Two-stage first type lithium bromide absorption heat pump with two-stage evaporator connected at the bottom

Abstract

The application discloses a two-stage first-type lithium bromide absorption heat pump machine with two-stage evaporators connected at the bottom, which comprises a condenser, a secondary generator, a high-pressure stage secondary absorber, a high-pressure stage evaporator, a low-pressure stage secondary absorber, a low-pressure stage evaporator, a primary generator, a primary absorber, a primary heat exchanger, a secondary heat exchanger and pipelines arranged between the components. The main feature of the machine set is that the low-temperature waste heat source is divided into two sections, the high-temperature coolant water enters the high-pressure stage evaporator after flashing, then enters the high-pressure stage evaporator liquid tank, and the amount of coolant water used in the high-pressure stage evaporator and the low-pressure stage evaporator is automatically distributed through the coolant water connecting pipe. After being divided into sections, the concentration difference of the solution circulation is increased, the heat exchange temperature difference is increased, the heat exchange area is reduced, the material cost of the machine set is reduced, the equipment investment cost is reduced, the machine set is beautiful in appearance, compact in structure, high in performance coefficient, more waste heat can be recycled, and the comprehensive utilization rate of energy is improved.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment technology, and more specifically, to a two-stage type I lithium bromide absorption heat pump with two-stage evaporators connected at the bottom. Background Technology

[0002] In existing technologies, medium-temperature hot water is needed in production processes or daily life, but obtaining this water requires energy. Simultaneously, a large amount of medium (low) temperature waste heat is generated during production processes, some of which is discharged unusable, resulting in waste. To save energy and reduce emissions, lithium bromide heat pump heating technology, driven by a high-temperature heat source, recovers and utilizes this low-temperature waste heat to produce medium-temperature hot water, saving 40% of energy consumption and achieving comprehensive energy utilization.

[0003] In applications of lithium bromide heat pump heating technology, different types of heat pump units are selected based on the quality of the driving heat source, low-temperature waste heat, and required medium-temperature hot water parameters. Commonly used lithium bromide heat pumps include single-effect, double-effect, and two-stage type I lithium bromide absorption heat pumps. When the provided external parameters cannot be met by single-effect and double-effect lithium bromide heat pumps, a two-stage type I lithium bromide absorption heat pump with a lower coefficient of performance (COP) is considered. The COP of a typical two-stage type I lithium bromide absorption heat pump is around 1.4.

[0004] The structure of a typical two-stage lithium bromide absorption heat pump is as follows: Figure 1 As shown, it includes a condenser 1, a secondary generator 2, a secondary absorber 3, an evaporator 4, a primary generator 5, a primary absorber 6, a secondary dilute solution pump 7, a refrigerant pump 8, a primary concentrated solution pump 9, a primary dilute solution pump 10, a primary heat exchanger 11, and a secondary heat exchanger 12.

[0005] However, in practical applications, when the driving heat source has a low grade, the low-temperature waste heat source outlet temperature is low, and the medium-temperature hot water outlet temperature requirement is high, ordinary two-stage type I lithium bromide absorption heat pump units struggle to meet the requirements or incur high investment costs due to the limitations of these poor parameter conditions. How to solve these problems—that is, how to ensure the heat pump unit meets parameter requirements even under poor external conditions, while also reducing investment costs, improving the coefficient of performance, recovering more waste heat, and saving energy—has become one of the important research topics.

[0006] In summary, how to ensure that heat pump units can meet usage requirements, improve the coefficient of performance, recover more waste heat, and save energy under poor external operating conditions is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a two-stage type I lithium bromide absorption heat pump with two-stage evaporators connected at the bottom, which can ensure that the heat pump unit can meet the usage requirements and save more energy even under poor external operating conditions.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A two-stage lithium bromide absorption heat pump with two-stage evaporators connected at the bottom includes: a condenser, a secondary generator, a high-pressure secondary absorber, a high-pressure evaporator, a low-pressure secondary absorber, a low-pressure evaporator, a primary generator, a primary absorber, a primary heat exchanger, a secondary heat exchanger, and piping for connecting the components.

