JPH02150631A - Hot water supply system flow intake method and device therefor - Google Patents

Abstract

PURPOSE:To make it possible to measure and process an output signal transmitted from every flow rate sensor even in a single measurement circuit by switching over reciprocally output signals transmitted from a water flow quantity sensor of a heat exchanger and a water flow quantity sensor installed in a flow passage from a mixing cock to a low temperature hot water discharge port and sending the signals into a single flow rate measurement circuit. CONSTITUTION:A hot water supply system measures a flow rate of water flowing in a main water channel 13 and a flow rate of hot water discharged from a low temperature hot water discharge port 21 simultaneously under combustion control. An output signal transmitted from a water flow quantity sensor 25 of a heat exchanger 15 installed to a main water channel 13 and an output signal transmitted from a water flow quantity sensor 29 provided in a passage on the way to the low temperature hot water discharge port 21 from a mixing cock 20 are switched over alternately and sent out to a single flow rate measurement circuit in a control device 11. The signals switch over operations are carried out on a command given from the measurement circuit side either when the flow rate measurement circuit has read the output signal of the water flow quantity sensor on one side or when the sensor has failed to read a significant flow rate value signal which exceeds the minimum flow rate value. If prompt switch over operations are carried out to a satisfactory extent, one measurement circuit is applicable to measure the flow rates from the output signals in a sense equivalent to actual time in terms of the two sensors.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flow rate intake method and device for a hot water supply system, and in particular to a relatively high flow rate intake method and device for hot water supply systems such as for filling hot water from a single heat exchanger to a bathtub. High-temperature hot water and relatively low-temperature hot water, such as those used for cooking or washing dishes, can be dispensed independently from each hot water supply system. A hot water supply system that simultaneously enables low-temperature hot water to be drawn by mixing the high-temperature hot water that flows through the system at a predetermined ratio at a mixer faucet with water that is fed through a separate bypass waterway that does not go through a heat exchanger. , relates to improvements in measuring at least the flow rate passing through a heat exchanger and the flow rate of hot water tapped from a low-temperature tapping port, and incorporating them into a control device in order to calculate the amount of combustion required in each case.

[Prior Art] As mentioned above, a hot water supply system that can distribute and supply hot water at both high and low temperatures to two systems even if only one heat exchanger is used,
The applicant is already in the process of developing it.

Therefore, the schematic configuration of such a hot water supply system is shown in a relatively basic form in FIG. 3, and will be explained. Water flowing in from the water inlet 12 is first branched into a main waterway 13 and a bypass waterway 14.

The main waterway 13 passes through a heat exchanger 15 and is then divided into a first branch waterway 16 and a second branch waterway 17.

The first branch waterway 16 is connected via a stop valve 18 to a hot water outlet 19, such as a hot water supply inlet to a bathtub, where relatively high temperature hot water ranging from 45°C to 60°C or higher is desired, and a second The branch waterway 17 is controlled by the control device 11 as described below.
It is connected to a mixing faucet 20 that controls the mixing ratio with water flowing through the bypass waterway 14.

Although the output of the mixing faucet 20 is not shown, it can be a normal faucet, etc.
It is applied to the low temperature tap 21, which is left to the user's opening and closing operations, including the adjustment of the valve opening.

The temperature required for hot water to be tapped from the low-temperature tap 21 may, in special cases, be about the same temperature as that required for the high-temperature tap 19, but normally it is less than 40°C at most, and generally The temperature will be on the order of 30-odd degrees Celsius.

Of course, in the figure, only one system is shown regarding this low-temperature hot water tap system, but generally the output system of the mixing faucet 20 is distributed to a plurality of faucets.

The combustion section for heating the heat exchanger 15 through which the main waterway 13 passes has a burner 26, and the fuel burned here includes oil, gas, etc.

For convenience of explanation and in accordance with the product actually developed by the present applicant, if we take gas as an example of fuel, no hot water is required to be tapped from either the high temperature tap 19 or the low temperature tap 21. Naturally, at times, the combustion control device 11 fully closes the gas amount control valve 22, which is generally called a gas proportional valve.
The gas electromagnetic valve 23, which is provided solely to open or shut off the gas supply path, is also fully closed, and the fan motor 24, which supplies an appropriate amount of air to the combustion section, is also stopped.

