Waste heat recovery steam-electricity double-drive heat pump unit

Abstract

The utility model belongs to the technical field of waste heat recovery heating, and particularly discloses a waste heat recovery steam-electricity double-drive heat pump unit which comprises an absorption type circulation subsystem, and the absorption type circulation subsystem comprises a generator, a first absorber, a second absorber, a first condenser, a first evaporator, a second evaporator, a heat exchanger and a solution pump set which are communicated through working medium channels. By combining an absorption type double-circulation subsystem and a compression type double-circulation subsystem, a unique structure of waste heat three-stage cascade heat extraction and hot water four-stage series heating is constructed, the technical bottleneck of a single-circulation heat pump is effectively overcome, low-grade industrial waste heat and driving heat energy are fully utilized, and the energy utilization potential is deeply excavated; the hot water output temperature of the heat pump system is obviously increased, and the industrial high-temperature heat utilization requirement is met; the energy transfer process is optimized, reasonable matching of waste heat temperature grades and multi-stage efficient utilization of heat energy are achieved, and the overall energy efficiency of the system is greatly improved; the structural design is reasonable, the operation is stable and reliable, and an efficient solution is provided for industrial energy conservation and consumption reduction.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery heating technology, and specifically discloses a waste heat recovery steam-electric dual-drive heat pump unit. Background Technology

[0002] In the industrial and residential heating sectors, boilers, direct-fired gas boilers, and heat pumps are the main heating technologies. However, the recovery and utilization rate of a large amount of medium- and low-temperature waste heat resources generated in industrial processes (such as flue gas, cooling water, and process waste heat) is generally less than 30%, resulting in significant energy waste.

[0003] Existing heat pump technology faces significant bottlenecks in efficiently recovering this type of waste heat and producing high-temperature hot water (>80℃):

[0004] Due to the thermodynamic properties of the refrigerant (such as critical temperature and exhaust temperature limitations) and the temperature and pressure resistance of the compressor, the hot water outlet temperature of conventional compression heat pumps is usually difficult to exceed 100℃, which cannot meet the high-temperature heat requirements of many industrial processes (such as cleaning, sterilization, and steam preheating).

[0005] Although absorption heat pumps (such as lithium bromide units) can use thermal energy to drive the production of hot water at higher temperatures, their coefficient of performance (COP) decreases significantly with temperature rise. When the waste heat source temperature is low or the required hot water temperature is high, their energy efficiency and economy deteriorate sharply. A single absorption cycle is difficult to achieve deep waste heat recovery and high-temperature heat output simultaneously over a wide temperature range and with high efficiency.

[0006] Whether it is a compression or absorption heat pump, a single-cycle system, while pursuing high-temperature output, often leads to an excessively large system pressure ratio or concentration difference, resulting in reduced efficiency, increased equipment costs, and difficulty in fully utilizing the cascade temperature quality of the waste heat source. Utility Model Content

[0007] This utility model proposes a waste heat recovery steam-electric dual-drive heat pump unit. By combining absorption and compression dual-cycle subsystems, it constructs a unique structure of three-stage waste heat extraction and four-stage series heating of hot water, effectively overcoming the technical bottleneck of single-cycle heat pumps. It makes full use of low-grade industrial waste heat and driving heat energy, significantly improves the hot water output temperature of the heat pump system, and meets the high-temperature heating needs of industry.

[0008] This utility model is implemented as follows: a waste heat recovery steam-electric dual-drive heat pump unit, comprising:

[0009] The absorption cycle subsystem includes a generator, a first absorber, a second absorber, a first condenser, a first evaporator, a second evaporator, a heat exchanger, and a solution pump unit, all connected by a working fluid channel.

[0010] The compression cycle subsystem includes a compressor, a second condenser, and a third evaporator connected via a refrigerant passage;

[0011] A driving heat source circuit is provided with a driving heat source inlet and a driving heat source outlet, both of which are connected to the generator.