[0010] A refrigerant-water connecting pipeline is provided between the bottom of the liquid bladder of the high-pressure section evaporator and the bottom of the liquid bladder of the low-pressure section evaporator. A high-pressure section refrigerant pump is provided at the bottom of the liquid bladder of the high-pressure section evaporator, and a high-pressure section refrigerant-water pipeline is provided between the outlet of the high-pressure section refrigerant pump and the spray pipe of the high-pressure section evaporator. A low-pressure section refrigerant pump is provided at the bottom of the liquid bladder of the low-pressure section evaporator, and a low-pressure section refrigerant-water pipeline is provided between the outlet of the low-pressure section refrigerant pump and the spray pipe of the low-pressure section evaporator.

[0011] The bottom of the condenser is provided with a high-temperature refrigerant water throttling pipe, which is connected to the flash tube of the high-pressure section evaporator;

[0012] A low-pressure section secondary intermediate solution pump is provided at the bottom of the liquid bladder of the low-pressure section secondary absorber. An intermediate solution pipeline is provided between the outlet of the low-pressure section secondary intermediate solution pump and the spray pipe of the high-pressure section secondary absorber. A high-pressure section secondary dilute solution pump is provided at the bottom of the liquid bladder of the high-pressure section secondary absorber. A secondary dilute solution pipeline is provided between the outlet of the high-pressure section secondary dilute solution pump and the primary heat exchanger.

[0013] Preferably, the high-pressure section evaporator and the high-pressure section secondary absorber are in one cavity; the low-pressure section evaporator and the low-pressure section secondary absorber are in another cavity.

[0014] Preferably, the low-pressure section evaporator and the low-pressure section secondary absorber, the condenser and the secondary generator are disposed in the first cylinder, which is divided into two chambers by a vertical partition and is located at the top of the unit;

[0015] The high-pressure section evaporator, the high-pressure section secondary absorber, the primary generator, and the primary absorber are housed in the second cylinder, which is divided into two chambers by a vertical partition and located at the bottom of the unit.

[0016] Preferably, the driving heat source is connected in series and enters the heat transfer tubes of the secondary generator and the primary generator in sequence;

[0017] Alternatively, the driving heat source may be connected in parallel to enter the heat transfer tubes of the secondary generator and the heat transfer tubes of the primary generator.

[0018] Preferably, the low-temperature waste heat source is connected in series and enters the heat transfer tubes of the high-pressure section evaporator and the low-pressure section evaporator in sequence.

[0019] Preferably, the medium-temperature hot water first enters in parallel into the heat transfer tubes of the high-pressure section secondary absorber and the low-pressure section secondary absorber, and then enters in series into the heat transfer tubes of the primary absorber and the condenser.

[0020] When using the two-stage lithium bromide absorption heat pump provided by the present invention, the solution circulation process of the unit consists of two relatively independent solution circulations. One solution circulation consists of a primary generator, a low-pressure secondary absorber, a high-pressure secondary absorber, and a primary heat exchanger; the other solution circulation consists of a primary absorber, a secondary generator, and a secondary heat exchanger.

[0021] The refrigerant cycle of the entire unit is as follows: High-temperature refrigerant vapor generated by the secondary generator enters the condenser and is condensed into high-temperature refrigerant water. The high-temperature refrigerant water enters the high-pressure section evaporator for flashing through the high-temperature refrigerant water throttling pipeline. The unflashed refrigerant water enters the bottom of the liquid sac of the high-pressure section evaporator, and a portion of the refrigerant water enters the bottom of the liquid sac of the low-pressure section evaporator through the refrigerant water connecting pipeline. The low-pressure section refrigerant pump pumps a portion of the refrigerant water into the low-pressure section evaporator for evaporation into refrigerant vapor I. Refrigerant vapor I is absorbed by the concentrated solution at the primary generator to become an intermediate solution.

