JPH07243724A - Absorption refrigerator - Google Patents

Abstract

PURPOSE:To remove frost adhering to an outdoor heat exchanger without interrupting heating. CONSTITUTION:A pump P1 is provided at a brine outlet side tube line 15b of an outdoor heat exchanger 5 and a pump P2 is provided at a brine outlet side tube line 16b of an indoor heat exchanger 6. A discharge side tube line of the pump P1 is connected to a brine inlet side tube line 13a of a refrigerant condensing heat exchanger 2 through a switching valve V and a check vale V11 so that part of brine discharged from the outdoor heat exchanger can flow to the refrigerant condensing heat exchanger. A discharge side tube line of the pump P2 is connected to a brine inlet side tube line 15a of the exchanger 5 through a switching valve V2 and a check valve V21 so that part of brine discharged from the indoor heat exchanger can flow to the outdoor heat exchanger. A check valve V13 is provided at the line 13a, and a check valve 14 is provided at a brine inlet side tube line 15c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerating machine that can be used for heating and cooling operations, and more particularly to an absorption refrigerating machine having a defrosting function.

[0002]

2. Description of the Related Art For example, Japanese Patent Publication No. 51-2147 and Japanese Patent Publication No. 3-64784 disclose low-temperature absorption refrigerators that use ammonia as a refrigerant. 2. Description of the Related Art An absorption refrigerator having a configuration shown in 2 and using ammonia as a refrigerant and an aqueous ammonia solution as an absorbing liquid is well known.

In the absorption refrigerator illustrated in FIG. 2, a generator 1 equipped with heating means 1a such as a gas burner, a refrigerant condensation heat exchanger 2, a pressure reducing valve V31, a refrigerant evaporation heat exchanger 3 and an absorber 4 are connected by piping. Refrigerant circuit 11 in which ammonia as a refrigerant circulates
And the generator 1, the pressure reducing valve V32, and the absorber 4
The absorption liquid circuit 12 in which the absorption liquid circulates by connecting the pump P3 by piping, and the refrigerant circulated through the refrigerant circuit 11 is
In the refrigerant condensing heat exchanger 2, heat is exchanged with the brine (for example, antifreeze liquid such as ethylene glycol) flowing through the hot brine circuit 13 to heat it by the heat of condensation, and the refrigerant evaporating heat exchanger 3 flows through the cold brine circuit 14. Brine (for example, antifreeze such as ethylene glycol)
And heats it by cooling it with heat of vaporization.
A desired brine heated or cooled by flowing through the hot brine circuit 13 or the cold brine circuit 14 via 21 is circulated and supplied to the indoor heat exchanger 6 by the indoor brine circuit 16 to be used for cooling and heating, while the remaining The brine is circulated and supplied to the outdoor heat exchanger 5 by the outdoor brine circuit 15 to exchange heat with the outdoor air or the like to absorb or radiate heat.

[0004] P1 and P2 are pumps installed at the positions shown in the figure for circulating brine as a heat medium.

That is, in the absorption refrigerator having the above structure, when the eight-way valve V21 is set to the cooling operation mode, the brine flowing through the hot brine circuit 13 and heated by the absorber 4 / refrigerant condensing heat exchanger 2 becomes the outdoor brine. It is supplied to the outdoor heat exchanger 5 by the circuit 15 and exchanges heat with the outside air to radiate heat to the outside air, and then flows through the cold brine circuit 14 to flow through the refrigerant evaporation heat exchanger 3
The brine cooled in step 3 is supplied to the indoor heat exchanger 6 by the indoor brine circuit 16, and here the cooling operation is performed in which heat is exchanged with the indoor air to cool it.

On the other hand, when the eight-way valve V21 is set to the heating operation mode, the brine flowing through the hot brine circuit 13 and heated by the absorber 4 and the refrigerant condensing heat exchanger 2 is
The brine, which is supplied to the indoor heat exchanger 6 by the indoor brine circuit 16 to heat the indoor air, flows through the cold heat brine circuit 14 and evaporates the refrigerant in the refrigerant evaporation heat exchanger 3, and radiates heat, the brine is radiated by the outdoor brine circuit 15. Outdoor heat exchanger 5
The heating operation is performed, in which heat is drawn from outside air having a relatively high temperature.

