JPH0432653A - Temperature setting device for supplied hot water in hot water supplying device - Google Patents

Abstract

PURPOSE:To eliminate unevenness in AD value by comparing a set temperature determining definite digital value with the latest digital value subsequently input every constant short time, integrating difference therebetween and replacing the definite digital value by the latest digital value at that time when the absolute value of the integrated value reaches a constant value. CONSTITUTION:Temperature controlled analog input data adjusted by a supplied hot water temperature control volume 31 is input to a microcomputer 21 through an input/output circuit 22, A/D converted, compared and computed. The AD values obtained every 0.1 second are respectively regarded as an A/D value of this time and compared with a definite A/D value already adopted for setting the temperature of supplied hot water. When the absolute value of an integrated value is 20 or more, a counter is cleared to become zero and the latest input A/D value of this time is regarded as a definite A/D value. When the absolute value of the integrated value is less than 20, the current definite A/D value is continuously maintained as the definite AD value.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention converts temperature control data of a water heater input as analog values into digital values, and converts the temperature control data of a water heater inputted in analog values into digital values and the set water supply temperature stored in advance in a microcomputer. The present invention relates to a hot water temperature setting device for a water heater that determines a set hot water temperature using a table of correspondence with values.

<Prior art> In general, in a water heater, once the set temperature for hot water supply is determined, the required amount of heat to be supplied is calculated based on the set temperature, and the usage capacity of the water heater is switched based on the set temperature, and the on-time and on-off combustion operation are controlled based on the set temperature. Determine the ratio of off time.

Therefore, it is necessary to determine the set temperature correctly. As a means of determining this set temperature, a microcomputer converts the temperature control setting data input as an analog value into A/Di, and then uses the digital value after this conversion to determine the corresponding set temperature. Conventionally known.

This will be explained using FIG. 4. In other words, when the hot water temperature is controlled using an analog value by operating the temperature control volume on the water heater's remote controller, etc., the analog temperature control data is input to the microcomputer in the main unit control unit, etc. (step (a)). Convert to digital value (step (b)). The microcomputer stores in advance a temperature control table that associates digital values with set hot water supply temperature values. Then, the temperature control table value is read using the converted digital value (step (c)), and the corresponding set hot water supply temperature value is set as the set hot water supply temperature (step (d)). Once the set hot water supply temperature is determined, the amount of heat per unit time required for instantaneous hot water supply is calculated from the incoming water temperature and incoming water flow rate using that temperature, the number of hot water to be used (the hot water supply capacity to be used) is selected, and the required The on-off time ratio of on-off combustion is calculated from the amount of heat and the number of burners used.

<Problem to be solved by the invention> However, in the above device, analog temperature control data is
/D converted digital value (hereinafter referred to as A/D value)
Since variations over time are likely to occur due to errors in A/D conversion, for example, if variations occur in the A/D values that are input every 0.1 seconds, there is a problem that the set hot water temperature will change frequently. Yes (despite not actually operating the temperature control volume). There is a problem in that when the set hot water supply temperature fluctuates, it directly affects control calculations and control operations.

Regarding the temperature control table values, the relationship between the temperature value and the A/D value is closely defined near the temperature where the degree of use is high (near 40°C), but as the temperature reaches the high temperature range, the A/D value changes. Since the change in temperature value corresponding to the change is largely (roughly) determined, there is a problem in that the variation in the A/D value has a large adverse effect on the hot water tapping characteristics in the high temperature region.

Therefore, the present invention solves the drawbacks of the conventional device described above, eliminates the adverse effects of variations in A/D values, and provides a water heater that can promptly respond to changes in A/D values and determine a new appropriate set hot water temperature value. The purpose is to provide a hot water temperature setting device.

<Means for Solving the Problems> The device of the present invention that achieves the above object converts temperature control analog input data into digital values, and establishes a correspondence between the digital values stored in advance in the microcomputer and the set hot water temperature value. A hot water temperature setting device for a water heater that uses a table to determine the set hot water temperature, using a fixed digital value that has already been used to determine the set temperature and the latest digital value that is input at regular short intervals. When the absolute value of the integrated value reaches a certain value, the determined digital value is replaced with the latest digital value at that time, and both digital values to be compared during the integration. The present invention is characterized in that the integrated value is returned to zero when the difference between the two becomes zero.

