Efficient hot water type lithium bromide absorption unit arranged in left-right structure

Abstract

The utility model provides an efficient hot water type lithium bromide absorption unit arranged in a left-right structure, an evaporator, an absorber and a generator all adopt two-stage heat exchange, a condenser adopts single-stage heat exchange, and the unit mainly comprises two independent solution circulation loops and a refrigerant pipeline, the first-stage generator and the second-stage generator, the second-stage evaporator and the first-stage evaporator, and the second-stage absorber and the first-stage absorber and the condenser are connected in series through pipelines; the unit is arranged in a left-right structure, the first-stage generator and the second-stage generator and the condenser are arranged in a left-right mode, the first-stage absorber and the first-stage evaporator are arranged in a left-right mode, and the second-stage absorber and the second-stage evaporator are arranged in a left-right mode. According to the unit, the consumption of high-grade heat energy is reduced or replaced by recovering medium-low-temperature waste heat water in a factory, so that the comprehensive utilization efficiency of energy is improved, meanwhile, the left-right structural arrangement is beneficial to the compactness of the overall structure of the unit, and the occupied area is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat heating and refrigeration, and in particular to a high-efficiency hot water type lithium bromide absorption unit with a left-right structural arrangement. Background Art

[0002] Industrial production processes are often accompanied by the generation of a large amount of medium and low temperature waste heat. Due to the low temperature, it cannot be further utilized by the process. Usually, water cooling or air cooling is used to discharge the heat into the environment, resulting in a waste of heat energy. Therefore, strengthening the recovery and utilization of waste heat is the main way to save energy, which involves the application of various high-efficiency energy-saving equipment, waste heat recovery and utilization equipment and energy-saving technologies. Various lithium bromide absorption heat pumps and chillers based on lithium bromide absorption technology are driven by thermal energy, with lithium bromide solution as the absorbent and water as the refrigerant. They recycle the heat energy of waste hot water to achieve heating and cooling.

[0003] According to the different driving heat sources, they are generally divided into hot water type, steam type and direct-fired absorption units. Under most working conditions, medium and low temperature waste heat exists in the form of condensed water, heat medium water and cooling medium. Among them, hot water with a temperature of ≥90℃ can be used as the driving heat source for hot water absorption heat pumps and chiller generators, and hot water with a lower temperature between 25-50℃ can be used as the low-temperature heat source for hot water absorption heat pump evaporators.

[0004] The existing hot water absorption unit is composed of an evaporator, an absorber, a generator, a condenser, a solution heat exchanger, a solution pump, a refrigerant pump, a control system, and pipes and valves connecting the various components. At present, most of them adopt a single-stage up-and-down structure arrangement, with the condenser and the generator arranged up and down, and the condenser placed on the upper part of the generator; the evaporator and the absorber arranged up and down, and the evaporator placed on the upper part of the absorber; and the generator is located directly above the evaporator.

[0005] In actual application, the unit adopts a top-down structure, which results in a large space occupied by the overall structure of the unit, high manufacturing cost, large project construction investment, and is not conducive to the unit water pipeline configuration and vacuum pipeline configuration. At the same time, the top-down structure easily transfers the heat of the absorption solution to the refrigerant water, or uses an insulating layer at the bottom of the refrigerant plate of the evaporator and condenser, resulting in increased costs. When waste hot water is used as a driving heat source or a low-temperature heat source for heating, the temperature of the waste hot water fluctuates with the continuous changes in working conditions, so the temperature of the waste hot water may sometimes be low. The common lithium bromide absorption unit has only one generator. When the temperature of the waste hot water as a driving hot water is low, the temperature rise of the heating water is limited, which may cause the outlet temperature of the heating water to be low and fail to meet the water supply temperature requirements; similarly, the cooling range of the cold water is limited, which may cause the outlet temperature of the cold water to be high and fail to meet the water supply temperature requirements. Therefore, there is currently a lack of efficient lithium bromide absorption units, which can make a single unit have high heat exchange efficiency, small footprint, and improve the comprehensive performance coefficient of the unit. Summary of the invention

[0006] In view of this, the utility model aims to propose a high-efficiency hot water absorption unit with a left-right structural arrangement to solve the problems of low heat exchange efficiency and large floor space of lithium bromide absorption units in the prior art.

