JPS6014050A - Solar heat collecting apparatus - Google Patents

Abstract

PURPOSE:To enable to always obtain highly heated water even when solar radiation is low, although it is a small quantity, by constituting the secondary circuit of a heat exchanger which is provided to the outside of a storage tank by a heat pipe of looped type, and by carrying up heated water to the upper part only of a storage tank. CONSTITUTION:The solar heat absorbed by a heat collector 1 is heat-exchanged by a heat exchanger 4 provided to the outside of a storage tank 7, and the heat is transmitted into the storage tank 7. The inside of a storage tank 7 acts as a condenser 6, while the secondary circuit 4b of a heat exchanger 4 acts as an evaporator, as it is made of a heat pipe 5 of looped type. With such an arrangement, highly heated water only is carried up into the storage tank, so that hot water is obtainable even when solar radiation is low, although it is rather small quantity. Heat can be transmitted not depended on motor power, and hot water is not largely mixed with cold water. In addition, the secondary circuit of a heat exchanger rises in a short time, because it has small heat capacity. The coefficient of utilization to the collected heat energy is high.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a solar heat collector using a loop-type heat pipe.

Conventional Structure and Problems Conventionally, this type of solar heat collector has the structure shown in FIGS. 1 and 2. In the system shown in FIG. 1, solar heat obtained from a heat collector 1 is circulated through a primary hose 9 by a primary pump 2, and then transferred from a primary heat exchanger 4a to a secondary heat exchanger 4. Heat is conducted to the side heat exchanger 4b, and this is transferred to the secondary pump 5.
) The secondary hose 6 was passed through and guided into the heat storage tank 7. In this configuration, when a certain temperature difference occurs between the heat collector side temperature sensor Th18 and the heat storage tank side temperature sensor Th29 at the start of heat collection, the primary side pump 2 and the secondary side pump 5 are normally activated. If they are not operated at the same time, the low-temperature water in the secondary hose 6 will enter the heat storage tank 7, and if the circulation starts before the secondary heat exchanger 4b has reached a high temperature, the low-temperature water in the secondary hose 6 will enter the heat storage tank 7, and in some cases, In some cases, the temperature inside the heat storage tank 7 may be lowered. Especially in winter, when the outside temperature is low and the heat exchanger 4 and the secondary horn 6 are easily cooled, and the weather often changes from clear to cloudy, this type of solar heat collecting device The problem was that it was difficult to rise.

In addition, in the system shown in Fig. 2, heat is transferred by natural circulation on the secondary side, but circulation does not occur unless the inside of the heat exchanger 4 reaches -a certain temperature or higher, or heat transfer occurs during heat collection. When the hot water is discharged once, the cold water that entered the lower part of the heat storage tank 7 is
There is a problem in that the hot water that has been collected and stored is mixed with the cold water because it is lifted to the upper part of the heat storage tank 7 by the natural circulation on the next side.

In addition, in conventional systems, antifreeze can be used as the working fluid on the primary side, but in hot water systems, water is used on the secondary side, so there is a problem of freezing of the secondary piping system in cold winter regions. It was happening frequently.

Purpose of the Invention The present invention solves these conventional problems. Only high-temperature water is transported to the upper part of the heat storage tank, and a small amount of high-temperature water can be secured even during low solar radiation, and moreover, it can be carried out without power. It is an object of the present invention to provide a solar heat collecting device that can transport heat and is less likely to be mixed with cold water.

Structure of the Invention In order to achieve this object, the present invention comprises a loop-type heat pipe on the secondary side of a heat exchanger provided outside a heat storage tank.

According to this configuration, since heat is not transferred until the heat exchanger temperature becomes higher than the temperature inside the heat storage tank, cold water is not circulated to the upper part of the heat storage tank. In addition, since the heat capacity on the secondary side of the heat exchanger is small, the start-up is quick and the utilization rate of the collected heat energy is high. In addition, the secondary side of the heat exchanger operates by natural circulation and has self-control properties.Explanation of Embodiment In Fig. 3, 1 is a heat collector, 2 is a primary pump, 3 is a primary hose, 4 is a heat exchanger, 4a is a primary side heat exchanger, 4b
is the secondary side heat exchanger, and the evaporation part of the loop heat pipe 5, 6
is the same condensing section, 7 is the heat storage tank, 8 is the outlet, 9 is the water supply port, 1
0 is a heat collector temperature detector, 11 is a heat storage tank temperature detector 0 The heat collector 1 receives solar radiation, and the heat collector temperature detector 10 detects a temperature difference of more than a certain value from the heat storage tank temperature detector 11. When you realize it, 1
The next pump 2 starts operating.

Heat is transferred to the secondary side in the heat exchanger 4, and the working fluid sealed in the evaporation section 4b of the loop heat pipe 5 is heated. At this time, the evaporating section 4b is lower than the condensing section 6 of the loop heat pipe 5.
When the temperature reaches a high temperature, the working fluid vacuum-sealed in the loop heat pipe 5 begins to boil, and heat transfer to the heat storage tank 7 begins. Moreover, since heat exchange in the heat storage tank 7 is performed gradually downward from the top, high temperature heat is stored from the top of the heat storage tank.

Effects of the invention (1) In the case of weather where the presence or absence of solar radiation repeatedly occurs,
Even if the primary heat collection circuit operates, the loop-type upper-1 pipe will not operate unless the temperature inside the heat exchanger reaches or exceeds the temperature inside the heat storage tank.As in the conventional method, cold water during start-up is directed to the top of the heat storage tank. There is no chance that the hot water that has accumulated heat will warp and cool down.

(2) The internal volume of the evaporation part of the loop heat pipe can be reduced, and therefore the heat capacity can be reduced, which allows for faster startup and makes it possible to effectively utilize heat that was traditionally a dead area. (3) Since the secondary side of the heat exchanger is a non-powered heat transfer system that does not require a pump or the like, running costs can be reduced.

[Brief explanation of the drawing]

Figures 1 and 2 are configuration diagrams showing a conventional solar heat collector;
FIG. 3 is a configuration diagram 1 showing an embodiment of the solar heat collecting device according to the present invention. 1... Heat collector, 4... Heat exchanger, 4b
... Secondary heat exchanger, 7 ... Heat storage tank, 6.
...Name of agent of condensation department Patent attorney Satoshi Nakao
Male and 1 other personFigure 1Figure 2Figure 3

Claims (2)

[Claims] (1) The solar heat obtained by the heat collector is exchanged with a heat exchanger installed outside the heat storage tank and guided to the heat storage tank, and the secondary side of the heat exchanger is the evaporation part of a loop heat pipe, Solar heat collector surface with the inside of the heat storage tank as the condensing part. (2) The solar heat collecting device according to claim 1, wherein the heat exchanger is disposed below the bottom of the heat storage tank, and the amount of working fluid filled in the heat pipe is up to the upper part of the heat exchanger.