Function: Compare the final digital value currently used to determine the hot water supply temperature setting with new digital values that are input one after another, and when the cumulative difference reaches a certain value, the final digital value is determined. Since it is replaced with the latest digital value, firstly, the set hot water temperature value is not changed every time a different digital value is input. Secondly, the larger the difference between the newly input digital value and the newly input digital value, the faster it will reach a certain integrated value. You can respond by changing it. Furthermore, when the input digital value changes gradually, the fixed digital value can be replaced after a corresponding delay time.

Also, while the difference between the final digital value and the new digital value input manually is being accumulated, if the difference being compared becomes zero, the counter is cleared and the accumulated value is returned to zero. When chattering occurs in the A/D converted digital value, it is possible to eliminate the situation where the set hot water temperature is changed blindly due to chattering.

<Example> Fig. 1 is a configuration diagram showing an example of a water heater in which the device of the present invention is used, and Fig. 2 shows the main body controller and remote controller of the water heater.
FIG. 3, which is a circuit diagram of the controller, is a flowchart showing an example of control by the device of the present invention.

An instant heating type heat exchanger 2 is provided within the combustion can body 1, and a burner 3 is also provided. The J-burner 3 is supplied with air and combustion through a fuel supply pipe 4.

5 is an igniter.

Water enters the heat exchanger 2 through the water inlet pipe 6, undergoes heat exchange, and is sent to the outlet pipe 7. The inlet pipe 6 has an inlet water flow rate sensor 8
An inlet water temperature sensor 9 is provided, and the hot water outlet pipe 7 is provided with a hot water outlet 10 and a small capacity tank 11 in the middle. Further, the fuel supply pipe 4 is provided with an on-off valve 12 .

20 is a main controller of the microcomputer 21, into which analog data for hot water temperature adjustment from the remote controller 30 is input, as well as input water flow rate information from the water input flow rate sensor 8 and input water temperature information from the input water temperature sensor 9. Then, necessary opening/closing operation commands are issued to the opening/closing valve 12 and the like so that a predetermined hot water supply setting temperature is achieved.

As shown in FIG. 2, the main controller 13 includes a microcomputer 21 and its input/output circuit 22, a DC power supply 23, and a constant voltage circuit 24. Further, the remote controller 30 is provided with a hot water supply temperature control volume 31, a hot water supply operation priority switch 32, a hot water supply operation switch 33, a confirmation lamp drive circuit 34, a hot water supply combustion lamp 35, a hot water supply operation lamp 36, a hot water supply priority lamp 37, etc. .

The temperature control analog input data adjusted by the hot water supply temperature control volume 31 is input into the microcomputer 21 via the input/output circuit 22, A/D converted, and compared and calculated.

Temperature control A/ input in the microcomputer 21
The processing of the D value will be explained with reference to FIG. Now, analog temperature control data is input to the microcomputer 21 every 0.1 seconds via the hot water temperature control volume 31 of the remote controller 30 (step 101), and the input analog value is input to the microcomputer 21 every 0.1 seconds. A/D conversion is performed within (step 102). and 0
．． The A/D values obtained every second are compared as the current A/D values with the final A/D values already used for setting the hot water temperature (step 103). If the two values are not the same, calculate the difference (Step 104), and if the difference is +1 or -1, add +1 or -1 to a counter (not shown) in the microcomputer 21 (Step 105). If is greater than or equal to +2 or less than or equal to -2, add +4 or -4 to the counter (step 106). Then, when the absolute value of the integrated value becomes 20 or more (step 107), the counter is cleared and set to zero. shall be. If the absolute value of the integrated value is less than 20, the current determined A/D value is maintained as the determined A/D value.

For example, if the difference between the current A/D value and the confirmed A/D value +1 occurs 20 times in a row, that is, if it continues for 2 seconds, then after 2 seconds, the final A/D value is changed to the latest input value. A/
Replaced with D value. Further, if the difference +2 or more occurs five times in a row, that is, if it continues for 0.5 seconds, the final A/D value is replaced with the latest current A/D value after 045 seconds. If the difference continues in a mixed state of +1 or +2 or more, the A/D value is replaced between 0.5 seconds and 2 seconds.

