JPS6219644A - Control unit for electric hot water heater - Google Patents

Abstract

PURPOSE:To conduct suitable heating of hot water in accordance with season and reduce a heat radiation loss due to residual hot water by fitting a temperature sensor at a position where receives the thermal influence of both the temperature of hot water within a hot water storage tank and the external air temperature to detect the external air temperature, and using a memory element. CONSTITUTION:A comparator 8 compares the detected temperature of a temperature sensor 6 with data within a lowest temperature memory element 9, and gradually renews the lowest temperature to stores the same within the lowest temperature. A heater controller 12 conducts power supply to a heater 2, and when the detected temperature of the temperature sensor 6 has been raised up to a heating temperature which is the result of the operation of an arithmetic unit 11, the heater controller 12 stops the power supply to the heater 2. In winter season where the external air temperature is low, the temperature sensor 6 detects a temperature which is lower than the temperature of hot water within a hot water storage tank 1. Therefore, the temperature within the hot water storage tank 1 becomes higher than the result of the operation of the arithmetic unit 11. In view of the above matters, the amount of hot water stored in the electric hot water heater can be reduced in term of the amount of hot water of 45 deg.C, and increased in summer season.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to the control of an electric water heater, and controls the heater by determining a boiling temperature suitable for the amount of hot water used from the water supply temperature and the outside air temperature. In particular, the present invention relates to a control device for an electric water heater that reduces residual hot water and reduces heat loss.

[Background of the invention]

As a means to reduce residual hot water and reduce heat loss, for example, as shown in Japanese Patent Application Laid-Open No. 58-130939, the water supply temperature is detected so that the amount of hot water supplied is constant throughout the year. Devices that control the boiling temperature are known.

This method not only increases the amount of hot water remaining in the summer when the amount of hot water supply is low, but also causes problems such as a shortage of hot water in the winter, especially when the water temperature is maintained at a constant level through the use of underground water. Rarely.

[Purpose of the invention]

The object of the present invention is to solve this problem and provide a control device for an electric water heater that can provide a suitable boiling temperature throughout the year.

[Summary of the invention]

In general, in the summer, hot water is used in rooms where hot water is used for cooking, cleaning, laundry, etc., and water is often used instead of hot water for cooking, cleaning, laundry, etc., compared to the winter. tends to decrease. Therefore, by detecting both the water supply temperature and the outside temperature, which varies greatly depending on the season, the necessary amount of hot water to be supplied commensurate with the amount used can be calculated, and an appropriate boiling temperature can be obtained.

Furthermore, by effectively utilizing the memory element 7, the number of expensive temperature sensors to be used can be strictly limited.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

A hot water storage tank 1 stores hot water heated by a heater 2 inserted inside. A hot water outlet pipe 3 for supplying hot water is installed at the top of the hot water storage tank 1, and a water supply pipe 4 for supplying water into the hot water storage tank 1 is installed at the bottom. The insulation material 5 is installed.

Reference numeral 6 denotes a temperature sensor, which detects hot water in the hot water storage tank 1 near the upper part of the heater 2 by heat conduction through the hot water storage tank 1.
Install it so that it receives the influence of outside temperature #τ due to convection heat transfer. Furthermore, the heat insulating material 5 is removed from the mounting part of the temperature sensor 6, so that it is more susceptible to the influence of the outside temperature.

I is the Ichi 1j groaning device, and the internal structure of the Ichi 1j groaning device will be explained with reference to FIG.

The ratio s2 device 8 compares the amortized temperature of the temperature cell 6 with the data of the lowest temperature storage element 9bi1, updates the lowest temperature sequentially, and stores it in the lowest temperature storage element 9.

The hot water storage tank 1 is filled with hot water when the filling is completed, but by using d hot water, the water supply pipe 4 is filled! 1
1Kt, the injected water pushes up the ρ water from the bottom.Therefore, the data stored in the lowest temperature storage element 9 has the following meaning.

