JP2001174072A - Solar heat collecting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar heat collecting system which requires less maintenance by separately increasing a pressure loss to prevent boiling of a heat medium, even if the pressure loss decreases between an outlet 1a of a heat- collector 1 and an inlet 3a of an expansion tab 3 when the temperature of heat medium rises. SOLUTION: A heat-collector 1 for collecting solar heat, a heat storage layer 2 where a heat is exchanged between the supplied water and the heat of heat medium heated by the heat-collector 1 for storage, the expansion tab 3 in which the heat medium is kept, and a heat medium circulating pump 5 which circulates the heat medium of the expansion tab 3 between the heat- collector 1 and the heat storage layer 2 through a heat medium line 4, are provided. Between the outlet 1a of the heat-collector 1 and the inlet 3a of the expansion tab 3, a thermal boiling preventing valve 6 is provided wherein the heat medium flow path in the heat medium line 4 is narrowed to increase a pressure loss as the temperature of heat medium rises while that is widened to decrease the pressure loss as the temperature falls.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar heat collecting system capable of preventing a heat medium from boiling.

[0002]

2. Description of the Related Art A conventional technique will be described below with reference to FIG. FIG. 5 is an overall system diagram showing a conventional solar heat collecting system. A conventional solar heat collecting system generally includes a heat collector 101 for collecting solar heat, a heat storage tank 102 capable of storing the heat, and an expansion for storing a heat medium circulated between the heat collector 101 and the heat storage tank 102. A tank 103, a heat medium line 104 connecting these and a heat medium passing therethrough, and a heat medium circulation pump 105 for forcibly circulating the heat medium,
The solar heat collected by the heat collector 101 is carried to the heat storage tank 102 by circulating the heat medium in the expansion tank 103, and the heat is stored in the heat storage tank 102. And the expansion tank 103
Can be classified into an open type and a closed type according to the type. Both the open and closed solar heat collection systems
Antifreeze is used as a heat medium to prevent freezing.

[0003] Incidentally, the closed type solar heat collecting system, in which the expansion tank 103 is completely sealed and is not in contact with the atmosphere, is advantageous for deterioration of the heat medium and corrosion of the heat medium line 104. There is a disadvantage that the pressure in the solar heat collection system changes greatly due to volume expansion due to the rise and fall of the temperature of the medium.

On the other hand, in the open-type solar heat collecting system, since the expansion tank 103 is open to the atmosphere, the pressure fluctuation can be absorbed by the storage tank 103 so that the pressure in the solar heat collecting system can be suppressed low. it can. In addition, water supply port 102
a is for connecting the heat storage layer 102 to supply water to the heat storage tank 102, and the hot water outlet 102b is connected to the heat storage tank 102 for supplying hot water heated by the heat storage tank 102 to a faucet or an auxiliary heat source.

[0005]

However, in the case of the above-mentioned solar heat collecting system, the viscosity of the heat medium decreases as the temperature of the heat medium rises. The pressure loss from the outlet 101a of 101 to the inlet 103a of the expansion tank 103 is reduced.

Since the expansion tank 103 is open, the heat collector 10
When the pressure loss from the outlet 101a of the heat collector 101 to the inlet 103a of the expansion tank 103 decreases, the static pressure at the outlet 101a of the heat collector 101 decreases. Considering the effect of the static pressure on the saturated vapor pressure, the outlet 10 of the collector 101 is increased as the temperature of the heat medium increases.
The boiling point at 1a is lowered, and the heat medium becomes easier to boil.

[0007] When boiling occurs in the heat collector 101, not only deterioration of the quality of the heat medium is promoted, but also the heat medium overflowing from the expansion tank 103 due to volume expansion is stored in the heat storage tank 1.
In such a case, the frequency of maintenance is increased due to problems such as failure of the heat exchanger 02 or abnormal heating of the reduced amount of the heat medium.

The present invention has been made in order to solve the above-mentioned problem.
Even if the pressure loss from the outlet 101a of the expansion tank 103 to the inlet 103a of the expansion tank 103 is reduced, the pressure loss is separately increased to prevent the heating medium from boiling, thereby reducing the frequency of maintenance. That is the task.

