Heat pump heating system with multi-stage heat exchange

Abstract

The utility model relates to a waste heat recovery technical field especially, and it is a kind of multi-stage heat exchange's heat pump heating system.A kind of multi-stage heat exchange's heat pump heating system, including multiple plate heat exchanger groups, multiple centrifugal heat pump groups and at least one coupled heat pump group, system contains six heat exchange passages: first connection guarantee water supply pipe and high temperature return water pipe, and heat exchange is carried out through plate heat exchanger;Second, municipal water supply loop is connected using parallel design, and multi-stage heat exchange is realized;Third, cooling tower circulation line is connected, and heat exchange is carried out through coupled heat pump group;Fourth, through centrifugal heat pump group, medium temperature return water pipe and low temperature water supply pipe are connected;Fifth, medium temperature return water pipe and guarantee water supply pipe are connected using parallel branch design;Sixth, guarantee water supply pipe and high temperature return water pipe are connected.The system works cooperatively through multi-stage heat exchange unit, realizes the efficient heat exchange of different temperature medium, satisfies the diversified heating demand, with the characteristics of high energy efficiency, strong adaptability.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, and in particular to a multi-stage heat pump heating system. Background Technology

[0002] Existing heat pump systems generally employ a single-stage heat exchange structure, capable of recovering heat sources within a single temperature range. This simple structure cannot effectively handle the multi-grade waste heat commonly encountered in industrial processes. Furthermore, traditional systems often mix heat sources of different grades, leading to the degradation of high-grade waste heat and resulting in significant energy losses. Traditional heat pump systems typically use fixed series piping, meaning that load changes in any link will affect the overall operation. Conventional compression heat pumps are limited by refrigerant characteristics, with outlet water temperatures usually not exceeding 65°C; to achieve temperatures above 85°C, an electric heater must be connected in series. Traditional absorption heat pumps suffer from two major drawbacks: large footprint and poor partial load performance. Utility Model Content

[0003] The technical problem to be solved by this utility model is: in order to solve the problems of low waste heat recovery efficiency, insufficient system flexibility, high-temperature heating capacity and poor system reliability of the existing technology in the background art, a multi-stage heat exchange heat pump heating system is provided.

[0004] The technical solution adopted by this utility model to solve its technical problem is: a multi-stage heat exchange heat pump heating system, comprising: Multiple plate heat exchanger units, multiple centrifugal heat pump units, and at least one coupled heat pump unit; The multiple plate heat exchanger groups include a first plate heat exchanger group, a second plate heat exchanger group, and a third plate heat exchanger group; the multiple centrifugal heat pump groups include a first centrifugal heat pump group and a second centrifugal heat pump group. The system is equipped with: First heat exchange path: connects the 35℃ protection plate heat exchanger supply pipe and the 72℃ return pipe, and exchanges heat through the first plate heat exchanger group; The second heat exchange path connects the municipal water return pipe and the municipal water supply pipe. It has two parallel branches that converge after passing through different heat exchange devices. The third heat exchange path connects the cooling tower return water pipe and the cooling tower supply water pipe, and exchanges heat through a coupled heat pump unit. Fourth heat exchange path: connects the 38.6℃ return water pipe and the 32℃ supply water pipe, and exchanges heat through a centrifugal heat pump unit; The fifth heat exchange path connects the 50℃ return water pipe and the 35℃ protection plate heat exchange supply water pipe. It has two parallel branches that converge after passing through multi-stage heat exchange and single heat exchange, respectively. The sixth heat exchange path connects the 50℃ protection plate heat exchanger supply pipe and the 85℃ return pipe, and the heat is exchanged through the plate heat exchanger assembly.

