JPH0318107B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot water storage type water heater such as a hot water storage type electric water heater, in which the operation of the heating element is controlled by calculating the appropriate operating time of the heating element from the state of the remaining hot water in the hot water storage tank. It is something to do.

The main electrical circuit of a conventional hot water storage type electric water heater is the first
It looks like the picture. In the figure, 1 is a power supply,
2 is a heating element, and 3 is an automatic temperature controller.

Next, to explain the function and operation using the general case of using late-night power as an example, the heating element 2 is heated to 8°C, which corresponds to the water temperature in winter, during the late-night power supply time.
The capacity of the heating element is set to boil the water before and after it to approximately 85℃. In addition, the automatic temperature controller 3 has a normally closed contact, so that the water in the hot water storage tank reaches 85℃.
When this happens, a contact is opened to stop the power supply to the heating element 2, and the hot water storage tank is filled with hot water at 85°C every morning.

However, the amount of hot water used is not always the same, and varies greatly from day to day, depending on the season. In particular, whether or not a person takes a bath is a factor that greatly influences the amount of hot water used, and on days when a person does not take a bath, more than half of the stored hot water may remain.

Therefore, if there is any remaining hot water, the electricity will start all at once when the electricity is turned on late at night, and the water will boil in a short time. As a result, the power load is concentrated, making it impossible to equalize the power load, which is the original purpose of late-night power, resulting in poor power transmission efficiency, and the hot water that has been boiled cannot be used for a long time. This has the drawback of increasing heat loss due to natural heat radiation from the hot water storage tank and heat radiation from hot water stagnant in the pipes.

The present invention attempts to solve these conventional drawbacks, and is designed to control the operation of the heating element by calculating an appropriate operating time for the heating element from the state of the remaining hot water in the hot water storage tank.

One embodiment of the present invention will be described above based on the energization control block diagram of FIG. In Figure 2,
4 is a remaining hot water amount sensor for detecting the amount of remaining hot water in the hot water storage tank; 5 is a remaining hot water temperature sensor for similarly detecting the temperature of remaining hot water in the hot water storage tank; and 6 is a sensor for detecting the remaining hot water temperature in the hot water storage tank; Calculators A and 7 calculate the residual water heat calories from the residual water amount and residual water temperature, which calculates the amount necessary to raise the temperature in the hot water storage tank to the hot water temperature set value from the residual water heat calories calculated by the calculator A6. Calculator B calculates the thermal calorie; 8 is a calculator C that calculates the required energization time of the heating element from the thermal calorie calculated by the calculator B7; 9 energizes the heating element for the required energization time calculated by the calculator C8. It is a timer device.

Next, an example of the operation of the above configuration will be explained using symbols and formulas. First, the capacity of the hot water storage tank is V
liter (hot water temperature set value T ₁ ℃), the detected value of the remaining hot water amount sensor 4 is v liters, and the detected value of the remaining hot water temperature sensor 5 is T ₂ ℃, then the calculator A6 calculates K ₁ =
Calculate the thermal calories of the remaining hot water by calculating (T ₂ -a) x v, and the calculator B7 calculates K ₂ = (T ₁ -a) x V-
By calculating K ₁ , the thermal calories K ₂ required to raise the temperature in the hot water storage tank to the hot water temperature set value T ₁ °C by the end of the late-night power supply time are calculated. Here, a is a constant and is set to, for example, the annual minimum water supply temperature. Then, calculation unit _{C8 calculates T=K 2 ÷} (860×
W) and calculate the required energization time T(H) for the heating element.
Calculate. Here, W is the heating element capacity (kW),
Furthermore, 860 is the value required when converting kcal to kWh. Next, when the required energization time T is calculated by the computing unit C8, the timer device 9 controls the energization time to the heating element to the required energization time T, and the timer device 9 controls the energization time to the heating element to this required energization time T. can be dispersed. Therefore, the larger the amount of hot water remaining in the hot water storage tank and the higher the temperature of the remaining hot water, the lower the amount of electricity required for the heating element, and the amount of electricity required for the heating element should be always distributed over the entire late-night power supply period. This reduces the concentration of power load, and also reduces heat loss because hot water is not left in the hot water storage tank for a long time.

In particular, in such a configuration, a feed water temperature detection device that detects the feed water temperature is not installed, and the feed water temperature is fixed at the annual minimum feed water temperature, and the cost is increased by not providing a feed water temperature detection device. can be kept at low cost.

Although the above operation example describes the case of late-night power use, it is clear that the same effect can be obtained even for general power use, and furthermore, the present invention can be applied to heating elements such as combustors even if they are not electrical. It is.

As described above, the present invention includes a remaining hot water amount detecting means for detecting the amount of remaining hot water in a hot water storage tank, a remaining hot water temperature detecting means for detecting the temperature of remaining hot water in the hot water storage tank, and a remaining hot water amount detected by each of the above detection means. A calculator A that calculates the amount of heat of the remaining water from the temperature of the remaining water, etc., and a calculator B that calculates the amount of heat required to raise the temperature in the hot water storage tank to the hot water temperature setting value from the amount of heat of the remaining water calculated by the calculator A.
It is equipped with a calculator C that calculates the required operating time of the heating element from the amount of heat calculated by the calculator B, and a timer device that controls the operation of the heating element for the required operating time. It is possible to detect the hot water temperature, calculate the residual water heat, calculate the necessary heat to be added from the residual water heat, calculate the required operating time of the heating element, and spread this time within the operating time frame. This eliminates the need to leave hot water unused for long periods of time, reducing heat loss and lowering maintenance costs. In addition, in the case of an electric water heater, in addition to the above effects, it is possible to control the power load so that it is evened out, which makes it possible to equalize the power load and improve power transmission efficiency. In particular, in the present invention, a fixed water supply temperature is used without providing a water supply temperature detection device for detecting the water supply water temperature, so costs can be kept low by the amount of not providing a water supply water temperature detection device. It has the advantage of being able to

[Brief explanation of the drawing]

FIG. 1 is a main electrical circuit diagram of a conventional hot water storage type electric water heater, and FIG. 2 is an energization control block diagram according to an embodiment of the present invention. 4... Remaining hot water amount sensor, 5... Remaining water temperature sensor, 6... Arithmetic unit A, 7... Arithmetic unit B, 8... Arithmetic unit C, 9... Timer device.

Claims (1)

[Claims] 1. A remaining hot water amount detection means for detecting the amount of remaining hot water in the hot water storage tank, a remaining hot water temperature detecting means for detecting the temperature of the remaining hot water in the hot water storage tank, and a residual hot water amount and residual hot water temperature detected by each of the above detection means in advance. Calculator A calculates the amount of residual water heat from the fixed and set water supply temperature, and calculates the amount of heat required to raise the temperature in the hot water storage tank to the hot water temperature setting value from the residual water heat amount calculated by the calculator A. a computing unit B that calculates the required operating time of the heating element from the amount of heat calculated by the computing unit B; and a timer device that controls the operation of the heating element for the required operating time calculated by the computing unit C. A hot water storage type water heater equipped with .