Absorption and compression medium-high temperature heat pump system

Abstract

The invention relates to the technical field of high-temperature heat pumps, in particular to an absorption and compression medium-high temperature heat pump system which comprises a medium-temperature output subsystem and a high-temperature output subsystem. The medium-temperature output subsystem comprises a low-pressure absorber, a second liquid pump, a second solution throttle valve, a first heat exchanger, a medium-pressure generator and a condenser which are connected; an independent medium-temperature output loop is constructed by additionally arranging a low-pressure absorber, a medium-pressure generator, a first heat exchanger and other core components, and output of high-temperature steam of 150 DEG C or above and medium-temperature hot water of about 60 DEG C can be achieved at the same time; the high-temperature loop is responsible for outputting high-temperature steam, the medium-temperature loop is responsible for outputting medium-temperature hot water, the heat exchange temperature difference of cold and hot fluid is reduced through hierarchical design, and irreversible loss is reduced; through modular integration of the high-temperature output subsystem and the medium-temperature output subsystem, only a small number of components such as the low-pressure absorber, the medium-pressure generator and the first heat exchanger are additionally arranged, the double-temperature output requirement can be met at the same time, the number of heat exchange equipment, valves and pipelines is reduced, the structure is simplified, and the cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-temperature heat pump, in particular to an absorption-compression high-temperature heat pump system. BACKGROUND

[0002] From the perspective of energy utilization, in addition to vigorously developing clean low-carbon fuels and renewable energy, improving energy utilization is an important way to reduce energy waste and carbon emissions. For China, various industrial processes are major energy consumers, such as power, steel, chemical, and food, textile, papermaking and other industries, which have high energy consumption processes, and these major energy consumption accounts for about 70% of the total national energy consumption. About 50% of the energy consumed in these high-energy processes is converted into waste heat in the form of waste gas, waste water and product heat. Among them, the waste heat above 100℃ can be well recovered, while the low-temperature waste heat below 100℃ is difficult to recover, resulting in the emission of nearly half of the waste heat; on the other hand, sterilization, drying, distillation and other industrial processes have a heat demand of 120℃-200℃, and the surrounding workers' living areas also have a demand for 60℃ or so of domestic hot water. In order to recover the low-temperature waste heat above 100℃ and meet the heat demand of different temperature ranges, the current effective method is to use heat pump technology to recover low-temperature waste heat to achieve the purpose of energy saving and carbon reduction and obtain economic benefits.

[0003] The application with application number 202411098156.8 discloses an absorption-compression high-temperature heat pump system with liquid injection enthalpy enhancement, relating to the technical field of high-temperature heat pump, comprising a temperature rising subsystem and a liquid injection enthalpy enhancement refrigerant pressurization subsystem connected by pipelines, the liquid injection enthalpy enhancement refrigerant pressurization subsystem comprising a condenser, an evaporator, a compressor, a refrigerant flow control valve, a second liquid pump and a third liquid pump connected, the temperature rising subsystem comprising a generator, an absorber, a solution throttling valve, a first liquid pump, a first heat exchanger and a third heat exchanger connected, the third heat exchanger and the second heat exchanger being connected, and the second heat exchanger and the fourth liquid pump being connected.

[0004] The above scheme has the following defects:

[0005] 1. The condenser needs to cool the refrigerant vapor by cooling water, and the cooling water absorbs heat and is directly discharged in the form of "heated cooling water", this part of low-temperature heat is not recovered, which is equivalent to the output heat of the absorber, resulting in large system heat loss, and the single-stage system performance coefficient (COP) is only 0.395, and the heat utilization efficiency is low;

[0006] 2. The system can only output high-temperature steam above 150℃, and cannot provide medium-temperature heat demand outside industrial production, such as 60℃ or so of domestic hot water in the factory living area. If medium-temperature heat output is needed, other heat pump equipment needs to be additionally matched, resulting in complex system combination and equipment redundancy. SUMMARY

[0007] The present application aims at providing an absorption-compression medium-high temperature heat pump system to overcome the deficiencies of the prior art.

[0008] To achieve the above object, the technical scheme of the present application is as follows:

[0009] An absorption-compression medium-high temperature heat pump system comprises a medium temperature output subsystem and a high temperature output subsystem connected by pipelines.

[0010] The high temperature output subsystem comprises a third liquid pump, an evaporator, a fourth liquid pump, a compressor, a high pressure absorber, a second heat exchanger, a fifth liquid pump, a third heat exchanger, a fourth heat exchanger, a first liquid pump, a first solution throttle valve and a low pressure generator connected in sequence; and the medium temperature output subsystem comprises a low pressure absorber, a second liquid pump, a second solution throttle valve, a first heat exchanger, a medium pressure generator and a condenser connected in sequence.

[0011] The condenser has two refrigerant liquid outlets, one of which is connected to the refrigerant liquid inlet of the third liquid pump, the refrigerant liquid outlet of the third liquid pump is connected to the refrigerant liquid inlet of the evaporator, and the refrigerant vapor outlet of the evaporator is connected to the refrigerant vapor inlet of the compressor; the refrigerant liquid outlet of the fourth liquid pump is connected to the compression chamber of the compressor, and the refrigerant vapor outlet of the compressor is connected to the refrigerant vapor inlet of the high pressure absorber.