[0005] Multi-stage energy recovery is achieved through multiple plate heat exchanger groups, centrifugal heat pump groups, and coupled heat pump groups, improving system energy efficiency. The first heat exchange path utilizes low-temperature waste heat to raise it to a higher temperature, suitable for low-grade heat source recovery. The second heat exchange path adopts a parallel dual-branch design to improve heat exchange flexibility and adapt to different load requirements. The coupled heat pump group in the third heat exchange path optimizes cooling tower heat recovery and reduces cooling loss. The centrifugal heat pump group in the fourth heat exchange path is used for precise temperature control, suitable for medium and low temperature conditions. The multi-stage heat exchange in the fifth heat exchange path achieves deep cooling, suitable for deep waste heat recovery. The plate heat exchanger group in the sixth heat exchange path provides high-temperature heating to meet industrial or district heating needs. A tiered heat exchange network is formed to achieve efficient waste heat recovery, multi-temperature zone heating, and combined cooling and heating.

[0006] According to one embodiment of the present invention, the second heat exchange passage includes a first branch and a second branch. The first branch passes through a first plate heat exchanger group and a first centrifugal heat pump heat exchanger group in sequence, and the second branch passes through a second plate heat exchanger group and a third plate heat exchanger group in sequence.

[0007] The first branch line initially raises the temperature of the municipal return water, suitable for low-load conditions; the second branch line provides backup or enhances heat exchange capacity to meet high-load demands; the parallel design improves system redundancy and regulation capabilities, avoiding single-point failures from affecting overall operation.

[0008] According to one embodiment of the present invention, after the two branches of the second heat exchange path merge, they are connected to the municipal water supply pipe after heat exchange through the second centrifugal heat pump group and the coupled heat pump group in sequence.

[0009] After merging, the water is further heated by a second centrifugal heat pump unit to ensure a stable supply water temperature; the coupled heat pump unit performs the final heat exchange, using an absorption heat pump to improve energy efficiency, reduce electricity consumption, achieve precise control of municipal water temperature, and reduce energy consumption.

[0010] According to one embodiment of the present invention, the fifth heat exchange passage includes a third branch and a fourth branch. The third branch passes through a coupled heat pump group and a second centrifugal heat pump group in sequence, and the fourth branch passes through a second plate heat exchanger group for heat exchange.

[0011] The coupled heat pump unit provides initial cooling and recovers some heat; the second centrifugal heat pump unit provides deep cooling and improves waste heat utilization; the second plate heat exchanger unit ultimately outputs stable low-temperature water, achieving deep waste heat recovery from 50℃ to 35℃, suitable for refrigeration or low-temperature process requirements.

[0012] According to one embodiment of this utility model, the sixth heat exchange passage exchanges heat via a third plate heat exchanger assembly. By using only the third plate heat exchanger assembly, the high-temperature heat exchange process is simplified, energy loss is reduced, and high-temperature heating is achieved efficiently, making it suitable for industrial steam or district heating.

[0013] According to one embodiment of the present invention, the coupled heat pump unit is composed of five cylindrical coupling machines, including a first type coupling machine, a second type coupling machine and a third type coupling machine; the first type coupling machine includes a coupled heat exchanger and an absorber arranged vertically, the second type coupling machine includes a condenser and a generator arranged vertically, and the third type coupling machine includes a first evaporator and a second evaporator arranged vertically. Five coupling machines are connected by pipelines to form two coupled heat exchange units in series. Each coupled heat exchange unit contains a third type coupling machine, a first type coupling machine, and a second type coupling machine connected in sequence, and the two units share the same third type coupling machine.

