A composite absorption refrigeration unit

Abstract

The present invention discloses a composite absorption refrigeration unit, which includes at least two module units, each of which includes a low-pressure generator, a high-pressure generator, a hot water generator, an absorber and an evaporator. Each of the module units can be configured into the following working modes: a high-quality heat source heat exchange double-effect working mode, a waste hot water heat exchange single-effect working mode and a single-double-effect working mode of heat exchange of two heat sources at the same time; in this way, the module units in the entire unit can be configured into different working modes according to the different types of on-site driven heat sources and the different heat exchange amounts, which can meet the maximum recovery of waste heat and the maximum cooling capacity requirements in various situations such as insufficient waste hot water or failure to replenish or replace high-quality heat sources in time. In addition, by using two or more module units for circulation, the outlet concentration of each absorber can be reduced, thereby reducing the steam driving pressure, and the exhaust temperature of the natural gas or flue gas outlet can also be reduced, thereby achieving energy-saving and efficiency-enhancing effects.

Description

Technical Field

[0001] The invention relates to the technical field of energy recovery, and in particular to a composite absorption refrigeration unit. Background Art

[0002] At present, the processes of EO basin liquid cooling in the petrochemical industry, carbon dioxide removal in the petrochemical industry, and primary cooler cooling in coking plants require continuous cooling all year round. In these fields, there are generally waste hot water and high-grade heat sources. Therefore, in order to improve the utilization rate of waste heat, double-effect machines and single-effect machines are often set up at this stage to recover heat from high-grade heat sources and waste hot water respectively.

[0003] The double-effect machine mainly consists of an evaporator, an absorber, a condenser, a low-pressure generator and a high-pressure generator. The driving heat source of the double-effect machine is a high-grade heat source. The refrigerant evaporates inside the evaporator to cool the cold water. The evaporated refrigerant is absorbed by the concentrated solution in the absorber, and the concentrated solution becomes a dilute solution. The solution is then sent to the high-pressure generator through a low-temperature heat exchanger and a high-temperature heat exchanger. It is heated by a high-grade heat source inside the high-pressure generator to become an intermediate concentration solution, and then enters the low-pressure generator to evaporate into a concentrated solution, and finally flows into the absorber again.

[0004] The single-effect machine mainly includes an evaporator, an absorber, a condenser and a hot water generator. The solution circuit is: absorber-hot water generator. The hot water generator is mainly used for heat exchange between waste hot water and solution, and has concentrated the dilute solution into a concentrated solution. That is, the driving heat source of the hot water generator is the waste hot water.

[0005] From the above description, it can be seen that when there is only high-quality heat source or waste water in the use environment, only one of the double-effect machine or the single-effect machine can be operated, and the other is in a non-working state. In this way, the heat exchange area of ​​the evaporator and absorber in the unit cannot be fully utilized, the refrigeration capacity is low, and it cannot meet user needs. In addition, the waste water in the single-effect machine is circulated in a single stage, and it is impossible to achieve large temperature difference utilization.

[0006] Therefore, how to realize the large temperature difference utilization of waste hot water, improve the utilization rate of the heat exchange area of ​​the evaporator and the absorber, and improve the refrigeration capacity is a technical problem that needs to be solved urgently by technicians in this field. Summary of the invention

[0007] The present invention provides a composite absorption refrigeration unit, comprising at least two module units, each of which comprises a low-pressure generator, a high-pressure generator, a hot water generator, an absorber and an evaporator, the hot water generator having a heat exchange tube forming a loop with external waste hot water, and the high-pressure generator having a heat exchange tube forming a loop with an external high-quality heat source; each of the module units can be configured into the following working modes: a high-quality heat source heat exchange double-effect working mode, a waste hot water heat exchange single-effect working mode and a single-double-effect working mode of simultaneous heat exchange of two heat sources.

[0008] Each module unit in the composite absorption refrigeration unit provided by the present invention can be configured into three different working modes, so that the module units in the entire unit can be configured into different working modes according to the types of on-site driving heat sources and the different heat exchange amounts, which can meet the maximum recovery of waste heat and the maximum cooling capacity requirements in various situations such as insufficient waste hot water or failure to replenish or replace high-grade heat sources in a timely manner. In addition, by using two or more module units for circulation, the concentration at the outlet of each absorber can be reduced, thereby reducing the steam driving pressure, and the exhaust temperature of the natural gas or flue gas outlet can also be reduced, thereby achieving energy-saving and efficiency-enhancing effects.