[0012] The fifth liquid pump is connected to the third heat exchanger, the third heat exchanger is connected to the evaporator and the fourth heat exchanger, and the fourth heat exchanger is connected to the high pressure absorber; the absorber dilute solution outlet of the second heat exchanger is connected to the fourth heat exchanger, the fourth heat exchanger is connected to the low pressure generator through the first solution throttle valve, and the low pressure generator is connected to the second heat exchanger through the first liquid pump.

[0013] The absorber concentrated solution inlet of the low pressure absorber is connected to the absorber concentrated solution outlet of the second solution throttle valve, the absorber dilute solution outlet of the low pressure absorber is connected to the absorber dilute solution inlet of the second liquid pump, the refrigerant vapor inlet of the low pressure absorber is connected to the refrigerant vapor outlet of the low pressure generator; the absorber dilute solution outlet of the second liquid pump is connected to the absorber dilute solution inlet of the first heat exchanger; the absorber concentrated solution inlet of the second solution throttle valve is connected to the absorber concentrated solution outlet of the first heat exchanger; the first heat exchanger has an absorber concentrated solution inlet and an absorber dilute solution outlet, and the absorber concentrated solution inlet and the absorber dilute solution outlet are connected to the medium pressure generator respectively.

[0014] The beneficial effects of the present application: the system is composed of a high-temperature output subsystem and a medium-temperature output subsystem, through the addition of core components such as a low-pressure absorber, a medium-pressure generator and a first heat exchanger, an independent medium-temperature output circuit is constructed, and high-temperature steam above 150 DEG C and medium-temperature hot water around 60 DEG C can be output simultaneously; the cooling water cooling is cancelled, and the condenser is coupled with the medium-temperature output subsystem. The "low-temperature water after one-time heating" of the low-pressure absorber is input into the condenser, and the condensation waste heat is used to further heat to medium-temperature hot water products around 60 DEG C, so that the waste heat of the condenser is fully recovered; the generator is divided into a low-pressure generator and a medium-pressure generator, and the absorber is divided into a high-pressure absorber and a low-pressure absorber; the high-temperature circuit is responsible for high-temperature steam output, and the medium-temperature circuit is responsible for medium-temperature hot water output, and through the hierarchical design, the heat exchange temperature difference of the cold and hot fluids is reduced, and the irreversible loss is reduced; through the modular integration of the high-temperature output subsystem and the medium-temperature output subsystem, the high-temperature output subsystem and the medium-temperature output subsystem share a set of low-pressure generator and condenser, only a small number of components such as a low-pressure absorber, a medium-pressure generator and a first heat exchanger are added, the dual-temperature output demand can be met, compared with the combined system of a high-temperature output heat pump and a medium-temperature output heat pump, the number of heat exchange equipment, valves and pipelines is reduced, the structure is simplified, and the cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a working principle diagram of an absorption compression medium-high temperature heat pump system.

[0016] The reference signs include:

[0017] 1-low pressure generator; 2-low pressure absorber; 3-first heat exchanger; 4-medium pressure generator; 5-condenser;

[0018] 6-evaporator; 7-compressor; 8-high pressure absorber; 9-second heat exchanger; 10-third heat exchanger;

[0019] 11-fourth heat exchanger; V1-first solution throttling valve; V2-second solution throttling valve;

[0020] P1-first liquid pump; P2-second liquid pump; P3-third liquid pump; P4-fourth liquid pump;

[0021] P5-fifth liquid pump;

[0022] S1-first dilute absorbent solution; S2-second dilute absorbent solution; S3-third dilute absorbent solution;

[0023] S4-fourth dilute absorbent solution; S5-first concentrated absorbent solution; S6-second concentrated absorbent solution;

[0024] S7-third concentrated absorbent solution; S8-fifth dilute absorbent solution; S9-sixth dilute absorbent solution;

[0025] S10 - seventh absorbent dilute solution; S11 - fourth absorbent concentrated solution; S12 - fifth absorbent concentrated solution; S13 - sixth absorbent concentrated solution; R1 - first refrigerant vapor; R2 - second refrigerant vapor;

[0026] R3 - third refrigerant vapor; R4 - fourth refrigerant vapor; R5 - first refrigerant liquid;

[0027] R6 - second refrigerant liquid; R7 - third refrigerant liquid; R8 - fourth refrigerant liquid;

[0028] H1 - first heat source; H2 - second heat source; H3 - third heat source; H4 - fourth heat source;

[0029] H5 - fifth heat source; H6 - sixth heat source; H7 - seventh heat source; W1 - first normal temperature water;

[0030] W2 - low temperature water after first temperature increase; W3 - hot water product; W4 - second normal temperature water;

[0031] W5 - high pressure normal temperature water; W6 - high pressure water after first temperature increase; W7 - high pressure water after second temperature increase;

[0032] W8 - high temperature steam product. DETAILED DESCRIPTION

[0033] The present application will be described in detail below with reference to the accompanying drawings.

[0034] As shown in the drawings, the present application provides an absorption compression medium-high temperature heat pump system, which comprises a high temperature output subsystem and a medium temperature output subsystem. Figure 1

[0035] The first heat source H1, the second heat source H2, the third heat source H3, the fourth heat source H4, the fifth heat source H5, the sixth heat source H6 and the seventh heat source H7 are also included. The first heat source H1, the third heat source H3 and the fifth heat source H5 are derived from waste heat below 100℃ generated in industrial production processes.

