JP2729470B2 - Direct heat collecting solar water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct-collection solar water heating apparatus for directly supplying water to a heat collector to collect heat and storing the obtained hot water in a hot water tank.

[0002]

2. Description of the Related Art As a solar water heater, a direct heat collecting type in which water is directly supplied to a heat collector to collect heat and the obtained hot water is stored in a hot water storage tank, and a heat exchanger is provided in the hot water storage tank. There is an antifreeze liquid collecting type in which antifreeze is circulated between the heat exchanger and the heat collector.

The solar water heater of the antifreeze liquid collecting type has the following problems. (A) The heat collection method using an antifreeze requires a heat exchanger from the antifreeze to water, so that the cost is increased. (B) Due to heat exchange from antifreeze to water, heat exchange performance is reduced. (C) If the antifreeze leaks due to corrosion of the heat exchanger or the like, the antifreeze mixes into the water. (D) In the heat collection method using antifreeze, the heat exchanger is installed in the hot water storage tank. In such a structure, the temperature of the whole water in the hot water storage tank gradually increases, so it is hot until evening. Since hot water is not available and solar hot water cannot be used in the morning or afternoon, the efficiency of using the solar water heater is poor.

[0004] On the other hand, the solar water heater of the direct heat collection type has the advantages that it does not have the above-mentioned problems, is simple in structure, and can be constructed at low cost.

[0005]

However, in the solar water heater of the direct heat collecting type, when the circulation pump is operated when the solar radiation is weak, the low-temperature hot water returns to the upper part in the hot water storage tank, and the hot water is heated. When hot water is stored in a layered manner in the upper part of the hot water storage tank, the temperature of the hot water layer is lowered. In particular, when only a small amount of the hot water layer remains in the upper portion of the hot water tank, the operation of the circulation pump causes the remaining hot water layer to disappear. Also, in the morning, only a little hot water remains in the upper part of the hot water tank, and when the circulating pump is started when the sunlight starts to hit the collector, the solar radiation is still weak, so the upper part of the hot water tank A small amount of hot water will disappear with the start of operation of the circulation pump.

An object of the present invention is to provide a direct heat collecting solar water heater that can solve the problems of the direct heat collecting method. Another object of the present invention is to provide a direct-collection solar water heater in which the circulating pump does not start operating unless the temperature inside the collector reaches a temperature that can be used as hot water having a constant temperature. Another object of the present invention is to provide a direct heat collecting solar water heater that can control the rotation speed of a circulation pump in accordance with solar radiation. Another object of the present invention is to provide a direct-collection type solar water heater that can eliminate airlock, which is a problem associated with controlling the rotation speed of a circulation pump. Another object of the invention is when the temperature approaches the freezing temperature of water,
It is an object of the present invention to provide a direct heat collecting solar water heater capable of draining water in a heat collector.

[0007]

According to the present invention, there is provided a heat collector, a hot water storage tank provided below the heat collector, and a lower part of the hot water storage tank and a lower part of the heat collector connected to each other. A water pipe for supplying water in the hot water tank to the heat collector, and connecting an upper part of the heat collector and an upper part of the hot water tank to supply hot water generated by the heat collector to the hot water tank It is an object of the present invention to improve a direct-collection-type solar water heater provided with a hot water return pipe and a circulation pump connected to the water supply pipe and pumping water in the hot water tank to the heat collector.

According to a first aspect of the present invention, in the solar water heater of the direct heat collecting type, a first temperature sensor provided on an upper portion of the heat collector and the temperature signal from the first temperature sensor are provided. a controller for performing speed control operation stop of the circulation pump that features.