[0022] The high-pressure section refrigerant pump pumps another portion of the refrigerant water into the high-pressure section evaporator to evaporate into refrigerant vapor II. Refrigerant vapor II is absorbed by the intermediate solution from the low-pressure section secondary absorber and becomes a dilute solution. This dilute solution enters the primary generator to concentrate and produce low-temperature refrigerant vapor, which then enters the primary absorber. The low-temperature refrigerant vapor is absorbed by the higher-concentration concentrated solution from the secondary generator and becomes a low-concentration dilute solution. This low-concentration dilute solution enters the secondary generator to concentrate and produce high-temperature refrigerant vapor, and the cycle continues continuously.

[0023] This unit, through the aforementioned novel process and structural layout, divides the low-temperature waste heat source into two stages for cooling. High-temperature refrigerant water flashes in the high-pressure evaporator and then enters the liquid bladder of the high-pressure evaporator. The refrigerant water automatically distributes its usage between the high-pressure and low-pressure evaporators via a refrigerant water interconnection pipeline. The concentrated solution from the primary generator first absorbs refrigerant vapor in the low-pressure secondary absorber to become an intermediate solution, before entering the high-pressure secondary absorber to continue absorbing refrigerant vapor, resulting in an even lower concentration dilute solution. This increased concentration difference in the circulating solution leads to a higher heat exchange temperature difference, a smaller heat exchange area, a lower solution circulation volume, and a lower heat load on the heat exchanger. This reduces material costs and equipment investment costs, while also resulting in a more aesthetically pleasing, compact, and efficient unit that recovers more waste heat and improves overall energy utilization.

[0024] In summary, the two-stage lithium bromide absorption heat pump provided by the present invention, with its two-stage evaporator connected at the bottom, can ensure that the heat pump unit can meet the usage requirements, improve the coefficient of performance of the equipment, recover more waste heat, and save energy even under poor external operating conditions. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a typical two-stage type I lithium bromide absorption heat pump.

[0027] Figure 2 This is a schematic diagram of the structure of a two-stage, first-type lithium bromide absorption heat pump with two-stage evaporators connected at the bottom, as provided by the present invention.

[0028] Figures 1-2 middle:

[0029] 1 is the condenser, 2 is the secondary generator, 3 is the secondary absorber, 4 is the evaporator, 5 is the primary generator, 6 is the primary absorber, 7 is the secondary dilute solution pump, 8 is the refrigerant pump, 9 is the primary concentrated solution pump, 10 is the primary dilute solution pump, 11 is the primary heat exchanger, 12 is the secondary heat exchanger, 13 is the high-pressure section evaporator, 14 is the high-pressure section secondary absorber, 15 is the high-pressure section secondary dilute solution pump, 16 is the high-temperature refrigerant water throttling pipeline, and 17 is the intermediate solution pipeline. 8 is the low-pressure section secondary absorber, 19 is the low-pressure section evaporator, 20 is the low-pressure section secondary intermediate solution pump, 21 is the low-pressure section refrigerant pump, 22 is the secondary dilute solution pipeline, 23 is the medium-temperature hot water inlet, 24 is the refrigerant water connecting pipeline, 25 is the high-pressure section refrigerant pump, 26 is the high-pressure section refrigerant water pipeline, 27 is the low-pressure section refrigerant water pipeline, 28 is the driving heat source inlet, 29 is the low-temperature waste heat source inlet, 30 is the medium-temperature hot water outlet, 31 is the driving heat source outlet, and 32 is the low-temperature waste heat source outlet. Detailed Implementation

[0030] The core of this invention is to provide a two-stage, first-class lithium bromide absorption heat pump with two interconnected bottom sections of the evaporator, which can ensure that the heat pump unit can meet the usage requirements and save more energy even under poor external operating conditions.

[0031] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a two-stage, first-type lithium bromide absorption heat pump with two-stage evaporators connected at the bottom, as provided by the present invention.