[0014] Five cylindrical coupling units are used to integrate key thermal components, reducing equipment footprint and improving system integration. The classification of coupling units into Type I, Type II, and Type III clearly defines each functional unit, facilitating maintenance and replacement. Two coupled heat exchange units operate in series, adapting to higher temperature rise or greater heat load requirements. A shared Type III coupling unit, i.e., dual evaporators, reduces the number of devices and lowers costs. The two evaporators can operate independently, improving system redundancy. The coupled heat exchanger of the Type I coupling unit achieves efficient heat exchange between the refrigerant and the external heat source, while the absorber completes the absorption of refrigerant by the working fluid, enhancing heat energy conversion. The condenser of the Type II coupling unit releases heat for heating or cooling, and the generator drives solution regeneration through an external heat source to maintain circulation. The evaporator of the Type III coupling unit absorbs heat from a low-temperature heat source, improving system energy efficiency. This results in a highly efficient and compact heat pump unit suitable for medium- and high-temperature heat recovery. The series design enhances temperature rise capability, and the shared evaporator reduces costs and improves reliability.

[0015] According to one embodiment of the present invention, the inlet end of the condenser is directly connected to either the heating water inlet pipe or the cooling water inlet pipe, and its outlet end is connected to the corresponding outlet pipe; the inlet end of the generator is connected to the circulating water inlet pipe, and its outlet end is connected to the circulating water outlet pipe; the inlet end of the absorber is connected to the heating water inlet pipe, and its outlet end is connected to the heating water outlet pipe; the inlet of the refrigerant channel of the coupling heat exchanger is connected to the refrigerant supply pipe, and its outlet is connected to the refrigerant return pipe.

[0016] The condenser flexibly adapts to heating or cooling modes, and its inlet can be connected to heating or cooling water pipes, allowing the system to switch between heating and cooling modes as needed. A dedicated circulating water pipeline ensures a stable heat source for the generator, without affecting the main system water temperature. The heat from the absorber is directly used for heating, reducing intermediate heat exchange losses and improving energy efficiency. The refrigerant is completely isolated from the external water circuit to avoid contamination and optimize heat exchange efficiency. A branched design enables multi-functional operation, with each component operating independently, resulting in high system stability.

[0017] According to one embodiment of the present invention, the coupling heat exchanger and the condenser are connected by a liquid working fluid transmission pipe; the coupling heat exchanger and the absorber are connected by a gas working fluid transmission pipe; and a bidirectional lithium bromide solution circulation pipe is provided between the absorber and the generator.

[0018] The liquid working fluid transfer pipe ensures efficient delivery of high-pressure liquid working fluid to the condenser for heat release, reducing pressure drop and energy loss; low-pressure gaseous working fluid rapidly enters the absorber and is absorbed by the solution, maintaining continuous circulation; concentrated solution flows to the generator for regeneration, while dilute solution flows back to the absorber for reuse, forming a closed loop; the bidirectional connection design avoids flow resistance caused by one-way valves, improving solution circulation efficiency. Phase-separated working fluid transfer optimizes thermodynamic cycle efficiency, and bidirectional flow of lithium bromide solution enhances system response speed.

[0019] The beneficial effects of this utility model are: (1) Through six independent heat exchange channels, true cascade waste heat utilization is realized. The heat exchange channel from 35℃ to 72℃ focuses on heating low-grade heat sources, the heat exchange channel from 50℃ to 85℃ handles medium and high-temperature heat sources, and the heat exchange channel from 38.6℃ to 32℃ completes deep waste heat extraction. The synergy of multiple temperature zones can improve the overall energy efficiency of the system. (2) The plate heat exchanger and centrifugal heat pump in the first branch of the second heat exchange path handle the base load, and the double plate heat exchanger in the second branch serves as an elastic expansion unit. After the two branches merge, a secondary heat pump is also set up to enhance the system, so that the system can automatically adjust the flow ratio of each branch and perfectly adapt to various working conditions from full-load production to equipment maintenance. (3) The third plate heat exchanger group in the sixth heat exchange path improves the heat exchange efficiency on the high temperature side. The series coupled heat pump unit makes graded use of the heat source temperature gradient. Finally, through the optimization of the working fluid ratio, the system can stably output 95℃ municipal water without auxiliary heating. (4) The dual-coupled heat exchange units share an evaporator structure, which improves the efficiency of partial load, saves energy and is environmentally friendly, and occupies less space. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a process flow diagram of this utility model during the heating season.

