US20200064032A1

US20200064032A1 - High-efficiency absorption heat pump system having increased utilization rate of waste heat source

Info

Publication number: US20200064032A1
Application number: US16/489,317
Authority: US
Inventors: In Gwan Kim
Original assignee: World E&c Co ltd
Current assignee: World E&c Co ltd
Priority date: 2017-04-19
Filing date: 2017-08-18
Publication date: 2020-02-27
Also published as: WO2018194221A1; KR101851230B1

Abstract

The present invention relates to a high-efficiency absorption heat pump system having increased utilization rate of a waste heat source, including: an evaporator to which a waste heat source inlet line through which a waste heat source inflows, is connected to absorb thermal energy from the waste heat source, and to which a refrigerant inlet line for supplying a refrigerant is connected; an absorber connected to the evaporator such that steam evaporated in the evaporator is fed thereto, and to which a hot water inlet line and a hot water outlet line extending from a flash tank are connected; a high temperature regenerator through which a waste heat source divide line branching off from the waste heat source inlet line passes, which heats LiBr solution fed to the absorber and regenerates the same, and is provided with a concentrated solution line for supplying the LiBr solution to the absorber; an auxiliary absorber to which the steam evaporated from the high temperature regenerator is transferred and which is connected to the high temperature regenerator in order to cool the steam and circulate the same; a low temperature regenerator to which an intermediate solution line is connected to supply the LiBr solution to the high temperature regenerator, through which a waste heat source return line extending from the evaporator passes, and to which a diluted solution line extending from the absorber is connected; a condenser through which a chilled water inlet line for supplying the cooling water passes such that the steam evaporated from the low temperature regenerator is fed and cooled therein, and which is connected to the low temperature regenerator; and an auxiliary regenerator to which an auxiliary solution line is connected to supply auxiliary LiBr solution to the auxiliary absorber, through which the waste heat source divide line passes, and to which an auxiliary diluted solution line extending from the auxiliary absorber is connected.

Description

TECHNICAL FIELD

The present invention relates to a high-efficiency absorption heat pump system with increased utilization rate of a waste heat source and, more particularly, a high-efficiency absorption heat pump system having increased utilization rate of a waste heat source, which may feed a working fluid comprising a refrigerant and an absorption solution (“absorbent”) while pressurizing the same to elevate a temperature of thermal energy recovered from the waste heat source to a high level so as to supply steam or hot water at a high temperature required in industrial processes, and further, may reduce a feed amount of the waste heat source required for supplying hot water or steam at the temperature required in the industrial processes.

BACKGROUND ART

In general, an absorption heat pump uses heat of waste water dumped into a sewer, heat of underground water, heat of cooling water discharged from industrial facilities such as a power plant, etc. as a heat source, and may elevate a temperature of hot water used for heating, hot water supply, industrial facilities, or the like.
The absorption heat pump may use water as a refrigerant and a lithium bromide solution (“LiBr solution”) having similar properties to salt as the absorbent.
The absorption heat pump may absorb waste heat from a heat source medium and then drain the heat source medium, thus being environmentally friendly; may semi-permanently use the refrigerant and the absorbent (hereinafter, “LiBr solution”); and has an advantage of low maintenance cost.
The absorption heat pump may include a generator to heat a diluted solution fed from an absorber and isolate a refrigerant vapor, a condenser to condense and liquefy the refrigerant vapor transferred from the regenerator, an evaporator to spray the refrigerant liquid transferred from the condenser over a chilled water inlet line in order to evaporate the same, and an absorber to enable the refrigerant vapor transferred from the absorber to be absorbed into a concentrated solution transferred from the generator.
The background art of the present invention has been disclosed in Korean Patent Laid-Open Publication No. 10-2009-0103740 (Laid-Open on Oct. 1, 2009; entitled “absorption heat pump”).