However, depending on the device, the gas solenoid valve 23 may be omitted because the gas proportional valve 22 also has the function of opening and closing the fuel supply path that the gas solenoid valve has, and in some cases, the gas solenoid valve 23 may be omitted. Some have a volume control valve.

The combustion control device 11 has a built-in microcomputer (not shown), but it is also provided at a control panel (not shown) of the system, particularly at a location away from the combustion section, and is connected to the control device 11 by wire. The control panel included in the remote unit includes a hot water filling switch for the user to issue commands to fill the bathtub with hot water, a temperature setting knob for setting the temperature for filling the hot water, and a low-temperature switch such as a normal faucet. A temperature setting knob etc. is provided for setting the temperature of hot water dispensed when the valve provided at the outlet is opened, and based on these operations, at least two flow rate sensors 2 are also involved in the present invention.
Flow rate detection signals from 5 and 29 and each temperature sensor 27
, 28, etc., the microcomputer in the control device 11 creates control data, and controls each mechanical section shown in the figure via a suitable interface circuit.

For example, when the operating switch (not shown) of the system is turned on, a user opens a faucet or the like provided at the low-temperature outlet 21, thereby allowing water generally supplied from the water source to flow into the water inlet 12. If water flows from a person and starts flowing through the heat exchanger 15, the heat exchanger water flow rate sensor 25, which is in this flow path and had previously issued a water flow stop signal, indicates that a water flow has occurred. A signal is sent to the control device 11.

Upon receiving this, the control device 11 first acts on the mixing faucet 20, and the mixing faucet 20, which was in the above-mentioned combustion stop or combustion standby state and had both the bypass waterway 14 side and the second branch waterway 17 side fully open, By operating the valve means, the bypass waterway 14
Cut off the side.

Next, the amount of water that has started flowing through the heat exchanger 15 as described above reaches the low temperature outlet 21 even when the minimum amount of heat is supplied to the heat exchanger 15, that is, even in the minimum stable combustion state in the burner 26.
When the heat exchanger water flow sensor 25 detects that the flow rate has reached a level that can maintain the hot water temperature at the set temperature, the control device 11 opens the gas solenoid valve 23 and then closes the gas proportional valve 2.
After ignition in the combustion section, the system enters a low temperature operation mode and prepares for the output of the heat exchanger 15. Output hot water temperature detection sensor 27 such as a thermistor
The combustion section including the burner 26 is controlled so that the temperature detected by the burner 26 is as close as possible to the low-temperature set temperature set by the user.

On the other hand, if the user operates the hot water refilling switch on the remote unit (not shown) from the combustion stop or standby state, the control device 11 first opens the water stop valve 18 on the high temperature outlet 19 side, and thereby The heat exchanger water flow rate sensor 25 indicates that a fixed amount of water flow has started to occur in the heat exchanger 15.
After confirming this with After ignition, it enters high temperature operation mode.

Even in this high temperature operation mode, the control device 11 controls the heat exchanger 1
The combustion section including the burner 26 is set so that the temperature detected by the outlet hot water temperature detection sensor 27 such as a thermistor provided at the output of No. control.

This filling of hot water is also automatically stopped when a predetermined total flow rate is reached, which is set according to the size of the bathtub. It is used by the control device 11 to grasp the cumulative flow rate from the start of water flow.

Furthermore, in addition to the hot water dispensing operations at low temperature and high temperature individually as described above, when the user opens the valve (faucet, etc.) provided on the low temperature tap 21 side during hot water dispensing at high temperature alone, the following operations occur. Through such a mechanism, the system shown in the third figure enters a simultaneous hot water dispensing mode of both high and low temperatures.

When the valve of the low-temperature tap 21 is opened during high-temperature tapping, the high-temperature hot water from the heat exchanger 15 flows into the mixing faucet 20 via the second branch waterway 17, where it is sent through the bypass waterway 14. After being mixed with the flowing water, it also begins to flow out from the low temperature outlet 21.

