the season, time of day, and weather. The point is to get a good hot water system. Another object of the present invention is to achieve an energy saving effect by minimizing the input to the auxiliary heater by preferentially using the thermal energy obtained from the hot water supply heat source, and by increasing the contribution rate of solar heat to the hot water supply load, for example. It's about doing.

There are methods to heat water in a hot water tank using thermal energy collected by a solar heat collector, or to heat hot water by natural circulation by integrating a heat collector and a hot water tank, but in either case, the temperature of the hot water tank is It varies depending on the season, weather, and time of day. For this purpose, various auxiliary heat sources have been proposed. For example, in the case of an electric water heater or a hot water storage boiler using gas or oil, hot water is stored at a temperature of approximately 80°C, regardless of the temperature caused by solar heat. In this case, the effect of temperature stabilization is high, but in order to obtain hot water of around 40°C, which is generally required, it must be mixed with water again. If the water temperature was over 40℃ due to solar heat alone, extra heat energy would have been wasted to heat the water to 80℃ even though there was no need for supplementary heating. This was a problem caused by the hot water storage type, which stores a large amount of heat. Next, when performing auxiliary heating with an instantaneous water heater, as mentioned above, the temperature due to solar heat is not stable, so there is a risk of boiling if the heating capacity remains constant. Therefore, capacity control according to the hot water temperature has become an essential requirement. In this case, it is possible to set an arbitrary temperature and control the capacity accordingly, but this has no effect at all if the temperature due to solar heat is higher than the set temperature. Therefore,
It was not possible to obtain stable usability throughout the year.

Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a diagram showing the configuration of a hot water supply system, where 1 is a hot water heat source using solar heat, and the heat medium heated by a collector 2 is transferred to a heat exchange coil 5 in a tank 4 by a pump 3.
The water in the tank 4 is heated by circulating the water. Water supplied from the water supply circuit 6 passes through a pressure regulator 7 and is divided into a hot water circuit 9 and a water circuit 10, which pass through the hot water supply heat source 1 at a branch section 8, and after passing through the hot water supply heat source 1, the water is passed through a flow rate ratio control valve 11. join together. Next, in the auxiliary heater 12, the burner 1 is heated while passing through the heat exchanger 13.
4, and supplied from the hot water supply circuit 15 to the faucets of each terminal. Reference numeral 16 denotes a temperature detector provided in the hot water supply circuit 15, which compares the signal from the temperature setting device 17 provided near the hot water supply terminal with the control circuit 18, and detects the temperature in the burner 14 so that the difference is eliminated.
The capacity control device 19 and the flow ratio control valve 11 that control the input to the flow rate control valve 11 are drive-controlled. Furthermore, 20 is a temperature detector provided in the hot water circuit 9, and this signal is also applied to the control circuit 18 described above.

Next, the basic operation will be explained using the operation explanatory diagram in FIG. 2 and the control block diagram in FIG. 3.

Now, check the temperature and flow rate of hot water supplied from the hot water circuit.
The temperature and _{flow rate of water supplied from the water circuit 10 are shown as T C , Q C , the} combustion input and efficiency in the auxiliary heater 12 are shown as wi, η, and the hot water supply circuit 1
The temperature and flow rate at 5 are indicated as T and Q, and the temperature setting device 1
If the temperature set in step 7 is expressed as T _S , the following equations are obtained.

_{Q. _ _ _ _ _ _ H} T _H +Q _C T _C +ηwi=T _S Q ...3 Now, under the condition of T _H > T _S , there is no need for auxiliary heating, so we set wi = 0 in equation 3, and Q _H = KQ ...4 Q _C =(1-K)Q...5 If expressed as, the ratio of hot water circuit flow rate to the total flow rate K
is K=T _S -T _C /T _H -T _C . . . 6. If the control is performed as shown in range "A" in FIG. 2, the set target temperature can be obtained. In order to determine this flow rate ratio, the valve opening degrees of the hot water circuit 9 and the water circuit 10 are controlled by the flow rate ratio control valve 11.

