Single-effect tandem cascade lithium bromide absorption refrigeration / heat pump unit

Abstract

The present application relates to a single-effect tandem cascade lithium bromide absorption refrigeration / heat pump unit, belonging to the technical field of air conditioning equipment. It comprises a generator, a condenser, a high-temperature heat exchanger, a first absorber, a first evaporator, a second evaporator and a second absorber, characterized in that the unit further comprises a single-effect absorber and a single-effect evaporator, the single-effect evaporator is arranged in series with the first evaporator, and the single-effect absorber is in the same cavity as the single-effect evaporator; lithium bromide solution flows through the generator, the single-effect absorber, the second absorber and the first absorber; a high-temperature heat source flows through the generator; low-temperature water flows through the single-effect evaporator and the first evaporator in series; and medium-temperature water flows through the single-effect absorber. The present unit can reduce the refrigerating capacity of the second evaporator in the cascade unit, thereby improving the COP of the entire unit.

Description

Technical Field

[0001] This invention relates to a single-effect series cascade lithium bromide absorption chiller / heat pump unit. It belongs to the technical field of air conditioning equipment. Background Technology

[0002] Existing cascade single-effect lithium bromide absorption chiller / heat pump units (hereinafter referred to as cascade single-effect units, or units) such as Figure 1 As shown, the unit consists of a generator 1, a condenser 2, a high-temperature heat exchanger 3, a low-temperature heat exchanger 4, a first absorber 5, a first evaporator 6, a second evaporator 7, a second absorber 8, a refrigerant pump 9, a refrigerant connecting pipe 10, a first solution pump 11, a second solution pump 12, a control system, and pipes and valves connecting the various components. The first evaporator 6 and the first absorber 5 are located in one chamber, while the second evaporator 7 and the second absorber 8 are located in another chamber. The refrigerant water in the first evaporator 6 and the second evaporator 7 is connected by the refrigerant water connecting pipe 10. The low-temperature water flows through the first evaporator 6 to cool down; the medium-temperature water is divided into two streams: one stream flows in series through the second evaporator 7 and the first absorber 5, cooling down and then heating up, while the other stream flows through the second absorber 8 to heat up. The two streams merge and then flow through the condenser 2 to heat up; the high-temperature driving heat source flows through the generator 1, releasing heat to drive the entire unit. During unit operation, the refrigerant water, drawn out by refrigerant pump 9 and sprayed from the top of the first evaporator 6 and the second evaporator 7, exchanges heat with the low-temperature water flowing through the heat transfer tubes of the first evaporator 6 and the medium-temperature water flowing through the heat transfer tubes of the second evaporator 7, respectively, lowering their temperature. The refrigerant water itself then vaporizes into refrigerant vapor and enters the first absorber 5 and the second absorber 8, respectively. It is absorbed by the lithium bromide solution in the absorber and releases heat to heat the medium-temperature water flowing through its heat transfer tubes. The lithium bromide solutions in the first absorber 5 and the second absorber 8 are connected in series. The concentrated lithium bromide solution first absorbs refrigerant vapor in the first absorber 5 and becomes less concentrated. Then it is drawn out by the first solution pump 11, heats up by the low-temperature heat exchanger 4, and enters the second absorber 8. After absorbing refrigerant vapor again, it becomes less concentrated. Finally, it is drawn out by the second solution pump 12, heats up by the high-temperature heat exchanger 3, and enters the generator 1. The dilute lithium bromide solution is heated and concentrated in generator 1 by a high-temperature heat source. The concentrated refrigerant vapor enters condenser 2 and is cooled and condensed by medium-temperature water. The condensed refrigerant water is returned to the second evaporator 7 (the refrigerant water in the first evaporator 6 and the second evaporator 7 is connected by a connecting pipe 10). The concentrated solution is cooled by heat exchange in high-temperature heat exchanger 3 and low-temperature heat exchanger 4 and then returns to the first absorber 5 to absorb refrigerant vapor.

