JPH05272848A - Absorption type refrigerator - Google Patents

Abstract

PURPOSE:To continue heating operation even during defrosting operation by composing a heat source side heat exchanger and a heat exchanger for dissipating heat of cross fin coils sharing fins and flowing warm water through the heat exchanger for dissipating heat as a refrigerating cycle remains to be a heating cycle at the time of defrosting operation. CONSTITUTION:A heat source side heat exchanger 2 and a heat exchanger 5 for dissipating heat are constituted of cross fin coils sharing fins 71. In defrosting operation, a pump 53 is operated as a refrigerating cycle remains to be a heating cycle, and the heat exchanger 5 for dissipating heat is supplied with warm water, which absorbs the heat of absorption in a heat exchanger 48 in an absorber for cooling and a temperature of which is elevated. Consequently, heat is transmitted to the heat source side heat exchanger 2 side through the shared fins 71, and attached frost is melted. Accordingly, heating operation can be continued even during defrosting operation, thus improving accumulated heating capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-ammonia type or water-lithium bromide type absorption refrigerating apparatus.

[0002]

2. Description of the Related Art Absorption refrigeration systems are well known in the prior art. For example, in the case of water-ammonia absorption refrigeration system,
A generator for generating a high-concentration ammonia gas, a condenser for condensing the ammonia gas obtained by the generator, an evaporator for evaporating the ammonia liquid obtained in the condenser, and an evaporator for the evaporator. And an absorber that absorbs the ammonia gas thus obtained into a diluted ammonia solution.

By the way, as the absorption type refrigerating apparatus having the above-mentioned structure which can be used for both cooling and heating, a refrigerant (that is, ammonia) flowing through a generator, a condenser, an evaporator and an absorber is used. There is a method of switching the distribution direction of the reverse direction (for example, JP-A-2-251).
061).

[0004]

When an air-cooled heat exchanger is used as the heat source side heat exchanger in the absorption refrigeration system, it functions as an evaporator during heating operation due to a decrease in outside air temperature and the like. Frost may form on the heat source side heat exchanger. When such frost formation occurs, the heat transfer capacity of the heat exchanger decreases, and the required refrigerating capacity cannot be obtained. Therefore, the defrost operation for removing the frost formation is executed.

The defrosting operation is usually performed by switching the refrigerant circulation direction in the refrigerant cycle to the opposite direction (that is, the cooling operation cycle), but the heating operation cannot be performed during the defrosting operation. There is a problem that the integrated heating capacity decreases.

The present invention has been made in view of the above points, and an object thereof is to make it possible to continue the heating operation even during the defrost operation.

[0007]

In the present invention, as means for solving the above-mentioned problems, as shown in the drawings, the generator 1 acts as a condenser during cooling operation and as an evaporator during heating operation. Air-cooled heat source side heat exchanger 2
And a use-side heat exchanger 3 that acts as an evaporator during cooling operation and a condenser during heating operation, and an absorber 4
An air-cooling type heat-radiating heat exchanger 5 for radiating the absorbed heat generated in the absorber 4 to the outside air is attached to the refrigerant cycle consisting of and, and in the use-side heat exchanger 3, a circulating refrigerant and a use-side heat medium In the absorption refrigeration apparatus configured to exchange heat with each other, the heat source side heat exchanger 2 and the heat radiating heat exchanger 5 are constituted by a cross fin coil sharing the fins 71, 71 ,. In the above, the hot water is circulated to the heat radiating heat exchanger 5 while the refrigerant cycle is the heating cycle.

[0008]

In the present invention, the following actions are obtained by the above means.

That is, when frost forms on the heat source side heat exchanger 2 during the heating operation, a defrost operation for removing the frost on the heat source side heat exchanger 2 is performed. At this time, the refrigerant cycle is the heating cycle. Since the hot water is circulated through the heat radiating heat exchanger 5 that is left as it is and is integrated with the heat source side heat exchanger 2, the fins 71, The frost will be melted by the heat transferred via 71 ... Therefore, it becomes possible to continue the heating operation even during the defrost operation.