[0007] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0008] A high-efficiency hot water type lithium bromide absorption unit with a left-right structural arrangement, characterized in that the evaporator, absorber and generator all adopt two-stage heat exchange, the condenser adopts single-stage heat exchange, and the unit mainly includes two independent solution circulation loops and a refrigerant pipeline.

[0009] The first-stage generator and the second-stage generator are connected in series through pipelines, which improves the thermal energy utilization rate of the generator and also enables the generator to generate steam twice step by step, thereby increasing the absorption heat released; the second-stage absorber, the first-stage absorber and the condenser are connected in series through pipelines; the two-stage absorber releases the absorption heat, and the condenser releases the condensation latent heat. The series connection gradually heats up the water side of the internal heat exchange pipes of each stage of the absorber and the condenser, thereby increasing the heat exchange efficiency of the unit; the second-stage evaporator and the first-stage evaporator are connected in series through pipelines, and the two-stage evaporator provides sufficient refrigerant steam. The series connection enables the water side of the internal heat exchange pipes of the evaporator to release heat step by step, thereby reducing the heat loss of the evaporator and improving the thermal energy utilization rate of the water side of the heat exchange pipes of the evaporator.

[0010] The first-stage generator and the second-stage generator are arranged up and down, and are arranged on the left and right of the condenser respectively, and the vacuum sides are connected; the first-stage evaporator and the first-stage absorber are arranged on the left and right, and the vacuum sides are connected; the second-stage evaporator and the second-stage absorber are arranged on the left and right, and the vacuum sides are connected;

[0011] Furthermore, the solution circulation loop is divided into a first-stage solution circulation loop and a second-stage solution circulation loop, the first-stage solution circulation loop mainly includes a first-stage generator, a first-stage solution heat exchanger, a first-stage solution pump, a first-stage absorber and pipelines; the second-stage solution circulation loop mainly includes a second-stage generator, a second-stage solution heat exchanger, a second-stage solution pump, a second-stage absorber and pipelines.

[0012] Furthermore, the first-stage solution circulation loop and the second-stage solution circulation loop are connected in parallel, which can better adapt to the temperature conditions of the absorber and the generator water side and the working pressure of the absorber and the generator vacuum side in each loop, thereby achieving a better heat exchange effect.

[0013] Furthermore, the condenser is connected to the first-stage evaporator through a pipeline, and the second-stage evaporator is connected to the first-stage evaporator and the refrigerant pump through pipelines, respectively, to form a refrigerant pipeline.

[0014] Furthermore, the refrigerant pump, the first-stage evaporator, and the second-stage generator are connected in parallel to form a refrigerant water spray pipeline. The parallel connection mode only requires the installation of one refrigerant pump, which reduces the operating parts of the unit, reduces the power consumption of the unit, and improves the reliability of the unit operation.

[0015] Furthermore, the second-stage generator is arranged above the first-stage evaporator, and the condenser is arranged above the first-stage absorber.

[0016] Furthermore, a first-stage generation-condensation liquid baffle is arranged between the condenser and the first-stage generator, a second-stage generation-condensation liquid baffle is arranged between the condenser and the second-stage generator, a first-stage evaporation-absorption liquid baffle is arranged between the first-stage evaporator and the first-stage absorber, and a second-stage evaporation-absorption liquid baffle is arranged between the second-stage evaporator and the second-stage absorber.

[0017] Furthermore, the bottoms of the condenser, the first-stage evaporator, and the second-stage evaporator are all provided with a refrigerant tray; the bottoms of the first-stage generator, the second-stage generator, the first-stage absorber, and the second-stage absorber are all provided with a solution tray.

