JP2005155975A - Absorption refrigerating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the amount of heat recovery from exhaust gas from decreasing, and to minimize the ill effect even if vapor contained in the exhaust gas is condensed. <P>SOLUTION: An absorption refrigerating machine comprises a first heat recovery device 27 for recovering heat in exhaust gas from a gas burner 2 attached to a high-temperature regenerator 1 as an absorption liquid heating means for heating an absorption liquid; a second heat recovery device 28, and the like for heating air for combustion supplied to the gas burner 2 by recovering the heat of exhaust gas from the gas burner 2. The absorption refrigerating machine is connected via the first and second heat recovery devices 27, 28 and a condensate pipe 30, a neutralizing container 29 in which calcium carbonate is inherent is mounted so that condensate in vapor in the exhaust gas generated by condensation in the first heat recovery device 27 and condensate in vapor in the exhaust gas generated by condensation in the second heat recovery device 28 flow in, are discharged through the inside, and are disposed. Then, the area among the first and second heat recovery devices 27, 28, the neutralizing container 29, the neutralizing container 29 in the condensate pipe 30, and the first and second heat recovery devices 27, 29 is formed by a corrosion-resistant material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an absorption refrigerating machine provided with a heat recovery unit that is provided with a combustion device as an absorption liquid heating means in a high-temperature regenerator and that recovers heat held by exhaust gas discharged from the combustion device into an absorption liquid. It is about.

  As this type of absorption refrigerator, for example, as shown in FIG. 4, the exhaust gas discharged from the gas burner 2 that heats and boiles the rare absorbent in the high-temperature regenerator 1 is exchanged with the high-temperature heat exchanger 10 through the exhaust pipe 26. It is sent to a heat recovery device 27X provided between the regenerator 1 and a heat recovery device 27Y provided between the low temperature heat exchanger 9 and the high temperature regenerator 10, and is passed through the absorption liquid pipe 11 by the absorption liquid pump 14. An absorption refrigerator 100X devised to increase the temperature of the rare absorbent sent from the absorber 7 to the high-temperature regenerator 1, reduce the necessary heating amount by the gas burner 2, and reduce the fuel consumption is well known. (For example, refer to Patent Document 1).

In the absorption refrigerator 100X described in Patent Document 1, an absorption liquid pipe 11B is provided in which the rare absorption liquid that has exited the low-temperature heat exchanger 9 flows around the heat recovery unit 27Y interposed in the absorption liquid pipe 11A. The flow rate control valve V7 is provided in the absorption liquid pipe 11B, and the temperature sensor 40 provided in the downstream portion of the exhaust pipe 26 further measures the predetermined temperature higher than the dew point of the water vapor contained in the exhaust gas. A controller 41 for controlling the opening is provided.
JP 2003-130487 A

  In the absorption refrigerator proposed in Patent Document 1, the opening degree of the flow control valve is controlled by the controller so that the temperature sensor continues to measure a predetermined temperature higher than the dew point of water vapor contained in the exhaust gas. There is no concern that the water vapor contained in the water will condense to generate acidic drain water, but the amount of heat recovered from the exhaust gas will decrease, and the fuel consumed by the gas burner 2 will not be sufficiently reduced. was there.

  Therefore, the amount of heat recovered from the exhaust gas does not decrease, and even if the water vapor contained in the exhaust gas is condensed, it is necessary to minimize the adverse effects, which is a problem to be solved. It was.

  In order to solve the above-described problems of the prior art, the present invention discharges from a high-temperature regenerator, a low-temperature regenerator, a condenser, an evaporator, an absorber, and a combustion device provided with a combustion device as an absorption liquid heating means. In an absorption refrigerator having a heat recovery unit that recovers heat held in the exhaust gas by heat exchange between the exhaust gas and the absorption liquid and heats the absorption liquid, water vapor contained in the exhaust gas is contained in the heat recovery unit. The main feature is that a neutralization container in which an alkaline substance is present is provided in a pipe line through which a condensate of water vapor generated by condensation is flown.

  According to the present invention, the acidic condensate produced by the condensation of water vapor in the exhaust gas is neutralized by being guided to the neutralization container in which the alkaline substance is present, and then discharged. There is no negative impact on the environment.

