JPH05280820A - Absorption refrigeration system - Google Patents

Abstract

PURPOSE:To reduce a circulating power when absorption heat is utilized for heating absorption liquid at a generating device in order to improve efficiency. CONSTITUTION:A heat pipe structure is utilized as a heat transmitting means between an absorber 4 and the generator (or a heat exchanger for heating absorption liquid). In this case, when a heat pipe 70 having no wick is used, it is necessary to place the absorption device at a high position and there occurs a certain restriction in its arrangement. However, its cost is less expensive. In turn, in the case that a heat pipe having a wick is utilized, its cost is increased. However, degree of freedom in installation becomes high. In addition, in the case that a plurality of heat pipes are utilized, their efficiencies are increased in reference to their positional relationships to each other. Accordingly, a circulating power for the thermal medium becomes unnecessary, heat transferring characteristics between the absorber and the generator (or a heat exchanger for heating absorption liquid) is improved and then an efficiency (COP) of the absorption cooling or heating machine is increased. In addition, in the case that a plurality of heat pipes are used, a temperature distribution is easily generated at the absorption device, resulting in that absorption efficiency is increased and so the size of the absorber can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigeration system equipped with an absorber and a generator.

[0002]

2. Description of the Related Art An absorption refrigerating apparatus is equipped with an absorber, and the refrigeration is performed by absorbing vapor when a refrigerant is evaporated by using an absorbent. Therefore, there is no restriction on the installation location. Further, it has an advantage that it consumes little power and can utilize exhaust heat of steam, hot water, and the like.

Therefore, recently, the absorption type refrigerating apparatus has been used as a refrigerating machine for air conditioning.

By the way, in the apparatus, for example, water-
In the case of an ammonia-based device, the amount of steam contained in the ammonia gas that is heated and evaporated and that flows from the generator to the condenser decreases the enthalpy of the ammonia gas that exits the evaporator, and the refrigeration Since the capacity is reduced and the efficiency is deteriorated, it is originally necessary to allow 100% ammonia gas to flow into the condenser.

Therefore, for that purpose, a rectifier is usually installed in the generator to cool the ammonia gas to condense water, or alternatively, the concentrated solution is allowed to flow down from the upper part of the rectifier, and the lower part is further lowered. In this method, a part of the liquefied refrigerant is returned from the liquid receiver, and the liquefied refrigerant is allowed to flow down through the rectifier to remove water vapor from the ammonia vapor.

An absorption type refrigerating apparatus in which a rectifying section is provided in the generator as described above has been conventionally known (for example, Japanese Patent Application Laid-Open No. 4 (1999) -58,961).
9-88778).

[0007]

By the way, in the absorption type refrigerating apparatus having the above-mentioned structure, the heating efficiency in the generator decreases as the number of stages of the rectifier increases, and the temperature rises as it goes upward. descend. Therefore, in general, its cooling and heating efficiency
For the purpose of improving (COP), a dedicated refrigerant circuit is provided between the absorber and the generator to circulate the heat medium, and heat generated by the absorbing action in the absorber is used to heat the absorbing liquid in the generator. A heat transfer system that makes effective use is adopted.

However, in the heat transfer system, a considerably large circulating power is required to circulate the heat medium, and the cost is high.

[0009]

Claims 1 and 2 of the present application
The inventions described are intended to solve the above problems, and are configured as follows.

(1) Structure of the Invention According to Claim 1 The absorption refrigerating apparatus according to the invention described in claim 1 comprises a heating means (1
9), a generator (1) that is heated by the heating means (19) to generate a working fluid vapor (G) from a mixed working fluid of a refrigerant and an absorbent, and a condenser (condensed to condense the working fluid vapor). 2) and
Evaporator for evaporating the working fluid condensed in the condenser (2)
A generator (1) in an absorption refrigeration system comprising: (3) and an absorber (4) that absorbs the refrigerant vapor evaporated in the evaporator (3) into a working fluid. ) And generator (1)
Are connected by a heat pipe (70) so that the absorbed heat of the absorber (4) is transferred to the generator (1).