[0012] A hot water heating circuit is provided with a hot water inlet and a hot water outlet. The hot water inlet is connected in sequence to a second absorber, a first absorber, a first condenser, and a second condenser, and then leads out from the hot water outlet.

[0013] The waste heat source circuit is provided with a waste heat source inlet and a waste heat source outlet. The waste heat source inlet is connected in sequence to the second evaporator, the first evaporator and the third evaporator and then led out from the waste heat source outlet.

[0014] The working fluid outlet of the first evaporator is divided into two paths, one of which is connected to the first absorber, and the other is connected to the second evaporator through the first throttle valve. The working fluid outlet of the second evaporator is connected to the second absorber. The third evaporator of the compression cycle subsystem extracts heat from the waste heat source loop.

[0015] As a preferred embodiment of the waste heat recovery steam-electric dual-drive heat pump unit of this utility model, the second absorber, the first absorber, the first condenser and the second condenser constitute a four-stage series heating structure, and the second evaporator, the first evaporator and the third evaporator constitute a three-stage series heat extraction structure.

[0016] As a preferred embodiment of the waste heat recovery steam-electric dual-drive heat pump unit of this utility model, the solution pump unit includes a first solution pump and a second solution pump connected in series. The dilute solution outlet of the second absorber is connected to the generator in sequence via the second solution pump, the first solution pump, and a heat exchanger. The concentrated solution outlet of the generator is connected to the first absorber via a heat exchanger.

[0017] In a preferred embodiment of the waste heat recovery steam-electric dual-drive heat pump unit of this utility model, the solution outlet of the first absorber is connected to the solution inlet of the second absorber.

[0018] In a preferred embodiment of this utility model, a waste heat recovery steam-electric dual-drive heat pump unit is a positive displacement compressor or a centrifugal compressor.

[0019] In a preferred embodiment of the waste heat recovery steam-electric dual-drive heat pump unit of this utility model, the refrigerant outlet of the first condenser is connected to the first evaporator via a second throttle valve, and the refrigerant outlet of the second condenser is connected to the third evaporator via a third throttle valve.

[0020] The beneficial effects of this utility model are:

[0021] This invention combines absorption and compression dual-cycle subsystems to construct a unique structure that integrates three-stage waste heat extraction with four-stage series heating of hot water. This effectively overcomes the technical bottlenecks of single-cycle heat pumps, fully utilizing low-grade industrial waste heat and driving heat energy to deeply explore energy utilization potential. It significantly increases the hot water output temperature of the heat pump system, meeting the high-temperature heating demands of industry. Optimizing the energy transfer process achieves a reasonable match between waste heat temperature and grade, and multi-stage efficient utilization of heat energy, greatly improving the overall energy efficiency of the system. With its reasonable structural design and stable and reliable operation, it provides an efficient solution for industrial energy conservation and consumption reduction. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0023] Figure 1 This is a structural diagram of the present utility model.

[0024] The diagram shows the following components: 1. Generator; 2. First absorber; 3. Second absorber; 4. First condenser; 5. Second condenser; 6. First evaporator; 7. Second evaporator; 8. Third evaporator; 9. Compressor; 10. Second throttle valve; 11. First throttle valve; 12. Third throttle valve; 13. First solution pump; 14. Second solution pump; 15. Drive heat source inlet; 16. Drive heat source outlet; 17. Hot water inlet; 18. Hot water outlet; 19. Waste heat source inlet; 20. Waste heat source outlet; 21. Heat exchanger. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments to aid in understanding its content. Unless otherwise specified, the methods used in this invention are conventional methods; the raw materials and apparatus used, unless otherwise specified, are conventional commercially available products.

[0026] Please see Figure 1 A waste heat recovery steam-electric dual-drive heat pump unit, comprising:

[0027] The absorption cycle subsystem includes a generator 1, a first absorber 2, a second absorber 3, a first condenser 4, a first evaporator 6, a second evaporator 7, a heat exchanger 21, and a solution pump group, all connected by a working fluid channel.

