Double-absorption-re-absorption type parallel waste heat utilization synergistic warming heat pump system

Abstract

The invention relates to a double-absorption-re-absorption type parallel waste heat utilization synergistic warming heat pump system which comprises a re-absorber, a resolver, a first-stage absorber, a first-stage generator, a second-stage absorber, a second-stage generator and a solution heat exchanger. The re-absorber is sequentially connected with the solution heat exchanger and the resolver through a liquid discharging pipeline; the resolver is sequentially connected with the solution heat exchanger and the re-absorber through a liquid feeding pipeline; the first-stage generator is sequentially connected with the solution heat exchanger and the first-stage absorber through a liquid discharging pipeline; the first-stage absorber is sequentially connected with the solution heat exchanger and the first-stage generator through a liquid feeding pipeline; the second-stage generator is connected with the solution heat exchanger and the second-stage absorber through a liquid discharging pipeline; the second-stage absorber is sequentially connected with the solution heat exchanger and the second-stage generator through a liquid feeding pipeline. Large temperature rise amplitude and performance coefficient can be achieved, the operation pressure of the absorption heat pump system is further reduced, and the operation stability of the system is improved.

Description

Technical Field

[0001] The invention relates to a double absorption-reabsorption type parallel waste heat utilization synergistic temperature increase heat pump system, belonging to the technical field of heat pumps. Background Art

[0002] Energy is an important cornerstone of economic development and social progress. my country is a major energy consumer. Nearly half of the energy consumed by high-energy-consuming industries such as electricity, steel, cement, glass, nonferrous metals, and petrochemicals is discharged into the environment in the form of waste gas, waste water, waste residue liquid and other waste heat. These industrial waste heat, especially low-grade waste heat at 100°C, is difficult to use effectively and has huge energy-saving potential. Using absorption heat pumps to recover waste heat is an effective means to significantly improve energy utilization and reduce primary energy consumption, which is of great significance for energy conservation and emission reduction.

[0003] However, in the actual application of traditional absorption heat pumps, due to the non-fixed external parameter conditions, sometimes the temperature of waste heat is relatively low, or the user's demand for heat temperature is relatively high, which requires the system to have a large temperature rise. Ordinary single-stage absorption heat pumps cannot meet the requirements, so multi-stage circulation heat pumps are needed to raise the temperature to user requirements. At the same time, higher absorption temperatures bring higher absorption pressures, and high-pressure operation requires stronger and more complex components, which increases system costs. How to reduce the operating pressure while keeping the primary goal of increasing the absorption temperature and simplify the heat pump system structure as much as possible is one of the important research topics at present. Summary of the invention

[0004] Technical problem: The purpose of the present invention is to solve the technical problems of the above-mentioned traditional absorption heat pumps, and to provide a double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system, which uses waste heat to drive the system cycle and raise it to a higher temperature level, and uses the reabsorption cycle to reduce the operating pressure, thereby reducing the strength requirements for system components.

[0005] Technical solution: To achieve the above purpose, a double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system is invented, which adopts the following solution:

[0006] The heat pump system comprises a reabsorber, a resolver, a primary absorber, a primary generator, a secondary absorber, a secondary generator and a solution heat exchanger; the discharge end of the reabsorber is connected to the feed end of the resolver through a liquid discharge pipe, and the discharge end of the resolver is connected to the feed end of the reabsorber through a liquid feed pipe; the discharge end of the primary is connected to the feed end of the primary absorber through a liquid discharge pipe, and the discharge end of the primary absorber is connected to the feed end of the primary generator through a liquid feed pipe; the discharge end of the secondary generator is connected to the feed end of the secondary absorber through a liquid discharge pipe, and the discharge end of the secondary absorber is connected to the feed end of the secondary generator through a liquid feed pipe.

[0007] The steam outlet of the analyzer is connected to the steam inlet of the primary absorber and the secondary absorber through a steam pipeline; the steam outlet of the primary generator is connected to the steam inlet of the reabsorber and the secondary generator through a steam pipeline.