Further , an air vent valve provided on the upper part of the heat collector and a first electromagnetic valve provided on the water supply pipe on the discharge side of the circulating pump and whose opening and closing are controlled by a control signal from the controller. A valve, a check valve provided on the hot water return pipe for stopping the backflow of hot water from the upper part of the hot water storage tank, and one end connected to the hot water return pipe between the upper part of the heat collector and the check valve And a connecting pipe having the other end connected to the water pipe between the first solenoid valve and a lower portion of the heat collector, and a connecting pipe provided on the connecting pipe and opened and closed by a control signal from the controller. And a second solenoid valve provided in the hot water return pipe.
The controller comprises: a controller for controlling the operation of the circulation pump when the difference between the detected temperatures of the first temperature sensor and the second temperature sensor exceeds a certain value during the operation of the circulation pump. It is characterized in that control is performed to stop and open the second electromagnetic valve for a predetermined time.

According to a second aspect of the present invention, in the solar water heater of the direct heat collecting type, the first water heater is provided at an upper portion of the heat collector.
A temperature sensor and a temperature signal from the first temperature sensor.
Controller for stopping the operation of the circulating pump and controlling the number of revolutions
And Further, an air vent valve provided on the upper part of the heat collector, a first solenoid valve provided in the water pipe on the discharge side of the circulating pump, the opening and closing of which is controlled by a control signal from the controller, A check valve provided on the hot water return pipe to stop the backflow of hot water from the top of the hot water storage tank, and one end connected to the hot water return pipe between the top of the heat collector and the check valve A connecting pipe having the other end connected to the water pipe between the first solenoid valve and a lower portion of the heat collector, and opening / closing controlled by a control signal from the controller provided in the connecting pipe. A second solenoid valve, a second temperature sensor provided on the hot water return pipe, and a water supply pipe connected to a lower part of the hot water tank so as to always apply a required water pressure to the hot water tank. The controller opens the second solenoid valve for a predetermined time before the operation of the circulating pump and starts the circulation. When the difference between the temperature detected by the first temperature sensor and the temperature detected by the second temperature sensor during the operation of the circulating pump and the control of closing the second solenoid valve at the start of operation of the pump exceeds the predetermined value, It is characterized in that control for opening the second solenoid valve for a predetermined time is performed.

[0011]

[0012]

[0013]

According to the solar water heater of the direct heat collecting type according to the first aspect of the present invention, the first temperature sensor is provided on the upper part of the heat collector, and the controller operates according to the temperature signal from the first temperature sensor. By stopping the operation of the circulation pump and controlling the rotation speed, it is possible to control the controller so that the operation of the circulation pump is not started unless the temperature of the heat collector reaches a temperature that can be used as hot water. Further, by controlling the rotation speed of the circulation pump in accordance with the solar radiation, it is possible to efficiently generate hot water having a predetermined temperature.

[0014] Then, the controller is a control to open the first temperature sensor and the second solenoid valve a predetermined time when the difference between the detected temperature of the second temperature sensor exceeds a predetermined value during operation of the circulation pump By doing so, the difference between the detected temperature of the first temperature sensor and the detected temperature of the second temperature sensor when the air lock is established exceeds a certain value. At this time, when the second solenoid valve is opened for a predetermined time,
The air is pushed up by the water rising in the water supply pipe and the hot water return pipe and is removed from the air release valve, so that the air lock can be automatically released under the control of the controller.

[0015] wherein, according to the direct current thermal solar water apparatus according to claim 2, the controller of the second at the start of operation of the second circulation pump solenoid valve open a predetermined time before the start of operation of the circulating pump By performing control to close the solenoid valve, the air is pushed up by the water rising in the water supply pipe and the hot water return pipe by opening the second solenoid valve for a predetermined time before the operation of the circulation pump is started, and the air is removed from the air release valve. Therefore, the operation of the circulation pump can be started after the air is exhausted from the water circulation path. Then, by applying the required water pressure to the hot water storage tank at all times, the water pressure acts as a force to push up the water in the hot water storage tank to the heat collector side, and thus a circulating pump for pushing up the water in the hot water storage tank to the heat collector side. The capacity can be reduced in size.