[0028] The compression cycle subsystem includes a compressor 9, a second condenser 5, and a third evaporator 8 connected via a refrigerant passage;

[0029] A driving heat source circuit is provided with a driving heat source inlet 15 and a driving heat source outlet 16, both of which are connected to the generator 1.

[0030] The hot water heating circuit is provided with a hot water inlet 17 and a hot water outlet 18. The hot water inlet 17 is connected in sequence to the second absorber 3, the first absorber 2, the first condenser 4 and the second condenser 5 and then leads out from the hot water outlet 18.

[0031] The waste heat source circuit is provided with a waste heat source inlet 19 and a waste heat source outlet 20. The waste heat source inlet 19 is connected in sequence to the second evaporator 7, the first evaporator 6 and the third evaporator 8 and then led out from the waste heat source outlet 20.

[0032] The working fluid outlet of the first evaporator 6 is divided into two paths, one of which is connected to the first absorber 2, and the other is connected to the second evaporator 7 via the first throttle valve 11. The working fluid outlet of the second evaporator 7 is connected to the second absorber 3. The third evaporator 8 of the compression cycle subsystem extracts heat from the waste heat source loop.

[0033] In this embodiment: the absorption cycle subsystem uses working fluid A and working fluid B solution, wherein working fluid A is lithium bromide or a salt absorbent, and working fluid B is water or Freon refrigerant; the compression cycle subsystem uses working fluid C, which is a natural working fluid or a mixed refrigerant.

[0034] A driving heat source (such as steam or high-temperature hot water) enters the generator 1 through the driving heat source inlet 15 to heat the lithium bromide-water solution (working fluid A / B). The separated water vapor enters the first condenser 4, where it condenses and releases heat to heat the hot water. The liquid water is throttled by the second throttling valve 10 and then enters the first evaporator 6 to absorb residual heat and evaporate. Part of the water vapor evaporated in the first evaporator 6 directly enters the first absorber 2 and is absorbed by the intermediate-concentration lithium bromide solution cooled by the heat exchanger 21 from the generator 1, releasing heat to heat the hot water. The resulting dilute solution enters the second absorber 3. The remaining liquid water in the first evaporator 6 is throttled by the first throttling valve 11 and enters the second evaporator 7 to absorb residual heat and evaporate again. The water vapor enters the second absorber 3 and is absorbed by the dilute solution from the first absorber 2, releasing heat to heat the hot water, forming an even dilute solution. This dilute solution is pressurized by the second solution pump 14 and the first solution pump 13 connected in series, and then preheated by the heat exchanger 21. After being heated, the heat returns to generator 1 to complete the absorption cycle. Simultaneously, waste heat sources (such as industrial wastewater) flow sequentially through the waste heat source inlet 19 to the second evaporator 7 and the first evaporator 6, releasing heat for the absorption cycle evaporation. Then, it flows through the third evaporator 8 to release heat, causing the R134a (working fluid C) in the compression cycle to evaporate. The gaseous R134a is compressed and heated by the compressor 9 and then enters the second condenser 5 to condense and release heat to heat the high-temperature hot water. The liquid R134a returns to the third evaporator 8 after being throttled by the third throttling valve 12 to complete the compression cycle. The hot water flows sequentially through the hot water inlet 17 to the second absorber 3, the first absorber 2, and the first condenser 4 to absorb the absorption heat and condensation heat. Then, it flows through the second condenser 5 to absorb the condensation heat of the compression cycle. Finally, the high-temperature hot water is output from the hot water outlet 18. Through the dual-cycle synergy and multi-stage heat exchange structure, low-grade waste heat and driving heat energy are effectively utilized, significantly improving the production efficiency and upper temperature limit of high-temperature hot water.

[0035] As a technical optimization of this utility model, the second absorber 3, the first absorber 2, the first condenser 4 and the second condenser 5 constitute a four-stage series heating structure, and the second evaporator 7, the first evaporator 6 and the third evaporator 8 constitute a three-stage series heat extraction structure.