[0018] Furthermore, the first-stage generator, the second-stage generator, the first-stage absorber, the second-stage absorber, the first-stage evaporator, the second-stage evaporator and the condenser are each a heat exchange chamber, and multiple rows of heat exchange tube bundles are installed in each heat exchange chamber, and each heat exchange tube bundle is composed of multiple heat exchange tubes placed horizontally.

[0019] Furthermore, a spray device is provided above the heat exchange tubes of the first-stage generator, the second-stage generator, the first-stage absorber, the second-stage absorber, the first-stage evaporator and the second-stage evaporator.

[0020] Compared with the prior art, the high-efficiency hot water type absorption heat pump chiller with a left-right structural arrangement described in the utility model has the following advantages:

[0021] The utility model reduces or replaces the consumption of high-grade thermal energy by recycling the medium and low temperature waste hot water of the factory, thereby improving the comprehensive utilization efficiency of energy; the evaporator, absorber and generator all adopt two-stage heat exchange, and the condenser adopts single-stage heat exchange to reduce the irreversible heat loss in the heat transfer process and improve the performance of the unit; at the same time, two independent solution circulation loops are formed, and the lithium bromide solutions of the two circulation loops are not interconnected and have different concentrations, which can better adapt to the temperature conditions of the water channel side of the absorber and the generator in their respective loops and the working pressure of the vacuum side of the absorber and the generator, and by adjusting the working concentrations of the lithium bromide concentrated solution and the dilute solution of the two solution circulation loops, the heat loads of the two-stage evaporator, the two-stage absorber and the two-stage generator are more balanced, the total heat exchange area of ​​the unit is reduced, the material cost is reduced, and the performance coefficient of the unit is improved; the number of refrigerant pumps and refrigerant pipelines is controlled, the pipeline configuration of the refrigerant water circulation system is optimized, which is beneficial to the water channel pipeline configuration and vacuum pipeline configuration of the unit, and the overall structure of the unit is compact and occupies a small space. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of Embodiment 1 of the present utility model;

[0023] Figure 2 This is a schematic diagram of Embodiment 2 of the present utility model;

[0024] Figure 3 This is a schematic diagram of Embodiment 3 of the present utility model;

[0025] Figure 4 This is a schematic diagram of Embodiment 4 of the present utility model;

[0026] Description of Reference Numerals

[0027] Solution pump 1, first-stage solution pump 11, second-stage solution pump 12; refrigerant pump 2; generator 3, first-stage generator 31, second-stage generator 32; condenser 4; first-stage absorber 51, second-stage absorber 52; first-stage evaporator 61, second-stage evaporator 62; solution heat exchanger 7, first-stage solution heat exchanger 71, second-stage solution heat exchanger 72; first heat exchange tube bundle 311, second heat exchange tube bundle 321; third heat exchange tube bundle 411; fourth heat exchange tube bundle 511, fifth heat exchange tube bundle 521; sixth heat exchange tube bundle 611, seventh heat exchange tube bundle 621; first solution tray 3 12, second solution tray 322; first refrigerant tray 412; third solution tray 512, fourth solution tray 522; second refrigerant tray 612, third refrigerant tray 622; generation-condensation baffle plate 8, first-stage generation-condensation baffle plate 81, second-stage generation-condensation baffle plate 82; first-stage evaporation-absorption baffle plate 91, second-stage evaporation-absorption baffle plate 92; dilute solution circuit 13, first-stage dilute solution circuit 131, second-stage dilute solution circuit 132; concentrated solution circuit 14, first-stage concentrated solution circuit 141, second-stage concentrated solution circuit 142; refrigerant water spray pipeline 15. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] Figure 1 , 2 This is an implementation diagram of a high-efficiency hot water type lithium bromide absorption unit with a left-right structural arrangement involved in the utility model. The unit includes an evaporator, an absorber, a generator and a condenser. The evaporator and the absorber use two-stage heat exchange, and the generator 3 and the condenser 4 use single-stage heat exchange. The unit is a vacuum device with extremely high airtightness requirements (it can form a low-pressure environment to make the refrigerant water evaporate at a low temperature). In order to maintain the vacuum state inside the unit, an exhaust device is provided in the unit. This exhaust device can be a mechanical vacuum pump exhaust system or an automatic exhaust system. The exhaust device is not shown in the figure because it does not fall within the scope of application of this patent.