[0009]

According to the first aspect of the present invention,
A heat collector that collects solar heat, a heat storage layer that stores heat by exchanging heat between the supplied water and the heat medium heated by the heat collector, and an expansion tank that stores the heat medium, A heat medium circulating pump that circulates a heat medium in an expansion tank between the heat collector and the heat storage tank via a heat medium line, wherein a heat collector outlet and the expansion are provided. Between the inlet of the tank and the temperature of the heat medium, the heat medium flow path in the heat medium line is narrowed to increase the pressure loss, and as the temperature of the heat medium falls, the heat medium in the heat medium line decreases. Provided is a solar heat collecting system characterized by providing a heat boiling prevention valve for reducing a pressure loss by widening a flow path.

According to a second aspect of the present invention, the heat boiling prevention valve is attached to the heat medium line, and its volume is increased by melting as the temperature of the heat medium rises, and is increased by solidification as the temperature of the heat medium falls. A case in which a temperature sensing substance is reduced, a cylinder connected to the case, and in which a fluid or a semi-fluid is sealed, and a cylinder sandwiched between the case and the cylinder, A lid-like elastic body that seals the sensing substance and transmits an increase or decrease in the volume of the temperature sensing substance to the fluid or semi-fluid, and is slidably supported by a guide portion in the cylinder; And a piston that slides into and out of the guide portion to seal the fluid or semi-fluid, and moves the fluid or semi-fluid in the guide portion during the guide portion. Plug to transmit to A temperature sensor comprising a sexual body, and
2. A valve provided at an end of the piston on the advancing side, the valve comprising: a valve for narrowing a heat medium passage when the piston advances; and urging means for urging the valve in a backward direction. To provide a solar heat collection system.

According to a third aspect of the present invention, the heat-boiling prevention valve is provided in the heat medium flow path, and emits a heat medium temperature rise signal as the temperature of the heat medium rises. A temperature sensor for issuing a medium temperature lowering signal, a motor attached to the heating medium line, and a rod for the motor being rotationally driven in a heating medium flow path in the heating medium line by the heating medium temperature rising signal from the temperature sensor. And a control circuit for inverting and driving the rod by the heat medium temperature lowering signal from the temperature sensor, and a temperature sensing unit provided on the rod, which narrows the heat medium passage when the rod rotates. 2. A solar heat collecting system according to claim 1, comprising:

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG.
1 is an overall system diagram illustrating an example of a solar heat collecting system according to the present invention. FIG. 2 is a diagram showing a configuration of a thermal-boiling prevention valve used in one embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of a temperature sensing unit used in one embodiment of the present invention.

First, the overall system of the present invention will be described with reference to FIG. The solar heat collecting system collects solar heat usually installed on the roof or the roof of a building, and heats the water supplied from the water supply port 2a and the heat medium heated by the heat collector 1. A heat storage layer 2 for storing heat by exchanging heat, an expansion tank 3 for storing a heat medium, an outlet 1a of the heat collector 1 and a heat storage tank 2
Inlet 2c, outlet 2d of heat storage tank 2 and inlet 3 of storage tank 3
a, a heat medium line 4 that connects the outlet 3b of the storage tank 3 and the inlet 1b of the heat collector 1 and through which a heat medium flows.
A heat medium circulating pump 5 for forcibly circulating the heat medium in the storage tank 3 between the heat collector 1 and the heat storage tank 2 via the heat medium line 4; an outlet 1 a of the heat collector 1 and an expansion tank 3, the static pressure at the outlet 1a of the heat collector 1 is increased by narrowing the heat medium flow path in the heat medium line 4 and increasing the pressure loss as the temperature of the heat medium rises. A heat-boiling prevention valve 6 that increases the boiling point of the heat medium, increases the heat medium flow path in the heat medium line 4 as the temperature of the heat medium decreases, and reduces the pressure loss.