(2) Structure of the invention according to claim 2 The absorption refrigeration system of the invention according to claim 2 is the above-mentioned claim 1.
The heat pipe (70) in the configuration of the absorption refrigeration system of the invention described is a plurality of heat pipes (71), (72),
It is characterized by being composed of (73).

[0012]

The absorption type refrigerating apparatus of the present invention according to claims 1 and 2 of the present application is configured as described above, and as a result, the following operation is achieved corresponding to each configuration.

(1) Operation of the absorption type refrigeration system of the invention described in claim 1 In the absorption type refrigeration system of the invention described in claim 1, as described above, the absorber and the generator are connected by a heat pipe, and heat transfer is performed. Is supposed to do.

Therefore, the absorbed heat can be transferred to the generator side to heat the absorbing liquid without requiring any driving force.

In this case, for example, if a heat pipe without a wick is used, it is necessary to place the absorber side at a high position and the arrangement is restricted, but the cost is low. On the other hand, using a heat pipe with a wick increases the cost but increases the degree of freedom in arrangement.

(2) Operation of the absorption refrigeration system of the invention described in claim 2 In the absorption refrigeration system of the invention described in claim 2, a plurality of heat pipes are provided in the absorption refrigeration system of the invention described in claim 1. It consists of

As a result, the temperature distribution is likely to occur in the absorber and the absorption efficiency is improved.

[0018]

Therefore, according to the present invention, the absorption heat of the absorber can be utilized for heating the absorbing liquid without circulating the heat medium, and the circulation power is unnecessary.

Further, in particular, as in the invention described in claim 2,
If a plurality of heat pipes are used, the temperature distribution is likely to occur in the absorber, and the absorption efficiency is increased. As a result, there is an advantage that the absorber can be downsized.

[0020]

1 to 3 show an absorption type refrigerating apparatus according to an embodiment of the present invention.

First, FIGS. 2 and 3 show circuit configurations of a solution and a refrigerant in the absorption type refrigerating apparatus. 2 and 3, reference numeral 1 is a generator, 2 is a condenser during the cooling operation shown in FIG. 2, and is a first heat exchanger that serves as an evaporator during the heating operation shown in FIG. 3, and 3 is also during the cooling operation. The second heat exchangers 4 that serve as evaporators and condensers during heating operation are absorbers.

By the way, although the principle of the absorption refrigeration cycle itself is already well known, the following briefly describes how the refrigeration cycle is executed in the absorption refrigeration apparatus of FIGS. 2 and 3. explain.

First, the cooling operation shown in FIG. 2 will be described. When the working fluid (ammonia aqueous solution in this embodiment) is heated by the heater (burner) 19 in the generator 1 during the cooling operation, a refrigerant ( A mixed vapor of (ammonia) and an absorbing liquid (water) is generated, and the mixed vapor rises through the rectifier section 13 formed in the container 11 of the generator 1.

In the rectification section 13, tray-shaped liquid storage sections D _{1 to} D ₄ having an appropriate number of steps (4 steps in this embodiment) are formed, and are supplied to the generator 1 from the absorber 4 side described later. The working fluid Bc to be stored is sequentially stored from the uppermost liquid storage portion D ₄ to the lower liquid storage portions D ₃ and D.
It is designed to flow down to ₂ , D ₁ .

In the rectifier section 13, every time the mixed vapor of ammonia and water rising from below passes through each storage rack (D _{1 to} D ₄ ), the temperature drop and the contact with the concentrated solution from above. The concentration of ammonia in the mixed vapor is increased by and, and the ammonia-water mixed vapor concentrated in the rectification unit 13 is further separated in the upper dephlegmator unit 14 to have about 99.8% ammonia. It becomes gas (gas refrigerant). This gas refrigerant is
In the figure, as shown by the arrows A ₁₁ and A ₁₂ , it is supplied to the first heat exchanger 2 which serves as a condenser through the first four-way switching valve 31. In the first heat exchanger 2, the air is cooled by the fan 68 to release the heat of condensation and the ammonia gas is liquefied to become ammonia liquid (liquid refrigerant).