[0003] In the cascade single-effect unit, the unit needs to refrigerate the low-temperature water flowing through the first evaporator 6 and the medium-temperature water flowing through the second evaporator 7 at the same time, and in the case of the same single-effect refrigeration COP, the greater the refrigeration load in the second evaporator 7, the lower the unit COP. If the refrigeration demand in the second evaporator 7 can be reduced, the COP of the unit can be improved. SUMMARY

[0004] The purpose of the present application is to provide a single-effect cascade lithium bromide absorption refrigeration / heat pump unit, which can reduce the refrigeration demand of the second evaporator and improve the COP of the cascade single-effect unit.

[0005] The purpose of the present application is achieved by a single-effect cascade lithium bromide absorption refrigeration / heat pump unit (hereinafter referred to as a single-effect cascade unit or unit), comprising a generator, a condenser, a high-temperature heat exchanger, a first absorber, a first evaporator, a second evaporator and a second absorber, the first evaporator and the first absorber being in one cavity and being provided with a first solution pump, the second evaporator and the second absorber being in another cavity; the refrigerant water of the first evaporator and the second evaporator is connected by a refrigerant water communication pipe; the unit further comprises a single-effect evaporator and a single-effect absorber, the single-effect evaporator is arranged in series with the first evaporator; the single-effect absorber is in the same cavity as the single-effect evaporator and corresponds to it; the lithium bromide solution flows through the generator, the single-effect absorber, the first absorber and the second absorber in series or in parallel; the refrigerant vapor generated by the solution concentration in the generator enters the condenser, and after condensation, it returns to the second evaporator and the first evaporator; the high-temperature heat source flows through the generator; the low-temperature water flows through the single-effect evaporator and the first evaporator in series; the medium-temperature water flows through the single-effect absorber.

[0006] The medium-temperature water is divided into two paths, one of which is sequentially passed through the single-effect absorber and the second absorber to be heated, and the other of which is sequentially passed through the second evaporator and the first absorber to be cooled and then heated, and the two paths of water are combined and then passed through the condenser to be heated; or, one of the paths is sequentially passed through the single-effect absorber and the condenser to be heated, and the other of the paths is sequentially passed through the second evaporator and the first absorber to be cooled and then heated, and the two paths of water are combined and then passed through the second absorber to be heated; or, one of the paths is sequentially passed through the single-effect absorber, and then passed through the second absorber and the condenser in any order in series or in parallel, and the other of the paths is sequentially passed through the second evaporator and the first absorber to be cooled and then heated; or, one of the paths is sequentially passed through the single-effect absorber, and then passed through any one of the second absorber and the condenser, and the other of the paths is sequentially passed through the second evaporator and the first absorber to be cooled and then heated, and then passed through the other one of the second absorber and the condenser; or, one of the paths is sequentially passed through the single-effect absorber, and the other of the paths is sequentially passed through the second evaporator and the first absorber to be cooled and then heated, and the two paths of water are combined and then passed through the second absorber and the condenser in any order in series or in parallel; or, one of the paths is sequentially passed through the single-effect absorber, and the other of the paths is sequentially passed through the second evaporator and the first absorber to be cooled and then heated, and then passed through the second absorber and the condenser in any order in series or in parallel.

[0007] Alternatively, the medium-temperature water is sequentially passed through the single-effect absorber, and then divided into two paths, one of which is passed through the second absorber and the condenser in any order in series or in parallel, and the other of which is sequentially passed through the second evaporator and the first absorber to be cooled and then heated; or, one of the paths is passed through any one of the second absorber and the condenser, and the other of the paths is sequentially passed through the second evaporator and the first absorber to be cooled and then heated, and then passed through the other one of the second absorber and the condenser; or, one of the paths is sequentially passed through any one of the second absorber and the condenser, and the other of the paths is sequentially passed through the second evaporator and the first absorber to be cooled and then heated, and the two paths of water are combined and then passed through the other one of the second absorber and the condenser.