[0030] The first-stage evaporator 61 and the first-stage absorber 51 are arranged on the left and right, and are interconnected through the first-stage evaporation-absorption liquid baffle plate 91; the second-stage evaporator 62 and the second-stage absorber 52 are arranged on the left and right, and are interconnected through the second-stage evaporation-absorption liquid baffle plate 92; the first-stage evaporator 61 is directly above the second-stage evaporator 62, and the two are separated into two independent spaces by the second refrigerant plate 612 at the bottom of the first-stage evaporator 61; the first-stage absorber 51 is directly above the second-stage absorber 52, and the two are separated into two independent spaces by the third solution plate 512 at the bottom of the first-stage absorber 51; the generator 3 and the condenser 4 are arranged on the left and right, and are interconnected through the generator-condensation liquid baffle plate 8, the generator 3 is arranged directly above the first-stage evaporator 61, and the condenser 4 is arranged directly above the first-stage absorber 51.

[0031] Using a left-right arrangement structure, the first-stage evaporator 61 and the first-stage absorber 51, the second-stage evaporator 62 and the second-stage absorber 52 are arranged left-right, and there is enough space to arrange the liquid baffle, so that the resistance loss between the evaporator and the absorber is reduced and the absorption effect is improved; the spray pipe group can also be arranged at the same height, and the structure is compact; on the other hand, the left-right arrangement of the generator 3 and the condenser 4 can also increase the channel area, reduce the flow resistance of the refrigerant vapor, and also make the unit structure compact and reduce the volume.

[0032] The unit mainly includes a solution circulation loop and a refrigerant pipeline. The solution heat exchanger 7 is connected to the generator 3 and the first-stage absorber 51 through pipelines to form a concentrated solution loop 14. The second-stage absorber 52 is connected to the first-stage absorber 51, the solution pump 1 and the solution heat exchanger 7 to form a dilute solution loop 13; wherein the dilute solution loop 13 and the concentrated solution loop 14 together constitute a solution circulation loop; the condenser 4 is connected to the first-stage evaporator 61 through a pipeline, and the second-stage evaporator 62 is connected to the second refrigerant plate 612 at the bottom of the first-stage evaporator 61 and the refrigerant pump 2 to form a refrigerant pipeline; the refrigerant pump 2 is connected in parallel with the first-stage evaporator 61 and the second-stage evaporator 62 through a spray device.

[0033] The condenser 4, the first-stage evaporator 61, and the second-stage evaporator 62 are all provided with a refrigerant pan at the bottom, which is used to store unevaporated or collected condensed water. The first-stage generator 31, the second-stage generator 32, the first-stage absorber 51, and the second-stage absorber 52 are all provided with a solution pan at the bottom, which is used to collect the lithium bromide solution falling from the outside of the heat exchange tube bundle. The generator 3, the first-stage absorber 51, the second-stage absorber 52, the first-stage evaporator 61, the second-stage evaporator 62, and the condenser 4 are each a heat exchange chamber, and multiple rows of heat exchange tube bundles are installed in each heat exchange chamber, and each heat exchange tube bundle is composed of multiple heat exchange tubes placed horizontally. The inside of the heat exchange tube is the waterway side, and the outside of the heat exchange tube is the vacuum side. Spraying devices are provided above the heat exchange tubes of the generator 3, the first-stage absorber 51, the second-stage absorber 52, the first-stage evaporator 61, and the second-stage evaporator 62.