Here, a tap hole 2b for supplying hot water heated by the heat storage tank 2 to a faucet or an auxiliary heat source is connected to the heat storage tank 2. Next, a detailed configuration of the thermal-boiling prevention valve 6 will be described with reference to FIGS. Thermal boiling prevention valve 6
Is a substantially L-shaped connecting pipe 7 having a reduced diameter portion 7c smaller than the other pipe diameters, and a temperature sensing section 8 attached to the connecting pipe 7.
When the temperature sensing unit 8 senses a rise in the temperature of the heat medium, the piston 14 described below proceeds to the heat medium flow path in the connection pipe 7.
And a valve 16 provided at the end 14a on the advancing side of the piston 14 to narrow the heat medium flow path when the piston 14 advances.
And at least one spring 17, one end of which is fixed to the reduced diameter portion 7 c of the case 7, and the other end of which is locked to the valve 16 and biases the valve 16 in a retreating direction.

Here, the connecting pipe 7 is connected to the inlet 3a of the expansion tank 3.
The first connecting portion 7a to which the heat medium line 4 on the side is connected and the second connecting portion 7a to which the heat medium line 4 on the inlet 2c side of the heat storage tank 2 are connected.
A wax or the like, which has a connecting portion 7b and is attached to the heating medium line 4 and has a volume that is increased by melting due to a rise in temperature of the heating medium, and is reduced by solidification due to a fall in temperature of the heating medium. A case 9 in which a temperature sensing substance 10 is sealed, a fluid or semi-fluid 12 is enclosed therein, and a cylinder 11 having a guide portion 11a is provided between the case 9 and the cylinder 11. An elastic body having a curved portion 13a protruding toward the cylinder 11 side and sealing the temperature sensing substance 10;
When the volume of the lid 13 increases or decreases, the curved portion 13a is elastically deformed, so that the lid-like elastic body 13 is transmitted to the fluid or semi-fluid 12.
And a piston 14 slidably supported by the guide portion 11a in the cylinder 11 and moving forward and backward in the heat medium flow path in the heat medium line 4, and slidably fitted in the guide portion 11a to form a fluid or The semi-fluid 12 is sealed, and the fluid or the semi-fluid 12 is guided by increasing or decreasing the volume of the temperature sensing unit 10.
Lid-like elastic body 15 for transmitting movement within 1a to piston 14
And consisting of

The first embodiment is not limited to the above configuration. The connection pipe 7 may be a straight pipe, or a block made of an elastic material such as rubber may be used in place of the spring 17. Good.

Next, the operation of the first embodiment will be described. When the temperature of the heat medium rises, the temperature sensing substance 10 sealed in the case 9 of the temperature sensing unit 8 and sealed by the case 9 and the lid elastic body 13 expands, and the curved part 13 of the lid elastic body 13 expands.
a to the fluid or semi-fluid 12 side,
a projects to the fluid or semi-fluid 12 side. Curved part 1
When 3a protrudes toward the fluid or semi-fluid 12, the fluid or semi-fluid 12 sealed by the cylinder 11 and the plug-like elastic body 15 seeks a destination and moves in the guide 11a in a direction approaching the heat medium flow path. I do.

The fluid or semi-fluid 12 is guided by a guide 11a.
When moving in the direction approaching the heat medium flow path, the plug-like elastic body 15 is also pushed by the fluid or semi-fluid 12 and moves in the direction approaching the heat medium flow path, and moves the piston 14 into the heat medium flow path. Let it. When the piston 14 advances into the heat medium flow path, the valve 16 provided at the end 14a on the advance side of the piston 14 causes the reduced diameter portion 7c of the connection pipe 7 to resist the urging force of the spring 17.
(The position indicated by the two-dot chain line in FIG. 2) to narrow the flow path of the heat medium.

When the flow path of the heat medium becomes narrow, the pressure loss from the outlet 1a of the heat collector 1 to the inlet 3a of the expansion tank 3 increases, and the static pressure at the outlet 1a of the heat collector 1 increases. Due to the effect of the static pressure on the saturated vapor pressure, the boiling point of the heat medium at the outlet 1a of the heat collector 1 rises, and the heat medium hardly boils.