[0008] Further, the first solution pump draws the dilute solution in the first absorber and the second absorber (the solutions in the first absorber and the second absorber are communicated) out, sends it to the generator through the high-temperature heat exchanger, and the concentrated solution enters the single-effect absorber and the second absorber in parallel after passing through the high-temperature heat exchanger, wherein the single-effect absorber enters the first absorber again;

[0009] Alternatively, the first solution pump draws the dilute solution in the first absorber and the second absorber (the solutions in the first absorber and the second absorber are communicated) out, sends it to the generator through the high-temperature heat exchanger, and the concentrated solution enters the single-effect absorber and the first absorber in parallel after passing through the high-temperature heat exchanger, wherein the single-effect absorber enters the second absorber again;

[0010] Or, the second absorber of the unit is equipped with a second solution pump (the solution of the first absorber and the second absorber is not connected), the first solution pump extracts the dilute solution in the first absorber, and sends it to the generator through the high-temperature heat exchanger, and the concentrated solution enters the single-effect absorber through the high-temperature heat exchanger, and then enters the second absorber, and the second solution pump extracts the dilute solution in the second absorber and sends it back to the first absorber;

[0011] Or, in addition to the second absorber being equipped with a second solution pump (the solution of the first absorber and the second absorber is not connected), the unit also includes a low-temperature heat exchanger, the second solution pump extracts the dilute solution in the second absorber, and sends it to the generator through the high-temperature heat exchanger, and the concentrated solution enters the single-effect absorber through the high-temperature heat exchanger and the low-temperature heat exchanger, and then enters the first absorber, and the first solution pump extracts the dilute solution in the first absorber and sends it back to the second absorber through the low-temperature heat exchanger.

[0012] The beneficial effects of the present application are:

[0013] Compared with the existing cascade single-effect unit, the present application increases a single-effect evaporator by segmenting the first evaporator, and increases a single-effect absorber corresponding to the single-effect evaporator, directly forms an evaporation-absorption process by using the high-temperature section of the low-temperature water and the low-temperature section of the medium-temperature water, thereby reducing the refrigeration load of the original first evaporator, and further reducing the refrigeration demand of the second evaporator, to improve the COP of the cascade single-effect unit. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the working principle diagram of the previous cascade single-effect lithium bromide absorption refrigeration / heat pump unit.

[0015] Figure 2 It is the working principle diagram of the single-effect cascade lithium bromide absorption refrigeration / heat pump unit of the present application.

[0016] Figure 3 It is the working principle diagram of the present application.

[0017] Figure 4 It is the working principle diagram of the present application.

[0018] Figure 5 It is the working principle diagram of the present application.

[0019] Figure 6 It is the working principle diagram of the present application.

[0020] Figure 7 It is the working principle diagram of the present application.

[0021] Reference numerals in the drawings:

[0022] Generator 1, condenser 2, high temperature heat exchanger 3, low temperature heat exchanger 4, first absorber 5, first evaporator 6, second evaporator 7, second absorber 8, refrigerant pump 9, refrigerant communication pipe 10, first solution pump 11, second solution pump 12, single-effect absorber 13, single-effect evaporator 14.

[0023] Low temperature water in A1, low temperature water out A2, medium temperature water in B1, medium temperature water out B2, heat source in C1, heat source out C2. DETAILED DESCRIPTION

[0024] For a further understanding of the present application, reference will be made to the following detailed description of the application taken in conjunction with the accompanying drawings.