DISCLOSURE

Technical Problem

The absorption heat pump in the prior art uses only a single cycle consisting of an evaporator, an absorber, a regenerator and a condenser, and entails a problem of limitation in increasing a temperature of hot water outflow from the condenser.
Accordingly, such conventional problem needs to be solved.
An object of the present invention is to provide a high-efficiency absorption heat pump system with increased utilization rate of a waste heat source, which may feed a working fluid comprising a refrigerant and LiBr solution while pressurizing the same to elevate a temperature of thermal energy recovered from the waste heat source to a high level so as to supply steam or hot water at a high temperature required in industrial processes, and further, may reduce a feed amount of the waste heat source required to supply the hot water or steam at the temperature required in the industrial processes.

Technical Solution

The present invention provides a high-efficiency absorption heat pump system having increased utilization rate of a waste heat source, including: an evaporator to which a waste heat source inlet line through which a waste heat source inflows, is connected to absorb thermal energy from the waste heat source, and to which a refrigerant inlet line for supplying a refrigerant is connected; an absorber connected to the evaporator such that steam evaporated in the evaporator is fed thereto, to which a hot water inlet line and a hot water outlet line extending from a flash tank are connected; a high temperature regenerator through which a waste heat source divide line branching off from the waste heat source inlet line passes, which heats LiBr solution fed to the absorber and regenerates the same, and is provided with a concentrated solution line for supplying the LiBr solution to the absorber; an auxiliary absorber to which the steam evaporated from the high temperature regenerator is transferred and which is connected to the high temperature regenerator in order to cool the steam and circulate the same; a low temperature regenerator to which an intermediate solution line is connected to supply the LiBr solution to the high temperature regenerator, through which a waste heat source return line extending from the evaporator passes, and to which a diluted solution line extending from the absorber is connected; a condenser through which a chilled water inlet line for supplying the cooling water passes such that the steam evaporated from the low temperature regenerator is fed and cooled therein, and which is connected to the low temperature regenerator; and an auxiliary regenerator to which an auxiliary solution line is connected to supply auxiliary LiBr solution to the auxiliary absorber, through which the waste heat source divide line passes, and to which an auxiliary diluted solution line extending from the auxiliary absorber is connected.
Further, the concentrated solution line of the present invention is characterized by passing through a high temperature solution heat exchanger disposed in the diluted solution line.
Further, the intermediate solution line of the present invention is characterized by passing through a low temperature solution heat exchanger disposed in the diluted solution line.
Further, the auxiliary solution line of the present invention is characterized by passing through an auxiliary solution heat exchanger disposed in the diluted solution line.

Advantageous Effects

With regard to the high-efficiency absorption heat pump system having increased utilization rate of a waste heat source according to the present invention, the waste heat source divide line is branched off from the waste heat source inlet line to supply the waste heat source; the LiBr solution discharged from the absorber for absorbing thermal energy from the evaporator may be subjected to heat exchange again along with the waste heat source discharged through the evaporator; the LiBr solution discharged from the low temperature regenerator may circulate to the absorber after heat exchange along with the waste heat branch, followed by being subjected to heat exchange along with the hot water circulating in the flash tank. Therefore, there is an advantage of double absorption of thermal energy from the waste heat source.
Further, the high-efficiency absorption heat pump system having increased utilization rate of a waste heat source according to the present invention may be provided with the low temperature regenerator that performs first heat exchange in the evaporator, absorbs thermal energy from the waste heat source discharged by the heat exchange process, and supplies the absorbed thermal energy to the absorber. Therefore, there is another advantage of more efficiently recovering the waste heat source.
Further, with regard to the high-efficiency absorption heat pump system having increased utilization rate of a waste heat source according to the present invention, the LiBr solution for absorbing the thermal energy in the low temperature regenerator fed to the high temperature regenerator, and the LiBr solution for absorbing the thermal energy in the high temperature regenerator is fed to the absorber, so that the LiBr solution circulating through the absorber, the low temperature regenerator and the high temperature regenerator may circulate to the absorber in a high temperature state. Further, there is an advantage of efficiently heating the hot water circulating to flash tank while the LiBr solution is sprayed in the absorber maintained in a pressure state of more than a set pressure.