On the other hand, if the current A/D value is the same as the final A/D value in step ([+), the counter is cleared even if the counter is accumulating the difference at that point (step 110). , returns the integrated value to zero.

Of course, the final A/D value is not changed.

When the final A/D value is maintained or changed as described above, the temperature control table value stored in advance in the microcomputer is read using the final A/D value (
Step 111), obtain the set hot water temperature value corresponding to the determined A/D value, and determine the set hot water temperature (step 112).
). Then, from the set hot water temperature, incoming water flow rate, and incoming water temperature, the required amount of heat per unit time is integrated, the number of units to be used is determined, and the combustion on and off times are calculated (
Stembu 113).

The temperature control table is a one-to-one correspondence between the hot water supply temperature value to be set and the digital value, and a temperature value is determined for each digital value, and this table is stored in the microcomputer.

In this temperature control table, for example, due to storage capacity, etc., the correspondence between digital values and temperature values is determined closely around 40°C, which is usually used frequently, but at temperatures that are less frequently used, The value is set roughly. Therefore, for example, in a high temperature range that is rarely used, a slight difference in digital values results in a large difference in the set hot water supply temperature value, and errors in A/D conversion become a big problem.

In the embodiment, even if chattering or the like of the A/D value occurs due to an error in the A/D conversion, steps 103 and 11
Since the counter is cleared at 0 and the fixed A/D value is not changed, there is no problem that the set hot water temperature value is frequently changed even though the temperature control volume 31 is constant. This has a large effect in contributing to improving the hot water output characteristics in terms of stabilizing the hot water supply temperature, especially in high temperature regions where the temperature control table is rough.

In addition, as a means of suppressing variations in A/D conversion, a method using hysteresis can be considered, such as not changing the set temperature value unless a difference of more than a certain value occurs in the A/D value, but in this case, There is a drawback that it is difficult to change settings between adjacent temperatures. However, in this embodiment, even if the set temperature is changed between adjacent temperatures, the time until the change (time until the final AZD value is changed) is only slightly longer.
Changes can definitely be made. In other words, it is also possible to set the hot water temperature in detail.

In the description of the above embodiment, step 104 of FIG.
What numerical value is added to the counter based on the difference in A/D values in step 105 and 106, and how much integrated value to change the determined A/D values in step 107 is limited to the embodiment. It is not subject to change, but is subject to change depending on various conditions.

<Effects> The present invention has the above configuration and operation, and the hot water temperature setting device for a water heater according to claim 1 solves the problem that the set temperature value is frequently changed due to an error in A/D conversion. is resolved. Therefore, it is possible to prevent a change in the hot water supply temperature particularly in a region where the temperature control table is rough, and to perform stable hot water supply with good hot water discharge characteristics. Furthermore, if the temperature control input changes significantly, the set hot water temperature can also be changed in a short period of time, making it possible to respond smoothly.

Furthermore, compared to a method that uses hysteresis to suppress the chattering phenomenon, there is an effect that settings can be changed easily and reliably between adjacent temperatures.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a water heater in which the device of the present invention is used, FIG. 2 is a circuit diagram of the main controller and remote controller of the water heater, and FIG. 3 is a flowchart showing an example of control by the device of the present invention. FIG. 4 is a flowchart showing an example of control by a conventional device. 1: Combustion can body 3: Burner 6: Water inlet pipe 20; Main body controller 2 Microcomputer 30: Remote controller 31: Temperature control volume

Claims (1)

[Claims] (1) Hot water temperature setting for a water heater that converts temperature control analog input data into digital values and determines the set hot water temperature using a correspondence table between digital values and set hot water temperature values stored in advance in the microcomputer. A device,
The final digital value that has already been used to determine the set temperature is compared with the latest digital value that is continuously input at regular intervals, and the differences are integrated, so that the absolute value of the integrated value becomes a constant value. When the final digital value is reached, the final digital value is replaced with the latest digital value at that time, and if the difference between the two compared digital values becomes zero during the integration, the integrated value is returned to zero. Features a hot water temperature setting device for water heaters.