[0010]

According to the present invention, the generator 1, the air-cooling type heat source side heat exchanger 2 that acts as a condenser during the cooling operation and the evaporator during the heating operation, and the evaporator as the evaporator during the cooling operation. An air-cooling type heat exchange for heat radiation that radiates the absorbed heat generated in the absorber 4 to the outside air in the refrigerant cycle consisting of the utilization side heat exchanger 3 that acts as a condenser during heating operation and the absorber 4 An absorption type refrigerating apparatus, which is provided with a heat exchanger 5 and is configured to exchange heat between a circulating refrigerant and a use side heat medium in the use side heat exchanger 3, the heat source side heat exchanger 2 and a heat radiating heat exchanger. 5 and fins 71,
71 ... Is shared by a cross fin coil, and hot water is circulated to the heat radiating heat exchanger 5 while the refrigerant cycle is a heating cycle during the defrost operation, so that the refrigerant can be used even when the defrost operation is started. The heat exchange for heat dissipation 5 while keeping the cycle as a heating cycle
Since the heat transmitted from the heat exchanger 2 to the heat source side heat exchanger 2 via the fins 71, 71 ...
The heating operation can be continued even during the defrosting operation, and there is an excellent effect that the integrated heating capacity can be significantly improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 FIGS. 1 and 2 are circuit configuration diagrams of an absorption refrigerating apparatus according to Embodiment 1 of the present invention.

The absorption refrigerating apparatus of this embodiment is of a water-ammonia type, and reference numeral 1 is a generator for generating ammonia gas, 2 is a condenser during cooling operation, and is an evaporator during heating operation. The air-cooling type heat source side heat exchanger 3 that acts as a heat source side heat exchanger acts as an evaporator during the cooling operation, and the utilization side heat exchanger 4 that acts as a condenser during the heating operation indicates an absorber.

By the way, since the principle of the absorption refrigeration cycle itself is already well known, how the refrigeration cycle is executed in the absorption refrigeration apparatus of FIGS. 1 and 2 will be briefly described below. ..

(I) During cooling operation (see FIG. 1) The generator 1 comprises a steam generator 1 in a container 11 in order from the bottom.
2, is provided with a rectifying section 13 and a dividing section 14,
The container 11 is heated by a heating means (burner in this embodiment) 19.
When the working fluid (ammonia aqueous solution in this embodiment) stored in the vapor generating part 12 formed at the bottom of the working fluid is heated, a mixed vapor of a refrigerant (ammonia) and an absorbing liquid (water) is generated from the working fluid. The mixed vapor rises through the rectifying section 13.

In this rectification section 13, liquid storage sections D _{1 to} D _{5 of} an appropriate number of stages (five in this embodiment) are formed, and the operation is to be supplied to the generator 1 from the absorber 4 side described later. The liquid (that is, the concentrated ammonia solution) Bc is made to flow from the upper liquid storage portion D ₅ to the lower liquid storage portions D ₄ , D ₃ , D ₂ , and D _{1 in} sequence.

In the rectifying section 13, every time the mixed vapor of ammonia and water rising from below passes through each storage rack (D _{1 to} D ₅ ), the temperature drop and the ammonia-rich solution from above are generated. Upon contact, the ammonia concentration in the same mixed vapor rises, and the ammonia-water mixed vapor concentrated in the rectifying section 13 is further separated in the upper partial condenser section (details will be described later) 14
The water is separated by and becomes about 99.8% ammonia gas (gas refrigerant). This gas refrigerant is indicated by arrows A ₁₁ and A ₁₂ in FIG.
As shown in (1), it is supplied to the heat source side heat exchanger 2 acting as a condenser through the first four-way switching valve 31. In the heat source side 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 a heat exchanger between refrigerants (details will be described later) 32 as shown by an arrow A ₁₃ in FIG. 1 and is decompressed by a capillary tube 33 acting as a decompression means, and then has a double pipe structure. In the use side heat exchanger (acting as an evaporator) 3, the heat and the use side heat medium (in this embodiment, water) supplied from the indoor unit through the use side heat medium flow path 35 by driving the pump 52. The gas is exchanged and evaporated (water is cooled to serve as a cooling heat source for cooling), and becomes gas refrigerant (ammonia gas) again. This gas refrigerant is sent to the above-mentioned inter-refrigerant heat exchanger 32 through the second four-way switching valve 36 as shown by an arrow A ₁₄ in FIG. 1, and the liquid refrigerant from the heat source side heat exchanger 2 is there.
After pre-cooling (passing through the coil 32C), the first four-way switching valve 31 and the second four-way switching valve 36 described above are used (see FIG. 1).
The arrows A ₁₅ and A _{16 in the} inside are fed 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 fluid is provided at the uppermost stage in the container 41 of the absorber 4, and the steam generation of the generator ₁ is indicated by the arrow L ₁ with respect to the sprayer 42. The working liquid (3% ammonia dilute solution) Ba is supplied from the part 12 through the heat exchanger 27 in the rectification part and the capillary tube 28 which functions as a pressure reducing means. This diluted ammonia solution Ba is sprayed from the sprayer 42 in the absorber container 41,
The gas refrigerant supplied from the utilization side heat exchanger 3 into the absorber container 41 is absorbed and dropped into the container bottom liquid pool 49.