As a result, when the low-temperature side water flow rate sensor 29 provided between the mixing faucet 20 and the low-temperature outlet 21 detects a flow rate equal to or higher than a predetermined flow rate value, the control device 11 controls the temperature of the hot water at the output of the heat exchanger 15. As in the case of tapping hot water only from the high-temperature tap 19 described above, in order to maintain the set temperature on the high-temperature side, the valve opening of the mixing faucet 20 is controlled at the same time while controlling the combustion section in the high-temperature operation mode. Control and heat exchanger water flow rate sensor 2
The amount of water passing through the heat exchanger 15 side detected by 5, the amount of hot water coming out from the low temperature outlet 21 detected by the low temperature side water flow rate sensor 29, and the amount of hot water actually being tapped from the low temperature side outlet 21. Based on the temperature data taken in from the low-temperature outlet hot water temperature sensor 28 that detects the hot water temperature, the temperature of the second branch water channel 17 is adjusted so that the actual outlet hot water temperature is as equal as possible to the low-temperature preset temperature set by the user. The mixing ratio of the high-temperature hot water and the cold water sent via the bypass waterway 14 is controlled.

[Problems to be Solved by the Invention] The basic configuration and operation examples of hot water systems that have been developed so far and have hot water dispensing modes at both high and low temperatures at the same time have been described above. What we should be aware of is the signal from multiple flow rate sensors (for example, the heat exchanger water flow rate sensor 25 in Fig. 3 and the water flow rate sensor 29 that detects the amount of water flowing to the low-temperature outlet 21 side). This is the intake of

In general, this type of flow rate sensor is of the flow rate versus pulse frequency conversion type, that is, an actuator part is inserted into the water channel where the flow rate is to be measured, and the flowing water or hot water causes the actuator part to rotate once, e.g. A type that generates two pulses is used.

Therefore, since the cross-sectional area of the water channel is known from the design perspective, how many pulses are generated per certain period of time?
Or, conversely, if a measuring circuit measures how long it takes for a given number of pulses to occur, the number of measured pulses or the measuring time will be directly proportional to the fluid flow rate flowing through the waterway. becomes.

However, prior to the present invention, the applicant had constructed a hot water supply system as shown in FIG. 3, which was excellent as a system as described above, but
, 29 were initially provided with dedicated measurement circuits within the control device 11.

Therefore, the present invention considers this to be wasteful and devised a system that can measure and process the output signals of all these flow rate sensors with a single measurement circuit in a hot water supply system that requires multiple flow rate sensors as shown in Figure 3. The purpose is to provide a signal acquisition method or circuit.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has the following objectives: Among the plurality of flow rate sensors used in the hot water supply system as described above, these are the lowest flow rate sensors for the required water flow rate of the heat exchanger. Regarding the sensor and the water flow rate sensor provided in the flow path from the mixer faucet to the low-temperature outlet, the output signals of each of them are alternately switched and sent to a single flow rate side window circuit.

This switching is performed based on a command from the measurement circuit after the output signal of one of the water flow rate sensors is reliably read, or after a significant flow rate value signal higher than the minimum flow rate is not read. .

[Function] Since the present invention is configured as described above, if the switching is performed at a sufficiently high speed, even if only one measurement circuit is used, the feeling for both sensors is almost the same as real time. A flow rate measurement can be made based on the output signal.

Of course, during the minimum time required to analyze the signal from each sensor, the signal will be continuously captured for each sensor, but on the other hand, the form of the signal obtained at the minimum flow rate can be known in advance. You can also know that a significant flow rate value higher than the minimum flow rate value cannot be detected, but in this case, you can save time by immediately acquiring the signal from the other flow rate sensor. It will disappear even more.

[Embodiment] Hereinafter, an example of operation when the present invention is applied to the hot water supply system described above with reference to FIG. 3 will be described with reference to FIG. 1.2. Therefore, as a matter of course, the reference numerals of each part used in the explanation of the tree as necessary are the same as those shown in FIG. 3.

FIG. 1 shows an intake circuit for alternately capturing flow rate detection signals PI and P2 from two flow rate sensors, particularly the heat exchanger water flow rate sensor 25 and the water flow rate sensor 29 to the low-temperature side outlet shown in FIG. 30, and FIG. 2 shows an example of its operation.As mentioned earlier, the sensors 25 and 29 used in this embodiment are both
The actuator part is inserted into a water channel in which the flow rate is to be measured, and the actuator part is of a flow rate versus pulse frequency conversion type in which, for example, two pulses are generated during one revolution of the actuator part due to flowing water or hot water.

Therefore, since the cross-sectional area of each water channel portion in which the sensors 25 and 29 are provided is known from the design point of view,
If a measuring circuit measures how many pulses occur per unit time or how long it takes to generate a predetermined number of pulses, the number of measured pulses or the measured time can be directly calculated by It is proportional to the flow rate of the fluid flowing.