[0022] Figure 2 This is a schematic diagram of the coupled heat pump unit in this utility model.

[0023] Figure 3 yes Figure 2 A schematic diagram of the structure of the intermediate coupled heat exchange unit.

[0024] Figure 4 yes Figure 2 Schematic diagram of a medium-coupled heat pump unit.

[0025] Figure 5 yes Figure 2 Process flow diagram of a medium-coupled heat pump unit used in the non-heating season.

[0026] In the diagram: 1. First plate heat exchanger group; 2. Second plate heat exchanger group; 3. Third plate heat exchanger group; 4. First centrifugal heat pump group; 5. Second centrifugal heat pump group; 6. Coupled heat pump group; 61. First type of coupler; 62. Second type of coupler; 63. Third type of coupler; 611. Coupled heat exchanger; 612. Absorber; 621. Condenser; 622. Generator; 631. First evaporator; 632. Second evaporator; 64. Circulating water inlet pipe; 65. Circulating water outlet pipe; 66. Heating water inlet pipe; 67. Heating water outlet pipe; 68. Refrigerant supply pipe; 69. Refrigerant return pipe; 610. Liquid working fluid transfer pipe. 620. Gas phase working fluid transfer pipe; 630. Lithium bromide solution circulation pipe; 7. 35℃ protection plate replacement water supply pipe; 8. 72℃ return water pipe; 9. Municipal water return pipe; 10. Municipal water supply pipe; 11. Cooling tower return water pipe; 12. Cooling tower supply water pipe; 13. 38.6℃ return water pipe; 14. 32℃ supply water pipe; 15. 50℃ return water pipe; 16. 50℃ protection plate replacement water supply pipe; 17. 85℃ return water pipe; 18. First coupled heat pump unit; 19. Second coupled heat pump unit; 20. Flash tank; 21. First steam compressor unit; 22. Second steam compressor unit; 23. Third steam compressor unit; 25. Boiler water supply pipe; 26. Steam pipeline. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0028] Example 1 like Figure 1 As shown, a multi-stage heat pump heating system suitable for the heating season includes multiple plate heat exchanger groups, multiple centrifugal heat pump groups, and at least one coupled heat pump group 6. The multiple plate heat exchanger groups include a first plate heat exchanger group 1, a second plate heat exchanger group 2, and a third plate heat exchanger group 3; the multiple centrifugal heat pump groups include a first centrifugal heat pump group 4 and a second centrifugal heat pump group 5. The system is provided with a first heat exchange passage, a second heat exchange passage, a third heat exchange passage, a fourth heat exchange passage, a fifth heat exchange passage, and a sixth heat exchange passage.

[0029] The first heat exchange passage connects the 35°C protection plate heat exchanger supply pipe 7 and the 72°C return water pipe 8. The 35°C water output from the 35°C protection plate heat exchanger supply pipe 7 is heated to 72°C through the first plate heat exchanger group 1 and then enters the 72°C return water pipe 8.

[0030] The second heat exchange path connects the municipal water return pipe 9 and the municipal water supply pipe 10, and has two parallel branches that converge after passing through different heat exchange devices. Specifically, the 30°C water output from the municipal water return pipe 9 is heated to 70°C by the first plate heat exchanger group 1, and then heated to 82°C by the centrifugal heat pump. At the same time, the other branch is heated to 48°C by the second plate heat exchanger group 2, and then heated to 82°C by the third plate heat exchanger group 3. The two 82°C waters are mixed and enter the first centrifugal heat pump group 4, where they are heated to 86°C. Then they enter the coupled heat pump group 6, where they are heated to 95°C, and then enter the municipal water supply pipe 10.

[0031] The third heat exchange passage connects the cooling tower return water pipe 11 and the cooling tower supply water pipe 12. The 11°C cooling water output from the cooling tower return water pipe 11 is heated to 16°C by the coupled heat pump unit 6 and then enters the cooling tower supply water pipe 12.