[0034] Embodiment 1

[0035] As one embodiment of the utility model, the device structure and connection method are the same as above, the second-stage evaporator 62 and the first-stage evaporator 61 are connected in series through pipelines, and the second-stage absorber 52, the first-stage absorber 51 and the condenser 4 are connected in series through pipelines. Specifically, when the high-efficiency hot water type lithium bromide absorption unit with left and right structural arrangements is in heating condition:

[0036] The heat exchange tubes inside the generator 3 are connected to the driving hot water inlet and the driving hot water outlet; the heat exchange tube openings of the second-stage evaporator 62 and the first-stage evaporator 61 are respectively connected to the waste hot water inlet and the waste hot water outlet through pipelines; the heat exchange tubes of the second-stage absorber 52 are respectively connected to the heating water return inlet and the heat exchange tubes of the first-stage absorber 51 through pipelines, and the heat exchange tubes of the condenser 4 are respectively connected to the heat exchange tubes of the first-stage absorber 51 and the heating water supply outlet through pipelines.

[0037] The hot water is driven to enter the heat exchange tube of the generator 3 as a high-temperature heat source. The dilute lithium bromide solution on the vacuum side outside the tube is heated and concentrated by the driving hot water in the generator 3. Refrigerant vapor is generated in the process. The dilute lithium bromide solution becomes a concentrated solution and then flows out. The concentrated solution passes through the solution heat exchanger 7 to release heat and cool down before entering the first-stage absorber 51. It is sprayed from the top to the vacuum side outside the tube of the heat exchange tube bundle of the first-stage absorber 51, absorbs the refrigerant vapor from the first-stage evaporator 61, and releases absorption heat. After the concentrated solution is diluted, it flows out through the solution flow channel and enters the second-stage absorber 52 to absorb the refrigerant vapor from the second-stage absorber 62, and releases absorption heat. The lithium bromide solution is further diluted and becomes a dilute solution. The lithium bromide concentrated solution absorbs the refrigerant vapor from the evaporator step by step through the two absorbers, gradually diluting the lithium bromide concentrated solution, releasing absorption heat twice, increasing the heat source of the unit, and reducing the heat loss of the unit under working conditions. Driven by the booster of the solution pump 1, the solution passes through the solution exchanger 7 to exchange heat with the high-temperature lithium bromide concentrated solution, and after the temperature is increased, it enters the generator 3 and is driven by hot water to heat and concentrate, thus completing the solution circulation loop.

[0038] The refrigerant vapor generated in the generator 3 enters the condenser 4 through the generator-condenser baffle 8, condenses on the external vacuum side of the heat exchange tube bundle, releases condensation heat, and becomes refrigerant water, which is sprayed into the top of the first-stage evaporator 61 through the pipeline. A part of the refrigerant water absorbs the heat in the waste hot water on the outside of the heat exchange tube of the first-stage evaporator 61 and evaporates. The generated refrigerant vapor enters the first-stage absorber 51 through the first-stage evaporation-absorption baffle 91 and is absorbed by the lithium bromide concentrated solution. The other part of the unevaporated refrigerant water flows out of the first-stage evaporator 61 and enters the second-stage evaporator 62 to continue to absorb the heat in the waste hot water for evaporation. The generated refrigerant vapor enters the second-stage absorber 52 through the second-stage evaporation-absorption baffle 92 and is absorbed by the solution. The two-stage evaporator can provide refrigerant vapor to the corresponding absorber step by step, and its refrigerant vapor output rate is significantly higher than that of the single-stage evaporator. By spontaneously maintaining a stable working pressure state, the lithium bromide concentrated solution in the corresponding absorber is promoted to absorb the refrigerant vapor and release a large amount of absorption heat, thereby improving the heat exchange efficiency of the unit. The remaining refrigerant water in the second-stage evaporator 62 is driven by the booster of the refrigerant pump 2 and then enters the first-stage evaporator 61 and the top of the second-stage evaporator 62 for spray evaporation, and the refrigerant water circulates back and forth.