  In addition, the acidic drain water generated from the water vapor in the exhaust gas is guided to the neutralization container containing the alkaline substance and neutralized / discharged, so that the exhaust gas discharged from the combustion device as the absorption liquid heating means absorbs the exhaust water. When exchanging heat with liquid etc., it is possible to recover the retained heat to absorption liquid etc. to the maximum extent. Therefore, the fuel consumed by the absorption liquid heating means can be greatly reduced.

  A first heat recovery unit that recovers heat held in the exhaust gas by absorbing heat flowing into the high-temperature regenerator from the absorber and exhaust gas discharged from the combustion apparatus and exchanging heat; and combustion A second heat recovery unit that recovers heat held in the exhaust gas by flowing into the combustion air supplied to the device and the exhaust gas discharged from the combustion device and exchanging heat; The water vapor in the exhaust gas condensed and generated in the second heat recovery unit by heat exchange with the combustion air and the condensate of the water vapor in the exhaust gas condensed and generated in the first heat recovery unit by heat exchange with An absorption refrigerator in which a condensate conduit is provided so that the condensate can be introduced into the same neutralization container in which the alkaline substance is present.

  A first embodiment of the present invention will be described with reference to FIGS. In order to facilitate understanding, in these drawings, parts having the same functions as those described with reference to FIG.

  In the figure, reference numeral 1 denotes a high-temperature regenerator configured to evaporate and separate the refrigerant by heating the absorbing liquid by the heating power of a gas burner 2 using, for example, city gas, 3 is a low-temperature regenerator, 4 is a condenser, A high temperature cylinder in which the low temperature regenerator 3 and the condenser 4 are accommodated, 6 is an evaporator, 7 is an absorber, 8 is a low temperature cylinder in which the evaporator 6 and the absorber 7 are accommodated, 9 is a low temperature heat exchanger, 10 is a high-temperature heat exchanger, 11 to 13 are absorption liquid pipes, 14 and 15 are absorption liquid pumps, 16 to 18 are refrigerant pipes, 19 is a refrigerant pump, 20 is a cold / hot water pipe, 21 is a cooling water pipe, and 22 is cooling / heating. A communication pipe connecting the cold / hot water pipe 20 and the cooling water pipe 21 through the switching valve V3, 23 is a fuel supply pipe through which city gas of fuel supplied to the gas burner 2 flows, and 24 is supplied by a fan 25. An air supply pipe 26 for supplying combustion air to the gas burner 2, The exhaust pipe 27 through which the exhaust gas from the sburner 2 passes, and the absorption liquid flowing through the absorption liquid pipe 11A and the exhaust gas flowing through the exhaust pipe 26 flow in to exchange heat, and the heat held by the exhaust gas is recovered in the absorption liquid. A first heat recovery unit 28 for heating the absorbing liquid, the combustion air flowing in the air supply pipe 24 and the exhaust gas flowing in the exhaust pipe 26 flow in to exchange heat, and the heat held by the exhaust gas is burned. A second heat recovery unit 29 for recovering the combustion air and heating the combustion air, 29 is a neutralization container in which an alkaline substance, for example, calcium carbonate is contained, and the first heat recovery unit 27 and the second heat Heat exchange between the condensate of water vapor in the exhaust gas, which is connected to the recovery unit 28 via the condensate tube 30 and condensed in the first heat recovery unit 27 by heat exchange with the absorption liquid, and combustion air. Condenses in the second heat recovery unit 28 And condensate and flows of water vapor in the exhaust gas, discharged through the inside, is mounted to be disposed.

  The neutralization container 29 has a configuration in which a plurality of baffle plates 31 are disposed inside, for example, as shown in FIG. Therefore, the condensate of the water vapor in the exhaust gas flowing into the neutralization vessel 29 from the inlet 29A is filled in the vessel by meandering until the path is frequently changed by the plurality of baffle plates 31 and discharged from the outlet 29B. The chance of contact with calcium carbonate (not shown) is increased, and the acidic condensate is neutralized before being discharged from the outlet 29B.

  The first heat recovery device 27, the second heat recovery device 28, the neutralization vessel 29, the neutralization vessel 29 of the condensate tube 30, and the first and second heat recovery devices 27, 28 are provided. The space is formed of a corrosion-resistant material such as SUS-304 (which may be a non-ferrous metal, a synthetic resin, or the like), and can be prevented from being corroded by an acidic condensate.