[0009] In addition, the unit formed by the present invention has multiple uses, which reduces equipment investment and saves equipment space.

[0010] Optionally, the cold water pipelines of the evaporators in each module unit are connected in series in sequence, and the heat exchange tubes of each hot water generator are connected in series in sequence; and during operation, the cold water and the waste hot water flow through each module unit in the opposite order.

[0011] Optionally, the solution channels of the absorber, the hot water generator, the low-pressure generator and the high-pressure generator in each module unit are connected in series to form a series solution circulation system or a reverse series solution circulation system;

[0012] Alternatively, each of the module units includes a first solution circulation loop and a second solution circulation loop connected in parallel, the absorber, the hot water generator and the low-pressure generator form the first solution circulation loop; the absorber and the high-pressure generator form the second solution circulation loop.

[0013] Optionally, the heat exchange tubes of the hot water generator and the heat exchange tubes of the low-pressure generator are integrated inside the same box, and the two are arranged up and down or left and right; a solution inlet and a solution outlet are arranged on the box.

[0014] Optionally, each of the module units also includes a condenser for heat exchange between external cooling water and refrigerant water generated by at least one of the hot water generator, the low-pressure generator, and the high-pressure generator; the cooling water pipelines of all condensers and all absorbers in the unit are arranged in series, or the cooling water pipelines of all condensers in the unit and the cooling water pipelines of all the absorbers are arranged in series and parallel.

[0015] Optionally, the heat exchange tubes of each of the high-pressure generators are connected in parallel to an external high-quality heat source pipeline.

[0016] Optionally, the module unit also includes a solution mixing box, which is arranged downstream of the low-pressure generator. The outlet of the solution mixing box is provided with a first branch pipe and a second branch pipe in parallel. The other end of the second branch pipe is connected to the solution inlet of the absorber, and the first branch pipe is connected to the solution inlet of the high-pressure generator, so that part of the solution in the solution mixing box enters the high-pressure generator through the first branch pipe, and the solution outlet of the high-pressure generator is connected to the second branch pipe.

[0017] Optionally, a low-temperature heat exchanger and / or a high-temperature heat exchanger is also included.

[0018] Optionally, the number of the module units is two.

[0019] Optionally, it also includes a solution pump for providing solution circulation power; or / and, it also includes a pump for realizing the circulation pumping of the refrigerant water in the evaporator. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a composite absorption refrigeration unit in a specific embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of a module unit series solution circulation loop in one embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of a parallel solution circulation loop of module units in one embodiment of the present invention;

[0023] Figure 4 It is a partial structural schematic diagram of module units arranged on the left and right of a hot water generator and a low-pressure generator in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In view of the technical problem of low utilization rate of heat exchange area of ​​evaporator and absorber in the prior art, this paper conducts in-depth research and proposes a technical solution to the above technical problem based on the research, which is described in detail as follows.

[0025] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0026] Please refer to Figures 1 to 3 , Figure 1 It is a structural schematic diagram of a composite absorption refrigeration unit in a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a module unit series solution circulation loop in one embodiment of the present invention; Figure 3This is a schematic diagram of the structure of the parallel solution circulation loop of the module unit in one embodiment of the present invention. In each figure, 1A-1A' and 2A-2A' are cooling water loops, 1D-1D' and 2D-2D' are high-quality heat source loops; C-C' is a waste water loop.

[0027] The present invention provides a composite absorption refrigeration unit, comprising at least two module units, each of which comprises a low-pressure generator, a high-pressure generator, a hot water generator, an absorber and an evaporator, wherein the hot water generator has a heat exchange tube that forms a loop with the external waste hot water, that is, the heat exchange tube of the hot water generator forms a waste heat heat exchange loop with the external waste hot water. The high-pressure generator has a heat exchange tube that forms a loop with the external high-quality heat source, and the heat exchange tube of the high-pressure generator can form a high-quality heat source heat exchange loop with the external high-quality heat source.

[0028] Each module unit in the present invention can be configured into the following working modes: a high-quality heat source heat exchange double-effect working mode, a waste hot water heat exchange single-effect working mode, and a single-effect and double-effect working mode of heat exchange with two heat sources at the same time.

