JPS58160794A - Heat exchanger - Google Patents

Abstract

PURPOSE:To prevent a refrigerant that will come from a pipe line due to its damage from mixing with water, by winding a refrigerant condensing pipe helically around the outer circumference of a pipe with fins therein through which water flows, in a heat exchanger of a hot water service apparatus that utilizes solar heat by a heat pump. CONSTITUTION:A water heater 7 comprises a cylindrical pipe having a plurality of the vertical fins on the inner surface thereof, and an outer cylinder 8 is arranged around the water heater 7 with a certain distance between them. The lower open end formed by the water heater 7 and the outer cylinder 8 is closed by a closing cap 9. The refrigerant condenser 3 is wound helically around the outer circumference of the water heater 7, and a filler such as alumina, magnesia, or the like fills the circumference of the refrigerant condenser 3. The upper open end formed by the water heater 7 and the outer cylinder 8 is sealed with a sealer 11 such as epoxy resins. Thus, the refrigerant and water come in contact with each other with the double wall, that is, the condenser 3 and the water heater 7 therebetween.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger for a solar hot water supply system using a heat pump.

Conventional solar water heaters require a large collector area due to the dilution of solar radiation, and require transparent glass and heat insulating materials to effectively absorb solar radiation, making them heavy and expensive. There were certain drawbacks. Father, when there is no solar radiation, there is no heat collecting effect, so an auxiliary heat source is required, which has the disadvantage of increasing the cost of hot water supply equipment.

A solar hot water supply system using a heat pump may be considered as a solution to these drawbacks of conventional solar water supply systems.

That is, as shown in FIG. 1, there is a heat collecting circuit which sequentially connects a heat collector 1 consisting of a fin-tube heat exchanger, a compressor 2, a condenser 3, and an expansion valve 4, a hot water storage tank 6, and a heat exchanger. pong 6
, constitutes a water heating circuit formed by sequentially connecting water heaters 7,
The condenser 3 of the heat collection circuit and the water heater 7 of the water heating circuit are maintained in a heat transfer relationship. For example, as shown in Fig. 2, a double pipe is used, with the inner pipe serving as the refrigerant condenser 3 and the outer pipe as the water heater 7, or as shown in Fig. 3, flat pipes are installed side by side and both are connected by a lead dig or the like. This is a heat exchanger in which wire flat tubes are tightly fixed and one side is used as a refrigerant condenser 3 and the other side is used as a water heater 7.

In the solar water heating system having the above configuration, the compressor 2
The high-temperature, high-pressure discharged refrigerant gas compressed by the compressor flows into the condenser 3, radiates heat to the flowing water through the water heater element in a heat transfer relationship with the condenser 3, condenses and liquefies, and then passes through the expansion valve 4. The refrigerant is depressurized to a low temperature and low pressure, flows into the heat collector 1 constituted by a Finnerve heat exchanger, and evaporates, but the evaporation temperature of the refrigerant is set to be lower than the outside air temperature. Then, the refrigerant that has flowed into the heat collector 1 absorbs heat from the solar radiation and atmospheric heat and is evaporated and gasified, and flows into the compressor 2 again where it is compressed. The water in the hot water storage tank 6 is sent to the water heater 7 by the water circulation pump 6, heated and heated by the latent heat of condensation of the refrigerant (as described above), and is stored in the hot water storage tank 7.

As described above, according to the solar heat water heater using a heat pump, since the heat collector absorbs not only solar heat but also atmospheric heat, it is possible to increase the amount of collected heat by enabling heat collecting operation even when there is no sunlight.

In addition, the heat collector is composed of a Finnerp heat exchanger, which eliminates the need for transparent glass and heat insulating material, and has the advantage of being smaller and lighter.

However, one of the problems with the solar hot water supply system using a heat pump is the heat exchange section between the condenser 3 and the water heater 7. That is, in a double tube heat exchanger as shown in FIG. 2, where the inner tube is used as a condenser 3 to flow the refrigerant and the outer tube is used as the water heater 7 to flow water, the inner tube (condenser 3
) is damaged, the pressure of the refrigerant is high, so there is a problem that the refrigerant and refrigeration oil mix into the outer pipe (water heater 7) and contaminate the hot water supply.

In addition, in a double-wall heat exchanger in which flat tubes as shown in Fig. 6 are arranged side by side, both hot tubes are fixed with lead dip, etc., and the refrigerant is passed through one flat tube and water is allowed to flow through the other. Even if the condenser 3 is damaged, it is possible to prevent refrigerant and refrigeration oil from entering the water heater 7. However, flat tube processing is necessary, and high-precision flat tube processing is indispensable in order to increase the degree of adhesion between both warm and flat tubes. It has drawbacks such as difficulty in subsequent processing and the need for lead dip treatment after secondary processing to obtain a predetermined shape, making it difficult to process and expensive.