In accordance with the latter, the acquisition pulse train P is provided as a single circuit in the control circuit 11 in FIG. 3 and is the output of the acquisition circuit 30 shown in FIG. 1. The flow measurement circuit that receives
The time required to generate two pulses shall be measured.

Note that the measuring circuit itself for measuring the time required to generate a predetermined number of pulses is well known, so it is not specifically illustrated in this embodiment, and is generally measured via a suitable interface circuit. Such time can also be measured by software processing in a microcomputer built into the control device 11.

The flow rate pulse acquisition circuit 30 shown in the first figure receives a first output pulse train P1 obtained from the water flow rate sensor 25 shown in the third figure, and a second output pulse train P2 obtained from the water flow rate sensor 29 on the low temperature outlet side. Dedicated inverter Q+ for each
, received in Q2.

These inverters Q+ and Q2 are each filled with a single simple transistor configuration in the case shown, and their base inputs are used as enable terminals, and when the base inputs are selectively grounded, The input pulse P or P2 is disabled, and the output terminal, which is the collector of each transistor Q++Q2, remains pulled up to the power supply level. Therefore, if one inverter Q1 or Q2 is disabled and the other transistor Q2 or Q is enabled, the collector output of the enabled transistor becomes significant. , this is the output P of the main import circuit 30.

is applied to a measurement circuit (not shown).

In other words, the respective collectors of both transistors Q+ and Q2 are connected to the pulse train output terminal to the measuring circuit via a so-called wired OR.

However, in the case of the first illustrated embodiment, which input pulse is effectively handled, that is, which inverter is enabled, depends on the logic level of the switching command signal θ1 sent from a measurement circuit (not shown). determined by

The switching command signal θL is applied to the transistor Q3. The collector output of one transistor is directly connected to the base, which is the enable terminal of input inverter Q2, while the other transistor Q4 is further cascaded to a second switching transistor Q5. , the collector of this first switching transistor Q5 is connected to the base, which is the enable terminal of the input inverter Q+.

Therefore, when the switching command signal θ1 is at logic “H”,
In this embodiment, both transistors Q3. Q4 are both turned on, but transistor Q, which is cascaded to transistor q4, is turned off, so of the two input inverters Q+ and Q2, only input inverter Q+ is enabled. This is because the base of the input inverter Q2 is pulled down to ground via the collector-emitter line of the turned-on transistor q3, and becomes disabled.

Conversely, when the switching command signal becomes logic "L", an on-off relationship opposite to the above occurs, and the two input inverters Q
+, in Q2, input inverter Q2 is enabled,
Input inverter q is disabled.

In this embodiment that incorporates the present invention, the flow rate pulse acquisition circuit 30 configured as described above is used to control the flow rate measurement circuit or microcomputer provided in the control circuit 11 as shown in FIG. Make it work.

As mentioned above, in this embodiment, the measuring circuit measures the time required for counting the two pulses emitted by the water flow rate sensors 25 and 29, and thereby obtains the flow rate accordingly. After each two-pulse count is completed, the measurement circuit generates a switching command signal θ1 that alternately inverts the logic from "H" to "°L" and from "L" to "H" at the falling edge of the second pulse. emanate.

The pattern is shown in FIG. 2. When the second pulse of the low temperature side water flow rate sensor 29 (denoted as the second flow rate sensor 29) falls, the measurement circuit in the control circuit 11 sends the switching command signal θ1. Inverted to logic “H” and sent to the acquisition circuit 30,
As a result, in the acquisition circuit 30, the input inverter Q
1 is enabled, and the output pulse P1 of the water flow rate sensor 25 (denoted as first flow rate sensor 25) provided on the main waterway 13 side appears at the output terminal and is sent to the measurement circuit.

Regarding the output pulse p of the first flow rate sensor 25, the measuring circuit measures the time T1 required for two consecutive pulses, and after measuring the corresponding flow rate, switches the switching command signal θ5 at the falling edge of the second pulse. Invert the logic and make it "L".

Then, in the flow rate pulse acquisition circuit 25 shown in the first diagram, the input inverter Q2 is enabled instead of the input inverter Q1, so that the second output pulse P2 output from the second flow rate sensor 29 is transmitted to the acquisition circuit 30. This appears in the output, and this is sent to the measurement circuit in the control circuit 11, the time T2 required for those two pulses is measured, and the corresponding flow rate is measured. At the falling edge of the second pulse, the measurement circuit starts again. The logic of the switching command signal θl is inverted and
”.