[0016]

[0017]

[0018]

1 and 2 show one embodiment of a direct heat collecting solar water heater according to the present invention. In the direct-collection type solar water heater according to the present embodiment, the heat collector 1 is inclined and installed on a roof or the like that easily collects solar heat. The heat collector 1 is formed by seam welding two stainless steel thin plates 2a and 2b around each other in a bag shape and bonding them together, and a plurality of upward water passages 3 are provided in the middle part thereof in the width direction. The stainless steel plates 2a and 2b are bent and formed into a waveform. The heat collector main body 4 formed by processing the stainless steel thin plates 2a and 2b in this manner is housed in a case 5 whose upper part is opened. A heat insulating material 6 is arranged between the bottom of the case 5 and the heat collector body 4. Case 5
A transparent plate 7 such as a plastic plate is attached to the opening.

A hot water storage tank 8 is provided on the ground or the like below the heat collector 1. Hot water storage tank 8 is housed in heat insulation container 9. The lower part of the hot water storage tank 8 and the lower part of the heat collector 1 are connected by a water pipe 10, whereby the water in the hot water storage tank 8 is supplied to the heat collector 1. The upper part of the heat collector 1 and the upper part of the hot water storage tank 8 are connected by a hot water return pipe 11, whereby the hot water generated by the heat collector 1 is supplied to the hot water storage tank 8. Water pipe 1 adjacent to hot water storage tank 8
A circulation pump 12 is connected to 0 so that the water in the hot water storage tank 8 is sent to the heat collector 1.

A first electromagnetic valve 13 is provided in the water pipe 10 on the discharge side of the circulation pump 12. Further, a drain pipe 14 is branched and connected to the water supply pipe 10 at a position near the first solenoid valve 13 between the first solenoid valve 13 and the heat collector 1, and a third pipe is connected to the drain pipe 14. An electromagnetic valve 15 is provided. A connecting pipe 16 connecting the hot water return pipe 11 to the water pipe 10 is connected to the water pipe 10 between the branch connection point 17 of the drain pipe 14 and the first solenoid valve 13, and the connecting pipe 16 has a second pipe. Are provided. A check valve 20 is provided in the hot water return pipe 11 between the connection point 19 of the connecting pipe 16 to the hot water return pipe 11 and the hot water storage tank 8 as a water stopping means for stopping the flow of water or hot water as needed. ing. The check valve 20
The hot water flow from the heat collector 1 to the hot water storage tank 8 is allowed, but the flow of hot water from the hot water storage tank 8 to the heat collector 1 is not allowed.

The water pipe 10, the hot water return pipe 11, and the connecting pipe 16 are formed of a flexible plastic pipe such as a polybutene pipe. The sizes of the water pipe 10, the hot water return pipe 11, and the connecting pipe 16 are preferably 13 mm or less in inner diameter.

An air vent valve 21 and a first temperature sensor 22 are provided above the heat collector 1. In this case, the air vent valve 21 is connected to the hot water return pipe 1 located above the heat collector 1.
The first temperature sensor 22 is provided at the top of the heat collector 1 and inserted therein.

A second temperature sensor 23 is attached to the hot water return pipe 11 between the check valve 20 and the hot water storage tank 8 to detect the temperature of hot water passing through the hot water return pipe 11. A third temperature sensor 24 is attached to a lower portion of the hot water storage tank 8 to detect a water temperature in the hot water storage tank 8.

These first, second and third temperature sensors 2
The detection signals from 2, 23, and 24 are input to the controller 25. The controller 25 outputs control signals to the circulation pump 12, the first, second, and third solenoid valves 13, 18, and 15 based on these detection signals.

The water supply pipe 10 at the lower part of the heat collector 1 is provided with a relief valve 26 for releasing abnormal water pressure acting on the heat collector 1, the lower part of the water storage tank 8 is provided inside the water storage tank 8. A water supply pipe 28 directly connected to the water supply via an adjustment pressure reducing valve 27 is connected so as to always apply a required water pressure. A hot water pipe 29 is connected to an upper part of the hot water storage tank 8. The tapping pipe 29 is connected to a tapping faucet 30. An air vent valve 31 and a safety valve 32 are connected to an upper part of the tapping pipe 29.