  Moreover, the absorption liquid pipe | tube 11 for conveying a rare absorption liquid from the absorber 7 to the high temperature regenerator 1 is equipped with the absorption liquid pump 14 in the upstream part, and passed through the low temperature heat exchanger 9 and the high temperature heat exchanger 10. Later, it branches into an absorption liquid pipe 11A in which the first heat recovery device 27 and the cooling / heating switching valve V4 are interposed, and an absorption liquid pipe 11B in which the cooling / heating switching valve V5 is interposed, and then merges to reach the high temperature regenerator 1. .

  One end of the absorption liquid pipe 12 is connected to the liquid phase portion of the high temperature regenerator 1, and the other end is branched into an absorption liquid pipe 12A reaching the low temperature regenerator 3 and an absorption liquid pipe 12B reaching the absorber 7. A high temperature heat exchanger 10 is interposed in the pipe 12A, and a cooling / heating switching valve V2 is interposed in the absorbing liquid pipe 12B.

  One end of the absorption liquid pipe 13 is connected to the liquid phase part of the low-temperature regenerator 3, and an intermediate part is an absorption liquid pipe 13A in which the refrigerant pump 15 and the low-temperature heat exchanger 9 are interposed, and an absorption liquid pipe 13B in which no equipment is interposed And then merge to reach the absorber 7.

  One end of the refrigerant pipe 16 is connected to the gas phase part of the high temperature regenerator 1, and the other end is connected to the refrigerant pipe 16 </ b> A that reaches the lower side of the condenser 4 via the inner bottom part of the low temperature regenerator 3 and the absorber 7. The refrigerant pipe 16B is branched, and a cooling / heating switching valve V1 is interposed in the refrigerant pipe 16B.

  One end of the refrigerant pipe 18 is connected to the liquid phase part of the evaporator 6, the refrigerant pipe 19 is provided in the upstream part, and the downstream part thereof has the refrigerant pipe 18 </ b> A leading to the sprayer provided in the upper part of the evaporator 6, and the absorber. 7 branches to a refrigerant pipe 18B that reaches the lower side of the No. 7, and an open / close valve V6 is interposed in the refrigerant pipe 18B.

  First, the operation when the absorption refrigerator 100 of the present invention having the above configuration is subjected to a cooling action such as cooling will be described. With only the cooling / heating switching valve V4 interposed in the absorption liquid pipe 11A opened and all other valves closed, the city gas of the fuel is burned by the gas burner 2 and the high-temperature regenerator 1 supplies the rare absorption liquid. When heated and boiled, the high-temperature regenerator 1 obtains the refrigerant vapor evaporated and separated from the rare absorption liquid and the intermediate absorption liquid in which the concentration of the absorption liquid is increased by separating the refrigerant vapor.

  The high-temperature refrigerant vapor generated in the high-temperature regenerator 1 enters the low-temperature regenerator 3 through the refrigerant tubes 16 and 16A, and is generated in the high-temperature regenerator 1 and passes through the high-temperature heat exchanger 10 through the absorption liquid tubes 12 and 12A. Then, the intermediate absorption liquid that has entered the low-temperature regenerator 3 is heated and condensed by heat dissipation, and enters the condenser 4.

  Further, the refrigerant heated by the low temperature regenerator 3 and evaporated and separated from the intermediate absorption liquid enters the condenser 4, and exchanges heat with water flowing in the cooling water pipe 21 to be condensed and liquefied and condensed from the refrigerant pipes 16 and 16 </ b> A. Together with the supplied refrigerant, it enters the evaporator 6 through the refrigerant pipe 17.

  The refrigerant liquid that has entered the evaporator 6 and accumulated in the refrigerant liquid reservoir is sprayed by the refrigerant pump 19 on the heat transfer pipe 20A connected to the cold / hot water pipe 20 and supplied through the cold / hot water pipe 20. The water flowing through the heat transfer tube 20A is cooled by evaporating with heat.

