JPH01263457A - Hot-water supply device - Google Patents

Abstract

PURPOSE: To eliminate trouble to manufacturing process when heating water in a reservoir up to boiling point upon turning a switch on, calculating a maximum temperature lower than the boiling point by a specified level through a controller upon detecting the boiling point and keeping the temperature of water in the reservoir at a desired level not higher than the calculated maximum temperature. CONSTITUTION: When the switch of an apparatus is turned on, a switch on signal is delivered to the output section of a comparator 17 and the switch of a heater 2 is turned on through a buffer amplifier 18. Consequently, cold water initially present in the apparatus is heated up gradually and begins to boil eventually. When the water in a reservoir reaches the boiling point, a variation detector 14 detects the fact that temperature variation has not occurred within a specified time based on the invariant boiling point thus determining boiling of water. A signal is then delivered from the detector 14 to a subtractor 13 where a temperature difference signal received at a second input through a connecting part 15 is subtracted from a temperature signal from a first input part.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a reservoir equipped with a heating device that maintains a certain amount of water at a desired temperature, and a signal from a temperature sensor attached to the reservoir. and a control device for controlling the heating device accordingly, and particularly relates to a hot water supply device for supplying hot water for the purpose of producing beverages.

[Prior Art and Problems to be Solved by the Invention] There are various kinds of devices, but in these conventional devices, the control device and temperature sensor are usually combined into a relatively simple thermostat. It is formed as a circuit that maintains the water in the reservoir at the desired temperature. Since this Mostat circuit is temperature-controlled to a specific temperature value during the manufacturing process, the user cannot freely change it later.

At least not easily.

In these devices, the temperature of the water is preferably maintained below the boiling point in order to minimize the power consumption of the heating device. For example, in a beverage manufacturing device such as a coffee maker, the temperature is regulated so as not to exceed 98°C to keep water below the boiling point temperature (approximately 100'C). However, if we assume that such a device is used at a fairly high altitude, such as in a mountainous area, the boiling point temperature of water will be very low, especially as shown in the example above. It is expected that the temperature will be lower than the 98°C mentioned above. As a result, the heating device is always kept on and the water continues to boil, resulting in a large amount of power being wasted.

Previously, if you needed to use this device at a fairly high altitude where the boiling point temperature of water was below 100°C, you would adjust the thermostat to prevent the water in the reservoir from boiling. It was common. However, this still means that each user has to make special adjustments to the thermostat at the manufacturer's factory, which disrupts the manufacturing process.

The present invention aims to provide a device that solves these problems.

[Means to solve the problem]

In order to solve this problem, the features of the device of the present invention are: (1) When the switch is turned on, the water in the reservoir is heated to the boiling point, and (2) When the boiling point is detected, the control device c) maintaining the water in the reservoir at a desired temperature not higher than the calculated maximum temperature;

[Effect]

First, when the device is switched on, the water in the reservoir is boiled, the boiling point temperature is calculated, and then the water temperature is reduced to such an extent that the user can control the water regardless of the height of the area where the device is used. One can be confident that the temperature is kept below the local boiling point temperature.

In the simplest embodiment, the desired temperature is equal to the maximum temperature (desired temperature means the temperature at which the water needs to be held continuously). in this case,
The maximum temperature, and therefore the desired temperature, can be obtained by simply performing a subtraction of extinguishing the sensor signal by a predetermined value.

However, it is also possible to go further and select a temperature below the fixed maximum temperature as the desired temperature using the regulating means. In this way, the user is not constrained to a maximum temperature determined by the device. Of course, even in this case, continuous boiling of water can be prevented regardless of the altitude of the place of use.

〔Example〕

The present invention will now be described in detail with reference to the accompanying drawings.

In FIG. 1, a reservoir 1 with a heating device 2 and a temperature sensor 3 inside is shown simply.

The reservoir 1 is connected to a water pipe 5, only a portion of which is shown, via a tap 4.

The temperature sensor 3 is connected via a conductor 6 to an input 11 of the circuit shown in the frame 8 .

The heating device 2 receives signals from the output 9 of the circuit via a conductor 7.

This circuit, shown in the frame 8, is an element of a known control device for the device and is also capable of controlling the opening and closing of the tap 4, for example. However, since the other functions of this control device are not important to the invention and are well known, a detailed description thereof will be omitted.

As already mentioned, the circuit in frame 8
1 receives a signal from the temperature sensor. This signal is sent via the switch 12 (which is in the ON position shown in FIG. 1) to the first manual section of the subtraction device 13 and to the input section of the change detection device 14. A signal representing the predetermined temperature difference ΔT is input to the other input of the subtraction device 13.