[0036] The refrigerant of the present application is water, and the absorbent can be salt, alkali, alcohol, ionic liquid or a mixture of the above substances. In the embodiment, the refrigerant circulating in the refrigerant circulation pipeline is water, and the circulating solution in the absorbent dilute solution circulation pipeline and the absorbent concentrated solution circulation pipeline is lithium bromide solution.

[0037] The high temperature output subsystem comprises a connected third liquid pump P3, an evaporator 6, a fourth liquid pump P4, a compressor 7, a high pressure absorber 8, a second heat exchanger 9, a fifth liquid pump P5, a third heat exchanger 10, a fourth heat exchanger 11, a first liquid pump P1, a first solution throttling valve V1 and a low pressure generator 1. ​

[0038] The condenser 5 has two refrigerant liquid outlets, one of which is connected to the refrigerant liquid inlet of the third liquid pump P3, the refrigerant liquid outlet of the third liquid pump P3 is connected to the refrigerant liquid inlet of the evaporator 6, and the refrigerant vapor outlet of the evaporator 6 is connected to the refrigerant vapor inlet of the compressor 7; the other refrigerant liquid outlet of the condenser 5 is connected to the refrigerant liquid inlet of the fourth liquid pump P4, and the refrigerant liquid outlet of the fourth liquid pump P4 is connected to the compression chamber of the compressor 7. The refrigerant vapor outlet of the compressor 7 is connected to the refrigerant vapor inlet of the high-pressure absorber 8. The evaporator 6 is provided with a fifth heat source H5 inlet for introducing the fifth heat source H5, which is converted into the sixth heat source H6 after being cooled by the evaporator 6; the third heat exchanger 10 is provided with a sixth heat source H6 inlet for introducing the sixth heat source H6, which is converted into the seventh heat source H7 after being cooled. The fifth liquid pump P5 is provided with a second normal-temperature water W4 inlet and a high-pressure normal-temperature water W5 outlet, and the high-pressure normal-temperature water W5 outlet is connected to the third heat exchanger 10; the third heat exchanger 10 is provided with a once-heated high-pressure water W6 outlet, which is connected to the fourth heat exchanger 11; the fourth heat exchanger 11 is provided with a twice-heated high-pressure water W7 outlet, which is connected to the high-pressure absorber 8. The high-pressure absorber 8 has an absorbent concentrated solution inlet and an absorbent dilute solution outlet, which are connected to the second heat exchanger 9; the high-pressure absorber 8 has a twice-heated high-pressure water W7 inlet, which is connected to the fourth heat exchanger 11; the high-pressure absorber 8 has a high-temperature steam product W8 outlet for discharging the high-temperature steam product. The absorbent dilute solution outlet of the second heat exchanger 9 is connected to the fourth heat exchanger 11, and the fourth heat exchanger 11 is connected to the low-pressure generator 1 through the first solution throttling valve V1; the low-pressure generator 1 is connected to the second heat exchanger 9 through the first liquid pump P1.

[0039] The third liquid pump P3 is a liquid pressurizing device for increasing the liquid pressure of the first refrigerant liquid R5. The evaporator 6 is an evaporating device for absorbing heat of the fifth heat source H5 to evaporate the second refrigerant liquid R6 into the third refrigerant vapor R3. The fourth liquid pump P4 is a liquid pressurizing device for increasing the liquid pressure of the third refrigerant liquid R7. The compressor 7 is a refrigerant vapor pressurizing device for pressurizing a refrigerant vapor to produce the high pressure fourth refrigerant vapor R4. The high pressure absorber 8 is a gas-liquid mixed absorbing device in which the third absorbent concentrated solution S7 absorbs the fourth refrigerant vapor R4 to heat the once warmed high pressure water W7 using heat released in the absorption process to produce the high temperature steam product W8. The second heat exchanger 9 is a fluid heat exchanging device for exchanging heat between the first absorbent dilute solution S1 and the second absorbent concentrated solution S6. The fifth liquid pump P5 is a liquid pressurizing device for increasing the liquid pressure of the second normal temperature water W4. The third heat exchanger 10 is a fluid heat exchanging device for exchanging heat between the sixth heat source H6 and the high pressure normal temperature water W5. The fourth heat exchanger 11 is a fluid heat exchanging device for exchanging heat between the second absorbent dilute solution S2 and the once warmed high pressure water W6. The first solution throttling valve V1 is a fluid throttling pressure reducing device for reducing the pressure of the third absorbent dilute solution S3. The low pressure generator 1 is a refrigerant vapor generating device for generating the low pressure first refrigerant vapor R1 and the first absorbent concentrated solution S5 by absorbing heat of the first heat source H1 in the generation process. The first liquid pump P1 is a liquid pressurizing device for increasing the liquid pressure of the first absorbent concentrated solution S5.

[0040] The medium temperature output subsystem includes the connected low pressure absorber 2, the second liquid pump P2, the second solution throttling valve V2, the first heat exchanger 3, the medium pressure generator 4, and the condenser 5.