[0039] The hot water is driven as a high-temperature heat source to enter the heat exchange tube of the generator 3, and is countercurrently heat-exchanged with the dilute lithium bromide solution on the vacuum side outside the tube. The heat of the high-temperature hot water is used to heat the dilute solution, and after cooling, it flows out of the generator 3 along the heat exchange tube; the waste hot water is used as a low-temperature heat source, and passes through the heat exchange tubes of the second-stage evaporator 62 and the first-stage evaporator 61 in turn, and is heat-exchanged with the refrigerant water on the vacuum side outside the tube, so that the refrigerant water evaporates, and refrigerant steam is provided to the corresponding absorber step by step; the heating water return water passes through the heat exchange tube bundle of the second-stage absorber 52, the heat exchange tube bundle of the first-stage absorber 51 and the heat exchange tube bundle of the condenser 4 in turn, and absorbs the absorption heat released by the refrigerant steam absorbed by the concentrated lithium bromide solution on the vacuum side of the absorber step by step. Compared with the existing single-stage absorber, the heating water absorbs heat step by step and is heated twice, which reduces the heat loss in the heating water transportation process. Finally, the condensation latent heat of the condenser 4 produces a large inlet and outlet temperature difference between the obtained heating water supply and the imported heating water return water.

[0040] Embodiment 2

[0041] Similar to the first embodiment, when the high-efficiency hot water type lithium bromide absorption unit with left and right structural arrangement is in refrigeration condition, the difference lies in the different inlet and outlet water connected to the unit and the different principles inside the evaporator and absorber.

[0042] The heat exchange tubes inside the generator 3 are connected to the driving hot water inlet and the driving hot water outlet; the heat exchange tube ports of the second-stage evaporator 62 and the first-stage evaporator 61 are respectively connected to the cold water return inlet and the cold water supply outlet; the heat exchange tubes of the second-stage absorber 52 are respectively connected to the cooling water inlet and the heat exchange tubes of the first-stage absorber 51 through pipelines, and the heat exchange tubes of the condenser 4 are respectively connected to the heat exchange tubes and the cooling water outlet of the first-stage absorber 51 through pipelines.

[0043] Since the inside of the unit is in a vacuum state, a low-pressure environment can be formed, so that the refrigerant water can evaporate at a low temperature. The refrigerant water is sprayed from the top into the first-stage evaporator 61 and the second-stage evaporator 62 through the drive of the refrigerant pump 2 in parallel, and rapidly expands and vaporizes in the evaporator. The cold water return water passes through the heat exchange tubes of the second-stage evaporator 62 and the first-stage evaporator 61 in turn, and releases the heat required for the evaporation of the refrigerant water in the evaporator step by step. Compared with the single-stage evaporator, the cold water return water is cooled twice to obtain the cold water supply; the cooling water pipeline passes through the heat exchange tubes of the second-stage absorber 52, the first-stage absorber 51 and the condenser 4 in turn for heat exchange, cooling the lithium bromide solution on the vacuum side outside the heat exchange tubes of the second-stage absorber 51 and the first-stage absorber 52. Since the lithium bromide solution has a strong ability to absorb refrigerant vapor, and within a certain range, its ability to absorb refrigerant vapor is inversely proportional to the temperature of the lithium bromide solution. The ability of the cooled lithium bromide solution on the vacuum side of the absorber to absorb refrigerant vapor is enhanced. In order to spontaneously maintain the same working pressure in the refrigerant vapor flow pipelines between the absorbers and evaporators at each stage, the refrigerant water in the evaporators at each stage will increase its vaporization volume and absorb a large amount of heat from the cold water return water, causing a larger inlet and outlet water temperature difference between the cold water return water and the cold water supply water, thereby better achieving the purpose of cooling.

[0044] Embodiment 3

[0045] On the basis of Example 1, when the high-efficiency hot water type lithium bromide absorption unit with left and right structural arrangements is a two-stage generator and two independent solution circulation loops: the difference lies in the structural arrangement of the two-stage generator and the connection method of the two solution circulation loops.

