JPS5842806Y2 - Solar air heating system - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an air heating system that uses solar heat to heat a room to be heated with hot air by storing heat in a heat storage tank using heated air from a solar heat collector.

In recent years, in the field of solar houses, the development of hot air type solar collectors (structures that allow air to be heated by solar heat) with high heat collection efficiency has progressed. Warm air is sent to a heat storage tank to temporarily store heat, and when necessary, heated air is taken out from the heat storage tank and sent to the room to be heated.If the amount of heat storage is insufficient, an auxiliary heater is used to generate warm air inside the room. Various heating systems have been proposed.

Here, FIG. 1 shows an air heating system using solar heat that was previously proposed by the applicant. To briefly describe its configuration, 1 in the figure is a room to be heated, and 2 is a structure that heats the air flow using solar heat. 3 is a heat storage tank containing a large number of heat mediums such as pebbles; 4 is a blower installed in a unitized box 5; the left and right air collectors are driven by a motor installed in the box 5; By switching between the pair of switching dampers 6A, 6B and the solenoid-driven opening/closing dampers 7A, 7B, 7C of the three-way duct 7 installed near the exhaust outlet of the heated room 1, solar heat is generated as shown by the solid line arrows in FIG. A heat collection heating circuit A that sends the heated air from the heat collector 2 as it is through the blower 4 into the heated room 1 and returns it to the solar heat collector 2, and a solar heat collector 2 as shown by the broken line arrow. A heat storage circuit B that causes the heated air to flow into the heat storage tank 3 from the upper air inlet/outlet 3a through the blower 4 and returns it to the solar heat collector 2 from the lower air inlet/outlet 3b, and heat storage circuit B as shown by the two-dot chain arrow. A thermal storage heating circuit C that sends the heated air in the tank 3 through the upper air inlet/outlet 3a through the blower 4 into the heated room 1 and returns it into the heat storage tank 3 through the lower air inlet/outlet 3b. It has become.

In addition, a heat exchanger 9 is provided as an auxiliary heater in the middle of the flow path 8 on the side of the air inlet of the blower 4 in the box 5, and hot water from a water heater 10 such as a boiler is stored in the heat exchanger 9 so that hot water can be used for taking a bath or the like at any time. A hot water supply tank 11 capable of supplying hot water to a sink etc. is connected via a hot water circulation circuit 12 with a pump, and by sending the hot water in the tank 11 to a heat exchanger 9 with a pump, the inside of the flow path 8 is heated by the hot water. It is possible to configure an auxiliary thermal heating circuit D (the air flow path is the same as the thermal storage heating circuit C indicated by the above-mentioned two-dot chain arrow) which auxiliary heats the passing air and sends it into the heated room 1. It has become.

Here, the switching of each of the circuits A, B, C, and D is based on the indoor temperature T1 in the heated room 1, the heat collection temperature T2 at the air outlet of the solar heat collector 2, and the heat storage temperature in the heat storage tank 3. T3 is detected by a temperature sensor (not shown) and controlled automatically or manually depending on each temperature condition.

That is, when the indoor temperature T1 is, for example, a set value of 18° C. or lower and heating is required, and the solar heat collection temperature T2 is sufficiently high, the heat collection heating circuit A performs indoor heating using solar hot air.

In addition, the indoor temperature T1 is high, heating is not required, and the solar heat collection temperature T
2 is sufficiently high, the heat storage circuit B is switched and solar hot air is introduced into the heat storage tank 3 to store heat.

In addition, when the indoor temperature T1 is low at night and requires heating, but the solar heat collection temperature T2 is also low, the indoor heating circuit is switched to the thermal storage heating circuit C and the indoor heating is performed using the thermal storage hot air taken out from the thermal storage tank 3. If the temperature T1 is low and heating is necessary, but both the solar heat collection temperature T2 and the heat storage temperature T3 are low, switch to the auxiliary heat heating circuit (leaving the heat storage heating circuit C and operating the pump of the hot water circulation circuit 12 as an auxiliary heat source). (a state in which the hot water in the hot water supply tank 11 is sent to the exchanger 9) The room is heated with warm air heated by auxiliary heat.

Furthermore, in the previous proposal, in addition to the hot air heating described above, when indoor heating is not required, it is also possible to heat the hot water in the hot water tank 11 via the heat exchanger 9 with solar hot air or thermally stored hot air, which can be used for hot water supply. This means that solar thermal energy can be used efficiently and without waste throughout the year.

However, in the heating system using solar heat described above, the timing of switching control of each circuit is not very accurate, resulting in wasted use of solar heat.

In other words, the timing of switching from thermal storage heating to auxiliary heating due to a decrease in the thermal storage temperature T3 in the heat storage tank 3 is too early, and auxiliary heating is performed even though there is still sufficient heat storage. condition, and the solar heat collection temperature T
Even if the heat storage temperature T2 rises, it is difficult to start storing heat due to the difference in temperature from the heat storage temperature T3 of the heat storage tank 3, and conversely, the timing of stopping the heat storage is too early.

This has the drawback of not being able to store as much solar heat as possible, and of insufficiently utilizing the stored heat, requiring a large amount of auxiliary heat.

This is because the air flows in the heat storage circuit B and the heat storage heating circuit C are completely opposite inside the heat storage tank 3, and even though the temperature change inside the heat storage tank 3 is quite different between the upper and lower parts, There was a problem in that the temperature of only the intermediate portion was detected by a sensor to control switching of the circuit.