The working liquid (concentrated ammonia solution) Bc stored in the liquid reservoir 49 at the bottom of the container is supplied by a pump 51 as shown in FIG.
After being pressure-fed as indicated by arrows L ₂ , L ₃ , L ₄ , and L ₅ in the middle, heat is exchanged (heat absorption) by the heat exchanger 29 in the partial condenser heat exchanger 29 and the heat exchanger 46 in the heat recovery absorber during that time, It is supplied to the uppermost liquid storage shelf D ₅ in the generator 1.

(II) During heating operation (see FIG. 2) Of the refrigeration circuit during cooling operation shown in FIG. 1, the first and second four-way switching valves 31 and 36 are switched and flow through the refrigeration circuit. The flow direction of the gas refrigerant (ammonia gas) is switched (arrows A _{21 to} A ₂₈ ).

Then, the gas refrigerant (concentration 99.8%) generated in the partial condensing unit 14 of the generator 1 has a first four-way switching valve 31 and a second four-way switching valve as shown by arrows A _{21 to} A _23. The heat exchanger 3 flows through the switching valve 36 and flows into the heat exchanger 3 on the side that acts as a condenser. Here, the heat medium on the user side (water ) And heat and condense. The water is heated by this, and becomes a heat source for heating in the indoor unit.

The refrigerant liquefied in the use side heat exchanger 3 is
After being decompressed by the capillary tube 33 as shown by an arrow A ₂₄ , it is evaporated by the heat source side heat exchanger 2 acting as an evaporator, and further, the first four-way switching valve 31 and the inter-refrigerant heat exchanger 3
2, supplied to the absorber 4 via the second four-way switching valve 36
(Arrows A _{25 to} 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. Further, the flow of the working liquid (concentrated ammonia solution and diluted ammonia solution) during that time is also the same as in the case of FIG. 1, and therefore its explanation is omitted.

In this embodiment, however, the heat exchanger internal heat exchanger 46 for heat recovery (a part of the absorption heat generated in the absorber 4 is recovered in the working fluid) in the absorber 4. In addition to the heat exchanger for
Further, an in-absorber heat exchanger 48 for cooling is provided.

The inlet side and the outlet side of the heating absorber internal heat exchanger 47 are branched from the use side heat medium flow passage 35 at the inlet side of the use side heat exchanger 3 via a three-way switching valve 61. The branched outbound path 64a and the branched inbound path 64b that join the downstream side of the three-way switching valve 61 are connected to each other. The three-way switching valve 61 is used for the branch outward path 6 during the cooling operation.
The 4a side is closed and the branch outward path 64a side is controlled to be open during the heating operation. In other words, the heat exchanger in the heating heat exchanger 47 operates only during the heating operation.

On the other hand, the heat exchanger 48 in the cooling absorber.
Is for releasing the absorption heat generated in the absorber 4 to the atmosphere during the cooling operation. The heat exchanger 48 in the cooling absorber has an air-cooling type heat exchanger 5 for heat radiation by a pump 53. As shown by arrows S ₁ and S ₂ , cooling water is supplied through the cooling water passage 60, and the absorption heat is released to the outside air by the cooling water. Therefore, the pump 53 and the fan 69
Is to be driven only during cooling operation. Reference numeral 69 is a fan for air cooling.

Therefore, in the case of this embodiment, the heat source side heat exchanger 2 and the heat radiating heat exchanger 5 are cross fins sharing the fins 71, 71, ... As shown in FIGS. 3 and 4. It is composed of a coil. Reference numeral 72 is a heat transfer tube of the heat source side heat exchanger 2, and 73 is a heat transfer tube of the heat radiating heat exchanger 5.

During the heating operation, the operation of the pump 53 and the fan 69 is stopped as described above, but the heat source side heat exchanger 2 acting as an evaporator due to a decrease in outside air temperature or the like. When frost is formed on the surface, defrost operation is started to remove the frost.

In the defrost operation, the pump 53 is operated while the refrigerant cycle remains the heating cycle, and the heat radiating heat exchanger 5 (specifically, the heat transfer tube 73) is connected to the heat exchanger in the cooling absorber. At 48, hot water that has absorbed the absorbed heat and has been raised in temperature is supplied. Then, the heat is transferred to the heat source side heat exchanger 2 side via the shared fins 71, 71, ..., and the frost is dissolved. Therefore, the heating operation can be continued even during the defrost operation, and the integrated heating capacity can be significantly improved.

Embodiment 2 FIGS. 5 and 6 are circuit configuration diagrams of an absorption refrigerating apparatus according to Embodiment 2 of the present invention.