[0008] The heat exchange outlet of the primary absorber is connected to the heat exchange inlet of the secondary generator through an intermediate heat exchange pipeline, and the heat exchange outlet of the secondary generator is connected to the heat exchange inlet of the primary absorber through an intermediate heat exchange pipeline to form a heat exchange loop.

[0009] The liquid discharge pipeline is provided with a solution pump.

[0010] The liquid feed pipeline is provided with a throttle valve.

[0011] A first solution heat exchanger is arranged between the reabsorber and the analyzer, a second solution heat exchanger is arranged between the primary absorber and the primary generator, and a third solution heat exchanger is arranged between the secondary absorber and the secondary generator.

[0012] The operation method of the ammonia solution and the refrigerant steam pipeline is as follows: the ammonia solution in the low-pressure reabsorber absorbs ammonia gas from the primary generator and the secondary generator, and releases heat to the environment of 8-12°C, and the generated ammonia solution with increased concentration is sent to the high-pressure resolver for resolution after being pressurized by the solution pump and preheated by the solution heat exchanger; the ammonia solution absorbs industrial waste heat or other low-grade heat at 70-110°C in the resolver, and the generated ammonia and water mixed steam is condensed through the condensation section of the resolver, and a part of the high-purity ammonia gas is generated and enters the primary absorber; the ammonia solution in the primary absorber absorbs the high-pressure ammonia gas from the resolver, and releases heat to the intermediate heat exchange pipeline, and the generated ammonia solution with increased concentration is sent to the low-pressure primary generator after being depressurized by the solution heat exchanger and the throttle valve; the ammonia solution is heated in a vacuum chamber, and the pressure is reduced by 200 ℃. The primary generator absorbs industrial waste heat or other low-grade heat at 70-110℃, and the generated ammonia and water mixed steam is condensed through the condensation section of the primary generator to produce high-purity ammonia gas, which enters the reabsorber and is absorbed by the ammonia water in the reabsorber; the other part of the high-purity ammonia produced by the high-pressure resolver enters the secondary absorber; the ammonia water in the secondary absorber absorbs the high-pressure ammonia from the resolver and releases high-temperature useful heat of 120-160℃, and the generated ammonia water with increased concentration is sent to the low-pressure secondary generator after being reduced in pressure by the solution heat exchanger and the throttle valve; the ammonia solution absorbs the heat of the intermediate heat exchange pipeline in the secondary generator, and the generated ammonia and water mixed steam is condensed through the condensation section of the secondary generator to produce high-purity ammonia gas, which enters the reabsorber and is absorbed by the ammonia water in the reabsorber.

[0013] Beneficial effects: Due to the adoption of the above technology, the present invention has the following advantages compared with the prior art:

[0014] The present invention discloses a double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system. The present invention provides the absorption heat released by the primary absorber to the generator of the secondary cycle, thereby increasing the generation temperature of the secondary cycle, and thus achieving a higher waste heat temperature increase. In addition, by adopting the reabsorption cycle, replacing the condenser of the traditional system with the reabsorber, and replacing the evaporator of the traditional system with the resolver, the operating pressure of the absorption heat pump system is reduced, thereby improving the safety of the system operation and reducing the strength requirements for the system components. In addition, the resolver and the reabsorber of the two-stage cycle are combined, and the system works at the optimal high-low pressure ratio of the two pressure levels, with a better performance coefficient and a simpler structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0016] Figure 1It is a structural schematic diagram of a double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system of the present invention; the solid line represents the solution pipeline in the solution and refrigerant vapor pipeline, the dotted line represents the refrigerant vapor pipeline, and the dot-dash line represents the intermediate heat exchange pipeline.