This liquid refrigerant passes through the inter-refrigerant heat exchanger 32 as shown by arrow A ₁₃ in FIG. 2 and is decompressed by the decompressor 33, and then the second heat exchanger (evaporator) having the double pipe structure. In 3, the heat is exchanged with the circulating water from the indoor unit (circulating and circulating in the circulating water piping 35) to evaporate (the circulating water is cooled and becomes a cooling heat source for cooling), and is again used as a gas refrigerant (ammonia gas). Become. This gas refrigerant is sent to the inter-refrigerant heat exchanger 32 through the second four-way switching valve 36 as shown by an arrow A ₁₄ in FIG. 2, where the liquid refrigerant from the heat exchanger 2 (in the coil 32C). Through the first four-way switching valve 31 and the second four-way switching valve 36 (arrows A ₁₅ , A in FIG. 2).
₁₆ ), and is sent to the absorber 4.

The absorber 4 serves to absorb the gas refrigerant again into the working fluid supplied from the generator 1, and carries out the same action in the following manner.

That is, a sprayer 42 of the working liquid is provided at the uppermost stage in the container 41 of the absorber 4, and the vapor generation of the generator ₁ is indicated by the arrow L ₁ with respect to the sprayer 42. The working liquid (3% dilute solution) Ba is supplied from the section 12 through the heat exchanger 27 in the rectifier and the pressure reducer 28. This dilute solution Ba
Absorbs the gas refrigerant that has been sprayed from the sprayer 42 in the absorber container 41 and is supplied into the absorber container 41, and falls into the container bottom liquid pool 49.

The working liquid (concentrated solution) Bc stored in the container bottom liquid pool 49 is pressure-fed by the pump 51 as indicated by arrows L ₂ and L ₃ in FIG. 29
After being heat-exchanged (heat-absorbed) in, the liquid is supplied to the next-stage liquid storage shelf D ₃ in the generator 1.

On the other hand, reference numeral 70 indicates a heat pipe section for transmitting absorption heat generated in the absorber 4 to the side of the generator 1. The heat pipe section 70 includes a plurality of first to third plurality as shown in FIG. Heat pipes 71 to 73, and the first to third heat pipes 71, 72, 73 are respectively connected to one end 71a, 7
2a and 73a are inserted and arranged in the upper surface portions of the second, third and fourth liquid storage shelves D ₂ , D ₃ and D ₄ of the generator 1,
Further, the other ends 71b, 72b, 73b are placed in the container 41 of the absorber 4 with different heights in the vertical direction with the positional relationship opposite to that of the generator 1 side. A large number of fins 74, 74 ..., 75, 75 ... Are provided in each insertion portion. In the heat pipes 71, 72, 73,
The specified working fluid has been delivered.

Therefore, the absorbed heat generated when the gas refrigerant is absorbed in the working fluid in the absorber 4 passes through the heat pipes 71, 72, 73 and the liquid storage shelves D ₂ in the generator 1 are transferred. , D ₃ , D ₄ are efficiently transmitted to the working fluid, and the working fluid is effectively heated.

As a result, the heating degree of the working fluid is further improved,
Eventually, the heating and cooling efficiency will be improved.

Moreover, as described above, the heat pipe portion 70
Considering the temperature distribution of the working fluid in the absorber 4 and the temperature distribution of the liquid storage portions D _{2 to} D ₄ in the generator 1, the first to the first are connected and arranged so that a sufficient temperature gradient can be obtained. Since it is composed of the third plurality of heat pipes 71, 72, 73,
In particular, since an appropriate temperature distribution is generated in the absorber 4 and the absorption efficiency is increased, the absorber 4 can be downsized.

Incidentally, two three-way switching valves 62, 63 are provided in the cooling water piping 60, and by switching the three-way switching valves 62, 63, the radiator 5 and the third absorber The cooling water piping 60 with the heat exchanger 48 is opened and closed.