[0032] The fourth heat exchange passage connects the 38.6℃ return water pipe 13 and the 32℃ supply water pipe 14. The 36.6℃ water output from the 38.6℃ return water pipe 13 passes through the first centrifugal heat pump group 4 and the second centrifugal heat pump group 5 respectively, and then outputs 31℃ water into the 32℃ supply water pipe 14.

[0033] The fifth heat exchange passage connects the 50℃ return water pipe 15 and the 35℃ protection plate heat exchanger supply pipe 7. It has two parallel branches that merge after undergoing multi-stage heat exchange and single heat exchange, respectively. Specifically, the 50℃ water output from the 50℃ return water pipe 15 is first cooled to 39℃ by the coupled heat pump group 6, and then cooled to 37℃ by the second centrifugal heat pump group 5. The other branch is directly cooled to 35℃ by the second plate heat exchanger group 2. The two waters mix to form 36.5℃ water, which enters the 35℃ protection plate heat exchanger supply pipe 7.

[0034] The sixth heat exchange passage connects the 50℃ protection plate heat exchanger supply pipe 16 and the 85℃ return water pipe 17. The 84.65℃ water output from the 85℃ return water pipe 17 is cooled to 50℃ by the third plate heat exchanger group 3 and then connected to the 50℃ protection plate heat exchanger supply pipe 16.

[0035] The multi-stage heat exchange heat pump heating system provided in this embodiment achieves efficient heat recovery, flexible temperature control, and energy saving and consumption reduction through multi-stage heat exchange path optimization, cascade energy utilization, and coordinated operation of coupled heat pump units.

[0036] The system employs a multi-stage plate heat exchanger assembly connected in series and / or parallel with centrifugal heat pump units, enabling the utilization of heat at different temperature levels in stages and reducing the waste of high-grade energy. The third heat exchange path heats the cooling tower return water to 16°C via a coupled heat pump unit 6, recovering low-temperature waste heat for use in other parts of the system. The fourth heat exchange path utilizes 36.6°C return water, which is then cooled to 31°C via two-stage centrifugal heat pump units, efficiently extracting the cooling capacity for other heat exchange needs. The second and fifth heat exchange paths adopt a parallel branch structure, allowing for flexible switching of operating modes according to load requirements. The system can simultaneously handle heat exchange needs ranging from low temperature (11°C cooling water) to high temperature (95°C supply water), making it suitable for complex scenarios such as district heating and industrial waste heat recovery.

[0037] Multi-stage heat exchange and coordinated heat pump regulation ensure stable output water temperature and avoid temperature fluctuations. Multiple centrifugal heat pump units and plate heat exchanger units serve as backups for each other, allowing partial operation to continue even in the event of a single unit failure. The plate heat exchangers handle part of the heating / cooling tasks, reducing the load on the heat pump units, extending compressor life, and lowering power consumption. By arranging the heat exchanger units and heat pump units side-by-side, pipe length and heat loss are reduced, saving installation space.

[0038] like Figure 2 and Figure 3 As shown, the coupled heat pump unit 6 consists of five cylindrical coupling units, including a first type coupling unit 61, a second type coupling unit 62, and a third type coupling unit 63. The first type coupling unit 61 includes a coupled heat exchanger 611 and an absorber 612 arranged vertically. The second type coupling unit 62 includes a condenser 621 and a generator 622 arranged vertically. The third type coupling unit 63 includes a first evaporator 631 and a second evaporator 632 arranged vertically. The five coupling units are connected by pipes to form two coupled heat exchange units in series. Each coupled heat exchange unit includes the third type coupling unit 63, the first type coupling unit 61, and the second type coupling unit 62 connected in sequence, and the two units share the same third type coupling unit 63.

