JPS6186531A - Control device for electric water heater - Google Patents

Abstract

PURPOSE:To obtain the control device for the electric water heater, reduced in natural heat dissipating loss, by a method wherein only the proper amount of hot-water is heated up in accordance with the actual result of heating up in the past and the conditions of feed water temperature as well as remaining hot-water while the conduction of an exothermal body is started at a proper time. CONSTITUTION:An operating means 16 operates at first the amount of electric power corresponding to the heat amount of remaining water based on respective detecting signals of a flow amount sensor 9, a water temperature sensor 8 and an upper temperature sensor 11, subsequently, a heat up object setting means 13 sets the amount of impressing electric power, estimated that it is necessary tomorrow, and heat up temperature based on the actual result of consumed amount of hot-water in the past, then a net conduction time for heating up the proper amount of hot-water is operated based on the operated result of the heat up object setting means 13 and the amount of electric power corresponding to said remaining hot-water. A time switch 7 is ut ON based on the results of above operations and a time until conducting the exothermal body 2 is operated while the exothermal body 2 is controlled by a control means 7 based on the result of operation of the time switch 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for an electric 1A water heater that uses late-night electricity.

[Conventional technology]

A conventional heel electric connection has a configuration as shown in Fig. 4.

In the figure, 1 is a hot water storage tank, and a heating element 2 is attached to the lower part of the tank.

3 is a thermostat for controlling the boiling quality, and is attached to the lower outer wall surface of the hot water storage tank 1.

Reference numeral 4 denotes a faucet for taking out hot water that has risen in the hot water storage tank 1. When the faucet 4 is opened, water in the hot water storage tank 1 is supplied with pressure from a water source connected to a water supply pipe 5.

Figure 5 shows an electrical circuit diagram of a conventional example, 6 is a power supply;
7 is a time switch for setting the late night power supply time.

Next, to explain the operation of the above configuration, the heating element capacity is set so that the heating element 2 boils water from approximately 8°C to the target temperature of 85°C within 8 hours during the late night power supply period. ing.

The thermostat 3, which has a normally closed contact, is configured to open the contact and stop supplying electricity to the heating element 2 when the water in the hot water storage tank 1 reaches 85°C. It is filled with hot water at ℃.

[Problem that the invention seeks to solve]

However, the usage of hot springs is not always the same, and changes greatly from day to day, depending on the season, and changes in family structure.

The above-mentioned conventional electric water dryers, which boil water at a constant temperature such as 85'C, require the boiling temperature to be set every day in order to keep up with these changes in the amount of heat required, making operation cumbersome. However, once set, there are many cases where the system does not produce even one mulberry. It is common practice to boil hot water for a long time and leave it unused for a long time. Therefore, there was a problem in that the natural heat radiation loss from the hot water storage tank increased.

This invention attempts to solve these conventional problems, and includes information on past boiling results, supply water temperature, and remaining hot water conditions. The object of the present invention is to obtain a control device for an electric water heater that starts the process at a positive time to reduce the natural heat radiation Ij.

[Means for solving problems]

The electric water heater control device according to the present invention includes temperature sensors that detect the water supply, the upper temperature of the hot water storage tank, and the boiling temperature, and a flow rate sensor that detects the amount of hot water used.
Boiling target setting means that sets the target applied power amount and target boiling temperature based on past boiling results, and calculates the amount of power remaining in the amount of hot water from the detection values of each sensor, and supplies the heating element to the heating element based on that value. a calculation means for calculating the net energization time and energization start time; and control to start energizing the heating element at the calculated energization start time and stop energizing the heating element when the target boiling temperature is reached. The heating element is provided with a control means for controlling the heating element, and a storage means for storing the energization time of the heating element and the water temperature at the time when the energization to the heating element is stopped.

[Effect]

In this invention, control is performed to boil only the appropriate amount of hot water based on the amount of hot water expected to be used the next day based on past results of hot water usage, the temperature of the supplied water, and the amount of hot water remaining in the hot water storage tank. The net energization time is calculated and the energization is controlled to start at a predetermined time.