  The refrigerant evaporated in the evaporator 6 enters the absorber 7 and is heated in the low-temperature regenerator 3 to evaporate and separate the refrigerant, so that the absorption liquid having a further increased concentration of the absorption liquid, that is, the absorption liquid pump interposed in the absorption liquid pipe 13A. 15 is supplied from the absorption liquid pipes 13 and 13A via the low-temperature heat exchanger 9 and is absorbed by the concentrated absorption liquid sprayed from above.

  Then, the absorption liquid whose concentration has been reduced by absorbing the refrigerant by the absorber 7, that is, the rare absorption liquid, is operated by the absorption liquid pump 14 so that the low-temperature heat exchanger 9, the high-temperature heat exchanger 10, and the first heat recovery device. 27 is heated and sent to the high-temperature regenerator 1.

  When the operation of the absorption refrigerator 100 of the present invention is performed as described above, the cold water cooled by the heat of vaporization of the refrigerant in the heat transfer pipe 20A piped inside the evaporator 6 passes through the cold / hot water pipe 20. Since it can be circulated and supplied to a load (not shown), cooling operation such as cooling can be performed.

  And in the absorption refrigerator 100 of the said structure, the rare absorption liquid conveyed from the absorber 7 to the high temperature regenerator 1 by the absorption liquid pump 14 is the low temperature heat exchanger 9, the high temperature heat exchanger 10, and the 1st heat. Since each of the recovery units 27 is heated, the temperature of the rare absorbent when flowing into the high-temperature regenerator 1 is higher than when the first heat recovery unit 27 is not interposed, and the fuel consumed by the gas burner 2 is reduced. Can do.

  The combustion air supplied to the gas burner 2 through the air supply pipe 24 is heated by exchanging heat with the exhaust gas discharged from the gas burner 2 by the second heat recovery device 28 and then supplied to the gas burner 2. As a result, the amount of heat generated in the gas burner 2 is increased, the effect of heating the absorbing liquid in the high-temperature regenerator 1 is increased, and the first heat recovery device 27 and the second heat provided in the exhaust pipe 26 are increased. The heating action in the collector 28 is also increased. Therefore, this part also has the effect of reducing the supply of fuel gas supplied to the gas burner 2 through the fuel supply pipe 23.

  Moreover, it is discharged from the gas burner 2 attached to the high-temperature regenerator 1 during the cooling operation such as cooling, and is heat-recovered by the absorbing liquid by exchanging heat with the absorbing liquid in the first heat recovery unit 27, and condensed at that time. The condensate of the water vapor in the exhaust gas and the heat condensate of the water vapor in the exhaust gas condensed by heat exchange with the combustion air in the second heat recovery unit 28 as described above are as described above. Since it is introduced into the neutralization vessel 29 via the condensate tube 30 formed of corrosion-resistant steel and neutralized with the calcium carbonate in the vessel and discarded, it does not adversely affect the environment.

  Next, an operation when the absorption refrigerator 100 having the above configuration is subjected to a heating action such as heating will be described. The gas burner can be used without closing the cooling / heating switching valve V4 interposed in the absorbing liquid pipe 11A and the on-off valve V6 interposed in the refrigerant pipe 18B, opening all other valves, and flowing cooling water through the cooling water pipe 21. When the city gas of fuel is burned in 2 and the rare absorbent is heated and boiled in the high-temperature regenerator 1, the refrigerant vapor evaporated and separated from the rare absorbent and the refrigerant vapor are separated to increase the concentration of the absorbent. Absorption liquid is obtained in the high temperature regenerator 1.

  The high-temperature refrigerant vapor generated by the high-temperature regenerator 1 enters the low-temperature cylinder absorber 7 via the refrigerant pipes 16 and 16B due to the pressure difference between the high-temperature cylinder 5 and the low-temperature cylinder 8. Further, the concentrated absorbent produced in the high temperature regenerator 1 also enters the absorber 7 in the low temperature cylinder 8 via the absorbent liquid pipes 12 and 12B.

  An evaporator 6 having a heat transfer tube 20A is arranged in parallel with the absorber 7 in the low temperature drum 8, and when water circulated and supplied through the cold / hot water tube 20 flows in the heat transfer tube 20A. The latent heat of the refrigerant vapor supplied from the high-temperature regenerator 1 through the refrigerant pipe 16 and the refrigerant pipe 16B and the sensible heat held by the concentrated absorbent supplied through the absorption liquid pipes 12 and 12B are heated. .