[0025] Example 1

[0026] Reference Figure 2The present application relates to a single-effect tandem cascade lithium bromide absorption refrigeration / heat pump unit, which is composed of a generator 1, a condenser 2, a high-temperature heat exchanger 3, a first absorber 5, a first evaporator 6, a second evaporator 7, a second absorber 8, a refrigerant pump 9, a refrigerant communication pipe 10, a first solution pump 11, a single-effect absorber 13, a single-effect evaporator 14, a control system, and pipes and valves connecting the components. The single-effect evaporator 14 and the single-effect absorber 13 are in one cavity, the first evaporator 6 and the first absorber 5 are in one cavity, the second evaporator 7 and the second absorber 8 are in another cavity, and the refrigerant water in the first evaporator 6 and the second evaporator 7 is communicated by the refrigerant water communication pipe 10. Low-temperature water flows through the single-effect evaporator 14 and the first evaporator 6 in series to be cooled; medium-temperature water flows through the second evaporator 7 and the first absorber 5 in series (first cooled and then heated) and through the single-effect absorber 13 and the second absorber 8 in series to be heated; and high-temperature driving heat source flows through the generator 1 to release heat and drive the whole unit to operate. When the unit operates, the refrigerant water pumped out by the refrigerant pump 9 and sprayed from the top of the single-effect evaporator 14, the first evaporator 6, and the second evaporator 7 exchanges heat with the low-temperature water flowing through the heat transfer pipes of the single-effect evaporator 14 and the first evaporator 6 and the medium-temperature water flowing through the heat transfer pipes of the second evaporator 7, respectively, and is vaporized into refrigerant steam, which enters the single-effect absorber 13, the first absorber 5, and the second absorber 8, respectively, and is absorbed by the lithium bromide solution therein to release heat and heat the medium-temperature water flowing through the heat transfer pipes. The lithium bromide solution in the single-effect absorber 13, the first absorber 5, and the second absorber 8 is in series, i.e. the concentrated lithium bromide solution is divided into two paths, one of which enters the single-effect absorber 13 to absorb refrigerant steam and become dilute, then enters the first absorber 5 to absorb refrigerant steam again and become dilute, and the other of which enters the second absorber 8 to absorb refrigerant steam and become dilute. The dilute solutions are combined and then pumped out by the first solution pump 11, heated by the high-temperature heat exchanger 3, and then enter the generator 1. The dilute lithium bromide solution is heated and concentrated in the generator 1, the concentrated refrigerant steam enters the condenser 2, is cooled and condensed by the medium-temperature water, and returns to the second evaporator 7 (the refrigerant water in the first evaporator 6 and the second evaporator 7 is communicated by the communication pipe 10); and the concentrated solution is cooled by the high-temperature heat exchanger 3 and then divided into two paths to return to the single-effect absorber 13 (and then enter the first absorber 5 in series) and the second absorber 8 to absorb refrigerant steam.

[0027] Figure 2In the shown single-effect series cascade lithium bromide absorption refrigeration / heat pump unit, the medium temperature water is divided into two paths, one of which is in series through the single-effect absorber and the second absorber to be heated, and the other of which is in series through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then flow through the condenser to be heated; it can also be that one of the paths is in series through the single-effect absorber and the condenser to be heated, and the other of the paths is in series through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then flow through the second absorber to be heated; or one of the paths flows through the single-effect absorber first, and then flows through the second absorber and the condenser in any order in series or in parallel, and the other of the paths is in series through the second evaporator and the first absorber to be cooled first and then heated; or one of the paths flows through the single-effect absorber first, and then flows through any one of the second absorber and the condenser, and the other of the paths is in series through the second evaporator and the first absorber to be cooled first and then heated, and then flows through the other one of the second absorber and the condenser; or one of the paths flows through the single-effect absorber, and the other of the paths is in series through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then flow through the second absorber and the condenser in any order in series or in parallel; or one of the paths flows through the single-effect absorber only, and the other of the paths flows through the second evaporator and the first absorber in series to be cooled first and then heated, and then flows through the second absorber and the condenser in any order in series or in parallel; or it can also be that the medium temperature water flows through the single-effect absorber first, and then is divided into two paths, one of which flows through the second absorber and the condenser in any order in series or in parallel, and the other of which is in series through the second evaporator and the first absorber to be cooled first and then heated; or the medium temperature water flows through the single-effect absorber first, and then is divided into two paths, one of which flows through any one of the second absorber and the condenser only, and the other of which is in series through the second evaporator and the first absorber to be cooled first and then heated, and then flows through the other one of the second absorber and the condenser; or the medium temperature water flows through the single-effect absorber first, and then is divided into two paths, one of which flows through any one of the second absorber and the condenser first, and the other of which is in series through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then flow through the other one of the second absorber and the condenser.

[0028] Example 2

[0029] Referring to Figure 3 The difference between this embodiment and Example 2 is that the medium temperature water flows through the single-effect absorber 13 first, and then is divided into two paths, one of which flows through the second absorber 8, and the other of which is in series through the second evaporator 7 and the first absorber 5 to be cooled first and then heated, and the two paths of water are combined and then flow through the condenser 2.