From the output of the subtraction device 13 a signal is sent to a memory 16, the output of which is connected to the input of a comparator 17. When the switch 12 is switched, the temperature signal generated by the sensor 3 is input to the other input of the comparator 17. The output of the comparator 17 is connected via a buffer amplifier 18 to the output 9 of this circuit, through which the signal for controlling the heating device 2 is sent to the conductor 7. .

The operation of this circuit will now be described in detail with reference to FIGS. 1 and 2.

When the device is switched on, the switch 12 is in the position shown in FIG. Furthermore, in this state, a switch-on signal is sent to the output of the comparator 17, which turns on the heating device 2 via the buffer amplifier 18. For this reason, the cold water initially present in the device gradually heats up and eventually begins to boil. At this stage of operation, the constantly changing temperature is detected by the sensor 3, and a signal corresponding to the temperature is sent to the change detection bag N14.
sent to. As long as the signal continues to change, the sensing device does not send an output signal to the subtraction device 13.

However, once the water in the reservoir reaches its boiling point, this boiling point temperature does not change any further, so when the water reaches its boiling point,
The change detection device 14 detects that there has been no temperature change within a predetermined period of time, which indicates that the water has reached its boiling point. As a result, the change detection device 14 sends a signal to the subtraction device 13, and in response, the subtraction device 13 sends a signal to the connection 15.
The temperature difference signal inputted to the second human power section via is subtracted from the temperature signal of the first human power section. This temperature difference signal △T is
It may be a fixed signal applied to the input unit 15 by a control device (not shown), or it may be a signal that can be adjusted according to the needs of the user. How this is possible to adjust according to the user's needs will now be explained in detail.

Now, in response to the activation signal issued by the change detection device 14, the subtraction device 13 issues a signal at its output, the temperature to which this signal corresponds is detected by the sensor 3 and is equal to the temperature difference ΔT. Equal to frozen temperature.

This temperature value is stored in memory 16. Memo IJ16
The signal corresponding to this stored temperature value is sent to comparator 1.
7 to the 1st Human Resources Department. By the way, during this time, the change detection device 14 sends a signal to the subtraction device 13 and at the same time switches 1 to 1.
2, the switch is changed, and the temperature signal from the sensor 3 is then applied to the second human power section of the comparator 17.

The comparator 17 first determines that the temperature of the water in the reservoir 1 has become too high, so that a switch-off signal is sent to the output of the comparator 17.

Therefore, the switch of the heating device 2 is turned off via the buffer amplifier 18. This OFF state continues until the temperature of the water in the reservoir 1 becomes equal to the temperature value indicated by the signal stored in the memory 16.

FIG. 2 is a graph showing the operation of this circuit.

As can be seen from this figure, at a low altitude H1 (e.g. close to sea level), the temperature decreases when the device is switched to OFF at time LO.
After reaching N, it gradually rises and reaches the boiling point temperature L at time t1.
Reach 1. At time t2, the change detection device 14 confirms that the boiling point has been reached and turns off the heating device 2 as described above.
Make it F. As a result, the temperature decreases, and at time t3 the temperature T
It becomes 2. Temperature T2 is equal to T1-ΔT. The comparator 17 then detects that the temperatures are equal at its two inputs and sends a switch-on signal to the heating device 2 at its output. From this point on, the circuit operates continuously as a normal thermostatic circuit, thereby maintaining the water in reservoir 1 at temperature T2.

The operation of the device described so far is independent of the actual boiling point temperature. However, in reality, the boiling point temperature of water varies significantly with altitude, as shown in the table below.

Altitude Boiling Point Temperature Om] 0000 11000 m 96°C 2400m 92'C 4000m 86°C 5600m 81'C If the device is used at an altitude higher than the altitude H1 in the above case, for example in a mountain restaurant at an altitude of 2400 m. In other words, the boiling point has already been reached at a lower temperature. However, the operation of the device in this case can be explained in exactly the same way as in the previous case.

In FIG. 2, the situation when using the device at a higher altitude H2 is illustrated by a second curve.

If used at this altitude, the boiling point will already be reached at temperature T3. The circuitry within frame 8 operates in the manner already described. That is, when the water temperature reaches the boiling point temperature T3 and this temperature T3 is detected, the water temperature decreases by the temperature ΔT, and thereafter the temperature of the water in the reservoir is maintained at the temperature T4.

During the above explanation, the temperature difference value △T
Mention has already been made regarding the possibility of adjusting the

To adjust the temperature difference value △T, a control knob that can adjust △T is attached to the outside of this device, but it is necessary to determine the minimum value of △T during manufacturing so that △T does not become 0. .

In the device schematically shown in FIG. 1, reservoir 1 is connected to tap 4.
Water is supplied from the water supply pipe 5 via the water supply pipe 5.