[0029] That is to say, each module unit is provided with a hot water generator and a high-pressure generator for exchanging heat with external waste hot water and a high-temperature quality heat source respectively, and can be configured into at least three working modes: the first is a high-quality heat source heat exchange double-effect working mode, that is, in this state, the driving heat source is only a high-quality heat source, and the low-pressure generator, the high-pressure generator, and the absorber form a solution circulation double-effect heat exchange loop; the second is a waste hot water heat exchange single-effect working mode, that is, in this mode, the driving heat source is only waste hot water, and the hot water generator and the absorber form a solution circulation single-effect heat exchange loop; the third is a waste hot water and high-quality heat source double-effect working mode, that is, in this mode, the driving heat source is waste hot water and a high-quality heat source, and the hot water generator, the low-pressure generator, the high-pressure generator, and the absorber form a solution circulation single and double-effect heat exchange loop, and the solution loop can be connected in series, in reverse series, or in parallel.

[0030] Among them, the high-quality heat source in this article can be steam or flue gas. Usually, the pressure of steam is ≥0.3Mpa; the temperature of flue gas is ≥250℃; under the condition of cold water outlet at 7℃, the outlet temperature of waste hot water can be as low as 60℃.

[0031] From the above description, it can be seen that each module unit in the composite absorption refrigeration unit provided by the present invention can be configured into three different working modes. In this way, the module units in the entire unit can be configured into different working modes according to the types of on-site driving heat sources and the different heat exchange amounts, which can meet the maximum recovery of waste heat and the maximum cooling capacity requirements in various situations such as insufficient waste hot water or failure to replenish or replace high-grade heat sources in a timely manner. In addition, by using two or more module units for circulation, the outlet concentration of each absorber can be reduced, thereby reducing the steam driving pressure, and the exhaust temperature of the natural gas or flue gas outlet can also be reduced, thereby achieving energy-saving and efficiency-enhancing effects.

[0032] In addition, the unit formed by the present invention has multiple uses, which reduces equipment investment and saves equipment space.

[0033] In particular, experiments have shown that when the unit has two module units, both of which are operated in a high-grade heat source cycle, the coefficient of performance of a double-effect machine can be achieved, and the COP can reach above 1.3.

[0034] As mentioned above, the number of module units may be two, or more than two, such as three or more. This article takes the number of module units as two as an example to introduce the technical effect of the technical solution.

[0035] by Figure 1 Taking the two module units shown in the figure as an example, in order to describe the technical solution concisely, the two module units are defined as the first module unit and the second module unit respectively. The first module unit includes absorber I1, evaporator I3, hot water generator I11, low pressure generator I13, high pressure generator I25 and condenser I51. The second module unit includes absorber II2, evaporator II4, hot water generator II12, low pressure generator II14, high pressure generator II26 and condenser II52.

[0036] In a specific implementation, the cold water pipelines of the evaporators in each module unit are connected in series, and the heat exchange tubes of each hot water generator are connected in series; and during operation, the cold water and the waste hot water flow through each module unit in the opposite order.

[0037] like Figure 1 As shown, cold water flows in from the evaporator I3 of the first module unit, flows through the evaporator I3, and then flows into the evaporator II4 of the second module unit. Then, the waste hot water from the outside flows in from the hot water generator II12 of the second module unit, flows through the hot water generator II12 and exchanges heat with the solution, and then flows into the hot water generator I11 to exchange heat with the solution in the first module unit.

[0038] By adopting the above method, large temperature difference utilization of waste hot water can be achieved.

[0039] In the above embodiments, the solution channels of the absorber, hot water generator, low-pressure generator and high-pressure generator in each module unit are sequentially connected in series to form a series solution circulation system or a reverse series solution circulation system.

[0040] Please refer to Figure 1 , Figure 1 The module units forming a reverse series solution circulation system are given in the figure. Taking the first module unit as an example, the flow paths of the solution, refrigerant, etc. are briefly explained.

[0041] When the driving heat source is only a high-grade heat source, the refrigerant evaporates in the evaporator Ⅰ3 to produce cold water. The evaporated refrigerant is absorbed by the concentrated solution sprayed in the absorber Ⅰ1, and the concentrated solution absorbs the refrigerant to become a dilute solution. The dilute solution can be sent to the hot water generator Ⅰ11 (passing but without heat exchange) after passing through the low-temperature heat exchanger Ⅰ7, the pipeline I47, and the liquid distribution device Ⅰ9 under the pumping power of the solution pump I5, and then enters the low-pressure generator Ⅰ13 after passing through the hot water generator Ⅰ11, and is heated and concentrated into an intermediate concentration solution by the refrigerant vapor generated by the high-temperature generator Ⅰ25. The intermediate concentration solution flows through the pipeline I15, the solution mixing box Ⅰ17, and the pipeline Ⅰ61, and is pumped to the high-pressure generator Ⅰ25 by the solution pump Ⅰ19, and is further concentrated into a concentrated solution by the high-grade heat source outside the pipe, and then mixed with the intermediate concentration solution from the solution mixing box Ⅰ17 and sent to the absorber Ⅰ1 by the solution spray pump I35 to absorb the refrigerant vapor from the evaporator Ⅰ3.