  The refrigerant liquid supplied from the high-temperature regenerator 1 through the refrigerant pipe 16 and the refrigerant pipe 16B and radiated and condensed to the water flowing in the heat transfer pipe 20A is supplied from the high-temperature regenerator 1 through the absorption liquid pipes 12 and 12B. The concentrated absorbent is mixed to become a rare absorbent, which is heated by the low temperature heat exchanger 9 and the high temperature heat exchanger 10 by the operation of the absorption liquid pump 14 and sent to the high temperature regenerator 1.

  When the operation of the absorption refrigerator 100 is performed as described above, the hot water heated by the latent heat of condensation of the refrigerant and the sensible heat of the absorption liquid in the heat transfer tube 20A piped inside the evaporator 6 is cooled / warm water. Since it can be circulated and supplied to a load (not shown) through the pipe 20, a heating operation such as heating can be performed.

  The combustion air supplied to the gas burner 2 through the air supply pipe 24 even during a heating operation such as heating is heated by exchanging heat between the exhaust gas discharged from the gas burner 2 and the second heat recovery device 28, After that, since it is supplied to the gas burner 2, the amount of heat generated in the gas burner 2 increases, the effect of heating the absorbing liquid in the high-temperature regenerator 1 increases, and the second heat recovery provided in the exhaust pipe 26. The heating action in the vessel 28 also increases, and the effect of reducing the supply of fuel gas supplied to the gas burner 2 via the fuel supply pipe 23 is great.

  Moreover, it is discharged from the gas burner 2 attached to the high-temperature regenerator 1 during a heating operation such as heating, and is heat-recovered by the absorbing liquid by exchanging heat with the absorbing liquid in the first heat recovery unit 27, and condensed at that time. As described above, the condensate of the water vapor in the exhaust gas and the condensate of the water vapor in the exhaust gas condensed at that time by heat exchange with the combustion air in the second heat recovery unit 28 and heat recovered by the combustion air. Since it is introduced into the neutralization vessel 29 via the condensate tube 30 formed of corrosion-resistant steel, and neutralized with the calcium carbonate in the vessel and discarded, it does not adversely affect the environment.

  A second embodiment of the present invention will be described with reference to FIG. In order to facilitate understanding, in FIG. 3, the same reference numerals are given to the portions having the same functions as those described in the drawings.

  In the absorption refrigerator 100 of the second embodiment shown in FIG. 3, a dilution container 29A is installed in place of the neutralization container 29 provided in the absorption refrigerator 100 of the first embodiment shown in FIG. At the same time, a water supply pipe 32 is connected to the dilution container 29A, and substantially neutral water, for example, industrial water is allowed to flow through the water supply pipe 32 to the dilution container 29A. The acidic condensate of the water vapor in the exhaust gas supplied from the heat recovery unit 28 through the condensate tube 30 is diluted with a large amount of neutral water to be discarded as a neutral water of slightly over Ph6. It is comprised so that it may do.

  Therefore, also in the absorption refrigerator 100 of the second embodiment shown in FIG. 3, the acidic condensate produced by condensation of the water vapor in the exhaust gas from the gas burner 2 is introduced into the dilution vessel 29A, where Since it is diluted and discharged by substantially neutral water supplied through the water supply pipe 32, for example, industrial water, the acid drain water does not adversely affect the environment.

  In the absorption refrigerator 100 of the second embodiment, the first heat recovery device 27, the second heat recovery device 28, the dilution container 29A, the dilution container 29A of the condensate tube 30 and the first heat recovery device 28 are also used. The space between the second heat recovery units 27 and 28 is formed of a corrosion-resistant material such as SUS-304 (may be non-ferrous metal, synthetic resin, etc.), and corrosion due to acidic condensate can be prevented. ing.

  Since the present invention is not limited to the above-described embodiment, various modifications can be made without departing from the spirit described in the claims.

  For example, in the absorption refrigerating machine 100 of the first embodiment shown in FIGS. 1 and 2, the neutralization container 29 containing an alkaline substance such as calcium carbonate is used for the water vapor in the exhaust gas flowing into the vessel from the inlet 29A. The baffle plate 31 may be arranged in the container so that the upper side and the lower side are alternately opened so that the condensate meanders in the vertical direction as well as the horizontal direction and reaches the outlet 29B.