[0039] The inlet of condenser 621 is directly connected to either heating water inlet pipe 66 or cooling water inlet pipe, and its outlet is connected to the corresponding outlet pipe; the inlet of generator 622 is connected to circulating water inlet pipe 64, and its outlet is connected to circulating water outlet pipe 65; the inlet of absorber 612 is connected to heating water inlet pipe 66, and its outlet is connected to heating water outlet pipe 67; the inlet of refrigerant passage of coupling heat exchanger 611 is connected to refrigerant supply pipe 68, and its outlet is connected to refrigerant return pipe 69.

[0040] The coupling heat exchanger 611 and the condenser 621 are connected by a liquid working fluid transfer pipe 610; the coupling heat exchanger 611 and the absorber 612 are connected by a gas working fluid transfer pipe 620; and a bidirectional lithium bromide solution circulation pipe 630 is provided between the absorber 612 and the generator 622.

[0041] like Figure 4 As shown, the working principle of the coupled heat pump unit 6 is as follows: Circulating water (such as industrial waste hot water) enters the generator 622 through the circulating water inlet pipe 64. The circulating water releases heat, heating the dilute lithium bromide solution inside, causing the water in it to evaporate and form water vapor, which enters the condenser 621 through the gas phase working fluid transfer pipe 620. The cooled circulating water is discharged from the circulating water outlet pipe 65, completing the heat release process.

[0042] After water vapor enters the condenser 621, it is cooled by external cooling water or heating return water (entering through the inlet end of the condenser 621) and condenses into liquid water. The heat released by condensation is absorbed by the cooling water / heating water, and after being heated, it is output from the outlet end of the condenser 621 (for heating or cooling tower circulation). The liquid water flows into the coupling heat exchanger 611 through the liquid phase working fluid transfer pipe 610.

[0043] Liquid refrigerant enters the first evaporator 631 and the second evaporator 632 of the third type coupling machine 63 from the coupling heat exchanger 611. It evaporates under low pressure and absorbs heat from external heat sources (such as low-temperature waste heat). The evaporated refrigerant vapor returns to the absorber 612 through the gas phase working fluid transfer pipe 620.

[0044] Refrigerant vapor enters absorber 612 and is absorbed by concentrated lithium bromide solution from generator 622 (transported through lithium bromide solution circulation pipe 630) to form a dilute solution; the heat released during the absorption process is carried away by low-temperature water input through heating water inlet pipe 66, and after being heated, it is output from heating water outlet pipe 67 for heating; the dilute solution is pumped back to generator 622 through lithium bromide solution circulation pipe 630 to complete the cycle.

[0045] The refrigerant supply line 68 supplies low-temperature refrigerant to the coupling heat exchanger 611. After absorbing the cooling capacity of the evaporator, the refrigerant returns to the external system through the refrigerant return line 69, thus achieving refrigeration or low-temperature heat recovery.

[0046] Heating water output: The high-temperature water heated by the absorber 612 (heating water outlet pipe 67) can be used directly for heating; the cooling water heated by the condenser 621 can also be used as an auxiliary heat source; the first evaporator 631 and the second evaporator 632 absorb low-temperature heat sources and can provide cooling function at the same time.