〔Example〕

FIG. 1 is an overall configuration diagram of an embodiment of a control device for an electric water dryer according to the present invention.

As is clear from FIG. 1, in this embodiment, a water temperature sensor 8 and a flow rate sensor 9 are provided in the middle of the water supply pipe 5, and a boiling water temperature sensor 10 and an upper temperature sensor 1 are provided at the bottom and top of the hot water storage tank 1. ) are provided respectively, and the above-mentioned flow rate sensor 9, water temperature sensor 8, and upper temperature sensor 1 are provided.
), the calculation means 16 first calculates the amount of electric power equivalent to the thermal motion of the remaining hot water, and then the boiling target setting means 1
3 sets the applied power amount and boiling temperature that are expected to be required the next day based on the past results of the amount of hot water used, and then only the appropriate amount of hot water is boiled based on the electric power amount of the remaining hot water amount and the result of the boiling target setting means 13. Based on the result, the time switch 7 is turned on, the time from 7 to the heating element 2 is energized, and the heating element 2 is controlled by the control means 17 based on the result. After the boiling is completed, the storage means 18 stores the water temperature detected by the hot water temperature sensor 10, the net energization time to the heating element 2, and the remaining amount of hot water detected by the flow rate sensor 9. ing.

FIG. 2 is a circuit diagram showing the electrical connections of the embodiment of FIG. 1.

In the figure, 19 is a microcomputer in the control circuit, and has CI'[J 20 , Me:r-If 21 , an input circuit 22, and an output circuit 23. Heating element control circuit 2
4, I-bar resistor 25, tranny resistor 26, relay 27.
It consists of 28.

The energizing coil 27a of the relay 27 is connected to the transistor 2
The base of the transistor 26 is connected to the output circuit 23 via a resistor 25.

A contact 27 of the relay 27 is connected in series to an energizing coil 28a of the relay 28 and a power source 29.

The contact 28b of the relay 28 connects the heating element 2 and the power source 6.
is connected in series with ζ.

29. 30, 31 are resistors connected in series with each temperature sensor 8, 10゜1), 32 is each temperature sensor 8, 10,
an analog multiplexer to which the detection output of 1) is input;
33 is an A/D converter that converts the output into digital;
34 is a pulse counter into which the detection output of the flow rate sensor 9 is input, and the output thereof and the output of the A/D converter 33 (the output thereof) are applied to the input circuit 22.

Next, the operation of the above embodiment will be explained with reference to FIG.

FIG. 3 is a flow chart showing heating element control stored in the memory 21 of the microcomputer 19. First, when the power is turned on, initial setting of the target applied power P and target temperature T for boiling starts at step 35 shown in FIG.

Next, in step 36, the applied power amount correction coefficient α is set. As initial values, P=4.4×8,
Give T=85°C and α=10.

In step 37, the water temperature Tw is read, in step 38, the remaining hot water temperature Tz is read, and in step 39, the remaining hot water amount Vz is read. Furthermore, in step 40, the remaining hot water iVz is stored in the memory 21.
to be memorized.

Next, in step 41, the power for the remaining hot water is JIK 2t! ! demand.

Here, r) indicates heating efficiency.

Next, in step 42, the net energization time 1[a for energizing the heating element 2 is calculated from the target applied power amount P for boiling and the amount of power equivalent to the remaining hot water 2.

W is the power dissipated by the heating element 2. Step 43 is the net energization time required for the boiling point determined in step 42.
υ [[a] is to be allocated to which time zone of the late-night power supply time zone (j), that is, whether to start energization after a certain period of time after the time switch 7 is turned on.

H= 8-Ha Step 44 is to check whether or not the time switch 7 is turned on. At the same time as the time switch 7 is turned on, step 45 is performed to adjust the elapsed time of the energization start time [1]. When 8 hours have passed, step 46 Start energizing the heating element 2 (7, check whether the water temperature has reached the target temperature T in step 47)
Judge by. When the determined results are equal, turn off the heating element 2 using the switch 49, and then! If the target temperature has not been reached, it is checked in step 48 whether the time switch 7 is 0FFt. As a result, if the state is ON, step 47 is executed, and if it is OFF, step 49 is executed. In step 50, the net energization time and the boiling water temperature up to the point of completion of boiling are stored in the memory 21.