[0030] Example 3

[0031] Referring to Figure 4The difference between the present embodiment and embodiment 2 is that the concentrated lithium bromide solution is divided into two paths, one path first absorbs refrigerant vapor in the single-effect absorber 13 and becomes diluted, and then enters the second absorber 8, and again absorbs refrigerant vapor in the second absorber 8 and becomes diluted; the other path absorbs refrigerant vapor in the first absorber 5 and becomes diluted, and the two paths of solution are combined and then pumped out by the first solution pump 11.

[0032] Embodiment 4

[0033] Reference is made to Figure 5The present application relates to a single-effect tandem cascade lithium bromide absorption refrigeration / heat pump unit, which is composed of a generator 1, a condenser 2, a high-temperature heat exchanger 3, a first absorber 5, a first evaporator 6, a second evaporator 7, a second absorber 8, a refrigerant pump 9, a refrigerant communication pipe 10, a first solution pump 11, a second solution pump 12, a single-effect absorber 13, a single-effect evaporator 14, a control system, and pipes and valves connecting the components. The single-effect evaporator 14 and the single-effect absorber 13 are in one cavity, the first evaporator 6 and the first absorber 5 are in one cavity, the second evaporator 7 and the second absorber 8 are in another cavity, and the refrigerant water in the first evaporator 6 and the second evaporator 7 is communicated by the refrigerant water communication pipe 10. Low-temperature water flows through the single-effect evaporator 14 and the first evaporator 6 in series to be cooled; medium-temperature water flows through the second evaporator 7 and the first absorber 5 in series to be cooled first and then heated, and flows through the single-effect absorber 13 and the second absorber 8 in series to be heated; and high-temperature driving heat source flows through the generator 1 to release heat and drive the whole unit to operate. When the unit operates, the refrigerant water pumped out by the refrigerant pump 9 and sprayed from the top of the single-effect evaporator 14, the first evaporator 6, and the second evaporator 7 exchanges heat with the low-temperature water flowing through the heat transfer pipes of the single-effect evaporator 14 and the first evaporator 6 and the medium-temperature water flowing through the heat transfer pipes of the second evaporator 7, thereby reducing the temperature of the water and vaporizing the water into refrigerant steam, which enters the single-effect absorber 13, the first absorber 5, and the second absorber 8, respectively, is absorbed by the lithium bromide solution therein, and releases heat to heat the medium-temperature water flowing through the heat transfer pipes. The lithium bromide solution in the single-effect absorber 13, the second absorber 8, and the first absorber 5 is in series, the concentrated lithium bromide solution first absorbs refrigerant steam in the single-effect absorber 13, becomes dilute, enters the second absorber 8, absorbs refrigerant steam again, becomes dilute, is pumped out by the second solution pump 12, enters the first absorber 5, absorbs refrigerant steam again, becomes further dilute, is finally pumped out by the first solution pump 11, is heated and warmed by the high-temperature heat exchanger 3, and enters the generator 1. The dilute lithium bromide solution is heated and concentrated by the high-temperature heat source in the generator 1, the concentrated refrigerant steam enters the condenser 2, is cooled and condensed by the medium-temperature water, and returns to the second evaporator 7 (the refrigerant water in the first evaporator 6 and the second evaporator 7 is communicated by the communication pipe 10); and the concentrated solution is cooled by the high-temperature heat exchanger 3 and returns to the single-effect absorber 13 to absorb refrigerant steam.