DESCRIPTION OF DRAWINGS

FIG. 1 is a configuration diagram illustrating the high-efficiency absorption heat pump system with increased utilization rate of a waste heat source according to one embodiment of the present invention.

BEST MODE

The most preferred embodiment of the high-efficiency heat pump system having increased utilization rate of a waste heat source according to the present invention may have a configuration of: an evaporator to which a waste heat source inlet line through which a waste heat source inflows, is connected to absorb thermal energy from the waste heat source, and to which a refrigerant inlet line for supplying a refrigerant is connected; an absorber connected to the evaporator such that steam evaporated in the evaporator is fed thereto, to which a hot water inlet line and a hot water outlet line extending from a flash tank are connected; a high temperature regenerator through which a waste heat source divide line branching off from the waste heat source inlet line passes, which heats an LiBr solution fed to the absorber and regenerates the same, and is provided with a concentrated solution line for supplying the LiBr solution to the absorber; an auxiliary absorber to which the steam evaporated from the high temperature regenerator is transferred and which is connected to the high temperature regenerator in order to cool the steam and circulate the same; a low temperature regenerator to which an intermediate solution line is connected to supply the LiBr solution to the high temperature regenerator, through which a waste heat source return line extending from the evaporator passes, and to which a diluted solution line extending from the absorber is connected; a condenser through which a chilled water inlet line for supplying the cooling water passes such that the steam evaporated from the low temperature regenerator is fed and cooled therein, and which is connected to the low temperature regenerator; and an auxiliary regenerator to which an auxiliary solution line is connected to supply auxiliary LiBr solution to the auxiliary absorber, through which the waste heat source divide line passes, and to which an auxiliary diluted solution line extending from the auxiliary absorber is connected.