[0032] This specific embodiment provides a two-stage type I lithium bromide absorption heat pump with two-stage evaporators connected at the bottom, including: a condenser 1, a secondary generator 2, a high-pressure secondary absorber 14, a high-pressure evaporator 13, a low-pressure secondary absorber 18, a low-pressure evaporator 19, a primary generator 5, a primary absorber 6, a primary heat exchanger 11, a secondary heat exchanger 12, and pipelines for connecting each component.

[0033] A refrigerant-water connecting pipe 24 is provided between the bottom of the liquid bladder of the high-pressure section evaporator 13 and the bottom of the liquid bladder of the low-pressure section evaporator 19. A high-pressure section refrigerant pump 25 is provided at the bottom of the liquid bladder of the high-pressure section evaporator 13, and a high-pressure section refrigerant-water pipe 26 is provided between the outlet of the high-pressure section refrigerant pump 25 and the spray pipe of the high-pressure section evaporator 13. A low-pressure section refrigerant pump 21 is provided at the bottom of the liquid bladder of the low-pressure section evaporator 19, and a low-pressure section refrigerant-water pipe 27 is provided between the outlet of the low-pressure section refrigerant pump 21 and the spray pipe of the low-pressure section evaporator 19.

[0034] The bottom of the condenser 1 is provided with a high-temperature refrigerant water throttling pipe 16, which is connected to the flash tube of the high-pressure section evaporator 13.

[0035] A low-pressure section secondary intermediate solution pump 20 is provided at the bottom of the liquid bladder of the low-pressure section secondary absorber 18. An intermediate solution pipeline 17 is provided between the outlet of the low-pressure section secondary intermediate solution pump 20 and the spray pipe of the high-pressure section secondary absorber 14. A high-pressure section secondary dilute solution pump 15 is provided at the bottom of the liquid bladder of the high-pressure section secondary absorber 14. A secondary dilute solution pipeline 22 is provided between the outlet of the high-pressure section secondary dilute solution pump 15 and the primary heat exchanger 11.

[0036] Preferably, the high-pressure section evaporator 13 and the high-pressure section secondary absorber 14 are in one cavity; the low-pressure section evaporator 19 and the low-pressure section secondary absorber 18 are in another cavity.

[0037] Preferably, the low-pressure section evaporator 19, the low-pressure section secondary absorber 18, the condenser 1, and the secondary generator 2 are located in the first cylinder, which is divided into two chambers by a vertical partition and located at the top of the unit; the high-pressure section evaporator 13, the high-pressure section secondary absorber 14, the primary generator 5, and the primary absorber 6 are located in the second cylinder, which is divided into two chambers by a vertical partition and located at the bottom of the unit, so as to make the device structure more compact.

[0038] Preferably, the driving heat source 28 is connected in series and enters the heat transfer tube of the secondary generator 2 and the heat transfer tube of the primary generator 5 in sequence, heating the solution outside the tube to concentrate it and generate refrigerant vapor. After the driving heat source releases heat, it flows out of the unit from the driving heat source outlet 31.

[0039] Alternatively, the heat source can be driven into the heat transfer tubes of the secondary generator 2 and the primary generator 5 in parallel, heating the solution outside the tubes to concentrate it and generate refrigerant vapor. After the heat source releases heat, the vapor flows out of the unit from the heat source outlet 31.

[0040] Preferably, the low-temperature waste heat source 29 is connected in series and enters the heat transfer tubes of the high-pressure section evaporator 13 and the low-pressure section evaporator 19 in sequence to heat the refrigerant water outside the tubes to make it evaporate. After releasing heat, the low-temperature waste heat source flows out of the unit from the low-temperature waste heat source outlet 32.

[0041] Preferably, the medium-temperature hot water inlet 23 first enters in parallel into the heat transfer tubes of the high-pressure section secondary absorber 14 and the low-pressure section secondary absorber 18, and then enters in series into the heat transfer tubes of the primary absorber 6 and the condenser 1. After the medium-temperature hot water absorbs heat and its temperature increases, it flows out of the unit from the medium-temperature hot water outlet 30.

[0042] Preferably, the driving heat source and the low-temperature heat source are water, heat transfer oil, steam, or other heat transfer media.

