JPS60221629A - Controlling method of regenerative electric space heater - Google Patents

Abstract

PURPOSE:To minimize an electric power for melting by a constitution wherein a preparatory period is divided into a plurality of time zones and a corresponding preparatory period zone is selected on the basis of the relationship between a room temperature and a set temperature so as to control a time of electrification in the titled heater utilizing a large latent heat material. CONSTITUTION:A preparatory period for a heater, e.g. a period of 2:00a.m.- 8:00a.m., is divided into three periods, i.e. 2:00-4:00, 4:00-6:00 and 6:00-8:00, and timers 13A-13C are made to correspond with these periods respectively, while a room temperature in an initial stage of the preparatory period or a temperature corresponding therewith is compared with the maximum, minimum and middle set temperatures 14A-14C to set the timers 13A-13C respectively. By this constitution, temperature controllers 14A-14C with minimum thermometers are made to operate at the room temperature to charge the corresponding timers 13A-13C. A relay 12 is closed in prescribed time zones by the timers thus operated, a heater 2 is electrified by a power source 10, and thereby a latent heat material is melted for regeneration. By this constitution, a required electric power can be minimized.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a method for controlling a heat storage type electric heater, and in particular, a composition having a large latent heat is used as a heat storage material. The present invention relates to a method of controlling the energization time in an electric heater that utilizes the heat of solidification of materials.

[Prior art]

A type of indoor heater that uses a special composition with a large amount of latent heat as a heat storage material, and heats and melts this heat storage material.When the hind limb heat storage material solidifies, it retains heat by the solidification heat (latent heat) released. has been adopted.

As the heat storage material, for example, sodium sulfate decahydrate (
Nat SO4” 10HM O, also called mirabilite)
A material having a predetermined contact point (around 28° C.) and a large latent heat (heat of fusion and heat of solidification) is used.

Further, as a method for heating this heat storage material, for example, a method is adopted in which heaters made of electrothermal resistors are arranged along the heat storage material and electricity is applied to the heaters to heat the heaters to about 40°C.

Such a latent heat type heater, for example, spreads the heat storage material and heater under the floor of a building room or gymnasium,
It is used as an underfloor heating device that heats the room from the floor.

The latent heat of the Glauber's salt is about 42°C, and when it is used as a heat storage material for the floor heating, it can be completely melted by heating it with electricity until it reaches the melting point or a temperature slightly higher than this. When doing so, the amount of heat released at a constant temperature is large and gradually dissipates, so the indoor temperature must be maintained at the desired comfortable temperature (for example, around 22°C) for a long time (for example, about 10 hours) even after the power is turned off. be able to.

For this reason, when heating inside a building, the heater is energized at night when the room is not in use to melt the heat storage material in advance, and during the day when the room is in use, the power is turned off to release the heat that solidifies (mainly).
A widely used method is to maintain the room temperature at a desired comfortable temperature. This method of use is also extremely economical in that heating can be done at night, when electricity demand is low and electricity rates are low (approximately one-third of daytime rates in Japan).

By the way, the conventional method of energizing a regenerative electric heater as described above is to set a certain preparation period in advance (for example, from 2:00 a.m. to 8:00 a.m.) during the time when the night rate is applied, and then to adjust the temperature and The energization is started at the beginning of this preparation period regardless of the outside temperature, and when the heat storage material reaches the upper limit set temperature which is higher than the melting point, the thermistor turns off the energization, and at the end of the preparation period (the usage period, i.e. the heating period). Until the beginning, the method used was to keep the heat storage material at a predetermined temperature using a thermostat.

FIG. 1 is a graph showing one aspect of such conventional energization control.

In Figure 1, the horizontal axis represents the day starting from midnight (24:00).
The vertical axis shows the temperature (g), and in the figure, curve A is the outside temperature, curve B is the room temperature, curve C is the floor temperature, the curved line is the heat storage material temperature, and the curve E is the heater temperature. Each indicates one temperature.