Preferred Embodiment of Invention

One embodiment of the high-efficiency absorption heat pump system having increased utilization rate of a waste heat source according to the present invention will be described below with reference to the accompanying drawings.
In the description, thicknesses of the lines and sizes of the components illustrated in the FIGURES may be exaggerated for clarity of explanation.
Further, terms described later are defined in consideration of functions in the present invention and may be altered according to custom or intention of users or operators.
Therefore, the definition of such terms should be made on the basis of contents throughout the disclosure.
FIG. 1 is a configuration diagram illustrating absorption heat pump type II system in accordance with one embodiment of the present invention.
Referring to FIG. 1, the high-efficiency heat pump system having increased utilization rate of a waste heat source according to one embodiment of the present invention may include: an evaporator 10 to which a waste heat source inlet line 12 through which a waste heat source inflows, is connected to absorb thermal energy from the waste heat source, and to which a refrigerant inlet line 76 a for supplying a refrigerant is connected; an absorber 30 connected to the evaporator 10 such that steam evaporated in the evaporator 10 is fed thereto, to which a hot water inlet line 32 and a hot water outlet line 34 extending from a flash tank 34 a are connected; a high temperature regenerator 50 through which a waste heat source divide line 12 a branching off from the waste heat source inlet line 12 passes, which heats an LiBr solution fed to the absorber 30 and regenerates the same, and is provided with a concentrated solution line 52 for supplying the LiBr solution to the absorber 30; an auxiliary absorber 54 to which the steam evaporated from the high temperature regenerator 50 is transferred and which is connected to the high temperature regenerator 50 in order to cool the steam and circulate the same; a low temperature regenerator 70 to which an intermediate solution line 72 is connected to supply the LiBr solution to the high temperature regenerator 50, through which a waste heat source return line 14 extending from the evaporator 10 passes, and to which a diluted solution line 36 extending from the absorber 30 is connected; a condenser 76 through which a chilled water inlet line 56 for supplying the cooling water passes such that the steam evaporated from the low temperature regenerator 70 is fed and cooled therein, and which is connected to the low temperature regenerator 70; and an auxiliary regenerator 80 to which an auxiliary solution line 82 is connected to supply auxiliary LiBr solution to the auxiliary absorber 54, through which the waste heat source divide line 12 a passes, and to which an auxiliary diluted solution line 58 extending from the auxiliary absorber 54 is connected.
The heat pump according to the present embodiment is a device to recover thermal energy from a waste heat source while passing the waste heat source discharged from a facility such as a power plant wherein a high temperature process proceeds through the same, thereby enabling the recovered thermal energy to be recycled in industrial processes.
The waste heat source fed to the evaporator 10 through the waste heat source inlet line 12 may be evaporated as steam when the refrigerant passing through the evaporator 10 is in contact with the waste heat source inlet line 12 bent in a heat exchanger shape and absorbs thermal energy, and the steam may move to the absorber 30 through a 1^steliminator and supply the thermal energy to hot water when the refrigerant is in contact with the hot water inlet line 32 passing through the absorber 30.
Herein, the LiBr solution spraying inside the absorber 30 through a concentrated solution distribution nozzle 52 a may be instantaneously heated under pressure conditions in the evaporator 10 and the absorber 30, in particular, by a high pressure of about 400 mmHg, and may be in contact with the hot water inlet line 32 passing through the absorber 30, thereby supplying the hot water at about 125 to 135° C. After supplying the thermal energy to the hot water inlet line 32, the LiBr solution is changed into a low temperature diluted solution in decreased concentration, is discharged through the diluted solution line 36, is fed to the low temperature regenerator 70, and is in contact with the waste heat source return line 14 extending from the evaporator 10, thereby absorbing the thermal energy again from the waste heat source.
The waste heat source inlet line 12 may be provided with the waste heat source divide line 12 a branching off from one side of the inlet line, wherein the waste heat source divide line 12 a passes through the high temperature regenerator 50 and is subjected to heat exchange with the LiBr solution fed from the low temperature regenerator 70. In this regard, the LiBr solution discharged from the high temperature regenerator 50 is fed to the absorber 30 along the concentrated solution line 52 and subjected to heat exchange with the hot water inlet line 32 to facilitate efficient heating of the hot water.
The steam evaporated from the high temperature regenerator passes through a 2^nd eliminator 24, is fed to the auxiliary absorber 54 and is in contact with the chilled water inlet lines 56 and 57, thereby being cooled under heat exchange with the cooling water.
The refrigerant cooled in the condenser 76 is fed to the evaporator through the refrigerant inlet line 76 a, and absorbs thermal energy from the waste heat source while being in contact with the waste heat source inlet line 12 to thus be evaporated. Then, the evaporated steam moves to the absorber 30 and thus may heat the hot water.
According to the present embodiment, the evaporator 10 absorbs the thermal energy from the waste heat source and supplies the absorbed thermal energy to the absorber. Then, the high temperature regenerator 50 and the low temperature regenerator 70 receive the thermal energy from the waste heat source and heat the LiBr solution discharged from the absorber 30 to increase a concentration of the LiBr solution, that is, perform a reproduction process.
Further, the LiBr solution fed under pressure from the low temperature regenerator 70 is supplied to the high temperature regenerator 50 and is heated by the waste heat source and converted into a concentrated solution. The LiBr solution-based concentrated solution is fed to the absorber 30, heated under a high pressure at a high temperature and sprayed.
Accordingly, the high temperature steam fed from the evaporator 10 and the high temperature LiBr solution sprayed from the concentrated solution distribution nozzle 52 a may be in contact with the hot water inlet line 32 inside the absorber 30, thereby supplying hot water at a high temperature.
Further, since the concentrated solution line 52 in the present embodiment passes through a high temperature solution heat exchanger 36 a disposed in the diluted solution line 36, heat exchange may be performed between the LiBr solution discharged from the absorber 30 and the LiBr solution discharged from the high temperature regenerator 50. Further, the thermal energy of the LiBr solution in the absorber 30, which is at a relatively high temperature, is absorbed by the LiBr solution in the high temperature regenerator 50, which in turn is heated and supplied to the absorber 30.