[0046] The generator is a two-stage heat exchange structure including a first-stage generator 31 and a second-stage generator 32. The first-stage generator 31 and the second-stage generator 32 are arranged up and down, and are arranged left and right with the condenser 4. The condenser 4 is connected to the vacuum side of the first-stage generator 31 and the second-stage generator 32 respectively. The generator adopts two-stage heat exchange, which can reduce the irreversible heat loss in the heat transfer process. The left-right arrangement can increase the channel area and reduce the flow resistance of the refrigerant vapor. At the same time, it also makes the unit structure compact, the volume is reduced, and the overall footprint is small. The condenser adopts a single-stage structure to ensure the excellent performance of the unit. At the same time, only one refrigerant pump needs to be installed to form a refrigerant pipeline; the number of refrigerant pumps is reduced, the operating parts of the unit and the power consumption of the unit are reduced, and the configuration of the refrigerant water circulation system pipelines is optimized, which is more conducive to the structural layout of the unit. Comprehensively considered, the left-right structural layout saves materials, reduces the volume, reduces economic costs, and can also play a role in improving heat transfer efficiency.

[0047] At the same time, two independent solution circulation loops are formed: the first-stage generator 31, the first-stage solution heat exchanger 71, the first-stage solution pump 11, and the first-stage absorber 51 are connected by pipelines to form a first-stage solution circulation loop; the second-stage generator 32, the second-stage solution heat exchanger 72, the second-stage solution pump 12, and the second-stage absorber 52 are connected by pipelines to form a second-stage solution circulation loop.

[0048] A first-stage generating-condensing liquid barrier plate 81 is arranged between the condenser 4 and the first-stage generator 31, and a second-stage generating-condensing liquid barrier plate 82 is arranged between the condenser 4 and the second-stage generator 32. The first-stage generator 31 and the second-stage generator 32 are each a heat exchange chamber, with a solution tray at the bottom and a spray device above the heat exchange tube.

[0049] The first-stage generator 31 and the second-stage generator 32 are connected in series through pipelines, the second-stage evaporator 62 and the first-stage evaporator 61 are connected in series through pipelines, and the second-stage absorber 52, the first-stage absorber 51 and the condenser 4 are connected in series through pipelines. Specifically, when the high-efficiency hot water type lithium bromide absorption unit with a left-right structural arrangement is in a heating condition: the first-stage heat exchange tube bundle 311 inside the first-stage generator 31 is connected in series with the second-stage heat exchange tube 321 inside the second-stage generator 32 through a pipeline, and the two heat exchange tube bundles are respectively connected to the driving hot water inlet and the driving hot water outlet, and the seventh-stage heat exchange tube bundle 621 inside the second-stage evaporator 62 and the sixth-stage heat exchange tube bundle 611 inside the first-stage evaporator 61 are respectively connected to the waste hot water inlet and the waste hot water outlet; the fourth-stage heat exchange tube 511 inside the first-stage absorber 51 is respectively connected to the heating water inlet and the fifth-stage heat exchange tube 521 inside the second-stage absorber 52 through a pipeline, and the third-stage heat exchange tube 411 inside the condenser 4 is respectively connected to the fourth-stage heat exchange tube 511 inside the first-stage absorber 51, the fifth-stage heat exchange tube 521 inside the second-stage absorber 52 and the heating water supply outlet through a pipeline.