The graph in FIG. 1 shows a case where the preparation period is set from 2:00 a.m. to 8:00 a.m., and energization of the heater is started at the beginning of the preparation period (2:00 a.m.). In addition, in order to prevent the temperature of the heat storage material from rising significantly beyond its melting point,
In other words, in order to prevent an excessive rise in sensible heat in the heat storage material, the power supply to the heater is controlled by a thermostat that operates at a predetermined temperature.The operating point of this thermostat is set at approximately 30°C in the graph of Figure 1. F in FIG. 1 indicates the energized state in that case.

The heat storage material is sodium sulfate decahydrate (Nap SO4・ioH,o) which melts at 28°C and solidifies at 25°C.
A material whose main component is
~45 kad/Kf.

In the conventional control method of the latent heat type electric heater explained above with reference to Fig. 1, the setting is fixed regardless of the room temperature or the corresponding temperature (floor temperature, heat storage material temperature, etc.). Since electricity is started at the beginning of the preparation period (2 o'clock), even after the heat storage material has melted, the thermostat must be operated to keep the heat storage material at a predetermined temperature until the end of the preparation period. However, it has the disadvantage of wasting electricity to keep it warm. In particular, if the room temperature is not too low and the heat storage material melts early, the heat retention period becomes longer and the proportion of power consumption required for heat retention increases.

〔the purpose〕

An object of the present invention is to provide a control method for a regenerative electric heater, which eliminates the drawbacks of the conventional energization method as described above and allows melting of the heat storage material during the preparation period using the minimum amount of power necessary. be.

〔composition〕

The present invention divides the preparation period into a plurality of time periods, detects the room temperature (or temperature corresponding to this) at the beginning of the preparation period, and uses a timer to set the energization time so that the higher the temperature, the later the energization starts. The aim is to achieve the above objectives by controlling the

That is, according to the present invention, there is provided a regenerative electric heater that melts the heat storage material by energizing the heater during the preparation period, and maintains the room temperature within a predetermined temperature range mainly by the solidification heat of the heat storage material during the use period. In the IJ control method, a certain preparation period is divided into multiple time periods in advance, the room temperature or the corresponding temperature at the beginning of the preparation period is detected, and when the detected temperature is higher than the highest setting, the energization time is reduced to zero. , when the detected temperature is below the minimum set value, it is energized throughout the entire time period, and when the detected temperature is between these values, it is energized from the beginning of the preset time period to the end of the preparation period according to the value, and the detected temperature is 4! Control with a timer so that the higher the 11J'l is, the shorter the 11J'l is in stages when energized. A method of controlling the image is provided.

〔Example〕

The present invention will be specifically explained below with reference to FIGS. 2 to 7.

FIG. 2 is a diagram showing the structure of a regenerative electric heater embodying the present invention, in which a board 1 of heat insulating material (for example, urethane) is laid on the floor of a building (floor slab, etc.), and a band-shaped The heaters 2 are arranged and laid at predetermined intervals as shown in the figure, and the heat storage material 3 in the shape of a mother tongue is arranged and laid on top of each heater 2 to form a floor heating structure. After finishing the installation, the finished surface is completed, and the floor structure with built-in underfloor heating is completed.

As the heater, for example, one having a structure in which a sheet-shaped electric heating resistor 4 is covered with a plastic sheet and electric wires 5.5 are connected to both ends (for example, a heat roll commercially available under the trademark "Plaheat") may be used. I can do it.

As the heat storage material 3, a composition having a melting point and freezing point within a desired temperature range (for example, 25°C to 35°C) and a large latent heat, such as sodium sulfate decahydrate or calcium chloride, is used. It is used by filling plastic cases etc. A specific example of this heat storage material is one commercially available under the trademark "Heat No Kunku 28" with a melting point of 2.
One example is a substance whose main component is sodium sulfate decahydrate stored in a case at 8°C.

Figure 3 is a graph illustrating the amount of heat stored in a heat storage material whose main component is sodium sulfate decahydrate (mirabilite).As is clear from this graph, the amount of heat stored is 2
It solidifies at 5°C and has a latent heat (40 to 45 kcall per serving) that is extremely large compared to the sensible heat of water.