Next, in step 51, the net running time m of the past n days already stored in the memory 21 is calculated.
-・If atl, boiling water temperature TI, 'r2・Tn
Read the remaining amount of hot water V z+ and V 22Vzn, and calculate the net energization time I[al,] (from aL·■an to equal consumption 'R?1)i force 1Pav in step 52.

In step 53, the residual hot water amounts ■zI, ■Z2■zn are compared with the previously determined standard residual hot water f#, VB, and if the residual hot water amount is greater than the standard residual hot water amount vB, it is determined that the day when the amount is higher is, for example, m
If it is more than m days, the applied power amount correction coefficient α is negatively modified (for example, α=α−0, 1) in step 55.

Further, if the remaining γ yield is less than the standard residual hot water VB, it is determined in step 56 whether the number of days when the quantity is less is equal to or more than m consecutive days, and m
If it is more than one day, in step 57, the applied power amount modification coefficient α is modified to be positive (for example, α−α+0.1).

The correction coefficient α obtained here is used in step 58 to set the target applied power MP for boiling. That is, P=PavXα Next, in step 59, the step knob 51 reads out: 7Q Q', 1. "j, T"2 rn
(7) Select the maximum value 'r m & X, step 5
Step 9 determines the next day's boiling point target temperature T.

〔Effect of the invention〕

As described above, according to the present invention, the next day's boiling temperature is predicted from the actual amount of hot water used in the past, and an appropriate amount of hot water is boiled based on the water temperature and the state of the remaining hot water in the hot water storage tank. It can automatically predict the appropriate amount of hot water to match the rhythm of life, reducing the amount of remaining hot water and lowering maintenance costs. Furthermore, since it is possible to predict the energization time, a peak shift effect can be expected.

[Brief explanation of drawings]

FIG. 1 is an overall h1 configuration showing an embodiment of the control device for an electric water heater according to the present invention, FIG. 2 is a circuit diagram showing its electrical connections, and FIG. 3 is a flowchart showing its operation. 4 and 5 show a conventional hot water storage type electric water heater, FIG. 4 is a schematic structural diagram thereof, and FIG. 5 is a main electric circuit diagram. In the figure, 8, 10, 1) 1: r temperature sensor, 9: flow rate sensor, 1-213: υ raising target setting means, 16: calculation means, 17: control means, 18 (storage means, 19(
2 micro: non-computer, 24 is the heating element I1) control circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Figure 1 1 4-cho 1. N, ri2 So-na=I1- //
8: ,"x＞'!-'Boo Figure 3 Figure 4

Claims (3)

[Claims] (1) In an electric water heater that uses late-night electricity, there is a water temperature sensor that detects the temperature of water supplied to the hot water storage tank, an upper temperature sensor that detects the temperature at the top of the hot water storage tank, a flow rate sensor that detects the amount of hot water used, and a water temperature sensor inside the hot water storage tank. A water temperature sensor that detects the boiling temperature of the water, a boiling target setting means that sets the target applied power amount and temperature for boiling based on the past boiling time and boiling water temperature, and a boiling target setting means that determines the remaining water from the detected values of each of the above sensors. Calculate the electric energy equivalent to the amount of heat, calculate the net energization time to the heating element from the electric energy for the remaining hot water and the target applied electric energy set by the boiling target setting means, and calculate the net energization time to the heating element from the net energization time. a calculation means for calculating the start time of energization to the heating element; and when the energization start time calculated by the calculation means is reached, energization to the heating element is started, and when the water temperature reaches the temperature set by the boiling target setting means, to the heating element. A control device for an electric water heater, comprising: a control means for controlling the energization of the heating element to be stopped; and a storage means for storing the energization time and hot water temperature at the time when the energization to the heating element is stopped. (2) The electric water heater control device according to claim (1), wherein the target amount of applied power for boiling is configured based on an average value of past amounts of power consumption. (3) A control device for an electric water heater according to claim (1), wherein the boiling target setting means, the calculation means, and the storage means are realized by a microcomputer.