FIG. 3 shows an example of the configuration inside the controller 25. The controller 25 includes a DC power supply 34 and a one-chip microcomputer 35 that performs a control operation by receiving detection signals from the first, second, and third temperature sensors 22, 23, and 24 supplied with power from the DC power supply 34. An interface circuit 36 connected to the one-chip microcomputer 35; and a digital / analog conversion circuit (hereinafter referred to as D / A
It is called an A conversion circuit. ) 37. DC power supply 3
4 is connected to a commercial power line 38 of 100 VAC. Further, the controller 25 is connected to the circulating pump 1
And a pump control relay contact 40a connected to a power supply circuit 39 leading to the power supply circuit 2 to control power supply, and power supply circuits 41, 42 from the commercial power supply line 38 to the first, second, and third solenoid valves 13, 18, and 15. , 43, which are connected to the solenoid valve control relay contacts 44a, 45a, 46a for controlling power supply. The interface circuit 36 includes these pump control relay contacts 40a and solenoid valve control relay contacts 44a, 45a, 46a.
And a solenoid valve control relay coil 44b, 45b, 46b.

Next, the operation of such a direct heat collecting solar water heater will be described. When water is not contained in the heat collector 1, when a water supply command is issued from the controller 25, the first and second solenoid valves 13, 18 are opened, the third solenoid valve 15 is closed, and hot water is stored. Due to the water pressure in the tank 8, the water in the hot water tank 8 passes through the circulation pump 12 (not yet operating at this time) and the first solenoid valve 13, one through the water supply pipe 10, and the other through the water supply pipe 10. The heat is supplied to the heat collector 1 via the connection pipe 16, the second solenoid valve 18, and the hot water return pipe 11. At this time, the air existing inside the water pipe 10, the connecting pipe 16, the hot water return pipe 11, the heat collector 1 and the like is pushed up by the rise of the water and discharged from the air vent valve 21.

After one to two minutes, the second solenoid valve 18 is closed according to a command from a timer in the controller 25 and the circulation pump 12 is operated.
Into the heat collector 1 through the water pipe 10 through the solenoid valve 13 of
The water is heated by the solar heat in the heat collector 1, becomes hot water, passes through a hot water return pipe 11, passes through a check valve 20, and enters the upper portion of the hot water storage tank 8. Since this hot water has a low specific gravity,
The water accumulates in the upper portion of the hot water storage tank 8 in a layered manner without being mixed with the lower water.

As described above, the air existing in the water pipe 10, the connecting pipe 16, the hot water return pipe 11, the heat collector 1 and the like escapes from the air vent valve 21, and water is supplied to the water pipe 10 and the hot water return pipe 11. After being filled, the circulation pump 12 is operated, and a required water pressure is constantly applied to the hot water storage tank 8, and this water pressure acts as a force to push up the water in the hot water storage tank 8 to the heat collector 1 side. Water is circulated even if the pressure of the circulation pump 12 is low. Such circulation of water is repeated, and the water in the hot water storage tank 8 becomes hot water sequentially.

When the temperature detected by the first temperature sensor 22 becomes lower than a predetermined value or when the temperature detected by the first temperature sensor 22 becomes lower than the temperature detected by the third temperature sensor 24, the controller 25 instructs the circulation. The operation of the pump 12 stops, the first solenoid valve 13 closes, and the heat collection ends.

When the temperature of the hot water layer in the upper part of the hot water storage tank 8 is
For example, as a means for controlling the amount of circulating water of the circulating pump 12 in accordance with the amount of solar radiation so as to maintain the temperature at 40 ° C. or more, the circulating pump as a function of the temperature detected by the first temperature sensor 22 mounted on the upper part of the heat collector 1 A controller 25 that determines the number of rotations of twelve is used in this embodiment.

FIG. 4 shows a functional relationship between the detected temperature of the first temperature sensor 22 and the number of revolutions of the circulation pump 12, and FIG. 5 shows a control loop thereof. This control loop is a feedback control, and is performed until a change in the detected temperature of the first temperature sensor 22 appears after a command to change the rotation speed of the circulation pump 12 is issued from the one-chip microcomputer 35 via the D / A conversion circuit 37. Is considerably large, and includes a dead time delay until the water entering from the lower part of the heat collector 1 reaches the position of the first temperature sensor 22, so that the condition that the circulation pump 12 easily oscillates is set.