[0043] When the two-stage lithium bromide absorption heat pump provided by the present invention has a bottom-connected two-stage evaporator, its solution circulation process consists of two relatively independent solution circulations. One solution circulation with a relatively high concentration consists of a primary generator 5, a low-pressure secondary absorber 18, a high-pressure secondary absorber 14, and a primary heat exchanger 11. The other solution circulation with a relatively low concentration consists of a primary absorber 6, a secondary generator 2, and a secondary heat exchanger 12.

[0044] A relatively concentrated solution circulation process is as follows: The concentrated solution from the primary generator 5 is lifted by the primary concentrated solution pump 9, cooled by the primary heat exchanger 11, and enters the low-pressure secondary absorber 18 to absorb the refrigerant vapor evaporated by the low-pressure evaporator 19, becoming a lower concentration intermediate solution. The intermediate solution is pumped by the low-pressure secondary intermediate solution pump 20 into the high-pressure secondary absorber 14 to continue absorbing the refrigerant vapor evaporated by the high-pressure evaporator 13, becoming a dilute solution. The dilute solution is lifted by the high-pressure secondary dilute solution pump 15, heated by the primary heat exchanger 11, and then enters the primary generator 5 to be concentrated into a high concentration concentrated solution.

[0045] Another solution with a relatively low concentration is circulated as follows: The concentrated solution from the secondary generator 2 is cooled by the pressure difference and height difference through the secondary heat exchanger 12 and flows into the primary absorber 6 to absorb the refrigerant vapor generated by the primary generator 5 and become a low-concentration dilute solution. The low-concentration dilute solution is lifted by the primary dilute solution pump 10, heated by the secondary heat exchanger 12, and then enters the secondary generator 2 to be concentrated into a higher concentration solution.

[0046] The refrigerant cycle of the entire unit is as follows: High-temperature refrigerant vapor generated by the concentrated solution in the secondary generator 2 enters the condenser 1 and is condensed into high-temperature refrigerant water. The high-temperature refrigerant water enters the high-pressure section evaporator 13 for flashing through the high-temperature refrigerant water throttling pipe 16. The refrigerant water that does not flash enters the bottom of the liquid bladder in the high-pressure section evaporator 13. A portion of the refrigerant water enters the bottom of the liquid bladder in the low-pressure section evaporator 19 through the refrigerant water connecting pipe 24. The low-pressure section refrigerant pump 21 pumps a portion of the refrigerant water into the low-pressure section evaporator 19 to evaporate into refrigerant vapor I. Refrigerant vapor I is absorbed by the concentrated solution from the primary generator 5 and becomes an intermediate solution.

[0047] The high-pressure section refrigerant pump 25 pumps another portion of refrigerant water into the high-pressure section evaporator 13 to evaporate into refrigerant vapor II. Refrigerant vapor II is absorbed by the intermediate solution from the low-pressure section secondary absorber 18 and becomes a dilute solution. This dilute solution enters the primary generator 5 to concentrate and generate low-temperature refrigerant vapor, which then enters the primary absorber 6. The low-temperature refrigerant vapor is absorbed by the higher-concentration concentrated solution from the secondary generator 2 and becomes a low-concentration dilute solution. This low-concentration dilute solution enters the secondary generator 2 to concentrate and generate high-temperature refrigerant vapor, and so on in a continuous cycle.

[0048] This unit, through the aforementioned novel process and structural layout, divides the low-temperature waste heat source into two stages for cooling. High-temperature refrigerant water flashes into the high-temperature evaporator 13 and then enters the liquid bladder of the high-temperature evaporator 13. The refrigerant water automatically distributes its usage between the high-pressure evaporator 13 and the low-pressure evaporator 19 via the refrigerant water connecting pipe 24. The concentrated solution from the primary generator 5 first absorbs refrigerant vapor in the low-pressure secondary absorber 18 to become an intermediate solution, and then enters the high-pressure secondary absorber 14 to continue absorbing refrigerant vapor, making it a dilute solution with an even lower concentration. This increases the concentration difference of the circulating solution, improves the heat exchange temperature difference, reduces the heat exchange area, decreases the solution circulation volume, and reduces the heat load of the heat exchanger. This reduces the material cost of manufacturing the unit, lowers the equipment investment cost, and also makes the unit aesthetically pleasing, compact, and improves the coefficient of performance, allowing for the recovery of more waste heat and improving the overall energy utilization rate.