[0017] The figure includes: reabsorber 1, analyzer 2, primary absorber 3, primary generator 4, secondary absorber 5, secondary generator 6, first solution heat exchanger 7, second solution heat exchanger 8, third solution heat exchanger 9, intermediate heat exchange pipeline 10, liquid discharge pipeline 11, solution pump 12, liquid feed pipeline 13, throttle valve 14, and steam pipeline 15. DETAILED DESCRIPTION

[0018] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0019] Embodiment 1:

[0020] The heat pump system includes a reabsorber 1, a resolver 2, a primary absorber 3, a primary generator 4, a secondary absorber 5, a secondary generator 6 and a solution heat exchanger; the discharge end of the reabsorber 1 is connected to the feed end of the resolver 2 through a liquid discharge pipe 11, and the discharge end of the resolver 2 is connected to the feed end of the reabsorber 1 through a liquid feed pipe 13; the discharge end of the primary generator 4 is connected to the feed end of the primary absorber 3 through a liquid discharge pipe 11, and the discharge end of the primary absorber 3 is connected to the feed end of the primary generator 4 through a liquid feed pipe 13; the discharge end of the secondary generator 6 is connected to the feed end of the secondary absorber 5 through a liquid discharge pipe 11, and the discharge end of the secondary absorber 5 is connected to the feed end of the secondary generator 6 through a liquid feed pipe 13.

[0021] Embodiment 2:

[0022] As an improvement of the present invention, the steam outlet of the analyzer 2 is connected to the steam inlet of the primary absorber 3 and the secondary absorber 5 through a steam pipe 15; the steam outlet of the primary generator 4 is connected to the steam inlet of the reabsorber 1 and the secondary generator 6 through a steam pipe 15.

[0023] The remaining structural features and advantages are the same as those of Example 1.

[0024] Embodiment 3:

[0025] As an improvement of the present invention, the heat exchange outlet of the primary absorber 3 is connected to the heat exchange inlet of the secondary generator 6 through an intermediate heat exchange pipeline 10, and the heat exchange outlet of the secondary generator 6 is connected to the heat exchange inlet of the primary absorber 3 through an intermediate heat exchange pipeline 10, forming a heat exchange loop.

[0026] The remaining structural features and advantages are the same as those of Embodiment 1 or 2.

[0027] Embodiment 4:

[0028] As an improvement of the present invention, a solution pump 12 is provided on each of the liquid discharge pipes 11 .

[0029] The remaining structural features and advantages are the same as those of Embodiment 1, 2 or 3.

[0030] Embodiment 5:

[0031] As an improvement of the present invention, a throttle valve 14 is provided on each of the liquid feed pipelines 13 .

[0032] The remaining structural features and advantages are the same as those of Embodiment 1, 2, 3 or 4.

[0033] Embodiment 6:

[0034] As an improvement of the present invention, a first solution heat exchanger 7 is provided between the reabsorber 1 and the analyzer 2, a second solution heat exchanger 8 is provided between the primary absorber 3 and the primary generator 4, and a third solution heat exchanger 9 is provided between the secondary absorber 5 and the secondary generator 6.

[0035] The remaining structural features and advantages are the same as those of Embodiment 1, 2, 3, 4 or 5.

[0036] The present invention provides a double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system. The operating medium of the solution and refrigerant steam pipeline of the double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system is ammonia-water refrigerant; the operating medium in the intermediate heat exchange pipeline 10 is water.

[0037] The solution and refrigerant vapor pipeline includes a reabsorber 1 (low-pressure absorption), an analyzer 2 (high-pressure analysis), a primary absorber 3 (high-pressure absorption), a primary generator 4 (low-pressure generation), a secondary absorber 5 (high-pressure absorption), a secondary generator 6 (low-pressure generation), a first solution heat exchanger 7, a second solution heat exchanger 8, and a third solution heat exchanger 9. The liquid discharge pipeline 11 is provided with a solution pump 12, and the liquid feed pipeline 13 is provided with a throttle valve 14.

[0038] The ammonia solution in the reabsorber 1 comes from the analyzer 2, and the absorbed low-pressure ammonia gas comes from the primary generator 4 and the secondary generator 6. The ammonia solution absorbs ammonia gas in the reabsorber 1 and releases heat to the low-temperature environment of about 10°C. The generated ammonia solution with a higher concentration is pressurized by the solution pump 12 and preheated by the solution heat exchanger 7 before being finally sent to the analyzer 2.