Therefore, the capacity of the heater 2 and the heat storage material 3 is such that the heat storage material 3 is melted within a desired time (e.g., a preparation period of 2 to 8 hours) and the room temperature is maintained by the solidification heat for a desired period of time (e.g., an office room temperature). For example, the capacity is determined to be able to maintain the temperature at a desired temperature (for example, 20° C. to 25° C.) for about 8 to 10 hours, which corresponds to the daytime usage time.

In FIG. 2, a bed temperature sensor 6 is installed on the upper surface of the heat storage material 3, and detects the bed temperature as a temperature corresponding to room temperature.

On the other hand, the electric wire 5 for energizing the heater 2 is connected to a timer (not shown) that regulates the energization time, and the energization start timing and energization end timing are controlled based on the settings of the cough timer.

For example, a temperature detector such as a thermistor is used as the bed temperature sensor 6, and the operation of the cough timer, that is, the energization time is controlled by inputting its detection signal to the timer.

Therefore, in the present invention, the heater 2 is energized to melt the heat storage material 3 during the preparation period in step 4, and the room temperature is maintained within a predetermined temperature range mainly by the solidification heat of the heat storage material during the use period. Divide the preparation period into multiple time periods in advance,
The room temperature at the beginning of the preparation period or the corresponding temperature is detected, and when the detected temperature is higher than the maximum setting value, the energization time is set to zero.
When the detected temperature is below the minimum set value, electricity is applied throughout the entire time period, and when the detected temperature is between these values, electricity is applied from the beginning of the preset time period to the end of the preparation period according to the value, and the detected temperature is It is controlled by a timer so that the higher the value, the shorter the energization time is in stages.

A specific example of such energization control will be described below with reference to FIGS. 4 to 7 below.

Specific example: First, the period of use of the heater is 8 o'clock (from normal working hours, etc.).
8:00 am) to 5:00 pm (5:00 pm), and the preparation period will be from 2:00 am to 8:00 am. In addition, nighttime charges can be applied to electricity usage between 0:00 and 8:00, which is cheaper (about one-third) than during the day, and if the preparation period for turning on the heater is set within that time period, it will be economical. It is true.

The heat storage material 3 melts at 28°C and solidifies at 25°C, and has a temperature of about 4°C.
Sodium sulfate 10 with a latent heat of 3kcr11/Kf
Water salt (Na!5o4-10H!O) f Use the substance as the main component.

The aim is to maintain the room temperature at approximately 22° C. during use.

Therefore, the above-mentioned preparation period is divided into three time zones: 2:00 to 4:00 (first time zone), 4:00 to 6:00 (second time? t7)
and 6:00 to 8:00 (@3 hours), and the energization time is set by a timer as follows based on the value of the temperature detected by the bed temperature sensor 6 at the beginning of the preparation period (2:00).

That is, when the detected temperature is below 14°C (lowest setting (IL)), as shown by F in Figure 4, electricity is applied throughout the entire time period from 2:00 to 8:00, and the detected temperature is 14°C to 17°C.
℃ range, as shown by F in Figure 5, from the beginning of the second time period (4 o'clock) to the end of the preparation period (the end of the third time period 8 o'clock).
When the detected temperature is in the range of 17°C to 20°C, the current is turned on from the beginning of the third time period (6 o'clock) to the end of the preparation period (8 o'clock) as shown by F in Figure 6. When the detected temperature is higher than the maximum setting value of 20° C., the timer is set to open and close the energizing circuit so that the energizing time is zero, as shown in F in FIG.

Figures 41 to 7 show 1 day (2
Here are some graphs illustrating the temperature changes in each part over the course of 4 hours.
In these graphs, as in the case of Figure 1, the horizontal axis represents time and the vertical axis represents temperature (6). Curve A is the outside air temperature, curve B is the room temperature, curve C is the floor temperature, and the curve is The heat storage material temperature and the curve E indicate the temperature of the heater, respectively, and the line F indicates the above-mentioned energization state.