Conversely, when the temperature of the heat medium drops, the temperature sensing substance 10 contracts, and the valve 16 can move in the direction away from the reduced diameter portion 7c of the connection pipe 7 (the position indicated by the solid line in FIG. 2). Due to the urging force of the spring 17, the valve 16 moves in a direction away from the reduced diameter portion 7c of the connection pipe 7 (a position indicated by a solid line in FIG. 2) to widen the flow path of the heat medium. Thereby, even if the temperature of the heat medium rises and the pressure loss from the outlet 1a of the heat collector 1 to the inlet 3a of the expansion tank 3 decreases, the pressure loss is separately increased to prevent the heat medium from boiling and maintenance is performed. Frequency can be reduced.

Further, the use of the temperature sensing unit 6 as described above eliminates the need for an external power supply. The heat boiling prevention valve 6 is connected to the inlet 2c of the heat storage tank 2 or the inlet 3 of the expansion tank 3.
It is desirable to provide it near a. Thereby, the static pressure at the outlet 1a of the heat collector 1 can be more efficiently obtained.

(Second Embodiment) FIGS. 1, 4 and 5
A second embodiment of the present invention will be described with reference to FIG. 4 and 5
FIG. 7 is a diagram illustrating a configuration of a temperature sensing unit used in another embodiment of the present invention. First, the overall system of the present invention will be described with reference to FIG. 1, but only parts different from the first embodiment will be described, and the same parts will be omitted. In the second embodiment, the heat collector 1 is provided in the heat collector 1 in addition to the first embodiment, and issues a heat medium temperature rise signal as the temperature of the heat medium rises, and emits a heat medium temperature decrease signal as the temperature of the heat medium falls. It comprises a temperature sensor 18 and a control circuit 19 for controlling the heat-boiling prevention valve based on a signal from the temperature sensor 18.

Next, a detailed configuration of the thermal-boiling prevention valve 6 will be described with reference to FIGS. The heat boiling prevention valve 6 is attached to the heat medium line 4, and drives and rotates the rod 20 in the heat medium flow path in the heat medium line 4 by the control circuit 19 which receives the heat medium temperature rise signal from the temperature sensor 18. A motor 21 that inverts and drives a rod 20 by a control circuit 19 that has received a heat medium temperature lowering signal from a temperature sensor 18, and is attached to the rod 20 and rotates (inverts).
2 changes the area facing the flow of the heat medium
And 2. The second embodiment is not limited to the above configuration, and the temperature sensor 18 may be provided anywhere as long as it is a heat medium flow path.

Next, the operation of the second embodiment will be described. When the temperature of the heat medium rises, the temperature sensor 18 issues a heat medium temperature rise signal, and the control circuit 19 that has received the heat medium temperature rise signal rotates the rod 20 of the motor 21. When the rod 20 rotates, the valve 22 attached to the rod 20 also rotates integrally, and the position opposed to the flow of the heat medium becomes a position indicated by a two-dot chain line in FIG. .

When the flow path of the heat medium becomes narrow, the pressure loss from the outlet 1a of the heat collector 1 to the inlet 3a of the expansion tank 3 increases, and the static pressure at the outlet of the heat collector 1 increases. Due to the effect of the static pressure on the saturated vapor pressure, the boiling point of the heat medium at the outlet 1a of the heat collector 1 rises, and the heat medium hardly boils. Conversely, when the temperature of the heat medium decreases, the temperature sensor 18 issues a heat medium temperature decrease signal, and the control circuit 19 that has received the heat medium temperature decrease signal causes the rod 20 of the motor 21 to be inverted. When the rod 20 is inverted, the valve 22 attached to the rod 20
4 is also integrated and becomes a position shown by the solid line in FIG. 4 where the area facing the flow of the heat medium is reduced, and the flow path of the heat medium is widened. Thereby, even if the temperature of the heat medium rises and the pressure loss from the outlet 1a of the heat collector 1 to the inlet 3a of the expansion tank 3 decreases, the pressure loss is separately increased to prevent the heat medium from boiling and maintenance is performed. Frequency can be reduced.
Further, by using the temperature sensing unit 6 having the above configuration, it is possible to accurately cope with a temperature change.

If a solar cell is used as the power source for the sensor 18, the control circuit 19 and the motor 21, no external power source is required. The anti-boiling valve 6 is preferably provided near the inlet 2c of the heat storage tank 2 or at the inlet 3a of the expansion tank 3. Thereby, the static pressure at the outlet of the heat collector 1 can be obtained more efficiently.