Next, consider the case where T _H < T _S. At this time,
Since the temperature supplied from the hot water heat source 1 is low, supplementary heating is required. However, in general, in the instant heating type auxiliary heater 12, there is a lower limit to the minimum input that can be reduced relative to the rated input.
This is determined by factors related to the combustion performance of the burner. Therefore, heating is performed with the minimum input, but in this case, if the hot water is supplied only from the hot water circuit 9, the temperature may rise too much, so the auxiliary heater 12
It is necessary to control the flow rate ratio while maintaining the minimum input. This is the range "B" in FIG. 2, where the hot water supply load to be auxiliary heated is below the minimum capacity. Letting the lowest input be wi, then equation 3 is Q _H T _H +Q _C T _C +ηwi=T _S Q...7 From now on, when K is calculated by substituting equations 4 and 5, K=T _S −T _C ηWi/ Q/T _H −T _C ...8. If ηwi/Q is expressed as Δt and T _S =T _H +ΔT, equation 8 becomes K=T _H −T _C +ΔT−Δt/T _H −T _C =1−Δt−ΔT/T _H −
T _C ......9. Here, when ΔT=Δt, K=1, and the set temperature can be obtained by supplying only from the hot water circuit 9, and when Δt>ΔT, K is less than 1, that is, from the water circuit 10. This indicates that it is also necessary to supply Under the condition of Δt=T _S −T _C, K
= 0, and the set temperature can be obtained by supplying water only from the water circuit 10. However, in T _H = T _S , K = 1 in range "A" and hot water is supplied only from the hot water circuit, and depending on the control method, hot water may not be supplied at the switching point between range "A" and range "B". Since the state of supply from only the circuit 9 and the state of heating at the minimum capacity with only the supply from the water circuit 10 may be repeated, it is recommended to provide a slight hysteresis at this switching point as shown in Figure 2. good. However, Δt' in the figure should be within a practically acceptable range. This range "B" is a region where the hot water supply load is relatively low, and when the hot water supply load to be auxiliary heated exceeds the minimum capacity, the next range "C" occurs.

In the range "C", K=1, water is supplied only from the hot water circuit 9, and control is performed so that the auxiliary heating capacity is expressed by Equation 10 obtained by modifying Equation 3.

wi=Q(T _S −T _H )/η ……10 Capacity control is performed by a capacity control device 19 using an electronic proportional valve that controls the gas supply amount using an electric signal.
It is carried out by.

In the control block diagram of FIG. 3, the temperature detector 20 provided in the hot water circuit 9 is used to determine whether control should be performed in range "A" or range "B". , indicates that the flow ratio control valve 11 or the capacity control device 19 is operated depending on the result. This temperature detector 20 is not necessarily required and can be supplemented in terms of the operating sequence. For example, only the hot water circuit 9 may be opened for a while after opening the terminal faucet, and the control method may be determined after the temperature is detected by the temperature detector 16.

Next, various embodiments of the flow ratio control valve 11 will be described. In FIG. 4, there are two
The valves that are opened and closed by the motor are connected to the hot water circuit 9 and the water circuit 10.
A valve plug 23 energized in the closing direction is placed in a valve case 22, and its opening degree is controlled by a cam 25 rotated by a motor 24. The motor 24 may be a servo motor system in which the rotation angle is fed back, or a pulse motor whose rotation angle corresponds to the number of positive and negative pulses. The angles of the two motors 24 are controlled by the control circuit 18, and the hot water circuit 9 and the water circuit 1
The valve opening degree is adjusted so that the flow rate ratio of 0 is optimal.

FIG. 5 shows an example of control using one set of motor 24 and cam 25. As shown in FIG. 2, the flow rate increases and decreases in the opposite relationship between hot water circuit 9 and water circuit 10, so By installing the flow ratio control valve 11
It consists of

FIG. 6 shows an example of controlling the valve body by integrating the valve body, in which the hot water circuit 9 and the water circuit 10 are merged in the valve case 26, and the valve seat portion is made to correspond to each circuit immediately before the merge. By moving the valve plug 27, when the valve opening of one circuit increases, the valve opening of the other circuit decreases.
The motor 24 and the cam 2 are similar to those shown in Figs.
You can move it with 5. Although the valve case 26 becomes a little larger due to integration, only one valve case 26 is sufficient. Further, since the forces due to the supply pressures of the hot water circuit 9 and the water circuit that act on the valve plug 26 cancel each other in opposite directions, the valve plug 26 has the effect of easily stabilizing the operation.