In this way, the measuring circuit can alternately and periodically measure the flow rate information emitted by each flow rate sensor 25, 29 at any given time.

However, in this type of hot water supply system, there is a minimum flow rate at which combustion can be controlled, and for safety reasons, the combustion part is prevented from igniting at a flow rate below or below this value.

Therefore, in this embodiment as well, it is possible to detect the case where the actual flow rate is less than the minimum flow rate value (including the flow rate τ), and this means that the second flow rate is Output pulse P of sensor 29
2, the logic of the switching command signal 0 plate issued by the measuring circuit is reversed to "H" at time to, and as a result, the first flow rate sensor 25 is selected, but its output pulse P , in other words, if the flow rate is zero, the measuring circuit automatically inverts the logic of the switching command signal θ1 again after a predetermined time T1 has elapsed.

This time T is set in consideration of the longest pulse width of each pulse Pl and P2 at the minimum flow rate.In other words, if a significant pulse fall is not detected within the time T1, the measurement The circuit determines that the flow rate is at least below the minimum flow rate value and moves on to counting the output pulses of the other flow rate sensor.

[Effect] According to the present invention, even though a single flow rate measurement circuit is used,
Both the amount of water flowing through the heat exchanger and the amount of hot water coming out from the low-temperature tap can be measured rationally, contributing to circuit simplification and cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of one configuration example of a flow rate pulse acquisition circuit configured according to the present invention. FIG. 2 is an explanatory diagram of the operation of the flow rate pulse acquisition circuit. FIG. 3 is a schematic configuration diagram showing a configuration example of a hot water supply system to which the present invention can be applied. It is. In the figure, 11 is a combustion control device, 12 is a water inlet, 13 is a main waterway, 14 is a bypass waterway, 15 is a heat exchanger, 16 is a first branch waterway, 17 is a second branch waterway, 18 is a stop valve, 19 is a high temperature tap, 20 is a mixing tap, 21 is a low temperature tap, 22 is a gas proportional valve, 23 is a gas solenoid valve, 24 is a fan motor, 25 is a heat exchanger water flow rate sensor, 26 is a burner, 27 is a 28 is a hot water outlet temperature sensor on the low temperature outlet side, 29 is a water flow rate sensor on the low temperature side, 30 is a flow rate pulse acquisition circuit, Q+, Q2 are input inverters, and θI is a switching command signal.

Claims (2)

[Claims] (1) The waterway from the water inlet is divided into the main waterway and the bypass waterway, and the main waterway passes through a heat exchanger heated by the combustion section, and then branches into the first and second branch waterways, and the The branch waterway has a hot water supply system in which the second branch waterway is connected to the high temperature outlet via a stop valve, and the second branch waterway is connected to the low temperature outlet via a mixing tap with water sent through the bypass waterway. In a hot water supply system that controls combustion while measuring both the flow rate of water flowing in the main waterway and the flow rate of hot water discharged from the low-temperature outlet; The signal and the output signal of a water flow rate sensor provided in the flow path from the mixing faucet to the low-temperature tap are alternately switched and sent to a single flow rate measurement circuit; is performed by a command from the measuring circuit after the output signal of one of the water flow rate sensors is reliably read, or after a significant flow rate value signal equal to or higher than the minimum flow rate value cannot be read. Flow rate acquisition method for the system. (2) The waterway from the water inlet is divided into a main waterway and a bypass waterway, and after passing through a heat exchanger heated by the combustion section, the main waterway further branches into the first and second branch waterways, and the The branch waterway has a hot water supply system in which the second branch waterway is connected to the high temperature outlet via a stop valve, and the second branch waterway is connected to the low temperature outlet via a mixing tap with water sent through the bypass waterway. In a hot water supply system that controls combustion while measuring both the flow rate of water flowing in the main waterway and the flow rate of hot water discharged from the low-temperature outlet; The intake circuit has an intake circuit that alternately switches the signal and the output signal of a water flow rate sensor provided in a flow path from the mixing faucet to the low-temperature tap and sends it to a single flow rate measurement circuit; , has a command input for the above switching,
Based on the switching command signal sent to the command input after the flow rate measuring circuit reliably reads the output signal of one of the water flow rate sensors or after failing to read a significant flow value signal greater than the minimum flow rate, A flow rate intake device for a hot water supply system, characterized by: switching from one sensor to the other sensor.