  Further, in the absorption refrigerator 100 of the second embodiment shown in FIG. 3, the dilution container 29 </ b> A is not provided, and the water supply pipe 32 is directly connected to the condensate liquid pipe 30 and supplied through the water supply pipe 32. An acidic condensate of water vapor in the exhaust gas supplied from the first heat recovery device 27 and the second heat recovery device 28 by a large amount of substantially neutral water, for example, industrial water or the like, is supplied in the water supply pipe 32. It is also possible to dilute it so that it can be discarded in the form of substantially neutral water of Ph6.

  Further, the absorption liquid pipe 11B in which the cooling / heating switching valve V5 is interposed and the cooling / heating switching valve V4 of the absorption liquid pipe 11A are omitted, and the absorber is used not only during cooling operation such as cooling but also during heating operation such as heating. It is also possible to configure so that the absorbing liquid supplied from 7 to the high-temperature regenerator 1 passes through the first heat recovery device 27 and the heat of the exhaust gas emitted from the gas burner 2 is recovered by the absorbing liquid.

2 is an explanatory diagram of Embodiment 1. FIG. It is explanatory drawing of the neutralization container which removed the top plate and showed the internal state. FIG. 6 is an explanatory diagram of Example 2. It is explanatory drawing which shows a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Gas burner 3 Low temperature regenerator 4 Condenser 5 High temperature cylinder 6 Evaporator 7 Absorber 8 High temperature cylinder 9 Low temperature heat exchanger 10 High temperature heat exchanger 11-13 Absorption liquid pipes 14, 15 Absorption liquid pumps 16-18 Refrigerant pipe 19 Refrigerant pump 20 Cold / hot water pipe 21 Cooling water pipe 22 Communication pipe 23 Fuel supply pipe 24 Air supply pipe 25 Fan 26 Exhaust pipe 27 First heat recovery device 28 Second heat recovery device 29 Neutralization vessel 29A Dilution vessel 30 Condensate pipe 31 Baffle plate 32 Water supply pipe V1 to V5 Cooling / heating switching valve V6 On-off valve

Claims (6)

Exhaust gas is generated by heat exchange between the high-temperature regenerator equipped with the combustion device as the absorption liquid heating means, the low-temperature regenerator, the condenser, the evaporator, the absorber, the exhaust gas discharged from the combustion device and the absorption liquid. Condensate in which water vapor in the exhaust gas is condensed in the heat recovery unit and the water vapor condensate is generated in an absorption refrigeration machine equipped with a heat recovery unit that recovers the retained heat to the absorption liquid and heats the absorption liquid An absorption refrigerator comprising a neutralization container containing an alkaline substance in a pipeline. As the heat recovery device, the first heat that recovers the heat held in the exhaust gas by absorbing heat flowing from the absorber into the high-temperature regenerator and the exhaust gas discharged from the combustion device and exchanging heat. A second heat recovery unit that recovers heat stored in the exhaust gas by inflowing heat exchange between the combustion air supplied to the combustion device and the exhaust gas discharged from the combustion device; And is condensed and generated in the second heat recovery unit by heat exchange with the condensate of water vapor in the exhaust gas generated by condensation in the first heat recovery unit by heat exchange with the absorption liquid and combustion air. The absorption refrigerating machine according to claim 1, wherein a condensate conduit is provided so that the condensate of water vapor in the exhaust gas is introduced into the same neutralization vessel. The absorption refrigerating machine according to claim 2, wherein a pipe line through which the exhaust gas flows is provided so as to reach the second heat recovery device from the combustion device via the first heat recovery device. The absorption refrigeration according to any one of claims 1 to 3, wherein a water supply pipe capable of supplying substantially neutral water is connected to the condensate pipe instead of installing the neutralization container. Machine. The absorption refrigeration according to any one of claims 1 to 3, wherein the heat recovery unit, the neutralization vessel, and the condensate conduit between the heat recovery unit and the neutralization vessel are formed of a corrosion-resistant material. Machine. The absorption refrigerator according to claim 4, wherein a space between the heat recovery unit, the heat recovery unit of the condensate line, and the water supply line connection part is formed of a corrosion-resistant material.

Images