In the case of the present embodiment, one absorber internal heat exchanger 45 for both cooling and heating is provided in the absorber 4 below the internal heat exchanger 46 for heat recovery. On the inlet side and the outlet side of the cooling / heating combined heat exchanger 45, a branch forward path branched from the use-side heat medium flow path 35 at the inlet of the use-side heat exchanger 3 via a three-way switching valve 61. 64a
And the branch return path 6 that joins the downstream side of the three-way switching valve 61.
4b are respectively connected.

Further, the heat radiation heat exchanger 5 and the pump 53.
The outlet side of the pump 53 in the cooling water passage 60 is connected to the branch outward passage 64a via a three-way switching valve 63, while the inlet side of the heat dissipation heat exchanger 5 in the cooling water passage 60 is , Is connected to the branch return path 64b through a three-way switching valve 62.

Here, in the three-way switching valves 62, 63, the cooling water flow path 60 side is open and the branch outward path 64a and the branch return path 64b side are closed during the cooling operation as shown in FIG.
During heating operation, as shown in FIG.
The 0 side is controlled to be closed, and the branch outward path 64a and the branch return path 64b side are controlled to be open. Therefore, during the cooling operation, the heat medium in the absorber side heat exchanger 45 for heating and cooling is not supplied with the use side heat medium, but the cooling water from the heat radiating heat exchanger 5 is supplied. The heat transfer medium on the utilization side is supplied to the heat exchanger 45 in the absorber, and the cooling water from the heat exchanger 5 for heat radiation is not supplied. The three-way switching valves 62 and 63 are also opened on the cooling water flow passage 60 side during the defrost operation, but at that time, the flow rate of the flow on the branch outward path 64a and the branch return path 64b and the flow rate on the cooling water flow path 60 side. The ratio is set to be a predetermined ratio (for example, 8: 2).

Further, in the case of this embodiment, a bypass passage 65 for bypassing the pump 53 is provided, and an opening / closing valve 66 which is opened only during the defrost operation is provided in the bypass passage 65. That is, during the defrost operation, the hot water supplied from the branch outward path 64a to the cooling water flow path 60 is returned to the branch return path 64b via the heat radiating heat exchanger 5. The other configuration is similar to that of the first embodiment, and thus the description is omitted.

With the above-mentioned structure, in this embodiment, the heat radiating heat exchanger 5 is operated during the defrosting operation.
The hot water (that is, a part of the heat medium on the use side) is supplied to the heat source side heat exchanger 2 side through the shared fins 71, 71 ,. Will be done. Therefore, the heating operation can be continued even during the defrost operation, and the integrated heating capacity can be significantly improved.

The invention of the present application is not limited to the configuration of the above-described embodiment, and it goes without saying that the design can be changed as appropriate without departing from the gist of the invention.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an absorption refrigeration apparatus according to a first embodiment of the present invention during a cooling operation.

FIG. 2 is a circuit configuration diagram during the heating operation of the absorption refrigeration system according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing an integrated state of the heat source side heat exchanger and the heat radiation heat exchanger in the absorption refrigerating apparatus according to the first embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a circuit configuration diagram during the cooling operation of the absorption refrigeration apparatus according to the second embodiment of the present invention.

FIG. 6 is a circuit configuration diagram of the absorption refrigeration apparatus according to the second embodiment of the present invention during heating operation.

[Explanation of symbols]

1 is a generator, 2 is a heat source side heat exchanger, 3 is a use side heat exchanger, 4 is an absorber, 5 is a heat radiation heat exchanger, 31 is a four-way switching valve of the base 1, 35 is a use side heat medium A flow path, 36 is a second four-way switching valve, 45 is an internal heat exchanger for cooling / heating, an internal heat exchanger for heat recovery, 47 is an internal heat exchanger for heating, and 48 is cooling. Absorber heat exchanger, 60 is a cooling water flow path, 61, 62 and 63 are three-way switching valves, 64a is a branch outward path,
64b is a branch return path, 71 is a fin, and 72 and 73 are heat transfer tubes.

Claims (1)

[Claims] 1. A generator (1), an air-cooled heat source side heat exchanger (2) that acts as a condenser during cooling operation, and acts as an evaporator during heating operation, and acts as an evaporator during cooling operation. For air-cooling heat radiation, which radiates the absorption heat generated in the absorber (4) to the outside air in the refrigerant cycle consisting of the utilization side heat exchanger (3) acting as a condenser during heating operation and the absorber (4) An absorption type refrigerating apparatus, which is provided with a heat exchanger (5) to exchange heat between a circulating refrigerant and a use side heat medium in the use side heat exchanger (3), wherein the heat source side heat exchanger ( 2) and the air-cooling type heat exchanger for heat radiation (5)
(71), (71) ··· are shared, and hot water is circulated to the heat radiating heat exchanger (5) while the refrigerant cycle is in the heating operation cycle during defrost operation. A characteristic absorption refrigeration system.