[0036] In this embodiment: the four-stage series heating structure (second absorber 3, first absorber 2, first condenser 4, second condenser 5) increases the hot water temperature step by step, maximizing the utilization of the heat absorbed and condensed at different temperature levels; the three-stage series heat extraction structure (second evaporator 7, first evaporator 6, third evaporator 8) realizes the tiered utilization of waste heat temperature grade, deeply recovers waste heat energy, and jointly improves the system energy efficiency and hot water temperature.

[0037] As a technical optimization of this utility model, the solution pump group includes a first solution pump 13 and a second solution pump 14 connected in series. The dilute solution outlet of the second absorber 3 is connected to the generator 1 in sequence via the second solution pump 14, the first solution pump 13, and the heat exchanger 21. The concentrated solution outlet of the generator 1 is connected to the first absorber 2 via the heat exchanger 21.

[0038] In this embodiment: the first solution pump 13 and the second solution pump 14 connected in series provide sufficient pressure to drive the circulation of lithium bromide solution; the dilute solution is pressurized by the second solution pump 14 and the first solution pump 13 in sequence to ensure stable delivery to the high-pressure generator 1; the concentrated solution enters the first absorber 2 after the dilute solution is preheated by the heat exchanger 21, realizing the recovery of heat inside the solution and improving the system efficiency.

[0039] As a technical optimization of this utility model, the solution outlet of the first absorber 2 is connected to the solution inlet of the second absorber 3.

[0040] In this embodiment: the solution outlet of the first absorber 2 is directly connected to the solution inlet of the second absorber 3, forming a natural flow path of solution from the first absorber 2 to the second absorber 3, which simplifies the system structure and ensures the continuity of the absorption process and the effective establishment of the concentration gradient.

[0041] As a technical optimization of this utility model, compressor 9 is a positive displacement compressor or a centrifugal compressor.

[0042] In this embodiment, the compressor 9 is selected from positive displacement (such as piston, scroll, screw) or centrifugal structures. Mature and reliable compression technologies can be flexibly selected according to the system scale, pressure ratio and efficiency requirements to ensure stable and efficient operation of the compression cycle.

[0043] As a technical optimization of this utility model, the refrigerant outlet of the first condenser 4 is connected to the first evaporator 6 via the second throttle valve 10, and the refrigerant outlet of the second condenser 5 is connected to the third evaporator 8 via the third throttle valve 12.

[0044] In this embodiment: the second throttle valve 10 is connected to the refrigerant outlet of the first condenser 4 and the first evaporator 6, and the third throttle valve 12 is connected to the refrigerant outlet of the second condenser 5 and the third evaporator 8, respectively realizing the pressure reduction and throttling process of the absorption cycle refrigerant (water) and the compression cycle refrigerant (R134a), creating conditions for evaporation and heat absorption, and is the key structure for completing their respective cycle phase changes.

[0045] The working principle and usage process of this utility model are as follows: A heat source is driven into generator 1 to heat a concentrated lithium bromide solution. The separated water vapor enters the first condenser 4 and condenses into liquid water, releasing heat to heat the flowing hot water. The liquid water is depressurized by the second throttle valve 10 and enters the first evaporator 6 to absorb residual heat and evaporate. Part of the generated steam enters the first absorber 2 and is absorbed by the intermediate-concentration lithium bromide solution cooled by heat exchanger 21 from generator 1. The absorbed heat heats the hot water, and the resulting dilute solution enters the second absorber 3. Another portion of the liquid water in the first evaporator 6 is depressurized by the first throttle valve 11 and enters the second evaporator 7 to absorb residual heat and evaporate again. The steam enters the second absorber 3 and is absorbed by the dilute solution from the first absorber 2. The absorbed heat further heats the hot water, forming an even dilute solution. This dilute solution is pressurized by the second solution pump 14 and the first solution pump 13 connected in series, and then passes through heat exchanger 2. After being preheated by the concentrated solution from generator 1, the solution enters generator 1 for heating and concentration. The concentrated solution is cooled by heat exchanger 21 and returns to the first absorber 2, completing the absorption cycle. The waste heat source fluid flows sequentially through the second evaporator 7 and the first evaporator 6 to release heat for the working fluid of the absorption cycle to evaporate. It then flows through the third evaporator 8 to release heat to evaporate R134a in the compression cycle. The gaseous R134a is compressed by compressor 9 and enters the second condenser 5 to condense and release heat to heat the hot water flowing through the high-temperature section. The liquid R134a is depressurized by the third throttle valve 12 and returns to the third evaporator 8, completing the compression cycle. The cold water to be heated enters through the hot water inlet 17 and flows sequentially through the second absorber 3 to absorb heat, the first absorber 2 to absorb heat, the first condenser 4 to absorb condensation heat, and the second condenser 5 to absorb condensation heat. The temperature gradually increases and the water becomes high-temperature hot water, which is output from the hot water outlet 18.