However, the present invention allows other types of containers to be used without any modification, for example, a metered amount of cold water is poured through a downward separating tube and at the same time the same amount of hot water exits the reservoir tap via a siphon. It can also be applied to volumetric containers. Since such a device itself is well known, further explanation will be omitted.

Although FIG. 1 shows a block diagram of an embodiment of the circuit in frame 8, it will be clear that the signal processing described above can be performed in other ways.

For example, a digital processor may be used to operate the circuit shown in frame 8.

A signal is sent from the sensor 3 to this digital processor via an AD converter. This digital processor also sends control signals to control the heating device 2 via the DA converter. Processors incorporating AD and DA converters are commercially available as component parts.

Such a processor can be programmed according to the flowchart shown in FIG. This flowchart uses variable a, which is the first
It has the same function as the switch 12 shown in the figure.

Now, when the program is started in block 20, variable a is set to 0 in block 21.

Next, in block 22, the value of variable a is examined. Since variable a is set to O in block 21, block 2
2. Following this, block 23 is executed.

Thereby, the sensor signal is input and digitized to obtain the measured value Tn. In block 24, the measured value Tn is below the previous measured value. It is examined whether it is higher than -1. If it is high, it is delayed by a certain time in block 25 and then returns to block 23;
The next measured value is entered. This loop program according to blocks 23.24.25 is executed as soon as the device is switched on and the water is heated from the initial temperature to the boiling point.

Once the boiling point is reached, two consecutive measurements are always equal. Therefore, for the question in block 24, IT N
OII will be answered. Next, in block 26, the maximum temperature Tm
ax is calculated and variable a is set to 1. From block 26, the program returns to the input of block 22.

Since the variable a is equal to 1, II No II is answered to the question in block 22, and the program returns to block 2.
Execute step 7. In this block 27, the next measured value is entered and digitized. Block 28 compares this measured value with the maximum value Tmax. If the maximum value is higher, the heating device switch is turned to IT ON II (block 30). Also, if it is not high, the heating device is switched "OFF" (block 29).
. Thereafter, after a delay of time ΔT in block 31, the program returns to block 27, where the next measured value is again input.

To summarize, during the initialization phase of the device, the section consisting of blocks 23.24.25.26 of the flowchart is executed to determine the maximum temperature. On the other hand, in order to maintain the temperature at the desired value Tmax, the section of the flowchart consisting of blocks 27, 28, 29, 30, 31 is executed.

However, as is obvious to those skilled in the art,
The temperature may be maintained at a value lower than Tmax, which value can be selected by the user by adjusting means.

4 and 5 show another embodiment of the device according to the invention. FIG. 4 schematically shows the main parts of the apparatus of this second embodiment.

FIG. 5 shows a flowchart of a processing program executed by the processor 33 of FIG. 4.

Parts designated with reference numbers 1 to 7 in these drawings are
The parts are the same as those shown in the figure. The output signal from the temperature sensor 3 is in this embodiment sent via a conductor 6 to an ID converter 32, where the analog value of the measured temperature is converted into a digital value. This digital signal is then supplied to the processor 33. The processor 33 further receives a setpoint temperature value sent via an analog-to-digital converter 34 from a setting means 35 (which may for example be a potentiometer or similar device). The processor 33 sends signals for controlling the heating device 2 via a DA converter 36 and a buffer amplifier 37 to a conductor 7 connected to said heating device.

The processing that takes place within processor 33 is schematically illustrated in the flowchart of FIG. The process begins at block 40, which initializes the processor and memory. Next, in block 41, the memo=16- is changed. In other words, the maximum temperature (iT
If max is stored, the process moves to block 42 where the user is given the opportunity to change Tmax.

If it is desired to change the maximum temperature value, the process moves to block 43. The process also moves to block 43 when it is determined in block 41 that the maximum temperature value Tmax is not stored in the memory. In block 43 the heating device 2 is switched on. Following this, the instantaneous temperature Tn is measured (block 44). The measured value Tn is continuously compared with a fixed temperature value. This fixed temperature value is selected such that it is always below the boiling point temperature of water. In the embodiment shown in FIG. 5, this fixed temperature value is 80 DEG C., but any other value may be chosen as long as it is below the boiling point temperature of water. As long as the measured instantaneous temperature Tn is below the fixed temperature value, the heating device remains switched on and the loop blocks 43.44.45.43...
・is executed repeatedly.

When the measured temperature Tn becomes equal to the fixed temperature, the process moves from block 45 to block 46, and the cross-crossing function begins to measure a predetermined time. This predetermined delay time TD (tim
e delay) is chosen such that under all circumstances the water in the reservoir 1 reaches its boiling point temperature within this time. Needless to say, this predetermined delay time TD is determined depending on the amount of water in the reservoir 1, the capacity of the heating device 2, and the boiling point temperature of water at the location. Generally delay time TD
This may take several minutes for small to medium sized equipment.