[0047] Example 2 like Figure 5As shown, a heat pump heating system suitable for the non-heating season includes a first coupled heat pump unit 18, a second coupled heat pump unit 19, a flash tank 20, a first steam compressor unit 21, a second steam compressor unit 22, and a third steam compressor unit 23. It also includes a first circulation unit, a second circulation unit, a third circulation unit, and a fourth circulation unit. The first circulation unit includes a cooling tower return water pipe 11, the first coupled heat pump unit 18, the second coupled heat pump unit 19, and a cooling tower supply water pipe 12. Water at 25°C output from the cooling tower return water pipe 11 is heated to 30°C through heat exchange with the first coupled heat pump unit 18 and the second coupled heat pump unit 19 before entering the cooling tower supply water pipe 12. The second circulation unit includes an 85°C return water pipe 17, a first coupled heat pump group 18, a second coupled heat pump group 19, and a 50°C protection plate water supply pipe 16. The 85°C water output from the 85°C return water pipe 17 is first cooled to 77°C by the first coupled heat pump group 18, and then cooled to 69°C by the second coupled heat pump group 19 before entering the 50°C protection plate water supply pipe 16. The third circulation unit includes a 50°C return water pipe 15, a second coupled heat pump group 19, and a 35°C protection plate water supply pipe 7. The 50°C water output from the 50°C return water pipe 15 is cooled to 46°C by the first coupled heat pump group 18 and the second coupled heat pump group 19 before entering the 35°C protection plate water supply pipe 7. The fourth cycle includes a boiler water supply pipe 25, a first coupled heat pump unit 18, a second coupled heat pump unit 19, a flash tank 20, a first steam compressor unit 21, a second steam compressor unit 22, a third steam compressor unit 23, and a steam pipe 26. The boiler water supply pipe 25 outputs 95°C water, which enters the flash tank 20 to output 95°C steam. The 95°C steam is heated to 100°C by heat exchange with the first coupled heat pump unit 18 and the second coupled heat pump unit 19, and then returns to the flash tank 20. The 95°C steam output from the flash tank 20 is heated to 113°C by the first steam compressor unit 21, then to 133°C by the second steam compressor unit 22, and finally to 215°C by the third steam compressor unit 23 before entering the steam pipe 26. During this period, the 95°C steam output from the flash tank 20 is added to the first steam compressor unit 21 and the second steam compressor unit 22.

[0048] Through the coordinated operation of a multi-stage coupled heat pump unit, flash tank 20, and steam compressor unit, efficient recovery and cascaded utilization of heat energy during the non-heating season are achieved. Cooling tower return water (25℃) is heated to 30℃ by a two-stage coupled heat pump unit, recovering low-temperature waste heat and reducing cooling tower energy consumption. 85℃ return water is progressively cooled to 69℃ by the two-stage heat pump unit, releasing heat for other cycles (such as steam generation), achieving closed-loop energy utilization. 95℃ low-pressure steam is progressively compressed to 215℃ by flash tank 20 and a three-stage steam compressor unit, requiring no additional fuel input.

[0049] The system can simultaneously output low-temperature (35℃ guaranteed water supply), medium-temperature (50℃ guaranteed water supply), and high-temperature (215℃ steam) steam to meet different needs such as industrial processes and domestic hot water. Through parallel coupled heat pump units and multi-stage steam compressor units, equipment can be flexibly started and stopped according to load demand, avoiding inefficient operation. The coupled heat pump units directly utilize the heat from the return water, reducing dependence on coal / gas-fired boilers and lowering fuel costs and emissions treatment fees. The flash tank 20 directly converts high-temperature water (95℃) into steam, avoiding additional evaporation equipment and simplifying the system structure. The three-stage steam compressor units progressively increase the steam temperature, reducing the load on individual units and extending equipment life. Each circulation unit is interconnected through the coupled heat pump units, allowing for internal heat recycling and reducing dependence on external energy sources. Multiple heat pump units and steam compressor units operate in parallel, ensuring the system can maintain partial functionality even in the event of a single unit failure.