[0007]

In the absorption refrigerator having the above structure, if ethylene glycol, which is an antifreezing liquid, is used for the brine, the refrigerant condensing heat exchanger or the like can be used even when the temperature of the outside air drops below 0 ° C. It is possible to circulate and supply the heated brine to the indoor heat exchanger to continue the heating operation, but the outdoor where the brine cooled to, for example, −8 ° C. is supplied by the evaporation of the refrigerant in the refrigerant evaporation heat exchanger. The temperature of the heat transfer tube of the heat exchanger becomes 0 ° C. or lower when the temperature of the outside air decreases to about 1 ° C., and steam in the atmosphere sublimes to frost on this portion. When frost is formed, the thermal conductivity of the frosted part is significantly reduced and almost no heat can be pumped from the outside air, and the heating performance is significantly reduced.Therefore, the eight-way valve is temporarily switched to the cooling operation mode and the refrigerant condensation heat The brine heated by the exchanger is stopped from being supplied to the indoor heat exchanger, and the brine is supplied to the outdoor heat exchanger so as to be defrosted by the heat held by the brine.

However, in the above defrosting method, the heating operation is interrupted each time defrosting is performed, and the comfort of heating is impaired. In addition, since the brine with a low temperature is supplied to the pipe section up to the indoor heat exchanger by switching the eight-way valve, the indoor heat exchanger can be warmed up in a short time even if the defrosting is completed and the heating operation mode is switched to. There was also a problem that it could not be done and it took time to start the heating, and the solution to these problems was a problem.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. The indoor heat exchanger, the outdoor heat exchanger, the refrigerant condensing heat exchanger, the refrigerant evaporative heat exchanger, An absorber, a generator, an eight-way valve, etc. are connected by piping to form a circulation cycle of the refrigerant and the absorbing liquid, and the required brine heated and cooled by the refrigerant condensation heat exchanger and the refrigerant evaporation heat exchanger is supplied. In an absorption refrigerating machine that performs cooling and heating operation by circulatingly supplying the outdoor heat exchanger and the indoor heat exchanger,

A brine outlet side pipe 15b connected to the brine outlet portion of the outdoor heat exchanger is provided with a first brine circulation pump, and a brine outlet side pipe connected to the brine outlet portion of the indoor heat exchanger. Second on road 16b
And a brine inlet side pipeline 13a pipe-connected to the brine inlet section of the refrigerant condensing heat exchanger.
A part of the brine discharged from the outdoor heat exchanger is connected via a first on-off valve / check valve so that the brine can flow into the refrigerant condensing heat exchanger, and a discharge side pipe of the second brine circulation pump. The second passage is configured to allow a part of the brine discharged from the indoor heat exchanger to flow into the outdoor heat exchanger through the passage and the brine inlet-side conduit 15a connected to the brine inlet portion of the outdoor heat exchanger by piping. An absorption refrigerator connected via an on-off valve / check valve,

A brine outlet side pipe 15b connected to the brine outlet portion of the outdoor heat exchanger is provided with a first brine circulation pump, and a brine outlet side pipe connected to the brine outlet portion of the indoor heat exchanger is connected. Second on road 16b
And a brine inlet side pipeline 13a pipe-connected to the brine inlet section of the refrigerant condensing heat exchanger.
A part of the brine discharged from the outdoor heat exchanger is connected via a first on-off valve / check valve so that the brine can flow into the refrigerant condensing heat exchanger, and a pipeline on the downstream side of the first on-off valve. A check valve is provided in a brine inlet side conduit 13c that pipe-connects with the one brine outlet of the eight-way valve so that the brine can flow from the eight-way valve into the refrigerant condensing heat exchanger.
Part of the brine discharged from the indoor heat exchanger through the discharge side pipeline of the brine circulation pump and the outdoor heat exchanger brine inlet side pipeline 15a pipe-connected to the brine inlet section of the indoor heat exchanger. A brine connected to the outdoor heat exchanger via a second on-off valve and a check valve so that it can flow into the outdoor heat exchanger, and a pipe connecting the downstream side pipeline of the second on-off valve and one brine outlet of the eight-way valve. An absorption refrigerating machine provided with a check valve for allowing the brine to flow into the outdoor heat exchanger from the eight-way valve is provided in the inlet side pipe line 15c, and the problems of the conventional technology are solved.