This idea was created in view of the above circumstances, and its purpose is to control the switching from thermal storage heating to auxiliary heating, and to control the start and stop of thermal storage at appropriate times. The objective is to provide a system that is efficient in utilizing solar heat without any waste.

That is, this invention provides temperature sensors that detect the upper and lower temperatures of the heat storage tank, and controls switching from thermal storage heating to auxiliary heating based on the temperature detected by the upper temperature sensor. The system is characterized by a heating system using solar heat that controls the start and stop of heat storage based on the detected temperature.

An embodiment of this invention will be described below with reference to FIG.

Note that FIG. 2 is a cross-sectional view showing only the heat storage tank 3, and the rest is completely the same as the configuration shown in FIG. 1 described above, so illustration thereof is omitted.

The heat storage tank 3 has a structure in which a large number of heat mediums such as pebbles are stored inside, and has an upper air inlet/outlet 3a and a lower air inlet/outlet 3b. The air enters from the upper air outlet 3a and enters the lower air outlet 3.
b, and during thermal storage heating, the heated air in the thermal storage tank 3 is taken out from the upper air outlet 3a as shown by the double-dashed chain arrow (thermal storage heating circuit C), passes through the room to be heated, and returns from the lower air outlet 3b. It is set to be returned.

Here, one temperature sensor 13, 14 is provided in the upper and lower parts of the heat storage tank 3, respectively, and the upper heat storage temperature T3a and the lower heat storage temperature T3 in the heat storage tank 3 are provided.
b is detected and the circuit switching control shown in FIG. 1 is performed.

That is, switching from thermal storage heating to auxiliary thermal heating is performed based on the upper thermal storage temperature T3B detected by the upper temperature sensor 13 when this becomes lower than a set value, for example, 30°C, and the start and stop of heat storage is determined by the lower temperature sensor 13. Based on the lower heat storage temperature Tab detected by No. 14, the temperature difference between this temperature and the solar heat collection temperature T2 is determined to be, for example, 5 to 7°C.

When heat storage heating is being performed, the heated air in the heat storage tank 3 is taken out from the upper air outlet 3a and sent to the heated room 1, and the slightly cooled air from the room 1 is transferred to the lower air. By being returned through the entrance/exit 3b, the amount of heat stored in the heat storage tank 3 gradually decreases, and the temperature change at this time is such that the lower heat storage temperature T'3b drops quickly, and then the middle part drops slightly later. However, the upper heat storage temperature T3a does not easily decrease because the heat in the lower part moves upward.

For this reason, in the conventional configuration in which the system switches to auxiliary heating when the intermediate temperature T3 falls below the set value, auxiliary heating is performed even though there is still sufficient heat storage in the upper part, which is wasteful. .

On the other hand, in this case, since the switching to auxiliary heat heating is not performed until the upper heat storage temperature T3a falls below the setting, the heat storage heating time can be greatly extended, and the heat stored in the heat storage tank 3 can be maximized without wasting it. It will be possible to use it effectively and save as much as possible on auxiliary heat sources.

In addition, when solar heat is stored in the heat storage tank 3 in a state where heating is not performed, generally the solar heat collection temperature T1 and the heat storage tank 3 are
When the temperature difference from the heat storage temperature T3 becomes Tt T3≧5 to 7°C, the blower 4 is turned to start heat storage. However, if the intermediate temperature T3 is used as in the past, T1 = T3B and heat storage is possible. Despite the condition, the above temperature difference could not be detected, and as a result, the start of heat storage was delayed.

On the other hand, in the present invention, heat storage is performed based on the lowest lower heat storage temperature Tab, so it is possible to start heat storage early, for example in the morning.

Moreover, the heat storage stop can be delayed, and more solar heat can be stored over a long period of time.

Since this invention has been developed as detailed above, it is now possible to control the switching from thermal storage heating to auxiliary heating, and to control the start and stop of thermal storage at the appropriate timing, allowing for effective use of the thermal storage tank. As a result, it is highly effective in improving the utilization efficiency of solar heat and saving on auxiliary heat sources.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic system diagram of a conventional heating system, and FIG. 2 is a cross-sectional view of only the main parts showing an embodiment of this invention.

Claims (1)

[Scope of utility model registration request] A solar heat collector having a structure capable of heating airflow with solar heat, a heat storage tank having air inlets and outlets at the upper and lower parts and a heat medium such as pebbles inside, and an auxiliary heater, and the above solar heat collector There is a heat storage circuit that allows heated air from the heat storage tank to flow into the heat storage tank from the upper air inlet and outlet to store heat and returns it to the solar heat collector from the lower air inlet and outlet. A thermal storage heating circuit that sends air into the heating room for heating and then returns it to the heat storage tank from the lower air inlet and outlet, and an auxiliary heating circuit that sends heated air by an auxiliary heater to the heated room and heats the room can be switched. A temperature sensor that detects the upper temperature of the heat storage tank and a temperature sensor that detects the lower temperature of the heat storage tank are provided, and switching control between the thermal storage heating and auxiliary heat heating is performed based on the detected temperature of the upper temperature sensor. An air heating system using solar heat, characterized in that it is configured to perform heat storage start and stop control based on the temperature detected by a lower temperature sensor.