[0041] The low-pressure absorber 2 is provided with a first normal-temperature water Wl inlet and a once-heated low-temperature water W2 outlet, respectively for feeding the first normal-temperature water Wl and discharging the once-heated low-temperature water W2. The absorber concentrated solution inlet of the low-pressure absorber 2 is connected to the absorber concentrated solution outlet of the second solution throttling valve V2, and the absorber dilute solution outlet of the low-pressure absorber 2 is connected to the absorber dilute solution inlet of the second liquid pump P2. The refrigerant vapor inlet of the low-pressure absorber 2 is connected to the refrigerant vapor outlet of the low-pressure generator 1. The absorber dilute solution outlet of the second liquid pump P2 is connected to the absorber dilute solution inlet of the first heat exchanger 3. The absorber concentrated solution inlet of the second solution throttling valve V2 is connected to the absorber concentrated solution outlet of the first heat exchanger 3. The first heat exchanger 3 is provided with an absorber concentrated solution inlet and an absorber dilute solution outlet, which are connected to the medium-pressure generator 4. The medium-pressure generator 4 is provided with a third heat source H3 inlet and a fourth heat source H4 outlet, respectively for feeding the third heat source H3 and discharging the fourth heat source H4. The refrigerant vapor outlet of the medium-pressure generator 4 is connected to the refrigerant vapor inlet of the condenser 5. The condenser 5 is provided with two refrigerant liquid outlets, one of which is connected to the refrigerant liquid inlet of the third liquid pump P3, and the other is connected to the refrigerant liquid inlet of the fourth liquid pump P4. The condenser 5 is provided with a once-heated low-temperature water W2 inlet, which is connected to the low-pressure absorber 2, and a hot water product W3 outlet, which is used to discharge the hot water product W3.

[0042] The low-pressure absorber 2 is a gas-liquid mixed absorption device, in which the sixth absorber concentrated solution S13 absorbs the first refrigerant vapor Rl, and the heat released in the absorption process is used to heat the first normal-temperature water Wl, to generate the once-heated low-temperature water W2. The second liquid pump P2 is a liquid pressurizing device, which is used to increase the liquid pressure of the fifth absorber dilute solution S8. The second solution throttling valve V2 is a fluid throttling and pressure reducing device, which is used to reduce the pressure of the fifth absorber concentrated solution S12. The first heat exchanger 3 is a fluid heat exchange device, which is used to exchange heat between the sixth absorber dilute solution S9 and the fourth absorber concentrated solution SIl. The medium-pressure generator 4 is a refrigerant vapor generating device, which generates the medium-pressure second refrigerant vapor R2 and the fourth absorber concentrated solution SIl by absorbing the heat of the third heat source H3 in the generating process. The condenser 5 is a condensing device, which condenses the second refrigerant vapor R2 into refrigerant liquid by using the once-heated low-temperature water W2.

[0043] The high-temperature output subsystem is connected with the medium-temperature output subsystem, and the two form a working fluid circulation loop. The high-temperature output subsystem sequentially performs evaporation, compression and absorption on the refrigerant liquid generated by the medium-temperature output subsystem, releases high-temperature heat by using a high-pressure absorber to generate high-temperature steam products, and finally heats the absorbent dilute solution by using the first heat source in the low-pressure generator to generate refrigerant vapor. The medium-temperature output subsystem sequentially performs absorption, generation and condensation on the refrigerant vapor generated by the high-temperature output subsystem, and generates hot water products by using the medium-temperature heat released by the low-pressure absorber and the condenser.

[0044] The system is composed of a high-temperature output subsystem and a medium-temperature output subsystem, and by adding core components such as a low-pressure absorber, a medium-pressure generator and a first heat exchanger, an independent medium-temperature output circuit is constructed, which can simultaneously realize high-temperature steam output above 150 DEG C and medium-temperature hot water output around 60 DEG C; the cooling water cooling is cancelled, and the condenser is coupled with the medium-temperature output subsystem. The "low-temperature water after one-time heating" heated by the low-pressure absorber is fed into the condenser, and the condensation waste heat is further used to heat the low-temperature water to medium-temperature hot water products around 60 DEG C, so that the waste heat of the condenser is fully recovered; the generator is divided into a low-pressure generator and a medium-pressure generator, and the absorber is divided into a high-pressure absorber and a low-pressure absorber; the high-temperature circuit is responsible for high-temperature steam output, and the medium-temperature circuit is responsible for medium-temperature hot water output; by the staged design, the heat exchange temperature difference of the cold and hot fluids is reduced, and the irreversible loss is reduced; by the modular integration of the high-temperature output subsystem and the medium-temperature output subsystem, the high-temperature output subsystem and the medium-temperature output subsystem share a set of low-pressure generator and condenser, only a small number of components such as a low-pressure absorber, a medium-pressure generator and a first heat exchanger are added, and the dual-temperature output demand can be met, compared with the combination system of a high-temperature output heat pump and a medium-temperature output heat pump, the number of heat exchange equipment, valves and pipelines is reduced, the structure is simplified, and the cost is reduced.

[0045] The refrigerant of the application is water, and the absorbent can be salt, alkali, alcohol, ionic liquid or a mixture of the above substances. In the embodiment, the refrigerant circulating in the refrigerant circulation pipeline is water, and the absorbent in the absorbent dilute solution circulation pipeline and the absorbent concentrated solution circulation pipeline is lithium bromide.