[0012]

When the temperature of the outdoor heat exchanger is lowered more than necessary during the heating operation and frost is formed, the first and second opening / closing valves are opened to heat the refrigerant condensing heat exchanger. A part of the brine that flows into the indoor heat exchanger and exchanges heat with the indoor air and radiates heat, but still maintains a sufficient temperature and is discharged from the indoor heat exchanger is transferred to the frosted outdoor heat exchanger by the first heat exchanger. The temperature of the whole brine flowing through the outdoor heat exchanger rises because of the inflow through the open / close valve of No. 1 and the frost attached to the outdoor heat exchanger melts and disappears.

Even during the defrosting operation, since the brine heated by the refrigerant condensing heat exchanger is continuously supplied to the indoor heat exchanger, the heating operation is not hindered. Even when the defrosting is finished and the normal heating operation is resumed, it is said that the brine with a low temperature is flowing into the indoor heat exchanger as in the prior art, and it takes a long time to start the heating. It can return to normal heating operation immediately.

Most of the brine cooled by the defrosting operation of the outdoor heat exchanger flows into the refrigerant evaporative heat exchanger through the eight-way valve, but some of the brine passes through the second on-off valve. Circulation is carried out by flowing into the refrigerant condensing heat exchanger, where it is heated by the condensation heat released when the refrigerant condenses and then flows into the indoor heat exchanger again.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIG. In FIG. 1, the parts designated by the same reference numerals as those in FIG. 2 have the same functions as those described with reference to FIG. 2, and the description thereof is omitted within the range that does not hinder the understanding of the present invention.

The absorption refrigerating machine according to the present invention illustrated in FIG. 1 is an absorption refrigerating machine using, for example, ammonia as a refrigerant and an aqueous ammonia solution as an absorbing liquid, and the first brine circulation pump P1 is an outdoor brine circuit. 15 is provided in the brine outlet side pipe line 15b, the second brine circulation pump P2 is provided in the brine outlet side pipe line 16b of the indoor brine circuit 16, and the downstream side pipe line of the pump P1 and the thermal brine circuit 13 are provided. A part of the brine discharged from the outdoor heat exchanger 5 to the brine inlet side conduit 13a by the first on-off valve V1 and the first check valve V11, for example, 50%.
Is connected to the refrigerant condensing heat exchanger 2 so that it can directly flow into the refrigerant condensing heat exchanger 2, and the downstream side pipeline of the pump P2 and the outdoor brine circuit 15
The second inlet / outlet valve V2 and the second check valve V12 of the brine inlet side pipeline 15a of the outdoor heat exchanger 5 cause a part of the brine discharged from the indoor heat exchanger 6 to be, for example, 50%.
It is directly connected to.

Further, a brine inlet side pipe line 1 which connects the downstream side pipe line of the opening / closing valve V1, specifically, the downstream side pipe line of the check valve V11 and one brine outlet part of the eight-way valve V21 to each other.
3 c is provided with a check valve V13 so that the brine flows only from the eight-way valve V21 toward the refrigerant condensing heat exchanger 2, and a downstream pipe line of the opening / closing valve V2, specifically, a downstream pipe of the check valve V12. A check valve V14 is provided in a brine inlet-side conduit 15c that pipe-connects the passage and one brine outlet of the eight-way valve V21 so that the brine flows only from the eight-way valve V21 toward the outdoor heat exchanger 5. There is.

In the absorption refrigerator having the above-mentioned structure, the on-off valves V1 and V2 are closed, and the hot brine circuit 13 is caused to flow to the absorber 4 and the refrigerant condensing heat exchanger 2, for example, 50
The brine heated to ℃ is circulated and supplied to the outdoor heat exchanger 5, while flowing through the cold brine circuit 14 and circulated to the indoor heat exchanger 6 by the refrigerant evaporation heat exchanger 3, for example, cooled to 7 ℃. By setting the eight-way valve V21 to be supplied, the cooling operation is executed,

While closing the on-off valves V1 and V2, the brine heated in the hot brine circuit 13 and heated as described above is circulated and supplied to the indoor heat exchanger 6, while flowing in the cold heat brine circuit 14 and similarly cooled. The heating operation is executed by setting the eight-way valve V21 so that the generated brine is circulated and supplied to the outdoor heat exchanger 5.