[0039] The ammonia solution in the analyzer 2 comes from the reabsorber 1. The high-concentration ammonia solution absorbs industrial waste heat or other low-grade heat at about 70-110°C in the analyzer 2 to produce high-pressure ammonia-water mixed steam and low-concentration ammonia solution. The ammonia-water mixed steam is condensed through the condensation section of the analyzer 2, and the high-purity ammonia gas produced is divided into two paths, one of which is sent to the primary absorber 3 and the other is sent to the secondary absorber 5. The low-concentration ammonia solution produced by the analyzer 2 first passes through the solution heat exchanger 7 to release the waste heat, then passes through the throttle valve 14 to reduce the pressure, and then is sent to the reabsorber 1.

[0040] The ammonia solution in the primary absorber 3 comes from the primary generator 4, and the absorbed high-pressure ammonia gas comes from the analyzer 2. The ammonia solution absorbs ammonia gas in the primary absorber 3 and releases heat to the intermediate heat exchange pipeline. The generated ammonia solution with a higher concentration first releases waste heat through the solution heat exchanger 8, then passes through the throttle valve 14 to reduce the pressure, and then is sent to the primary generator 4.

[0041] The ammonia solution in the primary generator 4 comes from the primary absorber 3. The ammonia solution with a higher concentration absorbs industrial waste heat or other low-grade heat at about 70-110°C in the primary generator 4 to produce low-pressure ammonia-water mixed steam and low-concentration ammonia solution. The ammonia-water mixed steam is condensed through the condensation section of the primary generator 4 to produce high-purity ammonia gas, which is sent to the reabsorber 1. The low-concentration ammonia solution produced by the primary generator 4 is first pressurized by the solution pump 12, then preheated by the solution heat exchanger 8, and then sent to the primary absorber 3.

[0042] The ammonia solution in the secondary absorber 5 comes from the secondary generator 6, and the absorbed high-pressure ammonia gas comes from the analyzer 2. The ammonia solution absorbs ammonia gas in the secondary absorber 5 and releases high-temperature useful heat energy of about 120-160°C to the user. The generated ammonia solution with a higher concentration first releases waste heat through the solution heat exchanger 9, then passes through the throttle valve 14 to reduce the pressure, and then is sent to the secondary generator 6.

[0043] The ammonia solution in the secondary generator 6 comes from the secondary absorber 5. The ammonia solution with a higher concentration absorbs the heat of the intermediate heat exchange pipeline in the secondary generator 6 to produce low-pressure ammonia-water mixed steam and low-concentration ammonia solution. The ammonia-water mixed steam is condensed through the condensation section of the secondary generator 6 to produce high-purity ammonia gas and sent to the reabsorber 1. The low-concentration ammonia solution produced by the secondary generator 6 is first pressurized by the solution pump 12, then preheated by the solution heat exchanger 9, and then sent to the secondary absorber 5.

[0044] From the perspective of the coupling mode of the two-stage system, the present invention provides the absorption heat released by the primary absorber 3 to the generator 6 of the secondary cycle, thereby increasing the generation temperature of the secondary cycle and increasing the exhaust range of the secondary generator 6, thereby achieving a higher waste heat temperature increase. In addition, the reabsorption cycle is adopted, the reabsorber replaces the condenser of the traditional system, and the analyzer replaces the evaporator of the traditional system, which reduces the operating pressure of the absorption heat pump system, thereby improving the safety of the system operation and reducing the strength requirements for the system components, which is conducive to reducing costs. In addition, the analyzer and reabsorber of the two-stage cycle are combined, and the system works at the optimal high and low pressure ratio of the two pressure levels, with a better performance coefficient and a simpler structure, which is also conducive to reducing costs.