[0049] In summary, the two-stage lithium bromide absorption heat pump provided by the present invention, with its two-stage evaporator connected at the bottom, can ensure that the heat pump unit can meet the usage requirements, improve the coefficient of performance of the equipment, recover more waste heat, and save energy even under poor external operating conditions.

Claims

1. A two-stage, first-class lithium bromide absorption heat pump with two interconnected bottom sections of evaporators, characterized in that, include: Condenser (1), secondary generator (2), high-pressure section secondary absorber (14), high-pressure section evaporator (13), low-pressure section secondary absorber (18), low-pressure section evaporator (19), primary generator (5), primary absorber (6), primary heat exchanger (11), secondary heat exchanger (12) and piping for connecting the components. A refrigerant-water connecting pipe (24) is provided between the bottom of the liquid bladder of the high-pressure section evaporator (13) and the bottom of the liquid bladder of the low-pressure section evaporator (19). A high-pressure section refrigerant pump (25) is provided at the bottom of the liquid bladder of the high-pressure section evaporator (13). A high-pressure section refrigerant water pipe (26) is provided between the outlet of the high-pressure section refrigerant pump (25) and the spray pipe of the high-pressure section evaporator (13). A low-pressure section refrigerant pump (21) is provided at the bottom of the liquid bladder of the low-pressure section evaporator (19). A low-pressure section refrigerant water pipe (27) is provided between the outlet of the low-pressure section refrigerant pump (21) and the spray pipe of the low-pressure section evaporator (19). The bottom of the condenser (1) is provided with a high-temperature refrigerant water throttling pipe (16), which is connected to the flash tube of the high-pressure section evaporator (13). A low-pressure section secondary intermediate solution pump (20) is provided at the bottom of the liquid bladder of the low-pressure section secondary absorber (18). An intermediate solution pipeline (17) is provided between the outlet of the low-pressure section secondary intermediate solution pump (20) and the spray pipe of the high-pressure section secondary absorber (14). A high-pressure section secondary dilute solution pump (15) is provided at the bottom of the liquid bladder of the high-pressure section secondary absorber (14). A secondary dilute solution pipeline (22) is provided between the outlet of the high-pressure section secondary dilute solution pump (15) and the primary heat exchanger (11). The solution circulation process of the two-stage lithium bromide absorption heat pump with the bottom of the two-stage evaporator connected includes two relatively independent solution circulations. One solution circulation with a relatively high concentration includes the first-stage generator (5), the low-pressure section secondary absorber (18), the high-pressure section secondary absorber (14), and the first-stage heat exchanger (11). The other solution circulation with a relatively low concentration includes the first-stage absorber (6), the secondary generator (2), and the secondary heat exchanger (12). The circulation process of the relatively concentrated solution is as follows: the concentrated solution from the first-stage generator (5) is lifted by the first-stage concentrated solution pump (9), cooled by the first-stage heat exchanger (11), and enters the low-pressure section secondary absorber (18) to absorb the refrigerant vapor evaporated by the low-pressure section evaporator (19) to become a low-concentration intermediate solution. The intermediate solution is pumped by the low-pressure section secondary intermediate solution pump (20) into the high-pressure section secondary absorber (14) to continue absorbing the refrigerant vapor evaporated by the high-pressure section evaporator (13) to become a dilute solution. The dilute solution is lifted by the high-pressure section secondary dilute solution pump (15), heated by the first-stage heat exchanger (11), and then enters the first-stage generator (5) to be concentrated into a high-concentration concentrated solution. The circulation process of the relatively dilute solution is as follows: the concentrated solution coming out of the secondary generator (2) is cooled by the pressure difference and height difference through the secondary heat exchanger (12) and flows into the primary absorber (6) to absorb the refrigerant vapor generated by the primary generator (5) and become the low-concentration dilute solution. The low-concentration dilute solution is lifted by the primary dilute solution pump (10) and heated by the secondary heat exchanger (12) before entering the secondary generator (2) to be concentrated into the relatively concentrated solution. The refrigerant circulation process of the entire unit is as follows: the high-temperature refrigerant vapor generated by the concentrated solution of the secondary generator (2) enters the condenser (1) and is condensed into high-temperature refrigerant water. The high-temperature refrigerant water enters the high-pressure section evaporator (13) through the high-temperature refrigerant water throttling pipe (16) and flashes. The refrigerant water that does not flash enters the bottom of the liquid bladder of the high-pressure section evaporator (13). A portion of the refrigerant water enters the bottom of the liquid bladder of the low-pressure section evaporator (19) through the refrigerant water connecting pipe (24). The low-pressure section refrigerant pump (21) pumps a portion of the refrigerant water into the low-pressure section evaporator (19) and evaporates it into refrigerant vapor I. The refrigerant vapor I is absorbed by the concentrated solution from the primary generator (5) and becomes an intermediate solution. The high-pressure section refrigerant pump (25) pumps another portion of refrigerant water into the high-pressure section evaporator (13) to evaporate into refrigerant vapor II. The refrigerant vapor II is absorbed by the intermediate solution from the low-pressure section secondary absorber (18) to become the dilute solution. The dilute solution enters the primary generator (5) to concentrate and generate low-temperature refrigerant vapor, which then enters the primary absorber (6). The low-temperature refrigerant vapor is absorbed by the higher-concentration concentrated solution from the secondary generator (2) to become the low-concentration dilute solution. The low-concentration dilute solution enters the secondary generator (2) to concentrate and generate high-temperature refrigerant vapor, and so on in a continuous cycle.