Then, in the above heating operation, the temperature of the outside air becomes, for example, 1 ° C. or less, and the brine is pumped up from the outside air by the brine. A heat transfer tube (not shown) of the outdoor heat exchanger 5.
When the temperature of the outdoor heat exchanger 5 drops to 0 ° C. or less and frost forms, the heat from the outdoor air in the outdoor heat exchanger 5 is insufficiently pumped and the temperature difference between the inlet and outlet of the brine is reduced.
When frost formation is detected by monitoring the temperature difference between the brine coming in and going out, the on-off valves V1 and V2 are automatically opened in response to a control signal from a controller (not shown).

On-off valve V1 during operation in the heating operation mode
When V2 opens, not only the brine that has flowed through the cold heat brine circuit 14 and is cooled to -8 ° C in the frosted outdoor heat exchanger 5, but also the indoor heat exchanger that is heated to 55 ° C in the hot brine circuit 13. Although it exchanged heat with the indoor air and radiated heat to the indoor air, a part of the brine discharged to the indoor brine circuit 16b while maintaining a sufficient temperature, for example, 45 ° C, in this case, 50% is an opening / closing valve. Inflow through V2 and check valve V12. Therefore, the temperature of the entire brine flowing through the outdoor heat exchanger 5 rises to about 18 ° C., and the frost attached to the outdoor heat exchanger 5 melts and disappears.

Most of the brine cooled during defrosting of the outdoor heat exchanger 5 flows into the refrigerant evaporative heat exchanger 3 through the eight-way valve V21, but a part (usually in the range of about 20 to 50%). , The variable structure allows the optimum value to be selected according to the temperature of the area where the device is installed.)
It flows into the absorber 4 / refrigerant condensing heat exchanger 2 via the check valve V11, is heated by the absorption heat and the condensing heat released when the refrigerant condenses, and then flows into the indoor heat exchanger 6 again. Circulate to.

As described above, in the absorption refrigerating machine of the present invention, even when the outdoor heat exchanger 5 is being defrosted, the brine heated in the indoor heat exchanger 6 through the warm brine circuit 13 is heated. Since it is being supplied, there is almost no concern that heating performance will deteriorate.

It is preferable that an outdoor fan (not shown) for supplying outside air to the outdoor heat exchanger 5 is stopped during the defrosting.

When the completion of defrosting is confirmed by monitoring the temperature difference between the brine entering and exiting the outdoor heat exchanger 5,
Upon receiving a control signal transmitted from a controller (not shown), the on-off valves V1 and V2 are automatically closed to return to the normal heating operation.

By the way, since the present invention is not limited to the above-mentioned embodiments, various modifications can be made without departing from the scope of the claims.

For example, the downstream side of the brine inlet side pipeline 13c is connected to the pipeline between the opening / closing valve V1 and the check valve V11, and the downstream side of the brine inlet side pipeline 15c is connected to the opening / closing valve V.
2 is connected to the pipe line between the check valve V12 and the check valve V12.

Further, the heating brine circuit 13 is formed in the structure in which the internal pipe of the absorber 4 is removed, and the opening / closing valve V1.
It is also possible to configure V2 as a flow control valve. In addition, the check valves V11 and V12 are deleted, and the on-off valves V1 and V
2 is a two-way completely closed valve, or check valves V13 and V1
It is also possible to delete 4 and configure the on-off valves V1 and V2 as flow rate control valves or the pumps P1 and P2 as flow rate control types.

As the refrigerant, other than ammonia,
As long as the boiling temperature or sublimation temperature is lower than that of the solvent and heat is released during dissolution, propane, butane,
It may be a hydrocarbon containing halogen such as pentane or difluorochloromethane, fluorodichloromethane, or difluorodichloromethane.

Considering a solvent as the absorbing liquid for absorbing the refrigerant, dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, tetraethylene glycol, dimethyl ether, tributyl phosphate,
It may be an organic solvent such as ethylene glycol, diethylene glycol, benzyl alcohol, aniline, or a hydrocarbon selected from paraffinic hydrocarbons.

On the other hand, as the brine circulated in the hot brine circuit 13, cold brine circuit 14, outdoor brine circuit 15, indoor brine circuit 16 in addition to ethylene glycol used in this embodiment, calcium chloride solution, Saline solution, water, methylene chloride, propylene glycol and the like can be used.

[0032]

As described above, according to the invention of claim 1, it is possible to remove the frost attached to the outdoor heat exchanger while performing the heating operation which cannot be performed by the conventional technique. It does not impair comfort during heating.

Further, according to the invention of claim 2, it is possible to avoid the brine having a low temperature during defrosting from flowing into the indoor heat exchanger as in the prior art, and as a result, when returning to the heating operation. It has a remarkable effect such as quick rising.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an example.