FIG. 7 shows a flow rate ratio control valve 11 in another embodiment.
This is a case in which a pair of so-called pilot type control valves 28 are used. The hot water circuit 9 and the water circuit 10 have the same configuration, and there is a diaphragm chamber 29 continuous from the main water passage, from which the outlet is reached through a gap defined by a valve seat 30 and a diaphragm 31. On the other hand, another waterway is formed from the inlet side to the outlet side, and a fixed orifice 3
2 and a pilot valve 33 are connected in series, and the partial pressure between them acts on the diaphragm 31. The opening degree of the pilot valve 33 is determined depending on the balance point between the electromagnetic force generated in the plunger 35 by the coil 34 and the reaction force of the control spring 36. The main spring 37 is located in the back pressure chamber 38 and urges the diaphragm 31 in the closing direction.

Now, considering the case where the current to the coil 34 is cut off, the pilot valve 33 is fully closed by the force of the control spring 36, so the diaphragm 31
The pressure in the back pressure chamber 38 is equal to the supply pressure, and is greater than the force acting upward in the figure from the diaphragm chamber 29 side, and the force of the main spring 37 is also applied, causing the diaphragm 31 to come into pressure contact with the valve seat 30, closing the passage. closes. Next, when current flows through the coil 34 and the pilot valve 33 opens, the pressure in the back pressure chamber 38 drops to a value divided by the orifice 32 and the pilot valve 33. Since the supply source pressure is working in the diaphragm chamber 29, the diaphragm 31 starts to open when the pilot valve opening reaches a certain degree. When the coil current increases and the pilot valve 33 opens further, the pressure in the back pressure chamber 38 also decreases, so the force in the valve opening direction that the diaphragm 31 itself receives increases, and the position where it balances the force of the main spring 37 also changes. Move further toward the valve opening direction. In this way, controlling the opening degree of the pilot valve 33 by the current value applied to the coil 34 is equivalent to controlling the valve opening degree of the main water passage. Due to the pressure of the fluid itself, the diaphragm 31
, the minute displacement of the pilot valve 33 is converted into a large amount of displacement of the diaphragm 31, and the slight force generated by the plunger 35 is amplified into a large force that can control the opening degree of the main passage. It is. Therefore, compared to the direct drive system shown in FIGS. 4, 5, and 6, the actuator section, which is composed of a coil 34, a plunger 35, and a control spring 36 and can move the position of the pilot valve 33, is smaller and requires less power. becomes possible. In addition to the actuator configuration shown in FIG. 7, it is also possible to use a motor and cam as shown in FIG. It is what makes it possible.

In FIG. 7, the flow rate ratio control valve 11 is composed of two pilot type control valves, but FIG. 8 shows an example in which these are integrated. Here actuator 39
Although the internal configuration has been omitted, it may be possible to apply electromagnetic force as shown in FIG. 7, or it may be an example using a motor and a cam. The operation is also the same as that of the example shown in FIG. 7, so a description thereof will be omitted, but the feature is that the merging section 21 is built-in.

Next, FIG. 9 shows an example of a flow ratio control valve 11 using a pilot type control valve system and having only one actuator 33. Here, a diaphragm 31 is provided on the water circuit 10 side, an orifice 32, a pilot valve 3
3. The main spring 37, the back pressure chamber 38, and the actuator 39 have the same structure and function as the embodiments shown in FIGS. 7 and 8. A water side valve seat 41 and a hot water side valve seat 42 are provided in the valve case 40 on the same central axis as the diaphragm 31, and a common valve plug 43 controls the opening degree of each valve depending on its position. This valve plug 43 is connected to the diaphragm 31.

Now, if the pilot valve 33 is fully closed, the diaphragm 31 moves downward in the figure, closing the water circuit 10 and opening only the hot water circuit 9. On the other hand, the pilot valve 33
If is fully open, the diaphragm 31 moves upward, so the water circuit 10 is opened and the hot water circuit 9 is closed. Therefore, since the valve opening ratio of the hot water side and the water side can be changed by the valve opening degree of the pilot valve 33, the flow ratio control as shown in FIG. 2 can be performed even with a single actuator 39. This is also advantageous for simplifying the control system.