[0027]

According to the solar heat collecting system according to the first aspect, even if the temperature of the heat medium rises and the pressure loss from the outlet of the heat collector 1 to the inlet of the heat storage tank 2 decreases, it is separately required. It is possible to increase the pressure loss, prevent the heat medium from boiling, and reduce the frequency of maintenance.

According to the solar heat collecting system of the second aspect, an external power supply is not required in addition to the effect of the first aspect. According to the solar heat collecting system according to claim 3,
In addition to the effect of the first aspect, it is possible to accurately cope with a temperature change.

[Brief description of the drawings]

FIG. 1 is an overall system diagram showing one embodiment of a solar heat collecting system according to the present invention.

FIG. 2 is a diagram showing a configuration of a hot-boiling prevention valve used in one embodiment of the present invention.

FIG. 3 is a diagram illustrating a configuration of a temperature sensing unit used in one embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a temperature sensing unit used in another embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a temperature sensing unit used in another embodiment of the present invention.

FIG. 6 is an overall system diagram showing a conventional solar heat collecting system.

[Description of Signs] 1, 101 heat collector 2, 102 heat storage tank 2a, 102a water supply port 2b, 102b tap hole 3, 103 expansion tank 4, 104 heat medium line 5, 105 heat medium circulation pump 6 heat boiling prevention valve 7 Connection pipe 7a First connection part 7b Second connection part 7c Reduced diameter part 8 Temperature sensing part 9 Case 10 Temperature sensing substance 11 Cylinder 11a Guide part 12 Fluid or semi-fluid 13 Lid elastic body 13a Bending part 14 Piston 14a end Part 15 Plug-like elastic body 16, 22 Valve 17 Spring 18 Temperature sensor 19 Control circuit 20 Rod 21 Motor

Claims (3)

[Claims] 1. A heat collector for collecting solar heat, a heat storage layer for storing heat by exchanging heat between supplied water and a heat medium heated by the heat collector, and storing a heat medium. An expansion tank, a heat medium circulation pump that circulates the heat medium of the expansion tank between the heat collector and the heat storage tank via a heat medium line,
In a solar heat collecting system comprising: between the outlet of the heat collector and the inlet of the expansion tank, the heat medium flow path in the heat medium line is narrowed as the temperature of the heat medium rises to reduce pressure loss. A solar heat collecting system, comprising: a heat-boiling prevention valve for increasing the temperature of the heat medium and widening the heat medium flow path in the heat medium line to reduce pressure loss as the temperature of the heat medium decreases. 2. The temperature sensing substance, wherein the heat boiling prevention valve is attached to the heat medium line, the volume of the heat medium is increased by melting as the temperature of the heat medium rises, and the volume is decreased by solidification as the temperature of the heat medium falls. And a cylinder connected to the case and having a fluid or semi-fluid sealed therein, sandwiched between the case and the cylinder, sealing the temperature sensing substance, A lid-like elastic body that transmits an increase or decrease in the volume of the temperature sensing substance to the fluid or semi-fluid; and a slidably supported guide portion in the cylinder, and a heat medium flow path in the heat medium line. A piston that reciprocates; a plug-like elastic member that is slidably fitted into the guide portion, seals the fluid or semi-fluid, and transmits movement of the fluid or semi-fluid in the guide portion to the piston. Body and
A temperature sensing unit comprising: a valve provided at an end on the traveling side of the piston, which narrows a heat medium flow path when the piston advances, and an urging means for urging the valve in a backward direction. The solar heat collecting system according to claim 1, comprising: 3. The heat-boiling prevention valve is provided in the heat medium flow path, and emits a heat medium temperature rise signal as the temperature of the heat medium rises, and emits a heat medium temperature decrease signal as the temperature of the heat medium falls. A temperature sensor, a motor attached to the heat medium line, and a rod of the motor being rotationally driven in a heat medium flow path in the heat medium line by the heat medium temperature rise signal from the temperature sensor. A control circuit for inverting and driving the rod by the heat medium temperature lowering signal, and a valve provided on the rod and narrowing the heat medium passage when the rod rotates. The solar heat collecting system according to claim 1.