[0042] The intermediate concentration solution in the high-pressure generator Ⅰ25 is heated by the high-grade heat source in the tube to generate the refrigerant steam which is sent to the heat exchange tube of the low-pressure generator Ⅰ13 through the pipeline Ⅰ49. As the heating source of the low-pressure generator Ⅰ13, it heats the dilute solution outside the tube of the low-pressure generator Ⅰ13 to generate the refrigerant. The refrigerant is cooled and condensed by cooling water in the condenser Ⅰ51 and returns to the evaporator Ⅰ3 together with the refrigerant after the steam generated in the high-pressure generator Ⅰ25 is condensed by the low-pressure generator Ⅰ13. This constitutes a complete double-effect solution refrigerant circulation loop.

[0043] Of course, in order to improve the waste heat recovery efficiency, high-temperature heat exchangers and low-temperature heat exchangers can also be added to the module unit. Taking the above-mentioned reverse series connection as an example, the solution at the outlet of the absorber Ⅰ1 flows through the low-temperature heat exchanger Ⅰ7 and flows to the pipeline Ⅰ47 and the liquid distribution device Ⅰ9 to enter the hot water generator; the solution flowing out of the high-pressure generator Ⅰ25 is mixed with the solution of the low-pressure generator Ⅰ13 and flows through the low-temperature heat exchanger Ⅰ7 together, and then returns to the absorber Ⅰ3.

[0044] The intermediate concentration solution flows through pipeline 15, solution mixing box Ⅰ17, pipeline Ⅰ61 and high-temperature heat exchanger 121 into high-pressure generator Ⅰ25. The concentrated solution formed after being heated and concentrated passes through high-temperature heat exchanger Ⅰ21 again and is then mixed with the intermediate concentration solution.

[0045] From the above description, it can be seen that the module unit may also include a solution mixing box, which is arranged downstream of the low-pressure generator. The outlet of the solution mixing box is provided with a first branch pipeline and a second branch pipeline in parallel. The other end of the second branch pipeline is connected to the solution inlet of the absorber, and the first branch pipeline is connected to the solution inlet of the high-pressure generator, so that part of the solution in the solution mixing box enters the high-pressure generator through the first branch pipeline, and the solution outlet of the high-pressure generator is connected to the second branch pipeline.

[0046] The solution mixing tank plays a role in temporarily storing liquid to a certain extent and achieving the stability of the system solution circulation.

[0047] The flow path in the second module unit is the same as above and will not be described in detail herein.

[0048] In this embodiment, cold water enters from the evaporator I3 of the first module unit and exits from the evaporator II4 of the second module unit.

[0049] When the driving heat source is only waste hot water, the refrigerant evaporates in the evaporator Ⅰ3 to produce cold water. The evaporated refrigerant is absorbed by the solution sprayed in the absorber Ⅰ3. The diluted solution (dilute solution) absorbed by the refrigerant vapor is sent to the heat exchange tube of the hot water generator Ⅰ11 by the solution pump I5 through the low-temperature heat exchanger Ⅰ7, pipeline Ⅰ47, and liquid distribution device Ⅰ9. After being heated by the waste hot water in the tube, it becomes a concentrated solution and passes through the low-pressure generator Ⅰ13 (no heat source is introduced, no heat exchange), pipeline Ⅰ15, solution mixing box I17, pipeline Ⅰ31, and then sent to the absorber Ⅰ1 by the solution pump Ⅰ35 through the low-temperature generator Ⅰ7 to absorb the refrigerant vapor from the evaporator Ⅰ3.

[0050] The hot water generator I11 generates refrigerant vapor, which is cooled and condensed by cooling water in the condenser I51 and then returned to the evaporator I3. This constitutes a complete solution refrigerant circulation loop in the waste hot water heat exchange single-effect working mode.