Accordingly, a recovery operation may be performed such that the thermal energy of the LiBr solution discharged from the absorber 30 without heat exchange is circulated back to the absorber 30.
Further, the intermediate solution line 72 passes through a low temperature solution heat exchanger 36 b disposed in the diluted solution line 36 and may perform recovery of the thermal energy twice from the LiBr solution discharged from the absorber 30 through heat exchange between the LiBr solution discharged from the absorber 30 and the LiBr solution discharged from the low temperature regenerator 70.
Since the concentrated solution distribution nozzle 52 a connected to the concentrated solution line 52 to spray the LiBr solution throughout the inside of the absorber 30 is disposed in the absorber 30, the refrigerant may be uniformly in contact with the entire portion of the heat exchanger in the hot water inlet line 32 disposed in the absorber 30. Further, a refrigerant distribution nozzle 16 a is disposed in the evaporator 10 and, when the refrigerant fed to the evaporator 10 is supplied again along a refrigerant circulation line 16, the refrigerant sprayed from the refrigerant distribution nozzle 16 a may be uniformly sprayed throughout a coil connected to the waste heat source inlet line 12.
The high temperature regenerator 50 is provided with an intermediate solution distribution nozzle 74 connected to the intermediate solution line 72 wherein the LiBr solution circulating in the low temperature regenerator 70 may be uniformly sprayed throughout the heat exchanger connected to the intermediate solution line 72, thereby performing effective heat exchange.
The low temperature regenerator 70 is provided with a diluted solution distribution nozzle 36 c connected to the diluted solution line 36 wherein the LiBr solution may be uniformly sprayed throughout the heat exchanger connected to the waste heat source return line 14, thereby performing effective heat exchange operation.
Further, the auxiliary solution line 82 in the present embodiment passes through the auxiliary solution heat exchanger 58 a disposed in the auxiliary diluted solution line 58, so that the auxiliary LiBr solution discharged from the auxiliary absorber 54 and the auxiliary LiBr solution discharged from the auxiliary regenerator 80 may be subjected to heat exchange inside the auxiliary solution heat exchanger 58 a and, at the same time, the auxiliary LiBr solution in the auxiliary regenerator may be cooled by the auxiliary LiBr solution in the auxiliary absorber 54, which is at a relatively low temperature.
Accordingly, the auxiliary LiBr solution cooled while being subjected to heat exchange with the cooling water inside the auxiliary absorber 54 may cool the refrigerant discharged from the auxiliary regenerator 80, and further may be sprayed into the heat exchanger disposed in the auxiliary regenerator 80 through the auxiliary diluted solution distribution nozzle 58 b disposed in the auxiliary regenerator 80 and cool the waste heat source discharged along the waste heat source divide line 12 a.
As described above, since the waste heat source discharged along the waste heat source divide line 12 a is subjected to heat exchange inside the auxiliary regenerator 80 by the refrigerant cooled using the cooling water, the waste heat source discharged from the heat pump may be prevented from being discharged at a higher temperature than a predetermined temperature.
Further, the low temperature regenerator 70 and the condenser 76 in the present embodiment may be integrally installed to be connected and flow through each other by a 3^rdeliminator. Further, the condenser 76 and the auxiliary regenerator 80 may be integrally installed to be connected and flow through each other by a 4^theliminator 28. As a result, when the LiBr solution sprayed from the diluted solution distribution nozzle 36 c in the low temperature regenerator 70 through which the waste heat source return line passes, is evaporated, the evaporated LiBr solution may move to the condenser 76 through the 3^rdeliminator, be cooled therein, and be cooled again and liquefied while being in contact with the heat exchanger in the chilled water inlet line 56 passing through the condenser 76.
The refrigerant liquefied in the condenser 76 may be fed to the evaporator along the refrigerant inlet line 76 a, and subjected to heat exchange in order to absorb thermal energy from the waste heat source while being in contact with the heat exchanger in the waste heat source inlet line 12 by the refrigerant distribution nozzle 16 a.
The LiBr solution regenerated into a concentrated solution with increased concentration by absorbing the thermal energy in the high temperature regenerator 50 may be supplied again to the concentrated solution distribution nozzle 52 a in the absorber 30 along the concentrated solution line 52 and then sprayed in the heat exchanger in the hot water inlet line 32, thereby exhibiting effects of heating hot water in two-stages.
Further, the auxiliary regenerator 80 may be integrally installed with the condenser 76 to be connected and flow through each other by the 4^theliminator 28, so that steam evaporated while being in contact with the heat exchanger of the waste heat branch 12 in the auxiliary regenerator 80 may move to the condenser 76, be cooled and liquefied while being in contact with the heat exchanger in the chilled water inlet line 56 passing through the condenser 76, and then, be sprayed into the heat exchanger in the waste heat source inlet line 12 disposed in the evaporator 10 through the refrigerant distribution nozzle 16 a disposed in the evaporator 10, along the refrigerant inlet line 76 a.
Numerals 52 a and 84 refer to the concentrated solution distribution nozzle 52 a disposed in the absorber 30 and connected to the concentration solution line 52, and an auxiliary solution distribution nozzle 84 disposed in the auxiliary absorber 54 and connected to the auxiliary solution line 82, respectively.
As such, it is possible to supply steam or hot water required in industrial processes by circulating two kinds of working fluids consisting of a refrigerant and an LiBr solution to absorb thermal energy from the waste heat source. Further, it is possible to provide absorption heat pump type II system wherein two regeneration cycles for circulating the LiBr solution are associated with a refrigerant circulation cycle so as to efficiently recover waste heat.
Although the present invention has been described by one embodiment shown in the drawing by reference, this is proposed for illustrative purposes only and it will be appreciated by those skilled in the art, to which the present invention pertains, that various modifications and other equivalents are possible from the above embodiment.
Further, although a high-efficiency absorption heat pump system with increased utilization rate of a waste heat source has been described, this is proposed as an illustrative embodiment only, and the heat pump system of the present invention may also be applied to different products other than such a high-efficiency absorption heat pump system having increased utilization rate of a waste heat source as described above.
Therefore, a true technical scope of the present invention to be protected will be defined by the appended claims.