[0046] A refrigerant circulation pipeline is arranged between the medium-pressure generator 4, the condenser 5, the evaporator 6, the compressor 7 and the high-pressure absorber 8. The medium-pressure generator 4 absorbs heat of the third heat source H3 to generate second refrigerant vapor R2 from the seventh absorbent dilute solution S10, and the third heat source H3 is converted into the fourth heat source H4 after being cooled; the condenser 5 condenses the second refrigerant vapor R2 into the first refrigerant liquid R5 and the third refrigerant liquid R7 by using the low-temperature water W2 after being heated once; the first refrigerant liquid R5 is pressurized by the third liquid pump P3 to generate the second refrigerant liquid R6, and the second refrigerant liquid R6 flows into the evaporator 6 through the refrigerant liquid inlet of the evaporator 6; the evaporator 6 absorbs heat of the fifth heat source H5 to evaporate the second refrigerant liquid R6 into the third refrigerant vapor R3, and the fifth heat source H5 is converted into the sixth heat source H6 after being cooled; the third refrigerant vapor R3 enters the compressor 7 to be pressurized and heated, and the third refrigerant liquid R7 is pressurized by the fourth liquid pump P4 to generate the fourth refrigerant liquid R8, which is injected into the compression chamber of the compressor 7 to be evaporated by absorbing heat of the overheated third refrigerant vapor R3 in the compressor, and the compressor 7 outputs the fourth refrigerant vapor R4 which is heated and pressurized.

[0047] An absorbent dilute solution circulation pipeline is arranged between the high-pressure absorber 8, the second heat exchanger 9, the fourth heat exchanger 11 and the low-pressure generator 1. The third absorbent concentrated solution S7 in the high-pressure absorber 8 absorbs the fourth refrigerant vapor R4 to generate the first absorbent dilute solution S1 after releasing absorption heat; the first absorbent dilute solution S1 flows out through the absorbent dilute solution outlet of the high-pressure absorber 8, is cooled in the second heat exchanger 9 and is converted into the second absorbent dilute solution S2; the second absorbent dilute solution S2 is cooled in the fourth heat exchanger 11 and is converted into the third absorbent dilute solution S3 which flows out; the third absorbent dilute solution S3 is throttled and depressurized by the first solution throttle valve V1 and is converted into the fourth absorbent dilute solution S4; the fourth absorbent dilute solution S4 enters the low-pressure generator 1 through the absorbent dilute solution inlet of the low-pressure generator 1; the low-pressure generator 1 generates the first refrigerant vapor R1 and the first absorbent concentrated solution S5 by absorbing heat of the first heat source H1 from the fourth absorbent dilute solution S4.

[0048] An absorbent concentrated solution circulation pipeline is arranged between the low-pressure generator 1, the second heat exchanger 9 and the high-pressure absorber 8. The first absorbent concentrated solution S5 generated by the low-pressure generator 1 enters the first liquid pump P1, is pressurized and converted into the second absorbent concentrated solution S6 which flows out; the second absorbent concentrated solution S6 enters the second heat exchanger 9, is heated and converted into the third absorbent concentrated solution S7; and the third absorbent concentrated solution S7 flows into the high-pressure absorber 8 to participate in the absorption process of the fourth refrigerant vapor R4.

[0049] A dilute absorbent solution circulation pipeline is arranged between the low-pressure absorber 2, the first heat exchanger 3 and the medium-pressure generator 4. The sixth absorbent concentrated solution S13 in the low-pressure absorber 2 absorbs the first refrigerant vapor R1 generated by the low-pressure generator 1, releases the absorption heat to generate the fifth absorbent dilute solution S8; the fifth absorbent dilute solution S8 is converted into the sixth absorbent dilute solution S9 after being pressurized by the second liquid pump P2; the sixth absorbent dilute solution S9 is converted into the seventh absorbent dilute solution S10 after being warmed in the first heat exchanger 3; the seventh absorbent dilute solution S10 enters the medium-pressure generator 4 through the absorbent dilute solution inlet of the medium-pressure generator 4; the medium-pressure generator 4 generates the second refrigerant vapor R2 and the fourth absorbent concentrated solution S11 by absorbing the heat of the third heat source H3.

[0050] A concentrated absorbent solution circulation pipeline is arranged between the medium-pressure generator 4, the first heat exchanger 3 and the low-pressure absorber 2. The fourth absorbent concentrated solution S11 generated by the medium-pressure generator 4 enters the first heat exchanger 3, is cooled and converted into the fifth absorbent concentrated solution S12, is depressurized by the second solution throttling valve V2 and converted into the sixth absorbent concentrated solution S13, and flows into the low-pressure absorber 2 to participate in the absorption process of the first refrigerant vapor R1.

[0051] A water circulation pipeline is arranged between the low-pressure absorber 2 and the condenser 5. The first normal-temperature water W1 enters the low-pressure absorber 2 through the water circulation pipeline inlet of the low-pressure absorber 2, is warmed and converted into the once-warmed low-temperature water W2, enters the condenser 5 through the water circulation pipeline inlet of the condenser 5, is warmed and converted into the hot water product W2.

[0052] A water circulation pipeline is arranged between the fifth liquid pump P5, the third heat exchanger 10, the fourth heat exchanger 11 and the high-pressure absorber 8. The second normal-temperature water W4 is pressurized by the fifth liquid pump P5 and converted into the high-pressure normal-temperature water W5, the high-pressure normal-temperature water W5 enters the third heat exchanger 10, is warmed and converted into the once-warmed high-pressure water W6, the once-warmed high-pressure water W6 enters the fourth heat exchanger 11, is warmed and converted into the twice-warmed high-pressure water W7, and the twice-warmed high-pressure water W7 enters the high-pressure absorber 8, absorbs the heat of the high-temperature solution and is converted into the high-temperature vapor product W8.

