JPS60101451A - Solar heat collector - Google Patents

Abstract

PURPOSE:To enable to operate devices such as heat pump and the like with high efficiency regardless of insolation by a structure wherein an absorber pipe, in which outside air is selectively ventilated, is installed in the transparent tube of a solar heater. CONSTITUTION:An air duct consists in providing a group of a plurality of transparent tubes comprising glass tubes or transparent plastic tubes and a pair of header boxes 2a and 2b, each of which is arranged at one side of both sides of the group of the transparent tubes and on the respective end surface of which vent holes 3 are provided. A blower 4 is mounted in the header box 2b. A steel absorber pipe 5 is fitted in each transparent tube 1 so as to run in series along the center axis of the tube 1. Needle-shaped heat collecting fins 6 covered with black light absorbing film 7 are attached onto the absorber pipe 5 like quills of a hedgehog. When the sun shines, the blower 4 is in a standstill. The sunlight transmits through the upper part of the transparent tube 1 and strikes against the heat collecting fins 6 and is absorbed by the absorbing film 7 and finally is converted to heat. When the sun shines gently or no sun shines, the blower 4 is put into operation. The outside air is discharged by the blower 4 from the vent hole 3 of the header bos 2b. Accordingly, not only the changing-over from/ to the utilization of the solar heat to/from the utilization of the heat of the outside air but also the controlling of optimum amount of refrigerant are easily done by the starting and stopping of the blower 4.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a solar heat collector used as an evaporator in a direct expansion type solar heat pump device, etc. that performs hot water supply or space heating operation using solar heat and outside air heat as heat sources. be.

[Prior Art] Conventionally, there have been two types of saw 2-heat pump devices of this type. One type uses a bare type solar collector as an evaporator, and the solar collector consists only of heat collection fins and heat collection tubes, without an outer box or transparent cover. Also, there was no insulation material on the back side of the heat collecting fins, or if there was one, it was very simple. An absorbing film is applied to the surface of the heat collecting fin to better absorb sunlight. A compressor, a condenser, and an expansion valve are sequentially connected to this solar heat collector to form a refrigeration circuit. Additionally, a four-way valve, an accumulator, etc. are used as necessary.

Connecting the condenser to the hot water storage tank creates a hot water system.

By exchanging heat with indoor air using a blower, it becomes a heating system. Another type of system is a device that has both a solar collector for collecting solar heat and an outdoor coil for collecting outside air heat as an evaporator. The solar heat collector consists of an outer box, a transparent cover, an insulating moon, heat collection fins, and a heat collection tube, and the outdoor coil is a combination of a fin-tube heat exchanger and a blower. The solar collector and the outdoor coil are connected in parallel or series and are used selectively or simultaneously by a switching valve.1 Next, the operation of the device as described above will be explained.

First, in a solar heat pump device that uses a naked solar collector as an evaporator, the high temperature, high pressure refrigerant gas discharged from the compressor is used to heat indoor air or water in a hot water tank in a condenser, and then the pressure is reduced by an expansion valve. It becomes a low-temperature, low-pressure refrigerant liquid and enters the solar collector. When there is sufficient sunlight, the refrigerant liquid is heated and evaporated by the solar heat collected by the solar collector.

It changes into low temperature, low pressure refrigerant gas and returns to the compressor.

When there is little sunlight or at night, natural convection evaporates the refrigerant liquid that picks up heat from the outside air.

In addition, for solar heat pump equipment equipped with an evaporator consisting of a combination of a solar heat collector and an outdoor coil, use the solar heat collector when there is sufficient sunlight.

Also, when there is little sunlight, use the outdoor coil as an evaporator.
Absorbs solar heat and outside air heat.

Note that when the amount of solar radiation is intermediate, a solar collector and an outdoor coil may be used together.

The evaporator of a conventional solar heat pump device is constructed as described above, but the problem with heat pump devices that use solar heat and outside air heat as their heat sources is how to achieve low initial costs and operating costs. In general heat pump devices that use outside air as a heat source, the evaporation temperature is always set lower than the outside air temperature, so the lower the outside air temperature, the lower the coefficient of performance (cop).
) becomes small, and the ratio of electrical input per capacity becomes large, making it uneconomical. The purpose of combining solar heat with a heat pump is to use solar heat to raise the evaporation temperature and significantly improve the coefficient of performance. but.

Because solar heat and outdoor heat are both free energy.

The additional cost required to utilize solar heat must be fully recovered during the life of the kimono through the energy-saving cost due to the improvement in the coefficient of performance, and the relationship between the additional cost and the energy cost must be established.