[0051] The flow path in the second module unit is the same as above and will not be described in detail herein.

[0052] In this embodiment, cold water enters from the evaporator I3 of the first module unit and exits from the evaporator II4 of the second module unit.

[0053] Continue to refer Figure 1When waste hot water and high-quality heat source are both driving heat sources, the refrigerant vapor generated by evaporator Ⅰ3 is absorbed by the solution sprayed in absorber Ⅰ3. The solution diluted by absorbing the refrigerant vapor (dilute solution) is sent to the heat exchange tube of hot water generator Ⅰ11 by solution pump I5 through low-temperature heat exchanger Ⅰ7, pipeline Ⅰ47, and liquid distribution device Ⅰ9. It is heated by waste hot water outside the tube and concentrated into a slightly concentrated solution. Then it drips onto the heat exchange tube of low-pressure generator Ⅰ13 and is further heated by the refrigerant vapor generated by high-temperature generator Ⅰ25. The intermediate concentration solution flows through pipeline Ⅰ15, solution mixing box Ⅰ17, pipeline Ⅰ61, and is then sent to high-pressure generator Ⅰ25 by solution pump Ⅰ19 through high-temperature heat exchanger Ⅰ21. It is heated by a high-grade heat source outside the pipe (flow direction is 1D-1D') to further concentrate into a concentrated solution, and then flows through high-temperature heat exchanger Ⅰ21 to mix with the intermediate concentration solution from mixing box Ⅰ17, and is then sent by solution pump Ⅰ35 through low-temperature heat exchanger I7 to enter absorber Ⅰ1 to absorb the refrigerant vapor from evaporator Ⅰ3.

[0054] The first refrigerant steam is generated by heating the waste hot water in the hot water generator Ⅰ11, the second refrigerant steam is generated by heating the steam generated by the high pressure generator in the low pressure generator Ⅰ13, and the third refrigerant steam is generated by heating the high pressure generator Ⅰ25. The first refrigerant steam and the second refrigerant steam pass through the liquid baffle Ⅰ63 and enter the condenser Ⅰ51 to be cooled and condensed by the cooling water (cooling water is introduced in the direction 1A-1A'). The third refrigerant steam releases heat in the low pressure generator and condenses into a refrigerant, enters the condenser, and returns to the evaporator Ⅰ3 after mixing with the first refrigerant steam and the second refrigerant steam, forming a complete cycle.

[0055] The flow path in the second module unit is the same as above and will not be described in detail herein.

[0056] In this embodiment, cold water enters from the evaporator I3 of the first module unit and exits from the evaporator II4 of the second module unit.

[0057] Of course, the solution mixing box, the high-temperature heat exchanger and the second heat exchanger in the above embodiment are not necessary components, and the low-pressure generator can be directly connected to the high-pressure generator through a branch pipeline.

[0058] In another specific embodiment, the absorber, the high pressure generator, the hot water generator, and the low pressure generator are sequentially connected in series to form a circulation loop. Figure 2A specific series connection method is shown. Taking the second module unit as an example, the dilute solution in the absorber Ⅱ2 enters the high-pressure generator Ⅱ26 through the low-temperature heat exchanger Ⅱ8 and the high-temperature heat exchanger Ⅱ22, and is heated by the high-quality heat source inside the high-pressure generator Ⅱ26 to become an intermediate concentration solution. The intermediate concentration solution then enters the hot water generator Ⅱ12 and the low-pressure generator Ⅱ14 through the high-temperature heat exchanger Ⅱ22. The intermediate concentration solution is converted into a concentrated solution after heat exchange in the low-pressure generator Ⅱ14. The concentrated solution flows through the low-temperature heat exchanger Ⅱ8 and returns to the absorber Ⅱ2.

[0059] That is, the solution flow order is: absorber Ⅱ2→solution pump Ⅱ6→low-temperature heat exchanger Ⅱ8→high-temperature heat exchanger Ⅱ22→high-temperature generator Ⅱ26→high-temperature heat exchanger Ⅱ22→hot water generator Ⅱ12→low-pressure generator Ⅱ14→low-temperature heat exchanger Ⅱ8→absorber Ⅱ2.

[0060] Of course, the series connection sequence of the absorber, high-pressure generator, hot water generator, and low-pressure generator is not limited to the above, and other series connection sequences are also possible.

[0061] Evaporator Ⅰ3 and evaporator Ⅰ4 provide refrigerant steam to absorber Ⅰ1 and absorber Ⅰ2 respectively.