[0050] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A multi-stage heat exchange heat pump heating system, characterized in that, include: Multiple plate heat exchanger units, multiple centrifugal heat pump units and at least one coupled heat pump unit (6); The multiple plate heat exchanger groups include a first plate heat exchanger group (1), a second plate heat exchanger group (2), and a third plate heat exchanger group (3); the multiple centrifugal heat pump groups include a first centrifugal heat pump group (4) and a second centrifugal heat pump group (5). The system is equipped with: First heat exchange path: connects the 35℃ protection plate heat exchanger supply pipe (7) and the 72℃ return water pipe (8), and exchanges heat through the first plate heat exchanger group (1); Second heat exchange path: connects the municipal water return pipe (9) and the municipal water supply pipe (10), with two parallel branches that converge after multiple heat exchange stages; The third heat exchange path connects the cooling tower return water pipe (11) and the cooling tower supply water pipe (12), and exchanges heat through the coupled heat pump unit (6); Fourth heat exchange path: connects the 38.6℃ return water pipe (13) and the 32℃ supply water pipe (14), and exchanges heat through a centrifugal heat pump unit; The fifth heat exchange path connects the 50℃ return water pipe (15) and the 35℃ protection plate heat exchange supply water pipe (7), and has two parallel branches that merge after passing through multi-stage heat exchange and single heat exchange respectively. The sixth heat exchange path connects the 50℃ protection plate heat exchanger supply pipe (16) and the 85℃ return water pipe (17), and exchanges heat through the plate heat exchanger assembly.

2. The multi-stage heat exchange heat pump heating system according to claim 1, characterized in that, The second heat exchange path includes a first branch and a second branch. The first branch passes through the first plate heat exchanger group (1) and the first centrifugal heat pump group (4) in sequence, and the second branch passes through the second plate heat exchanger group (2) and the third plate heat exchanger group (3) in sequence.

3. The multi-stage heat exchange heat pump heating system according to claim 2, characterized in that: After the two branches of the second heat exchange path merge, they are connected to the municipal water supply pipe (10) after heat exchange through the second centrifugal heat pump unit (5) and the coupled heat pump unit (6) in sequence.

4. The multi-stage heat exchange heat pump heating system according to claim 1, characterized in that: The fifth heat exchange path includes a third branch and a fourth branch. The third branch passes through a coupled heat pump group (6) and a second centrifugal heat pump group (5) in sequence, and the fourth branch passes through a second plate heat exchanger group (2) for heat exchange.

5. The multi-stage heat exchange heat pump heating system according to claim 1, characterized in that: The sixth heat exchange passage exchanges heat through the third plate heat exchanger group (3).

6. The multi-stage heat exchange heat pump heating system according to claim 1, characterized in that: The coupled heat pump unit (6) consists of five cylindrical coupling units, including a first type coupling unit (61), a second type coupling unit (62), and a third type coupling unit (63); the first type coupling unit (61) includes a coupled heat exchanger (611) and an absorber (612) arranged vertically, the second type coupling unit (62) includes a condenser (621) and a generator (622) arranged vertically, and the third type coupling unit (63) includes a first evaporator (631) and a second evaporator (632) arranged vertically. Five coupling machines are connected by pipelines to form two series coupled heat exchange units. Each coupled heat exchange unit contains a third type coupling machine (63), a first type coupling machine (61), and a second type coupling machine (62) connected in sequence, and the two units share the same third type coupling machine (63).

7. The multi-stage heat exchange heat pump heating system according to claim 6, characterized in that: The inlet of the condenser (621) is directly connected to either the heating water inlet pipe (66) or the cooling water inlet pipe, and its outlet is connected to the corresponding outlet pipe; the inlet of the generator (622) is connected to the circulating water inlet pipe (64), and its outlet is connected to the circulating water outlet pipe (65); the inlet of the absorber (612) is connected to the heating water inlet pipe (66), and its outlet is connected to the heating water outlet pipe (67); the inlet of the refrigerant channel of the coupling heat exchanger (611) is connected to the refrigerant supply pipe (68), and its outlet is connected to the refrigerant return pipe (69).

8. The multi-stage heat exchange heat pump heating system according to claim 6, characterized in that: The coupling heat exchanger (611) and the condenser (621) are connected by a liquid working fluid transfer pipe (610); the coupling heat exchanger (611) and the absorber (612) are connected by a gas working fluid transfer pipe (620); a bidirectional lithium bromide solution circulation pipe (630) is provided between the absorber (612) and the generator (622).

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