Now, when a naked solar heat collector is used as an evaporator, since the collector is the only evaporator, there is no need for switching means for the refrigerant circuit, and the control means are simple, but since the collector is bare, heat is released during heat collection. There is a lot of loss, and this becomes more significant as the heat collection temperature (evaporation source #) increases. For example, if the heat collection temperature can be set 10 degrees higher than the outside air temperature, the coefficient of performance will greatly improve, but the heat collection efficiency of the bare collector will drop sharply. In order to secure a constant amount of heat in this temperature range, a large heat collection area is required, and the cost of bare collectors, which are cheap in unit price, increases overall, and the installation area must be widened. In addition, if the heat collection temperature is lowered to the outside temperature, the heat collection efficiency will be greatly improved, but the coefficient of performance will decrease, and there will be no point in using solar heat at a high cost. Furthermore, when the daily amount is low, such as in the morning and evening or on cloudy days, heat is absorbed from the outside air by natural convection, which causes poor heat transfer on the surface of the heat collection plate, which also has the disadvantage of requiring a large heat collection area. Ta.

In combination with solar collector and outdoor coil.

When there is sunlight, even if the heat collection temperature is set several degrees below the outside temperature, the solar heat collector maintains a sufficiently high heat collection efficiency because of the outer box and transparent cover. Also, when there is no sunlight, the outdoor coil can efficiently absorb outside air heat, similar to a general heat pump device. However, as an evaporator, an expensive collector and an outdoor coil must be installed separately, and problems such as IHJ issues regarding the installation location, complicated refrigeration piping, control of switching valves, and ensuring the optimum amount of refrigerant must be resolved. I encountered many problems.

[Synopsis of the invention]

The purpose of this invention is to eliminate the above-mentioned drawbacks of the conventional ones, and by installing a heat collecting tube inside a transparent tube and selectively ventilating outside air inside the tube, when sunlight hits,
The object of the present invention is to provide a compact solar heat collector that can operate a device such as a heat pump with high efficiency even when the solar heat pump is not in use.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a plan view of the collector, the second figure is a front view, and the third figure is an I
It is a sectional view taken along line ll-1. In these figures, (
1) are glass tubes or transparent plastic tubes; 2) are multiple transparent tubes with both ends open.

(2a) and (2b) are a pair of header boxes installed on both sides of these transparent tubes (11 m) to support the transparent tube (1) in a sealed manner.

(3) is a ventilation hole opened in each end face of the header boxes (2a) and (2b), and is provided on the side that will be downward when the collector is installed. (4) is a blower installed in one of the hetster lees (2b) facing the -1000 side of these ventilation holes (3).

(5) is a heat collecting tube made of a steel tube located along the center 111 of the transparent tube (1) and tracing each transparent tube (1) in one row;
(6) is a heat collecting fin consisting of a needle-shaped wrapped aluminum fin attached around this heat collecting pipe (5), (
7) is a black-painted sunlight absorption film applied to the surface of the heat collecting fin (6). Note that the transparent tube fi+ and the header boxes (2a) and (2b) constitute an air duct.

In addition, the dimensions of the heat collecting fins (6) can be determined based on the required surface area for collecting outside air heat and the required light receiving area for collecting solar heat, but it does not need to be too large. .

The solar heat collector configured as described above operates as a solar heat collector when there is sufficient solar radiation, and as an outside air heat collector when there is little solar radiation.

First, when there is sunlight, the blower (4) is stopped.

The sunlight passes through the upper part of the transparent tube 11+, and the heat collecting fins (6
) is absorbed by the absorption film (7) and converted into heat. This heat is transferred to the heat collecting tube (51) by thermal conduction.

The cold toad liquid flowing inside is heated to boiling and gasified. Therefore, solar heat is transferred to the refrigerant in the form of latent heat, and is sent to the condenser by the compressor (not shown in Figure 2), where it is used for hot water supply and I-wave protection. Heat collection 1 (5) and heat collection fins (6) as evaporators
) is surrounded by a transparent tube (1), so even if the heat collection temperature (evaporation temperature) becomes higher than the outside air, there is little heat radiation loss and it is possible to collect sunlight with a sufficiently high heat collection efficiency. It's nhi. In addition, there is some heat loss due to natural ventilation from the ventilation holes (3) provided in the header boxes (2a) and (2b), but the ventilation holes (3) face the same direction and the header boxes (7a) and ( 2b), the heat dissipation is small even through natural convection. Therefore, it is not necessary to have a large heat collecting area. The refrigerant liquid enters from one end of the heat collecting pipe (51) and flows through each heat collecting pipe (51) in a two-phase flow while evaporating quasi-j-order.
) directly to the exit.