[0046] In the description of this utility model, it should be understood that the terms "left", "right", "up", "down", "top", "bottom", "front", "back", "inner", "outer", "back", "middle", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0047] However, the above description is only a specific embodiment of this utility model and should not be construed as limiting the scope of implementation of this utility model. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of this utility model should still fall within the scope of the claims of this utility model.

Claims

1. A waste heat recovery steam-electric dual-drive heat pump unit, characterized in that: include: The absorption circulation subsystem includes a generator (1), a first absorber (2), a second absorber (3), a first condenser (4), a first evaporator (6), a second evaporator (7), a heat exchanger (21), and a solution pump group, all connected by a working fluid channel. The compression cycle subsystem includes a compressor (9), a second condenser (5), and a third evaporator (8) connected via a refrigerant passage. A driving heat source circuit is provided with a driving heat source inlet (15) and a driving heat source outlet (16), both of which are connected to the generator (1). A hot water heating circuit is provided with a hot water inlet (17) and a hot water outlet (18). The hot water inlet (17) is connected in sequence to the second absorber (3), the first absorber (2), the first condenser (4), and the second condenser (5) and then led out from the hot water outlet (18). Waste heat source circuit, the waste heat source circuit is provided with waste heat source inlet (19) and waste heat source outlet (20), the waste heat source inlet (19) is connected in sequence to the second evaporator (7), the first evaporator (6) and the third evaporator (8) and then led out from the waste heat source outlet (20); The working fluid outlet of the first evaporator (6) is divided into two paths, one of which is connected to the first absorber (2), and the other is connected to the second evaporator (7) through the first throttle valve (11). The working fluid outlet of the second evaporator (7) is connected to the second absorber (3). The third evaporator (8) of the compression cycle subsystem extracts heat from the waste heat source loop.

2. The waste heat recovery steam-electric dual-drive heat pump unit according to claim 1, characterized in that: The second absorber (3), the first absorber (2), the first condenser (4) and the second condenser (5) constitute a four-stage series heating structure, and the second evaporator (7), the first evaporator (6) and the third evaporator (8) constitute a three-stage series heat extraction structure.

3. The waste heat recovery steam-electric dual-drive heat pump unit according to claim 1, characterized in that: The solution pump group includes a first solution pump (13) and a second solution pump (14) connected in series. The dilute solution outlet of the second absorber (3) is connected to the generator (1) in sequence via the second solution pump (14), the first solution pump (13), and the heat exchanger (21). The concentrated solution outlet of the generator (1) is connected to the first absorber (2) via the heat exchanger (21).

4. The waste heat recovery steam-electric dual-drive heat pump unit according to claim 1, characterized in that: The solution outlet of the first absorber (2) is connected to the solution inlet of the second absorber (3).

5. The waste heat recovery steam-electric dual-drive heat pump unit according to claim 1, characterized in that: The compressor (9) is a positive displacement compressor or a centrifugal compressor.

6. The waste heat recovery steam-electric dual-drive heat pump unit according to claim 1, characterized in that: The refrigerant outlet of the first condenser (4) is connected to the first evaporator (6) via the second throttle valve (10), and the refrigerant outlet of the second condenser (5) is connected to the third evaporator (8) via the third throttle valve (12).

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