[0062] Furthermore, each module unit may also include a first solution circulation loop and a second solution circulation loop connected in parallel, wherein the absorber, the hot water generator and the low-pressure generator form the first solution circulation loop; and the absorber and the high-pressure generator form the second solution circulation loop.

[0063] like Figure 3 As shown, taking the second module unit as an example, the dilute solution in absorber Ⅱ2 is divided into two paths after passing through low-temperature heat exchanger Ⅱ8. One path flows into hot water generator Ⅱ12, and then flows into pipeline Ⅱ16 through low-pressure generator Ⅱ14; the other path flows into high-temperature heat exchanger Ⅱ22 and then flows to high-pressure generator Ⅱ26, and then flows into pipeline Ⅱ28 after being heated, and then flows through high-temperature heat exchanger Ⅱ22 and merges with the solution in pipeline Ⅱ16 to enter low-temperature heat exchanger Ⅱ8, and then returns to absorber Ⅱ2.

[0064] This embodiment includes two parallel solution circulation routes. Even if one solution circulation of the unit fails, the other solution circulation loop can operate normally, and the unit has a relatively high reliability.

[0065] In the above embodiments, the heat exchange tubes of the hot water generator and the heat exchange tubes of the low-pressure generator can be integrated inside the same box, and the two can be arranged up and down or left and right. Figures 1 to 3 The embodiment of the upper and lower arrangement of the hot water generator and the low pressure generator is given in the specification. Figure 4The embodiment of the left-right arrangement of the hot water generator and the low-pressure generator is given. The box body is provided with a solution inlet and a solution outlet, the solution flows in from the solution inlet, contacts and exchanges heat with the heat exchange tube of the hot water generator, contacts and exchanges heat with the heat exchange tube of the low-pressure generator, and then flows to the external pipeline from the solution outlet of the box body.

[0066] The integrated design of the low-pressure generator and the hot water generator can save space, and when the hot water generator is located above the low-pressure generator, the solution flows under its own gravity, reducing the solution circulation power.

[0067] Of course, the arrangement of the low-pressure generator and the hot water generator is not limited to the description herein, and may be other arrangements.

[0068] It can be seen from the above description that the condenser of each module unit in the above embodiments is mainly used for heat exchange between external cooling water and refrigerant water generated by at least one of the hot water generator, low-pressure generator and high-pressure generator.

[0069] When the heat source is only high-quality heat source, the external cooling water condenses the refrigerant produced in the high-pressure generator and the low-pressure generator. When the heat source is only waste hot water, the external cooling water condenses the refrigerant produced in the hot water generator; when the high-quality heat source and waste hot water work at the same time, the external cooling water cools the refrigerant produced by the hot water generator, the low-pressure generator and the high-pressure generator at the same time.

[0070] Combination Figure 1 , taking the operation of only high-quality heat source as an example to describe the flow path, the intermediate concentration solution in the high-pressure generator Ⅰ25 is heated by the high-quality heat source in the tube to generate refrigerant vapor, which is sent to the heat transfer tube of the low-pressure generator Ⅰ13 through the pipeline Ⅰ49. As the heating source of the low-pressure generator Ⅰ13, it heats the dilute solution outside the tube of the low-pressure generator Ⅰ13 to generate refrigerant. The refrigerant is cooled and condensed by cooling water in the condenser Ⅰ51, and then returns to the evaporator Ⅰ3 together with the refrigerant after the steam generated in the high-pressure generator Ⅰ25 is condensed by the low-pressure generator Ⅰ13.

[0071] The working principle of condenser II52 in the second module unit is the same as that of condenser I51 in the first module unit, and will not be described in detail herein.

[0072] In the above embodiments, the cooling water pipelines of all condensers and all absorbers in the unit are arranged in series. Alternatively, the cooling water pipelines of all condensers in the unit and the cooling water pipelines of all absorbers are arranged in series and in parallel, that is, the cooling water pipelines of all condensers and some of the absorbers in the unit are connected in series, and some of them are connected in parallel.

[0073] In addition, in the above-mentioned embodiments, the heat exchange tubes of each high-pressure generator are connected in parallel to the external high-quality heat source pipeline.