In order to suppress such oscillation, the first temperature sensor 22 can be attached to the heat collector 1 to detect both the temperature of the heat collector 1 and the amount of solar radiation as shown in FIG. It is preferable that the heat collector 1 is attached to the surface of the heat collector 1 which receives the solar radiation.

In this way, the heat collector 1
The temperature detected by the first temperature sensor 22 changes before the temperature of the circulating pump 12 changes, and the rotational speed of the circulation pump 12 can be controlled in advance,
Oscillation of the circulation pump 12 can be avoided.

If a sensor for detecting the amount of solar radiation itself such as a solar cell is used in place of the first temperature sensor 22 attached to the surface of the heat collector 1 as the heat collecting sensor, the control is completely open loop control. Although it is a system that does not cause oscillation at all, it has an undesirable point because there is no feedback. This is because the flow path resistance of the pipes 10 and 11 connecting the hot water storage tank 8 and the heat collector 1 is different for each property, and other conditions are different.
The reason is that the feedback control for detecting the temperature of the heat collector 1 has a function of correcting such a change in the condition, rather than determining the rotational speed of the heat collector only by the amount of solar radiation.

To prevent freezing in the winter night, the temperature detected by the first temperature sensor 22 is close to the freezing temperature, for example, 3 ° C.
When it becomes below, the first solenoid valve 13 is instructed by the controller 25.
Is closed and the third solenoid valve 15 and the second solenoid valve 18 are closed.
Is opened, and air enters the heat collector 1 and the hot water return pipe 11 from the air release valve 21, and the heat collector 1, the water supply pipe 10, and the hot water return pipe 1
1 and the water in the connecting pipe 16 are discharged through the drain pipe 14. In this case, if the water supply pipe 10, the hot water return pipe 11 and the connecting pipe 16 are formed of a relatively thin flexible plastic pipe, for example, a polybutene pipe or the like, there is no seam and there is no sharp bend. Even if there is a point where the flow resistance is small and the slope of these pipes is not necessarily downgraded in the direction of the drain pipe 14, if the drain pipe 14 is located at a position lower than the water supply pipe 10 and the hot water return pipe 11, The water in the heat collector 1, the water supply pipe 10, the hot water return pipe 11 and the connecting pipe 16 is discharged through the drain pipe 14 according to the so-called siphon principle. At this time, the water pressure in the hot water storage tank 8 is
The water supply pipe 10 and the hot water return pipe 11 are shut off and held by the electromagnetic valve 13 and the check valve 20. Water pipe 1
0. Even if water remains in the hot water return pipe 11 and the connecting pipe 16, there is no danger of freezing and damage if it is a flexible plastic pipe.

The heat collector 1 is made of two stainless steel sheets 2
When a and 2b are formed by seam welding, the cross-sectional area of the water passage 3 in the heat collector 1 can be easily expanded and contracted. However, the heat collector 1 having a structure in which the cross-sectional area of the water channel 3 easily expands and contracts and is hardly damaged by freezing has a disadvantage that it is weak against water pressure in principle. Therefore, in order to protect the heat collector 1 from water pressure damage, if a relief valve 26 is provided at the lower part of the heat collector 1 to hold the water pressure below the broken water pressure of the heat collector 1, the heat collector 1 generally has a roof. Since the hot water storage tank 8 is installed on the ground, the water pressure in the hot water storage tank 8 causes the heat collector 1
Is reduced by the difference in height, so that the water pressure applied to the heat collector 1 can be maintained in a safe range.

During operation of the circulation pump 12, the tap 30
When the hot water is discharged more vigorously, the amount of water supplied into the hot water storage tank 8 from the regulating pressure reducing valve 27 cannot keep up, the water pressure in the hot water storage tank 8 decreases, and the water pressure in the heat collector 1 placed at a high position Becomes negative pressure, and air may enter the heat collector 1 and the hot water return pipe 11 from the air vent valve 21. The pump pressure presses air down the hot water return pipe 11 or the air release valve 2.
It can not be ejected from 1 and becomes locked state,
There is a possibility that an airlock phenomenon in which the circulation of water stops will occur. In such a case, heat cannot be collected even if there is solar radiation.