[0053] The present application combines the second type of absorption heat pump with the refrigerant injection temperature control compressor, which can greatly improve the output temperature of the heat pump under the condition that the low-temperature heat source in the traditional second type of absorption heat pump is unchanged. The refrigerant injection temperature control compressor 7 is mainly used for refrigerant vapor pressure, and the high-temperature output relies on the high-pressure absorber 8, and the refrigerant injected into the compressor comes from the condenser, which does not change the total amount of refrigerant in the whole system, solves the problem of complex structure of the current multi-stage absorption high-temperature heat pump, and avoids the shortcomings of high compression power consumption and high superheat of the multi-stage compression high-temperature heat pump. The heat pump system of the present application only adds a solution circulation composed of a low-pressure absorber 2, a first heat exchanger 3 and a medium-pressure generator 4, which fully utilizes the medium-temperature heat of the low-pressure absorber 2 and the condenser 5 through the water circulation pipeline in turn, and outputs medium-temperature domestic hot water, so that the system does not need a large amount of cooling water, avoids the waste of low-temperature heat, and greatly improves the heat utilization efficiency of the system. Through the third heat exchanger 10, the fourth heat exchanger 11 and the high-pressure absorber 8, the cascade utilization of medium-high temperature heat energy in the system is realized, and the heat exchange temperature difference and irreversible loss of the cold and hot fluid are reduced. The modular integration of the high-temperature output subsystem and the medium-temperature output subsystem is realized, which can use industrial process waste heat below 100℃ as heat source, simultaneously generate high-temperature output of about 150℃ and medium-temperature output of about 60℃, and supply industrial production process and residential area around the factory, respectively, which further expands the application range of high-temperature heat pump.

[0054] In order to better reflect the beneficial effects of the absorption-compression medium-high temperature heat pump system provided by the present application, the example and a reference system are simulated and calculated under the same heat source and output conditions, and the performance differences of the two are compared. In order to realize the same output of about 150℃ and about 60℃, the reference system adopts a combination of a double-stage compression high-temperature heat pump and a first type of absorption heat pump, and the refrigerant and solution in it use the same refrigerant water and lithium bromide solution as the system of the present application. In order to ensure fairness, the double-stage compression high-temperature heat pump also uses a refrigerant injection compressor to reduce the power consumption and superheat of the compressor. The compression ratio of the compressor is defined as the ratio of the outlet vapor pressure to the inlet vapor pressure of the compressor. The main calculation results are summarized in Table 1.

[0055] Table 1

[0056]

[0057] As can be seen from Table 1, the temperature of the heat source in the two systems is 95℃, the temperature of the high-temperature steam output is 155.8℃, the temperature of the hot water output is 61.9℃, and the flow rates of the steam and hot water output are the same. Under the condition of the same heat source temperature, the high-temperature output of the system of the application relies on the combination of the temperature-controlled compressor 7 and the high-pressure absorber 8 by injecting the refrigerant, without the need to build a double-stage absorption or compression high-temperature heat pump, so as to achieve the output temperature of the double-stage compression heat pump. However, compared with the double-stage compression heat pump, the pressure ratio required by the system of the application is only 3.2, while the double-stage compression heat pump requires two-stage compression to reach the same output temperature, with a total pressure ratio as high as 12.96.

[0058] Since the compressor 7 is only used to increase the absorption pressure of the high-pressure absorber 8, the outlet temperature of the compressor and the power consumption of the compressor of the system of the application are lower than those of the reference system, so the structure of the system of the application can solve the problem of complex structure of the current multi-stage absorption high-temperature heat pump, and avoid the shortcomings of high power consumption and high superheat of the multi-stage compression high-temperature heat pump. In addition, the system of the application only adds the solution circulation composed of the low-pressure absorber 2, the first heat exchanger 3 and the medium-pressure generator 4, without adding all components of the first type of absorption heat pump, so as to fully recover and utilize the medium-temperature waste heat of the low-pressure absorber 2 and the condenser 5, to produce medium-temperature domestic hot water, greatly improve the heat utilization efficiency of the system, and the system does not require a large amount of cooling water. Finally, under the same output conditions, the total amount of input heat source required by the system of the application is also lower than that required by the reference system.

[0059] Compared with the patent scheme of the background technology “An absorption-compression high-temperature heat pump system with liquid injection for enthalpy increase (CN202411098156.8)”, the condenser pressure of the system of the application is increased, the pressure difference of the fourth liquid pump inlet and outlet for injecting the refrigerant into the compressor is reduced, and therefore the power consumption of the liquid pump is reduced. Under the condition of a heat source below 100℃, in order to simultaneously achieve high-temperature output above 150℃ and medium-temperature output around 60℃, a similar scheme as in the patent of the background technology and a combined system of the first type of absorption heat pump can be used. However, the high-temperature output subsystem and the medium-temperature output subsystem of the application share a set of low-pressure generator and condenser, so compared with the above combined system, the number of heat exchange equipment, valves and pipelines of the application is reduced, the system structure is simplified, and the cost is reduced.

[0060] As can be seen from the above, the application has the excellent characteristics described above, and can improve the performance of the prior art and has practicality, becoming a product with high practical value.