[0045] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The protection scope of the present invention should be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims, that is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system, characterized in that: The heat pump system comprises a reabsorber (1), a resolver (2), a primary absorber (3), a primary generator (4), a secondary absorber (5), a secondary generator (6) and a solution heat exchanger; the discharge end of the reabsorber (1) is connected to the feed end of the resolver (2) via a liquid discharge pipe (11), and the discharge end of the resolver (2) is connected to the feed end of the reabsorber (1) via a liquid feed pipe (13); the discharge end of the primary generator (4) is connected to the feed end of the primary absorber (3) via a liquid discharge pipe (11), and the discharge end of the primary absorber (3) is connected to the feed end of the primary generator (4) via a liquid feed pipe (13); the discharge end of the secondary generator (6) is connected to the feed end of the secondary absorber (5) via a liquid discharge pipe (11), and the discharge end of the secondary absorber (5) is connected to the feed end of the secondary generator (6) via a liquid feed pipe (13).

2. A double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system according to claim 1, characterized in that: The steam outlet of the analyzer (2) is connected to the steam inlet of the primary absorber (3) and the secondary absorber (5) through a steam pipe (15); the steam outlet of the primary generator (4) is connected to the steam inlet of the reabsorber (1) and the secondary generator (6) through a steam pipe (15).

3. A double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system according to claim 1, characterized in that: The heat exchange outlet of the primary absorber (3) is connected to the heat exchange inlet of the secondary generator (6) via an intermediate heat exchange pipeline (10), and the heat exchange outlet of the secondary generator (6) is connected to the heat exchange inlet of the primary absorber (3) via an intermediate heat exchange pipeline (10), thereby forming a heat exchange loop.

4. A double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system according to claim 1, characterized in that: The liquid discharge pipe (11) is provided with a solution pump (12).

5. The double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system according to claim 1, characterized in that: The liquid feed pipeline (13) is provided with a throttle valve (14).

6. A double absorption-reabsorption parallel waste heat utilization synergistic temperature increase heat pump system according to claim 1, characterized in that: A first solution heat exchanger (7) is provided between the reabsorber (1) and the analyzer (2), a second solution heat exchanger (8) is provided between the primary absorber (3) and the primary generator (4), and a third solution heat exchanger (9) is provided between the secondary absorber (5) and the secondary generator (6).

7. The double absorption-reabsorption parallel waste heat utilization synergistic warming heat pump system according to claim 1, characterized in that: The working fluid pair used in the heat pump system is an environmentally friendly working fluid pair of ammonia water. The operation method of the ammonia solution and the refrigerant steam pipeline is as follows: the ammonia water in the low-pressure reabsorber absorbs the ammonia gas from the primary generator and the secondary generator, and releases heat to the environment of 8-12°C. The generated ammonia water with increased concentration is pressurized by the solution pump and preheated by the solution heat exchanger and then sent to the high-pressure resolver for resolution; the ammonia solution absorbs 70-110°C industrial waste heat or other low-grade heat in the resolver, and the generated ammonia and water mixed steam is condensed through the condensation section of the resolver, and a part of the high-purity ammonia gas is generated and enters the primary absorber; the ammonia water in the primary absorber absorbs the high-pressure ammonia gas from the resolver and releases heat to the intermediate heat exchange pipeline. The generated ammonia water with increased concentration is sent to the low-pressure primary absorber after being depressurized by the solution heat exchanger and the throttle valve. Generator; the ammonia solution absorbs industrial waste heat or other low-grade heat of 70-110℃ in the first-stage generator, and the generated ammonia and water mixed steam is condensed through the condensation section of the first-stage generator to produce high-purity ammonia gas, which enters the reabsorber and is absorbed by the ammonia solution in the reabsorber; another part of the high-purity ammonia produced by the high-pressure analyzer enters the secondary absorber; the ammonia solution in the secondary absorber absorbs the high-pressure ammonia from the analyzer and releases high-temperature useful heat of 120-160℃, and the generated ammonia solution with increased concentration is sent to the low-pressure secondary generator after being reduced in pressure by the solution heat exchanger and the throttle valve; the ammonia solution absorbs the heat of the intermediate heat exchange pipeline in the secondary generator, and the generated ammonia and water mixed steam is condensed through the condensation section of the secondary generator to produce high-purity ammonia gas, which enters the reabsorber and is absorbed by the ammonia solution in the reabsorber.

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