FIG. 2 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Generator 1a Heating means 2 Refrigerant condensing heat exchanger 3 Refrigerant evaporative heat exchanger 4 Absorber 5 Outdoor heat exchanger 6 Indoor heat exchanger 11 Refrigerant circuit 12 Absorbing liquid circuit 13 Thermal brine circuit 13a Brine inlet side conduit 13c Brine Inlet side pipeline 14 Cold / heat brine circuit 15 Outdoor brine circuit 15a Brine inlet side pipeline 15b Brine outlet side pipeline 15c Brine inlet side pipeline 16 Indoor brine circuit 16b Brine outlet side pipeline V1 ・ V2 Open / close valve V11 ・ V12 ・ V13・ V14 Check valve V21 Eight-way valve V31 ・ V32 Pressure reducing valve P1, P2, P3 Pump

Claims (2)

[Claims] 1. A circulation cycle of a refrigerant and an absorption liquid by connecting an indoor heat exchanger, an outdoor heat exchanger, a refrigerant condensation heat exchanger, a refrigerant evaporation heat exchanger, an absorber, a generator, an eight-way valve, etc. The required brine, which has been formed and heated and cooled by the refrigerant condensation heat exchanger and the refrigerant evaporation heat exchanger, is circulated and supplied to the outdoor heat exchanger and the indoor heat exchanger, respectively, to perform cooling and heating operation, etc. In the absorption refrigerator, a first brine circulation pump was provided in a brine outlet side pipeline (15b) pipe-connected to the brine outlet of the outdoor heat exchanger, and piped to the brine outlet of the indoor heat exchanger. A second brine circulation pump is provided in the brine outlet side pipeline (16b), and a brine inlet pipe is connected to the discharge side pipeline of the first brine circulation pump and the brine inlet section of the refrigerant condensation heat exchanger. The mouth side pipe line (13a) is connected through a first on-off valve / check valve so that a part of the brine discharged from the outdoor heat exchanger can flow into the refrigerant condensing heat exchanger, A part of the brine discharged from the indoor heat exchanger through the discharge side pipeline of the second brine circulation pump and the brine inlet side pipeline (15a) pipe-connected to the brine inlet section of the outdoor heat exchanger is An absorption refrigerator, which is connected via a second on-off valve and a check valve so that it can flow into the outdoor heat exchanger. 2. A circulation cycle of the refrigerant and the absorption liquid is provided by connecting an indoor heat exchanger, an outdoor heat exchanger, a refrigerant condensation heat exchanger, a refrigerant evaporation heat exchanger, an absorber, a generator, an eight-way valve, etc. The required brine, which has been formed and heated and cooled by the refrigerant condensation heat exchanger and the refrigerant evaporation heat exchanger, is circulated and supplied to the outdoor heat exchanger and the indoor heat exchanger, respectively, to perform cooling and heating operation, etc. In the absorption refrigerator, a first brine circulation pump was provided in a brine outlet side pipeline (15b) pipe-connected to the brine outlet of the outdoor heat exchanger, and piped to the brine outlet of the indoor heat exchanger. A second brine circulation pump is provided in the brine outlet side pipeline (16b), and a brine inlet pipe is connected to the discharge side pipeline of the first brine circulation pump and the brine inlet section of the refrigerant condensation heat exchanger. The mouth side pipe line (13a) is connected through a first on-off valve / check valve so that a part of the brine discharged from the outdoor heat exchanger can flow into the refrigerant condensing heat exchanger, The brine can flow from the eight-way valve into the refrigerant condensing heat exchanger into a brine inlet-side pipe (13c) that pipe-connects the downstream pipe of the first on-off valve and one brine outlet of the eight-way valve. Is provided with a check valve, and the discharge side pipeline of the second brine circulation pump and the outdoor heat exchanger brine inlet side pipeline (15a) pipe-connected to the brine inlet of the indoor heat exchanger are connected to the inside of the room. A part of the brine discharged from the heat exchanger is connected via a second on-off valve / check valve so that the brine can flow into the outdoor heat exchanger, and the downstream side pipe line of the second on-off valve and the eight sides Brine inlet side pipe line (15c) that connects the valve with one brine outlet , The absorption refrigerating machine, characterized in that the brine is provided a check valve to allow flow into the outdoor heat exchanger from the Happo valve.