The present invention relates to a heat exchanger between condensed refrigerant and water in a solar hot water supply system using a heat pump, and its purpose is to ensure that even if the pipes through which the refrigerant flows are damaged, the refrigerant and refrigerating machine oil will remain intact. To prevent contamination with hot water supply water, to maintain a good heat transfer relationship between a condenser and a water heater, and to manufacture it at low cost.

In order to achieve the above object, the present invention is characterized by:
A certain gap is provided on the outer periphery of the cylindrical tube through which one of the fluids flows, and an outer tube is provided, and the upper and lower opening ends of the cylindrical gap formed by the cylindrical tube and the outer tube are closed with closing caps. The purpose of this method is to form a closed space, allow a pipe line through which another fluid flows into the closed space, and fill the gap with alumina, magnesia, etc.

In the heat exchanger of the present invention, the pipe through which the hot water flows and the pipe through which the refrigerant flows have double pipe walls, so that even if the pipe through which the refrigerant flows is damaged, the refrigerant will still flow. It does not mix with the hot water supply, and contamination of the hot water supply water can be prevented.

The pipes through which the hot water flows and the refrigerant pipes conduct heat through the alumina or magnesia filler, which has the same thermal conductivity as solder, so good heat transfer can be achieved.

The pipes through which the hot water flows and the pipes through which the refrigerant flows have the advantage that they do not require flattening or the like and can be manufactured at low cost.

Examples of the heat exchanger of the present invention will be described below with reference to FIGS. 4 and 6.

7 is a water heater made of a cylindrical tube with a plurality of vertical fins on its inner surface. 8 is the cylindrical tube (water heater 7)
It is an outer cylinder positioned with a certain gap around the outer periphery of the cylinder. 9
is a closing cap that closes the lower open end formed by the water heater 7 and the outer cylinder 8. Reference numeral 3 denotes a refrigerant condenser pipe, which is wound in a spiral shape along the outer periphery of the water heater 7. 10 is a filler such as alumina or magnesia. Reference numeral 11 denotes a sealant for sealing the upper open end formed by the water heater 7 and the outer cylinder 8, and is made of epoxy resin or the like.

In addition to alumina and magnesia, the filler may also be sintered alloy powder or the like.

According to the heat exchanger according to the embodiment of the present invention, the refrigerant and water are in contact with each other through the double wall surface of the condenser pipe and the internally finned pipe, so it is difficult to damage the high-pressure refrigerant condensing pipe. Also, refrigerant and freezing machine oil do not mix with hot water supply,
Contamination of the hot water supply water can be prevented. 6. The inner finned tube through which the water flows and the refrigerant condenser are made of alumina, magnesia, etc., which have a thermal conductivity similar to that of solder, i.e., the former has 70 x 10 cal/℃・・Toyo latter is 86
X10-3cal/1::-c+n-5ec, which allows good heat exchange between the refrigerant and water.

A certain gap is provided on the outer periphery of the inner finned tube, an outer cylinder is positioned, the lower open end of the space formed by the outer periphery of the inner finned tube and the outer cylinder is closed with a closing cap, and then the refrigerant is poured into the space. Peek into the condensation pipe, fill the gap with alumina, magnesia, etc. 2, and seal the upper opening end with epoxy resin.

It is easy to assemble and can be manufactured at low cost.

As explained above, the present invention provides a certain gap in the conduit through which one fluid flows, positions the outer cylinder, and connects the conduit through which the other fluid flows into this gap using alumina.

By maintaining a heat conductive relationship through a filler such as magnesia, the pipes in which the refrigerant flows and the pipes in which the hot water flows (/12) are in contact with each other with a double pipe wall, so in the unlikely event that the refrigerant flows Even if the piping is damaged, refrigerant and freezing machine oil will not mix into the hot water supply.

The pipes through which the hot water flows and the pipes through which the refrigerant flows conduct heat through fillers such as alumina and magcia.
Since the entire surface area of each conduit is in contact with the filler, good heat transfer is achieved.

In addition, since the filler is not fixed to each fluid pipe, it is strong against repeated thermal loads and does not cause cracks in the joints and reduce heat conduction when subjected to repeated thermal loads such as in the case of soldering. There are advantages such as being able to maintain a good heat conduction relationship over a long period of time.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of the hot water supply system, Figure 2 is a sectional view of a double tube heat exchanger, Figure 3 is a sectional view of a double wall heat exchanger, and Figure 4 is a sectional view of a double wall heat exchanger.
The figure is a plan sectional view of the heat exchanger of the present invention. FIG. 6 is a longitudinal sectional view of the heat exchanger of the present invention. 1... Heat collector, 2... Compressor, 3...
...Condenser, 4...Expansion valve, 6...
・Hot water tank, 6...Water circulation pump, 7...
Water heater, 8...Outer cylinder, 9...Closing cap, 10...Filling time], 1190000
．． Sealant. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] An outer cylinder is provided with a certain gap around the outer periphery of the cylinder through which one fluid flows, an open end of the gap is closed to form a sealed space, and a pipe line through which the other fluid flows A heat exchanger filled with alumina magnesia, etc.