Means for avoiding this is provided in the embodiment of FIG. That is, when the airlock phenomenon occurs, heat is not collected even when the circulating pump 12 is operating, so that the temperature of the second temperature sensor 23 is higher than the temperature at which the first temperature sensor 21 starts collecting heat. Will not rise. Therefore, when the state in which the difference between the detected temperature of the first temperature sensor 22 and the detected temperature of the second temperature sensor 23 is equal to or higher than a certain level continues for a certain period of time, the controller 25 determines that an air lock has occurred and issues a command. When the operation of the circulation pump 12 is stopped and the first and second solenoid valves 13 and 18 are opened, the air in the hot water return pipe 11 and the air in the heat collector 1 are pushed up by the water pressure in the hot water storage tank 8. Is discharged from the air vent valve 21. In this state, after a lapse of a predetermined time, for example, 1 to 2 minutes, the second solenoid valve 18 is closed again by a command from the controller 25 and the circulating pump 12 is driven. Circulation will begin. If air has not yet escaped in this series of operations, the same operation is repeated again by a command from the controller 25.

The check valve 20 can be replaced with a solenoid valve. In this case, the opening and closing of the solenoid valve is controlled by a command from the controller 25.

[0041]

According to the first aspect of the present invention, the first temperature sensor is provided above the heat collector, and the controller stops the operation of the circulation pump in response to the temperature signal from the first temperature sensor. Since the rotation speed control is performed, the controller can control the circulation pump so that the operation of the circulation pump is not started unless the temperature of the heat collector reaches the temperature that can be used as hot water. Further, the rotation speed of the circulation pump can be controlled according to the solar radiation. For this reason, the laminarity of the hot water layer in the hot water storage tank is well maintained, and a solar water heater with a high solar heat utilization rate can be realized.

Further , the controller may be configured to control the first during the operation of the circulation pump.
When the difference between the detected temperature of the temperature sensor and the detected temperature of the second temperature sensor exceeds a certain value, that is, when the air lock state is set,
The second solenoid valve is opened for a predetermined time, and air can be released from the air release valve by pushing up the air with water rising from the water supply pipe and the hot water return pipe, whereby the air lock is automatically controlled by the controller. Can be eliminated.

According to the second aspect of the present invention, the controller opens the second solenoid valve for a predetermined time before starting the operation of the circulation pump, and performs control to close the second solenoid valve when the operation of the circulation pump starts. Since the second solenoid valve is opened for a predetermined time before the operation of the circulation pump is started, air is pushed up by the rising water in the water supply pipe and the hot water return pipe, and the air can be removed from the air release valve, The operation of the circulating pump can be started when there is no more air in the water circulation path, and the required water pressure is always applied from the water supply pipe to the hot water tank. Can be
Thereby, the size of the circulation pump can be reduced.

[0044]

[0045]

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of one embodiment of a direct heat collecting solar water heater according to the present invention.

FIG. 2 is a partially cutaway perspective view showing a configuration of a heat collector used in the present embodiment.

FIG. 3 is a block diagram illustrating an example of a configuration in a controller illustrated in FIG. 1;

FIG. 4 is a characteristic diagram showing a functional relationship between a detected temperature of a first temperature sensor and a rotation speed of a circulation pump in the embodiment.

FIG. 5 is a control loop system diagram in the direct heat collecting solar water heater of the present embodiment.