TI=α・'11'a+,yTw・・・・・・・・・・
(1) Here, '1'a is the outside fi temperature and TW is the water supply temperature. α and β are numerical values indicating the degree of influence of the outside air temperature and the water supply temperature, and are determined by heat conduction with respect to the temperature set 6 and heat transfer with respect to the temperature set 6. In winter when the outside air temperature is lower than the water supply temperature, the water temperature in the hot water storage tank 1 is cooled by heat radiation and becomes lower than the water supply temperature.

10 is a calculator A that calculates the total amount of required hot water, and V4. =V
o ten r (T gate - T.)・・・・・・・・・・・・(2)
V here. is the standard amount of hot water, r is the temperature correction coefficient, and To is the standard temperature. Therefore, the lower the minimum hot water temperature T is, the larger v45 is.

11 uses the calculation result v45 of the calculation unit A1o and the minimum temperature T gate, using the calculation unit B that calculates the boiling temperature, T = V45 X (45T edition) / V + T
-・'' Calculate the heating temperature T according to the equation (3).

Here, V is the amount of hot water stored in the hot water storage tank 1.

V required to mix with water at temperature W to obtain hot water v451 at 45'C! The formula for determining the boiling temperature Th of hot water is Th = v4. x (45-Tw) /V+Tw-・
-" (4), but the calculation unit Bit calculates the boiling temperature 'vt- by using all the T factors affected by outside A @ anti-Ta instead of Tw in equation (4). Therefore, in the winter when the outside air temperature is lower than the water supply temperature, T>Th, and conversely, in the summer, dT<Th.

12 is a heater controller, which energizes the heater 2;
When the temperature detected by the temperature sensor 6 rises to the boiling temperature T which is the calculation result of the calculation fiBI+, the power supply to the heater 2 is stopped. In winter when the outside air temperature is low, the temperature sensor 6 detects a temperature υ lower than the hot water temperature in the hot water storage tank 1, so the temperature in the hot water storage tank 1 becomes higher than T, which is the calculation result of the calculator Bll.

According to the above structure, the hot water fV'i4 stored in the vessel at an electric temperature of 7
When converted to the amount of hot water at 5°C, as shown in Figure 3, it can be reduced in summer and increased in winter. The range of change in the amount of stored hot water with respect to temperature can be determined by γ in equation (2) and the degree of influence of the outside temperature and the internal temperature of the hot water storage tank 1 on the temperature sensor 6. Therefore, by selecting one of these, the amount of hot water stored can be controlled in accordance with the amount of hot water actually used in the garden, and an electric water heater with less residual hot water and less heat radiation loss can be supplied.

In addition, the influence of the outside temperature is determined by the minimum temperature storage element 9 and the arithmetic unit A.
Since it does not act on the four stages of the L01 computing unit B11 and the heater controller 12, even a small shadow V degree can be amplified and a large variation range can be obtained. μ
, the outside temperature table, the water supply temperature, and the tank internal uh temperature are detected with one 7/6 meter, so it can be easily manufactured into one piece.

〔Effect of the invention〕

According to the present invention, a control device is provided at low cost that detects the entire outside temperature and effectively uses a memory element to boil water appropriately depending on the season and reduce heat radiation loss caused by public baths. There is an effect that can be achieved.

[Brief explanation of the drawing]

Figure 6c1 is a schematic structural diagram of an embodiment of the present invention, Figure 2 is a block diagram of a control device of an embodiment of the present invention, and Figure 3
It is a line showing the annual amount of hot water stored. 2... Heater b... Temperature sensor 9... Lowest temperature sole element +[J, I+... Performance: JE61
2... Heater controller.

Claims (1)

[Claims] In an electric water heater that uses late-night electricity to heat water in a hot water tank with a heater, a temperature sensor is installed near the top of the heater at a position that is thermally affected by both the temperature in the hot water tank and the outside temperature. , a memory element that stores the lowest temperature detected by the temperature sensor for one day, a computing unit A that computes the amount of hot water required for one day from the lowest temperature stored in the memory element, and this computing unit A. Calculator B calculates the boiling temperature from the calculation result obtained in and the lowest temperature stored in the memory element, and the heater is energized and the temperature detected by the temperature sensor is the boiling temperature calculated by Calculator B. A control device for an electric water heater equipped with a heater controller that stops the supply of electricity to the heating element when the temperature reaches the specified temperature.