[0034] Figure 5In the shown single-effect series cascade lithium bromide absorption refrigeration / heat pump unit, the medium temperature water is divided into two paths, one of which is in series through the single-effect absorber and the second absorber to be heated, and the other of which is in series through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then flow through the condenser to be heated; it can also be that one path is in series through the single-effect absorber and the condenser to be heated, and the other path is in series through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then flow through the second absorber to be heated; or one path first flows through the single-effect absorber, and then flows through the second absorber and the condenser in any order in series or in parallel, and the other path is in series through the second evaporator and the first absorber to be cooled first and then heated; or one path first flows through the single-effect absorber, and then flows through any one of the second absorber and the condenser, and the other path is in series through the second evaporator and the first absorber to be cooled first and then heated, and then flows through the other one of the second absorber and the condenser; or one path flows through the single-effect absorber, and the other path is in series through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then flow through the second absorber and the condenser in any order in series or in parallel; or one path only flows through the single-effect absorber, and the other path first flows through the second evaporator and the first absorber in series to be cooled first and then heated, and then flows through the second absorber and the condenser in any order in series or in parallel; or it can also be that the medium temperature water first flows through the single-effect absorber and then is divided into two paths, one of which flows through the second absorber and the condenser in any order in series or in parallel, and the other of which is in series through the second evaporator and the first absorber to be cooled first and then heated; or the medium temperature water first flows through the single-effect absorber and then is divided into two paths, one of which only flows through any one of the second absorber and the condenser, and the other of which is in series through the second evaporator and the first absorber to be cooled first and then heated, and then flows through the other one of the second absorber and the condenser; or the medium temperature water first flows through the single-effect absorber and then is divided into two paths, one of which first flows through any one of the second absorber and the condenser, and the other of which is in series through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then flow through the other one of the second absorber and the condenser.

[0035] Example 5

[0036] See Figure 6The unit of the embodiment is composed of a generator 1, a condenser 2, a high-temperature heat exchanger 3, a low-temperature heat exchanger 4, a first absorber 5, a first evaporator 6, a second evaporator 7, a second absorber 8, a refrigerant pump 9, a refrigerant communication pipe 10, a first solution pump 11, a second solution pump 12, a single-effect absorber 13, a single-effect evaporator 14, and a control system and pipes, valves and the like connecting the components. The single-effect evaporator 14 and the single-effect absorber 13 are in one cavity, the first evaporator 6 and the first absorber 5 are in one cavity, the second evaporator 7 and the second absorber 8 are in another cavity, and the refrigerant water of the first evaporator 6 and the second evaporator 7 is communicated by the refrigerant water communication pipe 10. The low-temperature water flows through the single-effect evaporator 14 and the first evaporator 6 in series to be cooled; the medium-temperature water flows through the second evaporator 7 and the first absorber 5 in series (first cooled and then heated) and the single-effect absorber 13 and the second absorber 8 in series to be heated; and the high-temperature driving heat source flows through the generator 1 to release heat and drive the whole unit to operate. When the unit operates, the refrigerant water pumped out by the refrigerant pump 9 and sprayed from the top of the single-effect evaporator 14, the first evaporator 6 and the second evaporator 7 is respectively exchanged with the low-temperature water flowing through the heat transfer pipe of the single-effect evaporator 14 and the first evaporator 6 and the medium-temperature water flowing through the heat transfer pipe of the second evaporator 7 to reduce the temperature thereof, and is vaporized into refrigerant steam which enters the single-effect absorber 13, the first absorber 5 and the second absorber 8 respectively, is absorbed by the lithium bromide solution therein and releases heat to heat the medium-temperature water flowing through the heat transfer pipe thereof. The lithium bromide solution of the single-effect absorber 13, the first absorber 5 and the second absorber 8 is in series, the concentrated lithium bromide solution is first absorbed by the refrigerant steam in the single-effect absorber 13 and becomes dilute, then enters the first absorber 5, is again absorbed by the refrigerant steam and becomes dilute, is pumped out by the first solution pump 11, is heated by the low-temperature heat exchanger 4, enters the second absorber 8, is further absorbed by the refrigerant steam and becomes dilute, is finally pumped out by the second solution pump 12, is heated by the high-temperature heat exchanger 3, and enters the generator 1. The dilute lithium bromide solution is heated and concentrated by the high-temperature heat source in the generator 1, the concentrated refrigerant steam enters the condenser 2, is cooled and condensed by the medium-temperature water, and the condensed refrigerant water returns to the second evaporator 7 (the refrigerant water in the first evaporator 6 and the second evaporator 7 is communicated by the communication pipe 10); and the concentrated solution is heated and cooled by the high-temperature heat exchanger 3 and the low-temperature heat exchanger 4, and then returns to the single-effect absorber 13 to absorb the refrigerant steam.