Next, the heating operation shown in FIG. 3 will be described. During the heating operation, first, the first and second four-way switching valves 31, 3 of the refrigeration circuit in the cooling operation shown in FIG.
6 is switched, and the flow direction of the gas refrigerant (ammonia gas) flowing through the refrigeration circuit is switched (arrows A _{21 to} A ₂₈ ).
At the same time, the two three-way switching valves 62, 63 in the cooling water pipe line 60 are switched, and the cooling water flow between the radiator 5 and the third heat exchanger 48 in the absorber is cut off. instead, by switching the three-way valve 61 in the circulation water pipe passage 35, the third absorber in the heat exchanger 48 is connected to the circulating water pipe passage 35 (arrow C ₂₂ ~C _23).

In the refrigeration circuit of FIG. 3, the gas refrigerant (concentration 99.8%) generated in the dephlegmator section 14 of the generator 1 has a first four-way switching valve as indicated by arrows A _{21 to} A _23. 31 and second
Flows into the second heat exchanger 3 acting as a condenser through the four-way switching valve 36, and is condensed there by exchanging heat with the circulating water supplied from the indoor unit through the circulating water piping 35. .. The circulating water is heated by this and becomes a heat source for heating in the indoor unit. In this embodiment, the circulating water to the indoor unit, by switching the three-way switching valve 61, 62 and 63, first arrows C _22, first as shown by C ₂₃ 3 of the absorber in the heat exchanger 48 After exiting, the gas is returned to the indoor unit through the second heat exchanger 3 serving as a condenser. That is, in the absorption refrigeration system of FIG. 3, during the heating operation, the heat of absorption is obtained by the heat exchanger 48 in the third absorber and the heat of condensation obtained by the second heat exchanger 3. ..

The refrigerant liquefied in the second heat exchanger 3 acting as a condenser is decompressed by the decompressor 33 as shown by an arrow A ₂₄ , and then the first heat exchanger 2 acting as an evaporator.
Is evaporated (air heat exchange evaporation by the fan 68), and further supplied to the absorber 4 via the first four-way switching valve 31, the inter-refrigerant heat exchanger 32, and the second four-way switching valve 36 (arrow A). ₂₅ ~ A
₂₈ ).

The generation, rectification and partial condensation of the water-ammonia mixed vapor in the generator 1 and the absorption of the ammonia gas refrigerant in the absorber 4 are the same as in the cooling operation shown in FIG. The flow of the working fluid (concentrated solution and dilute solution) during that time is also the same as in the case of FIG.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a main part of an absorption refrigerating apparatus according to an embodiment of the present invention.

FIG. 2 is a refrigeration circuit diagram showing a refrigeration cycle during a cooling operation of the device.

FIG. 3 is a refrigeration circuit diagram showing a refrigeration cycle during the heating operation of the device.

[Explanation of symbols]

1 is a generator, 2 is a first heat exchanger, 3 is a second heat exchanger, 4 is an absorber, 11 is a container, 13 is a rectifier section, 71-
73 is the first to third heat pipes, and 74 and 75 are fins.

Claims (2)

[Claims] 1. A heating means (19), a generator (1) which is heated by the heating means (19) to generate a working fluid vapor (G) from a working fluid mixed with a refrigerant and an absorbent, and the above-mentioned operation. A condenser (2) for condensing the liquid vapor, an evaporator (3) for evaporating the working liquid condensed by the condenser (2), and a refrigerant vapor evaporated by the evaporator (3) in the working liquid. In a generator (1) in an absorption refrigeration system comprising an absorber (4) for absorbing, the absorber (4) and the generator (1) are connected by a heat pipe (70), An absorption type refrigeration system characterized in that the absorption heat of (4) is transferred to a generator (1). 2. The absorption refrigerating apparatus according to claim 1, wherein the heat pipe (70) comprises a plurality of heat pipes (71), (72), (73).