Next, if the sunlight is weak or absent, turn on the ventilation fan (41).The outside air is sucked into the header box (2a) through the ventilation hole (31) and flows through each transparent tube (1) in parallel in the header box (2b). )
The air is discharged through the ventilation hole (3) through the air blower m141.

Outside air inside the transparent tube (1) flows between the needle-shaped heat collecting fins (6) and between the heat collecting fins (6) and the transparent tube (1).

At this time, the heat collecting pipe (5) was kept at an evaporation temperature lower than the outside temperature.
give heat to.

Therefore, unlike conventional devices, a collector and outdoor coil are not required, and the structure can be relatively simple, inexpensive, and compact.
Another advantage is that it is not only possible to switch between solar heat utilization and outside air heat use by simply turning on and off the feeder (4) without changing the refrigerant, but also that it is easy to control the optimum refrigerant.

In the above embodiment, the transparent tube 11+ was made to have a low speed all around the circumference, but in order to prevent the downward light %19, there is a reflective sharp or black absorbing material on the inside or outside 1 of the lower half of the transparent tube (1). By providing a membrane, sunlight can be used without waste. In order to utilize sunlight more effectively, it is recommended to provide a large reflecting plate below the group of transparent tubes (1). This reflecting plate may be a white painted plate that scatters and reflects light. Furthermore, it is also possible to individually focus light on one side of each transparent tube fi+ using a gutter-like reflective sharpening point.

Further, in the above embodiment, the a-cut tube fi+ is a simple cylinder, but in order to reduce the loss of heat 1b from the heat collecting fins (6), it is preferable to apply a heat insulating material to the inside or outside 1+In of the lower part of the transparent tube il+.

Generally speaking, in the above embodiment, the transparent material M7th is cylindrical, but if plastic is used for the material, the cross section can easily be made into a rectangular or elliptical shape, or the thickness of the solar collector can be made thinner. I can do it.

Now, in the above embodiment, the heat collecting fins (6) were made of aluminum needle-shaped wrapped fins, or plate fins or cut-and-raised fins were used to provide a heat transfer area on the air side and a sunlight receiving area. It may be. Furthermore, if a heat collecting fin (6) is provided also in the U-ben 1 portion of the heat collecting tube (5) located at Vc II+ in the header boxes (2a) and (2b), the heat transfer area on the air side can be further increased.

In the above embodiment, all the heat collecting pipes (5) are connected in series, but they may be connected in parallel if they are installed so that the refrigerant can be divided properly. Also, in the above embodiment, the air flow may be configured so that it flows in parallel to each transparent tube tl+, or in series if the pressure loss is not significantly reduced. good.

In the above embodiment, the through hole (3) is inserted into each box (
For 2a) and (2b), they were installed at the lower end when installing 111M, but they may be placed at another location where the heat loss due to natural circulation is less, or several pieces may be removed from the suction side. It's okay. However, to completely eliminate natural circulation, it is better to provide a ventilation hole t31K damper. Also a blower (4)
may be distributed among multiple units.

〔Effect of the invention〕

As described above, according to the present invention, a heat collection tube with heat collection fins as a heat collector (evaporator) for solar heat and outside air heat is arranged in a gust duct composed of a transparent pipe and a heat glaze. ,
Due to the simple, inexpensive and compact structure of installing the feeder inside the header box.

With a small number of solar heat collectors and without switching refrigerant circuits, it is possible to efficiently utilize solar heat at a high evaporation temperature (high base area coefficient) when there is sunlight, and by operating a blower when there is no sunlight. effective.

[Brief explanation of drawings]

Figure 1 is a laugh at this invention! i 1911 k A plan view showing the solar collector; Figure 2 is its side view; Figure 3 is its side view;
'The diagram is! It is an enlarged sectional view taken along the line Ill-III of Figure @1. 11+...Transparent tube, (2a), C2b')--Header box, (31 is ventilation hole, (4)...Blower, (5
)... Heat collecting pipe, (6)... Heat collecting fin. In each figure, the same reference numerals indicate the same or equivalent parts. Substitute Masuo Oiwa

Claims (1)

[Scope of claims] (2) A solar heat collector equipped with a heat collecting pipe arranged in each of the fins, and a blower provided in the header box and feeding outside air into the transparent pipe through the ventilation hole. The solar collector according to claim (1), characterized in that it has a wrapped fin.