[0074] In order to provide power for solution circulation, a solution pump can also be provided in the module unit, such as Figure 1 The solution pumps Ⅰ5, Ⅱ6, Ⅱ20, Ⅱ36, Ⅰ35 and Ⅰ19 are respectively arranged in different pipe sections to provide solution circulation power. Similarly, the above embodiment can also include a refrigerant pump for realizing the circulation pumping of the refrigerant water in the evaporator, such as pumps Ⅰ44 and Ⅰ43.

[0075] It should be noted that the high-temperature heat source in this article is a high-quality heat source, and low-temperature hot water is one type of low-temperature heat source.

[0076] The above is a detailed introduction to a single-effect and double-effect composite absorption refrigeration unit provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A composite absorption refrigeration unit, characterized in that: The invention comprises at least two module units, each of which comprises a low-pressure generator, a high-pressure generator, a hot water generator, an absorber and an evaporator. The hot water generator has a heat exchange tube that forms a loop with the external waste hot water, and the high-pressure generator has a heat exchange tube that forms a loop with the external high-quality heat source. Each of the module units can be configured into the following working modes: a high-quality heat source heat exchange double-effect working mode, a waste hot water heat exchange single-effect working mode and a single-effect and double-effect working mode of heat exchange with two heat sources at the same time. In the high-quality heat source heat exchange double-effect working mode, the driving heat source is only the high-quality heat source, and the low-pressure generator, the high-pressure generator, and the absorber in the same module unit form a solution circulation double-effect heat exchange loop; in the waste hot water heat exchange single-effect working mode, the driving heat source is only the waste hot water, and the hot water generator and the absorber in the same module unit form a solution circulation single-effect heat exchange loop; in the single-effect and double-effect working modes of the waste hot water and high-quality heat source, the driving heat sources are waste hot water and high-quality heat sources, and the hot water generator, the low-pressure generator, the high-pressure generator, and the absorber in the same module unit form a solution circulation single-effect and double-effect heat exchange loop; the cold water pipelines of the evaporators in each module unit are connected in series in sequence, and the heat exchange tubes of each hot water generator are connected in series in sequence; and when working, the order in which the cold water and the waste hot water flow through each module unit is opposite.

2. The composite absorption refrigeration unit according to claim 1, characterized in that: The solution channels of the absorber, the hot water generator, the low-pressure generator and the high-pressure generator in each module unit are connected in series to form a series solution circulation system or a reverse series solution circulation system; Alternatively, each of the module units includes a first solution circulation loop and a second solution circulation loop connected in parallel, the absorber, the hot water generator and the low-pressure generator form the first solution circulation loop; the absorber and the high-pressure generator form the second solution circulation loop.

3. The composite absorption refrigeration unit according to claim 1, characterized in that: The heat exchange tubes of the hot water generator and the heat exchange tubes of the low-pressure generator are integrated and arranged inside the same box, and the two are arranged up and down or left and right; a solution inlet and a solution outlet are arranged on the box.

4. The composite absorption refrigeration unit according to claim 1, characterized in that: Each of the module units also includes a condenser, which is used for heat exchange between external cooling water and refrigerant water generated by at least one of the hot water generator, the low-pressure generator, and the high-pressure generator; the cooling water pipelines of all condensers and all absorbers in the unit are arranged in series, or the cooling water pipelines of all condensers in the unit and the cooling water pipelines of all absorbers are arranged in series and parallel.

5. The composite absorption refrigeration unit according to claim 1, characterized in that: The heat exchange tubes of each high-pressure generator are connected in parallel to an external high-quality heat source pipeline.

6. The composite absorption refrigeration unit according to any one of claims 1 to 5, characterized in that: The module unit also includes a solution mixing box, which is arranged downstream of the low-pressure generator. The outlet of the solution mixing box is provided with a first branch pipeline and a second branch pipeline in parallel. The other end of the second branch pipeline is connected to the solution inlet of the absorber. The first branch pipeline is connected to the solution inlet of the high-pressure generator so that part of the solution in the solution mixing box enters the high-pressure generator through the first branch pipeline. The solution outlet of the high-pressure generator is connected to the second branch pipeline.

7. The composite absorption refrigeration unit according to claim 6, characterized in that: It also includes a low temperature heat exchanger and / or a high temperature heat exchanger.

8. The composite absorption refrigeration unit according to any one of claims 1 to 5, characterized in that: The number of the module units is two.

9. The composite absorption refrigeration unit according to any one of claims 1 to 5, characterized in that: It also includes a solution pump for providing solution circulation power; or / and, it also includes a pump for realizing the circulation pumping of the refrigerant water in the evaporator.

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