Once this delay time TD has elapsed, the instantaneous temperature Tn is measured in block 47. At this time, since the water in the reservoir 1 is boiling, this instantaneous temperature Tn is equal to the boiling point temperature at the location. Thereafter, the maximum value Tmax is calculated by subtracting the predetermined temperature difference ΔT from the measured temperature Tn. This calculated value Tmax is then stored in memory. Thereafter, the heating device 2 is controlled using this temperature Tmax, and the water temperature in the reservoir 1 is maintained at this temperature Tmax. This is shown in blocks 48-53, but the processing process shown in these blocks is exactly the same as that shown in blocks 27-31 in the third round.

In this embodiment, the temperature value Tma can be maintained even when the main power supply switch is turned off, by connecting the temperature value Tma memory 33 to the power supply memory 33 or by using a non-volatile memory.
so that x is retained in memory, turn the switch I again
It is desirable to keep it in a state where it can be easily used if it is turned into I ON II. If the temperature value Tmax is stored in the memory, after the initialization in block 40, blocks 41 and 42 are executed, after which the process directly proceeds to block 48. Therefore, in this case the water temperature is T
It rises to max and then remains at this value. In other words, since the water in the reservoir 1 is not heated to boiling point, the energy consumption is significantly reduced when the device operates in this way.

In the above explanation, the value ΔT used to calculate the temperature value Tmax was a fixed value, but as explained in the embodiment of FIG. 1, the embodiment of FIG. 35, by which the user can set the desired temperature value ΔT
You may also be able to use cents. This setting value is A-
The signal is digitized by a D converter 34, supplied to the processor 33, and used for calculation in block 47.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a circuit used in the control device of the apparatus of the present invention to implement the present invention, FIG. 2 is a diagram showing a time graph explaining the operation of the circuit of FIG. 1, 3 is a flowchart showing the operation of the device of the present invention, FIG. 4 is a schematic diagram showing the main parts of the device of the second embodiment, and FIG. 5 is a flowchart showing the operation of the device of the present invention. Diagram shown in flowchart. 2...Heating device, 3...Temperature sensor, 4...Tap, 11...
・Input section, 12... Switch, 17...
...compare lake.

Claims (6)

[Claims] (1) A reservoir equipped with a heating device for maintaining a certain amount of water contained therein at a desired temperature, and a control device that controls the heating device according to a signal supplied by a temperature sensor provided in the reservoir. In a water heater for supplying hot water especially for the purpose of producing beverages, a) after switching on the device, the water in the reservoir is heated to the boiling point; and b) the control device detects the boiling point. and then determining a maximum temperature that is lower than the boiling point by a predetermined temperature, and c) the water in the reservoir is maintained at a desired temperature that is not higher than the determined maximum temperature. (2) The water heater according to claim 1, wherein the desired temperature is equal to the determined maximum temperature. 3. A water heater according to claim 1 or 2, characterized in that the user can increase the predetermined signal above a fixed minimum value by means of adjustment means. (4) The control device: a) detects a temperature change after the device is turned on;
(b) a first means for emitting a signal when detecting that the temperature has become constant; and (b) a second means for emitting a signal controlled by the signal emitted by the first means and representing a maximum temperature below the boiling point temperature determined by the first means. c) a buffer memory that stores this maximum temperature; and d) a comparator that stores the maximum temperature in the buffer memory and then compares this maximum temperature with the actual temperature and issues a control signal to control the heating device. The hot water supply device according to any one of claims 1 to 3, characterized in that it has the following. (5) The water heater according to claim 4, wherein the maximum temperature of the second means is determined by subtracting a predetermined signal representing a predetermined temperature difference from the signal emitted by the first means. (6) The water heating device according to any one of claims 1 to 3, further comprising a processor that executes the following steps to operate the device. (a) Switch on the heating device: (b) Measure the instantaneous temperature Tn: (c) Compare this measurement Tn with a fixed temperature selected below the expected minimum boiling temperature of the water: (d) If Tn step (b) while below the fixed temperature value;
) and (c) repeatedly: (e) As soon as Tn equals said fixed temperature value, start a time measurement process to measure a predetermined time TD sufficient to ensure that the water in the reservoir reaches its boiling temperature. (f) After the time TD has elapsed, measure the instantaneous temperature Tn, subtract the predetermined temperature difference value ΔT from the measured temperature to derive the reference temperature Tmax, and store this in the memory of the processor: (g ) The heating device is controlled using this reference temperature Tmax to maintain the water temperature at Tmax.