[0061] The above is only a preferred embodiment of the application, and those skilled in the art can make changes in specific implementation and application range according to the idea of the application. The content of the specification should not be understood as a limitation of the application.

Claims

1. An absorption compression medium- and high-temperature heat pump system, comprising a medium-temperature output subsystem and a high-temperature output subsystem connected by pipelines, characterized in that: The high-temperature output subsystem includes a connected third liquid pump, an evaporator, a fourth liquid pump, a compressor, a high-pressure absorber, a second heat exchanger, a fifth liquid pump, a third heat exchanger, a fourth heat exchanger, a first liquid pump, a first solution throttle valve, and a low-pressure generator; the medium-temperature output subsystem includes a connected low-pressure absorber, a second liquid pump, a second solution throttle valve, a first heat exchanger, a medium-pressure generator, and a condenser; The condenser has two refrigerant liquid outlets, one of which is connected to the refrigerant liquid inlet of the third liquid pump, the refrigerant liquid outlet of the third liquid pump is connected to the refrigerant liquid inlet of the evaporator, and the refrigerant vapor outlet of the evaporator is connected to the refrigerant vapor inlet of the compressor; the refrigerant liquid outlet of the fourth liquid pump is connected to the compression chamber of the compressor, and the refrigerant vapor outlet of the compressor is connected to the refrigerant vapor inlet of the high-pressure absorber; The fifth liquid pump is connected to the third heat exchanger, the third heat exchanger is connected to the evaporator and the fourth heat exchanger, and the fourth heat exchanger is connected to the high-pressure absorber; the absorbent dilute solution outlet of the second heat exchanger is connected to the fourth heat exchanger, the fourth heat exchanger is connected to the low-pressure generator via the first solution throttle valve, and the low-pressure generator is connected to the second heat exchanger via the first liquid pump; The absorbent concentrated solution inlet on the low-pressure absorber is connected to the absorbent concentrated solution outlet of the second solution throttle valve, the absorbent dilute solution outlet on the low-pressure absorber is connected to the absorbent dilute solution inlet of the second liquid pump, the refrigerant vapor inlet of the low-pressure absorber is connected to the refrigerant vapor outlet of the low-pressure generator; the absorbent dilute solution outlet of the second liquid pump is connected to the absorbent dilute solution inlet of the first heat exchanger; The absorbent concentrated solution inlet of the second solution throttle valve is connected to the absorbent concentrated solution outlet of the first heat exchanger; the first heat exchanger is provided with an absorbent concentrated solution inlet and an absorbent dilute solution outlet, which are respectively connected to the medium pressure generator.

2. The absorption-compression medium- and high-temperature heat pump system according to claim 1, characterized in that: It also includes a first heat source, a second heat source, a third heat source, a fourth heat source, a fifth heat source, a sixth heat source and a seventh heat source; the low-pressure generator is provided with a first heat source inlet and a second heat source outlet, which are respectively used to allow the first heat source to pass through and discharge the second heat source; the medium-pressure generator is provided with a third heat source inlet and a fourth heat source outlet, which are respectively used to allow the third heat source to pass through and discharge the fourth heat source; the evaporator is provided with a fifth heat source inlet and a sixth heat source outlet, which are respectively used to allow the fifth heat source to pass through and discharge the sixth heat source; the third heat exchanger is provided with a sixth heat source inlet and a seventh heat source outlet, which are respectively used to allow the sixth heat source to pass through and discharge the seventh heat source.

3. The absorption-compression medium- and high-temperature heat pump system according to claim 2, characterized in that: The low-pressure absorber is provided with a first normal temperature water inlet and a low-temperature water outlet after the first heating, which are respectively used to pass the first normal temperature water and discharge the low-temperature water after the first heating; the condenser is provided with a low-temperature water inlet after the first heating and a hot water product outlet, which are respectively used to pass the low-temperature water after the first heating and discharge the hot water product.

4. The absorption-compression medium- and high-temperature heat pump system according to claim 3, characterized in that: The fifth liquid pump is provided with a second normal temperature water inlet and a high-pressure normal temperature water outlet, which are respectively used to introduce the second normal temperature water and discharge the high-pressure normal temperature water; the third heat exchanger is provided with a high-pressure normal temperature water inlet and a high-pressure water outlet after the first heating, which are respectively used to introduce high-pressure normal temperature water and discharge the high-pressure water after the first heating; the fourth heat exchanger is provided with a high-pressure water inlet after the first heating and a high-pressure water outlet after the second heating, which are respectively used to introduce high-pressure water after the first heating and discharge the high-pressure water after the second heating; the high-pressure absorber is provided with a high-pressure water inlet after the second heating and a high-temperature steam product outlet, which are respectively used to introduce high-pressure water after the second heating and discharge the high-temperature steam product.

5. The absorption-compression medium- and high-temperature heat pump system according to claim 4, characterized in that: An absorbent dilute solution circulation pipeline is provided between the low-pressure absorber, the first heat exchanger and the medium-pressure generator; the low-pressure absorber discharges a fifth absorbent dilute solution through the absorbent dilute solution outlet, the fifth absorbent dilute solution is pressurized by the second liquid pump and converted into a sixth absorbent dilute solution, the sixth absorbent dilute solution enters the first heat exchanger and is converted into a seventh absorbent dilute solution and flows out, and the seventh absorbent dilute solution enters the medium-pressure generator through the absorbent dilute solution inlet of the medium-pressure generator; the medium-pressure generator utilizes the heat of the third heat source to generate a second refrigerant vapor and simultaneously generates a fourth absorbent concentrated solution, and continues to perform heat exchange, pressure reduction and absorption.