[0037] Figure 6In the shown single-effect series cascade lithium bromide absorption refrigeration / heat pump unit, the medium temperature water is divided into two paths, one of which is sequentially passed through the single-effect absorber and the second absorber to be heated, and the other of which is sequentially passed through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then passed through the condenser to be heated; it can also be that one path is sequentially passed through the single-effect absorber and the condenser to be heated, and the other path is sequentially passed through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then passed through the second absorber to be heated; or one path is first passed through the single-effect absorber, and then passed through the second absorber and the condenser in any order in series or in parallel, and the other path is sequentially passed through the second evaporator and the first absorber to be cooled first and then heated; or one path is first passed through the single-effect absorber, and then passed through any one of the second absorber and the condenser, and the other path is sequentially passed through the second evaporator and the first absorber to be cooled first and then heated, and then passed through the other one of the second absorber and the condenser; or one path is passed through the single-effect absorber, and the other path is sequentially passed through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then passed through the second absorber and the condenser in any order in series or in parallel; or one path is only passed through the single-effect absorber, and the other path is sequentially passed through the second evaporator and the first absorber to be cooled first and then heated, and then passed through the second absorber and the condenser in any order in series or in parallel; or it can also be that the medium temperature water is first passed through the single-effect absorber, and then divided into two paths, one of which is passed through the second absorber and the condenser in any order in series or in parallel, and the other path is sequentially passed through the second evaporator and the first absorber to be cooled first and then heated; or the medium temperature water is first passed through the single-effect absorber, and then divided into two paths, one of which is only passed through any one of the second absorber and the condenser, and the other path is sequentially passed through the second evaporator and the first absorber to be cooled first and then heated, and then passed through the other one of the second absorber and the condenser; or the medium temperature water is first passed through the single-effect absorber, and then divided into two paths, one of which is first passed through any one of the second absorber and the condenser, and the other path is sequentially passed through the second evaporator and the first absorber to be cooled first and then heated, and the two paths of water are combined and then passed through the other one of the second absorber and the condenser.

[0038] Embodiment 6

[0039] Reference Figure 7 The difference between the present embodiment and Embodiment 5 is that the medium temperature water is first passed through the single-effect absorber 13, and then divided into two paths, one of which is passed through the second absorber 8, and the other path is sequentially passed through the second evaporator 7 and the first absorber 5 to be cooled first and then heated, and the two paths of water are combined and then passed through the condenser 2.

Claims

1. A single-effect tandem cascade lithium bromide absorption refrigeration / heat pump unit, comprising a generator (1), a condenser (2), a high-temperature heat exchanger (3), a first absorber (5), a first evaporator (6), a second evaporator (7) and a second absorber (8), wherein the first evaporator (6) and the first absorber (5) are arranged in a first cavity, the second evaporator (7) and the second absorber (8) are arranged in a second cavity, and the first evaporator (6) and the second evaporator (7) are connected through a refrigerant communication pipe (10); characterized in that: The unit also comprises a single-effect absorber (13) and a single-effect evaporator (14), which are arranged in the third cavity, and the cold water flow path of the single-effect evaporator (14) is connected in series with the cold water flow path of the first evaporator (6); the lithium bromide solution flows through the generator (1), the single-effect absorber (13), the second absorber (8) and the first absorber (5); The high-temperature heat source flows through the generator (1); the low-temperature water flows through the single-effect evaporator (14) and the first evaporator (6) in series; and the medium-temperature water flows through the single-effect absorber (13).

2. A single-effect series-cascade lithium bromide absorption refrigeration / heat pump unit according to claim 1, characterized in that: The low-temperature water is the cold water of a refrigeration unit or the waste heat water of a heat pump unit; and the medium-temperature water is the cooling water of a refrigeration unit or the hot water of a heat pump unit.