By the way, if we consider the case where the opening degree of the hot water faucet is changed after the temperature has been set and controlled to obtain a predetermined flow rate ratio, the supply pressure will change to the hot water circuit 9.
If the opening area ratio is different in the water circuit 10, the flow rate ratio will change if the opening area ratio remains the same. For example, when the pressure regulator 7 is inserted only in the hot water circuit 9 side and the water circuit 10 side directly applies the source pressure, this tendency is noticeable.
Every time the flow rate is adjusted with a faucet, it is necessary to change the opening ratio in order to maintain the desired flow rate ratio. This not only shortens the life of the flow rate ratio control valve 11, but also causes transient temperature changes due to response delays, which is undesirable. Therefore, as shown in FIG. 1, it is effective to provide a pressure regulator 7 in the water supply circuit 6 that is common to the hot water circuit 9 and the water circuit 10.

Since the hot water circuit 9 and the water circuit 10 are supplied with equal pressure by the pressure regulator 7, the pressure difference between the branch section 8 and the confluence section 21 is always the same between the hot water circuit side 9 and the water circuit side 10. do. Therefore, even if the total flow rate changes due to a change in faucet opening, the flow rate ratio remains unchanged and the water temperature remains stable.

The flow rate ratio can be controlled not only at the junction of both circuits, but also at the branch section 8 from the water supply circuit 6. An example of this is shown in FIG. here,
The numbers assigned to the components correspond to those in FIG. Since the flow of water is continuous, varying the diversion ratio by controlling the diversion section 8 is the same as varying the confluence ratio, and the effect is the same as in the case of FIG. 1. It can be said that it is superior to FIG. 1 in that it has the effect of preventing deterioration of rubber parts such as rings and diaphragms because the water is controlled before it is heated. In addition, the flow rate ratio control valves for controlling the split flow ratio are shown in Figures 4 to 9.
The configuration described in the example shown in the figure can be used as is, or it can be handled by making some changes.

Furthermore, in the embodiment shown in FIG. 10, it is also possible to structurally integrate the pressure regulator 7 and the flow ratio control valve 11,
An example is shown in FIG. A check valve 44 is placed in the direction of water supply and is urged in the closing direction by a check spring 45, and is pushed open by the water supply pressure, but if negative pressure is generated on the water supply side, it closes to prevent backflow. There is. Following this check valve part, a pressure reducing valve seat 46
, and the valve seat 47 corresponds to this. on the other hand,
On the opposite side of the pressure reducing valve seat 46, a cylinder part 48 having substantially the same inner diameter is formed on the same axis, and a piston part 49 interlocking with the valve seat 47 is inserted inside the cylinder part 48. This part has the effect of increasing pressure adjustment accuracy by canceling out the force acting in the opening direction due to the water pressure applied to the valve seat 47 and the force acting in the closing direction due to the water pressure applied to the piston section. ing. The valve seat 47 and the piston portion 49 are fixed to the pressure reducing diaphragm 50 and move up and down as one. The pressure after passing through the pressure reducing valve seat 46 is led to the diaphragm chamber 51 and produces a force acting upwardly in the figure on the pressure reducing diaphragm 50. The pressure reducing spring 52 opposes this force.
Then, the pressure reducing valve seat 4 is moved at a position where the force of the pressure reducing spring 52 and the force generated by the pressure reducing diaphragm 50 are balanced.
The opening degree can be determined at 6. As the water supply pressure increases, the force in the closing direction generated by the pressure reducing diaphragm 50 increases, so the next stable position is a position closer to the valve closing position to absorb the pressure increase. Conversely, when the water supply pressure drops, the valve opening widens to absorb the pressure drop. In this way, even if the water supply pressure changes, water is supplied to the downstream side at a substantially constant pressure. On the downstream side, there is a flow rate ratio control valve 11 consisting of two pilot type control valves in this example, which performs the operation described above. If integrated in this way, it will be convenient for handling and piping work.