Claims

1. A high-efficiency absorption heat pump system having increased utilization rate of a waste heat source, comprising:

an evaporator to which a waste heat source inlet line 12 through which a waste heat source inflows, is connected to absorb thermal energy from the waste heat source, and to which a refrigerant inlet line for supplying a refrigerant is connected;

an absorber connected to the evaporator such that steam evaporated in the evaporator is fed thereto, to which a hot water inlet line and a hot water outlet line extending from a flash tank are connected;

a high temperature regenerator through which a waste heat source divide line branching off from the waste heat source inlet line passes, which heats LiBr solution fed to the absorber and regenerates the same, and is provided with a concentrated solution line for supplying the LiBr solution to the absorber;

an auxiliary absorber to which the steam evaporated from the high temperature regenerator is transferred and which is connected to the high temperature regenerator in order to cool the steam and circulate the same;

a low temperature regenerator to which an intermediate solution line is connected to supply the LiBr solution to the high temperature regenerator, through which a waste heat source return line extending from the evaporator passes, and to which a diluted solution line extending from the absorber is connected;

a condenser through which a chilled water inlet line for supplying the cooling water passes such that the steam evaporated from the low temperature regenerator is fed and cooled therein, and which is connected to the low temperature regenerator; and

an auxiliary regenerator to which an auxiliary solution line is connected to supply auxiliary LiBr solution to the auxiliary absorber, through which the waste heat source divide line passes, and to which an auxiliary diluted solution line extending from the auxiliary absorber is connected.

2. The system according to claim 1, wherein the concentrated solution line passes through a high temperature solution heat exchanger disposed in the diluted solution line.

3. The system according to claim 1, wherein the intermediate solution line passes through a low temperature solution heat exchanger installed in the diluted solution line.

4. The system according to claim 1, wherein the auxiliary solution line passes through an auxiliary solution heat exchanger disposed in the auxiliary diluted solution line.