3. A single-effect series-cascade lithium bromide absorption refrigeration / heat pump unit according to claim 1, characterized in that: The medium-temperature water is divided into two paths, one of which flows through the single-effect absorber and the second absorber in series to be heated, and the other of which flows through the second evaporator and the first absorber in series to be cooled first and then heated, and the two paths of water are combined and then flow through the condenser to be heated; or one of the paths flows through the single-effect absorber and the condenser in series to be heated, and the other of the paths flows through the second evaporator and the first absorber in series to be cooled first and then heated, and the two paths of water are combined and then flow through the second absorber to be heated; or one of the paths flows through the single-effect absorber first, and then flows through the second absorber and the condenser in any order in series or in parallel, and the other of the paths flows through the second evaporator and the first absorber in series to be cooled first and then heated; or one of the paths flows through the single-effect absorber first, and then flows through any one of the second absorber and the condenser, and the other of the paths flows through the second evaporator and the first absorber in series to be cooled first and then heated, and then flows through the other one of the second absorber and the condenser; or one of the paths flows through the single-effect absorber, and the other of the paths flows through the second evaporator and the first absorber in series to be cooled first and then heated, and the two paths of water are combined and then flow through the second absorber and the condenser in any order in series or in parallel; or one of the paths only flows through the single-effect absorber, and the other of the paths flows through the second evaporator and the first absorber in series to be cooled first and then heated, and then flows through the second absorber and the condenser in any order in series or in parallel.

4. A single-effect series-cascade lithium bromide absorption refrigeration / heat pump chiller-pack as defined in Claim 1, wherein: The medium-temperature water is divided into two paths after flowing through the single-effect absorber.

5. A single-effect series-cascade lithium bromide absorption refrigeration / heat pump chiller-pack as defined in Claim 4, wherein: The medium-temperature water flows through the single-effect absorber first, and then one of the paths flows through the second absorber and the condenser in any order in series or in parallel, and the other of the paths flows through the second evaporator and the first absorber in series to be cooled first and then heated; or one of the paths only flows through any one of the second absorber and the condenser, and the other of the paths flows through the second evaporator and the first absorber in series to be cooled first and then heated, and then flows through the other one of the second absorber and the condenser; or one of the paths flows through any one of the second absorber and the condenser first, and the other of the paths flows through the second evaporator and the first absorber in series to be cooled first and then heated, and the two paths of water are combined and then flow through the other one of the second absorber and the condenser.

6. A single-effect series-cascade lithium bromide absorption refrigeration / heat pump unit according to any one of claims 1 to 5, characterized in that: The solutions in the first absorber and the second absorber are connected, the dilute solution in the first absorber and the second absorber is pumped out by a first solution pump, sent to the generator through a high-temperature heat exchanger, and the concentrated solution is sent to the single-effect absorber and the second absorber in parallel after the high-temperature heat exchanger, and then the single-effect absorber enters the first absorber.

7. A single-effect series-cascade lithium bromide absorption refrigeration / heat pump unit according to any one of claims 1 to 5, characterized in that: The solutions of the first and second absorbers are connected, the first solution pump draws the dilute solution in the first and second absorbers, and sends it to the generator through the high-temperature heat exchanger, and the concentrated solution enters the single-effect absorber and the first absorber in parallel after passing through the high-temperature heat exchanger, and the single-effect absorber further enters the second absorber.

8. A single-effect series-cascade lithium bromide absorption refrigeration / heat pump unit according to any one of claims 1 to 5, characterized in that: The second absorber of the unit is equipped with a second solution pump, the solutions of the first and second absorbers are not connected, the first solution pump draws the dilute solution in the first absorber, and sends it to the generator through the high-temperature heat exchanger, and the concentrated solution enters the single-effect absorber and the second absorber after passing through the high-temperature heat exchanger, and the second solution pump further draws the dilute solution in the second absorber, and sends it back to the first absorber.

9. A single-effect series-cascade lithium bromide absorption refrigeration / heat pump unit according to any one of claims 1 to 5, characterized in that: The unit further comprises a second solution pump and a low-temperature heat exchanger, the solutions of the first and second absorbers are not connected, the second solution pump draws the dilute solution in the second absorber, and sends it to the generator through the high-temperature heat exchanger, and the concentrated solution enters the single-effect absorber and the first absorber after passing through the high-temperature heat exchanger and the low-temperature heat exchanger, and the first solution pump further draws the dilute solution in the first absorber, and sends it back to the second absorber through the low-temperature heat exchanger.

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