As explained above using various examples,
The present invention controls the mixing flow ratio with water when the temperature of hot water supplied from the hot water supply heat source 1 is higher than the set water temperature, and when the water temperature is lower than the set water temperature, the capacity of the auxiliary heater 12 is controlled. Control and flow rate ratio control are used alone or in combination, and hot water can be supplied at a constant set temperature regardless of the temperature supplied from hot water heat source 1.

In a hot water heat source using a solar heat collector, the temperature inside the tank 4 inevitably changes from around the water temperature to over 60°C depending on the season, solar radiation conditions, time of day, water temperature, etc. For example, when obtaining hot water around 40°C, which is suitable for bathing, the control device of the present invention absorbs temperature changes in the hot water supply heat source 1, whether it is too high or too low, so that it can maintain a good temperature throughout the season. It can bring ease of use.

Furthermore, compared to using a high-temperature hot water storage type electric water heater or boiler as an auxiliary heater, not only is it unnecessary to adjust the faucet, but there is no need to heat the faucet above a set temperature, resulting in a high energy saving effect. Furthermore, the heat radiation loss from the hot water supply piping can be reduced compared to the method of supplying hot water at a high temperature and mixing it with a faucet. Furthermore, the auxiliary heater operates to minimize operating energy, which is highly effective in reducing maintenance costs for hot water supply equipment. In particular, when a solar thermal system is used as a hot water supply heat source, the energy saving effect is enhanced because solar heat is used preferentially.

It is convenient to use because hot water at the intended temperature can be obtained at any temperature, whether it is high temperature or tap water temperature.

As described above, the present invention has excellent effects in terms of usability and energy saving.

[Brief explanation of drawings]

Fig. 1 is a hot water supply system configuration diagram of a hot water temperature control device according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of the same flow ratio control valve and capacity control device, Fig. 3 is a control block diagram, Figures 4, 5, 6, 7, 8, and 9 are cross-sectional views showing each embodiment of the same flow rate ratio control valve, and Figure 10 is a hot water supply system configuration in another embodiment. 11 are sectional views showing an example in which a pressure regulator and a flow ratio control valve are integrated. 1...Hot water heat source, 9...Hot water circuit, 10...Water circuit, 1
DESCRIPTION OF SYMBOLS 1... Flow rate ratio control valve, 21... Merging part, 12... Auxiliary heater, 19... Capacity control device, 16, 20... Temperature detector, 17... Temperature setting device, 8... Dividing part.

Claims (1)

[Scope of Claims] 1. A hot water supply heat source, a flow rate ratio control valve for controlling the respective flow rates of a hot water circuit passing through the hot water supply heat source and a water circuit not passing through the hot water supply heat source, and a flow rate ratio control valve provided downstream from the confluence of the hot water circuit and the water circuit. an auxiliary heater, a capacity control device for the auxiliary heater, a temperature detector and a temperature setting device, and a control circuit that drives the flow rate ratio control valve and the capacity control device based on signals from the temperature detector and temperature setting device. The control circuit has two cases: when the capacity of the auxiliary heater is zero and only the flow rate ratio control valve is driven, and when the capacity of the auxiliary heater is maintained at the minimum value and only the flow rate ratio control valve is driven. A hot water temperature control device having a flow rate ratio control valve that opens only a hot water circuit to drive a capacity control device. 2. The hot water supply according to claim 1, characterized in that a flow rate ratio control valve is provided at the confluence of the hot water circuit and the water circuit downstream of the hot water supply heat source, and an auxiliary heater and a temperature detector are installed downstream of the flow ratio control valve. Temperature control device. 3. A flow rate ratio control valve is provided at the branch part of the hot water circuit and the water circuit upstream of the hot water supply heat source, and an auxiliary heater and a temperature detector are installed downstream of the confluence of the hot water circuit and the water circuit downstream of the hot water supply heat source. A hot water supply temperature control device according to claim 1. 4. The hot water supply temperature control device according to claim 1, wherein a temperature detector is provided in each of the hot water circuit downstream of the hot water supply heat source and the hot water circuit downstream of the auxiliary heater provided downstream of the merging portion.