6. The absorption-compression medium- and high-temperature heat pump system according to claim 5, characterized in that: An absorbent concentrated solution circulation pipeline is provided between the medium-pressure generator, the first heat exchanger and the low-pressure absorber. The medium-pressure generator discharges a fourth absorbent concentrated solution through the absorbent concentrated solution outlet. The fourth absorbent concentrated solution enters the first heat exchanger and is converted into a fifth absorbent concentrated solution and flows out. The fifth absorbent concentrated solution is converted into a sixth absorbent concentrated solution after being reduced in pressure by the second solution throttle valve. The sixth absorbent concentrated solution flows into the low-pressure absorber through the absorbent concentrated solution inlet of the low-pressure absorber.

7. The absorption-compression medium- and high-temperature heat pump system according to claim 6, characterized in that: A refrigerant circulation pipeline is provided between the medium-pressure generator, condenser, evaporator, compressor and high-pressure absorber. The second refrigerant vapor generated by the medium-pressure generator enters the condenser, and the condenser uses the low-temperature water after the temperature is increased once to condense the second refrigerant vapor into a first refrigerant liquid and a third refrigerant liquid; the first refrigerant liquid is pressurized by the third liquid pump to generate a second refrigerant liquid, and the second refrigerant liquid flows into the evaporator through the refrigerant liquid inlet of the evaporator. The evaporator absorbs heat from the fifth heat source and evaporates the second refrigerant liquid into a third refrigerant vapor. The third refrigerant vapor enters the compressor for pressure and temperature increase; the third refrigerant liquid is pressurized by the fourth liquid pump to generate a fourth refrigerant liquid, and the fourth refrigerant liquid is injected into the compression chamber of the compressor, absorbs the heat of the superheated third refrigerant vapor in the compressor and evaporates; The compressor outputs the fourth refrigerant vapor, which enters the high-pressure absorber through the refrigerant vapor inlet of the high-pressure absorber to participate in the absorption process.

8. The absorption-compression medium- and high-temperature heat pump system according to claim 7, characterized in that: An absorbent dilute solution circulation pipeline is provided between the high-pressure absorber, the second heat exchanger, the fourth heat exchanger and the low-pressure generator. The high-pressure absorber discharges the first absorbent dilute solution through the absorbent dilute solution outlet, the first absorbent dilute solution enters the second heat exchanger and is converted into the second absorbent dilute solution and flows out, the second absorbent dilute solution enters the fourth heat exchanger and is converted into the third absorbent dilute solution and flows out, the third absorbent dilute solution is throttled and reduced in pressure by the first solution throttle valve and is converted into the fourth absorbent dilute solution, the fourth absorbent dilute solution enters the low-pressure generator through the absorbent dilute solution inlet of the low-pressure generator; the low-pressure generator uses the heat of the first heat source to generate the first refrigerant vapor and the first absorbent concentrated solution at the same time, which flows to the high-pressure absorber to continue absorbing the refrigerant.

9. The absorption-compression medium- and high-temperature heat pump system according to claim 8, characterized in that: An absorbent concentrated solution circulation pipeline is provided between the low-pressure generator, the second heat exchanger and the high-pressure absorber. The low-pressure generator discharges a first absorbent concentrated solution through the absorbent concentrated solution outlet. The first absorbent concentrated solution enters the first liquid pump and is converted into a second absorbent concentrated solution for outflow. The second absorbent concentrated solution enters the second heat exchanger and is converted into a third absorbent concentrated solution for outflow. The third absorbent concentrated solution flows into the high-pressure absorber through the absorbent concentrated solution inlet of the high-pressure absorber. A refrigerant circulation pipeline is provided between the low-pressure generator and the low-pressure absorber. The first refrigerant vapor generated by the low-pressure generator enters the low-pressure absorber through the refrigerant vapor inlet of the low-pressure absorber and is absorbed by the absorbent concentrated solution in the low-pressure absorber.

10. The absorption-compression medium- and high-temperature heat pump system according to claim 9, characterized in that: A water circulation pipeline is provided between the low-pressure absorber and the condenser. The first normal-temperature water enters the low-pressure absorber through the water circulation pipeline inlet of the low-pressure absorber, absorbs heat in the low-pressure absorber, and is converted into low-temperature water after a primary heating and flows out. The low-temperature water after a primary heating enters the condenser through the water circulation pipeline inlet of the condenser, absorbs heat in the condenser, and is converted into a hot water product and flows out. A water circulation pipeline is provided between the fifth liquid pump, the third heat exchanger, the fourth heat exchanger and the high-pressure absorber. The second normal-temperature water is pressurized into high-pressure normal-temperature water by the fifth liquid pump. The high-pressure normal-temperature water absorbs heat through the third heat exchanger and is converted into high-pressure water after primary heating. The high-pressure water after primary heating is converted into high-pressure water after secondary heating by the fourth heat exchanger. The high-pressure water after secondary heating enters the high-pressure absorber through the inlet of the water circulation pipeline of the high-pressure absorber, absorbs heat in the high-pressure absorber and is converted into high-temperature steam product for output.

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