2. The two-stage, first-type lithium bromide absorption heat pump with two interconnected bottom sections in claim 1, characterized in that, The high-pressure section evaporator (13) and the high-pressure section secondary absorber (14) are in one cavity; the low-pressure section evaporator (19) and the low-pressure section secondary absorber (18) are in another cavity.

3. The two-stage, first-type lithium bromide absorption heat pump with two interconnected bottom sections in claim 2, characterized in that, The low-pressure section evaporator (19), the low-pressure section secondary absorber (18), the condenser (1), and the secondary generator (2) are located in the first cylinder, which is divided into two chambers by a vertical partition and located at the top of the unit. The high-pressure section evaporator (13), the high-pressure section secondary absorber (14), the primary generator (5), and the primary absorber (6) are located in the second cylinder, which is divided into two chambers by a vertical partition and located at the bottom of the unit.

4. The two-stage, first-type lithium bromide absorption heat pump with two-stage evaporators connected at the bottom, as described in any one of claims 1 to 3, is characterized in that... The driving heat source (28) is connected in series and enters the heat transfer tube of the secondary generator (2) and the heat transfer tube of the primary generator (5) in sequence; Alternatively, the driving heat source (28) may be connected in parallel to the heat transfer tube of the secondary generator (2) and the heat transfer tube of the primary generator (5).

5. The two-stage first-type lithium bromide absorption heat pump with two-stage evaporators connected at the bottom according to claim 4, characterized in that, The low-temperature waste heat source (29) is connected in series and enters the heat transfer tube of the high-pressure section evaporator (13) and the heat transfer tube of the low-pressure section evaporator (19) in sequence.

6. The two-stage, first-type lithium bromide absorption heat pump with two interconnected bottom sections of the evaporator according to claim 5, characterized in that, The medium-temperature hot water (23) first enters in parallel into the heat transfer tube of the high-pressure section secondary absorber (14) and the heat transfer tube of the low-pressure section secondary absorber (18), and then enters in series into the heat transfer tube of the primary absorber (6) and the heat transfer tube of the condenser (1).

Images