FIG. 6 is a perspective view showing a preferred example of how to attach a first temperature sensor to be attached to a heat collector in the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heat collector 2a, 2b Stainless steel thin plate 3 Waterway 4 Heat collector main body 5 Case 6 Insulation material 7 Transparent plate 8 Hot water storage tank 9 Heat insulation container 10 Water supply pipe 11 Hot water return pipe 12 Circulation pump 13 First electromagnetic valve 14 Drain pipe 15 Third solenoid valve 16 Connecting pipe 17 Branch connection point 18 Second solenoid valve 19 Connection point 20 Check valve 21 Air release valve 22 First temperature sensor 23 Second temperature sensor 24 Third temperature sensor 25 Controller 26 relief valve 27 regulating the pressure reducing valve 28 feed water pipe 29 hot water pipe 30 hot water faucet 31 purge valve 32 safety valve 34 DC power supply 35 one-chip microcomputer 36 interface circuit 37 digital / analog converter circuit 38 commercial power line 40a pump control relay contact 40b pump control relay Coil 41, 42, 43 Power supply circuit 44a, 45a, 46a Solenoid valve control Relay contacts 44b, 45b, 46b solenoid valve control relay coil

Claims (2)

(57) [Claims] 1. A heat collector, a hot water tank installed below the heat collector, and a lower part of the hot water tank and a lower part of the heat collector connected to collect water in the hot water tank. A water pipe for supplying a hot water, a hot water return pipe for connecting the upper part of the heat collector and the upper part of the hot water tank to supply the hot water generated by the heat collector to the hot water tank, and the water pipe A direct-collection-type solar water heater provided with a circulation pump connected to the hot water storage tank and pumping the water in the hot water tank to the heat collector; a first temperature sensor provided on an upper portion of the heat collector; A controller for stopping the operation of the circulating pump and controlling the number of revolutions in response to a temperature signal from a first temperature sensor; and an air provided above the heat collector.
A drain valve, provided on the water pipe on the discharge side of the circulation pump.
And the opening and closing are controlled by a control signal from the controller.
And the hot water storage tank provided in the hot water return pipe.
A check valve for stopping the backflow of hot water from the top of the
One end is connected to the hot water return pipe between the upper part and the check valve
And the other end is below the first solenoid valve and the heat collector.
A connecting pipe connected to the water pipe between the section and the connecting pipe;
Opening / closing is controlled by a control signal from the controller.
And a second solenoid valve provided on the hot water return pipe.
And a controller for the circulation pump.
The first temperature sensor and the second temperature sensor during operation
If the difference between the detected temperature and
Operation is stopped and the second solenoid valve is turned on for a predetermined time.
A direct-collection-type solar water heater that performs opening control . 2. A heat collector, and installed below the heat collector.
A hot water tank, a lower part of the hot water tank, and a lower part of the heat collector.
Water supply to connect and supply water in the hot water tank to the heat collector
Connecting the pipe, the upper part of the heat collector and the upper part of the hot water tank
To supply the hot water generated by the heat collector to the hot water storage tank
A hot water return pipe, connected to the water pipe,
Direct collection with a circulating pump for pumping water to said collector
In a thermal solar water heater, provided above the heat collector
A first temperature sensor, and a signal from the first temperature sensor.
The operation of the circulating pump is stopped in accordance with the temperature signal and the rotation speed is controlled.
A controller for controlling the air and air provided above the heat collector
A drain valve, provided on the water pipe on the discharge side of the circulation pump.
And the opening and closing are controlled by a control signal from the controller.
And the hot water storage tank provided in the hot water return pipe.
A check valve for stopping the backflow of hot water from the top of the
One end is connected to the hot water return pipe between the upper part and the check valve
And the other end is below the first solenoid valve and the heat collector.
A connecting pipe connected to the water pipe between the section and the connecting pipe;
Opening / closing is controlled by a control signal from the controller.
And a second solenoid valve provided on the hot water return pipe.
Temperature sensor and always apply the required water pressure in the hot water tank.
Water supply pipe connected to the lower part of the hot water storage tank so that
The controller controls the second pump before starting operation of the circulation pump.
Open the solenoid valve for a predetermined time and start the operation of the circulation pump.
Control for closing the second solenoid valve and operation of the circulation pump
Detection of the first temperature sensor and the second temperature sensor
When the difference in the known temperature exceeds a certain value, the second solenoid valve is activated.
It is characterized by performing control to open for a predetermined time
Direct heat collector type solar water device that.