FIG. 8 is a diagram showing an example of the equipment configuration for controlling the energization shown in FIGS.
2 is provided, and the intermittent timing of the relay 12 is determined by three tires 13.
A.

It is configured to be controlled by 13B and 13C.

Each timer 13A, 13B, 13C has a minimum temperature control of 1
4A, 14B, and 14C are connected to each other, and the floor temperature sensor 6 detects the floor temperature or a temperature equivalent thereto, or in some cases detects the outside air temperature,
Based on the temperature detection signal, one of the minimum time temperature controls is activated and the corresponding timer is selected and turned on.

The timer 13A is turned on at 2 o'clock and turned off at 8 o'clock, and during that period the relay 12 is closed and energized as shown in Fig. 4, and the timer 13B is turned on at 4 o'clock and turned off at 8 o'clock.)
It operates to energize as shown in Figure 5, and the timer 13C
It turns on at 6 o'clock and turns off at 8 o'clock, and operates to conduct electricity as shown in Figure 6.

As is clear from the graphs in Figures 1g4 to 7, according to the heater energization control method according to the present invention, room temperature or a temperature corresponding thereto (floor temperature, heat storage material temperature, etc.)
is detected, and based on the detected value, the minimum necessary energization time is set so that the heat storage material reaches a molten state with sufficient latent heat at the end of the preparation period (preferably coincident with the beginning of the use period as in the example). Therefore, unnecessary power consumption can be eliminated and economical heating operation can be performed. At the same time, since the heating time can be minimized and the number of switching operations can also be minimized, the durability of the heater can be improved.

In the above specific example, the preparation period is divided into three time periods, but it can be divided into two, four or more, or into an appropriate number of time periods as required.

In addition, various conditions such as the length of preparation time, set values for room temperature and floor surface temperature, melting point or capacity of the heat storage material, set temperature and capacity of the heater, etc. It can be set as appropriate according to the request.

〔effect〕

As is clear from the above description, the present invention provides a method for controlling a regenerative electric heater that can improve economic efficiency by minimizing power consumption.

[Brief explanation of drawings]

FIG. 1 is a graph illustrating a conventional control method for a regenerative electric heater, and FIG. 2 is a partially cutaway perspective view illustrating the structure of a regenerative electric heater suitable for carrying out the control method of the present invention. Figure 3 is a graph illustrating the heat storage characteristics of heat storage materials, and Figure 4 is a graph illustrating the heat storage characteristics of heat storage materials.
7 to 7 are graphs illustrating the aspects of temperature changes in each part when implementing the control method for a regenerative electric heater according to the present invention, and FIG. 8 is a graph illustrating the energization control of FIGS. FIG. 2 is an explanatory diagram illustrating a suitable device configuration for carrying out the process. 2... Heater, 3... Heat storage material, 4... Electric heating resistor of heater, 5... Conductive wire, 6... Bed temperature (room temperature)
Detector, 10...Power supply, 12...Relay, 13A. 13B, 13C...Timer. Agent Patent Attorney Yasushi Ooto [1 copy (no changes to 11 of them) ta1 Figure □C) Figure 2 Figure 3 +0 20 30 TsutsumijjJ- (0c) Figure 4 Figure □C time) 5th Figure (a) □ (g now) - ([I) Figure 8 Procedural amendment (method) % formula % 3. Relationship with the person making the amendment Patent applicant

Claims (1)

[Claims] (1) In a control method for a regenerative electric heater, in which the heater is energized to melt the heat storage material during the preparation period, and the room temperature is maintained within a predetermined temperature range mainly by the solidification heat of the heat storage material during the use period, a certain Divide the preparation period into multiple time periods in advance,
The room temperature at the beginning of the preparation period or the corresponding temperature is detected, and when the detected temperature is higher than the maximum setting value, the energization time is set to zero.
When the detected temperature is below the minimum set value, electricity is applied throughout the entire time period, and when the detected temperature is between these values, electricity is applied from the beginning of the preset time period to the end of the preparation period according to the threshold value, and the detected temperature is A control method characterized by using a timer to control the energization time so that the higher the energization time is, the shorter the energization time is in stages.