[0050] The hot water is driven as a high-temperature heat source to enter the first heat exchange tube bundle 311 inside the first-stage generator 31 and the second heat exchange tube bundle 321 of the second-stage generator 32. The dilute lithium bromide solution on the vacuum side outside the tubes enters the first-stage generator 31 and the second-stage generator 32 through the top spray device, and is heated by the driving heat source in each generator to generate refrigerant vapor. The dilute lithium bromide solution is concentrated into a concentrated solution and stored in the first solution tray 312 at the bottom of the first-stage evaporator 31 and the second solution tray 322 at the bottom of the second-stage evaporator 32. After the solution is cooled by the first-stage solution heat exchanger 71 and the second-stage solution heat exchanger 72, it enters the first-stage absorber 51 and the second-stage absorber 52 through the top spray device, absorbs the refrigerant vapor from the corresponding first-stage evaporator 61 and the second-stage evaporator 62, and releases heat during the absorption process. The lithium bromide concentrated solution absorbs the refrigerant vapor from the evaporator step by step through the two absorbers, gradually dilutes the lithium bromide concentrated solution, releases the absorption heat twice, increases the heat source of the unit, and reduces the heat loss of the unit under the working state. At the same time, the concentrated solution becomes a dilute solution and is stored in the solution tray. The dilute solution is driven by the first-stage solution pump 11 and the second-stage solution pump 12, and then returns to the first-stage generator 31 and the second-stage generator 32 after being heated by the first-stage solution heat exchanger 71 and the second-stage solution heat exchanger 72, completing two independent solution cycles.

[0051] Since the driving heat source flows countercurrently with the lithium bromide solution after passing through the first-stage generator 31 and enters the second-stage generator 32 after heat exchange, the irreversible heat loss in the heat transfer process can be reduced. The driving heat source is cooled step by step. At this time, the first-stage generator 31 and the second-stage generator 32 use the same type of heat source but different temperatures, which enhances the adaptability of the unit to the heat source and improves the thermal energy utilization rate. The two-stage generator device increases the cooling range of the driving hot water in the generator, and the content of the lithium bromide concentrated solution generated on the vacuum side also increases, the ability to absorb refrigerant vapor increases, and the absorption heat released increases. The heating water absorbs heat step by step and is heated twice, reducing the heat loss in the heating water transportation process. At the same time, it has two independent solution circulation loops. By adjusting the working concentrations of lithium bromide concentrated solution and dilute solution in the two solution circulation loops, it can better adapt to the temperature conditions on the water side of the absorber and generator in each loop and the working pressure on the vacuum side of the absorber and generator, so that the heat load of the two-stage evaporator, two-stage absorber and two-stage generator is more balanced, reducing the total heat exchange area of ​​the unit and achieving better heat exchange effect.

[0052] The waste hot water, as a low-temperature heat source, sequentially passes through the seventh heat exchange tube bundle 621 inside the second-stage evaporator 62 and the sixth heat exchange tube bundle 611 inside the first-stage evaporator 61, and exchanges heat with the refrigerant water on the vacuum side outside the tube, so that the refrigerant water evaporates. At the same time, the two-stage evaporator can provide refrigerant steam to the corresponding absorber step by step. The refrigerant steam output rate is significantly higher than that of the single-stage evaporator. By spontaneously maintaining a stable working pressure state, the lithium bromide concentrated solution in the corresponding absorber is promoted to absorb the refrigerant steam and release a large amount of absorption heat, thereby improving the heat exchange efficiency of the unit;

[0053] The heating water inlet passes through the fifth heat exchange tube bundle 521 inside the second-stage absorber 52, the fourth heat exchange tube bundle 511 inside the first-stage absorber 51 and the third heat exchange tube bundle 411 inside the condenser 4, and absorbs the absorption heat released by the refrigerant vapor by the concentrated lithium bromide solution on the vacuum side of the absorber step by step. Compared with the existing single-stage absorber, the heating water absorbs heat step by step and is heated twice, which reduces the heat loss in the heating water transportation process. Finally, the condensation latent heat of the condenser 4 produces a large inlet and outlet temperature difference between the obtained heating water supply and the imported heating water return water.

[0054] Embodiment 4

[0055] Similar to the third embodiment, when the high-efficiency hot water type lithium bromide absorption unit with left and right structural arrangement is in refrigeration condition, the difference lies in the different inlet and outlet water connected to the unit and the different principles inside the evaporator and absorber.

[0056] The first heat exchange tube bundle 311 inside the first-stage generator 31 is connected to the second heat exchange tube 321 inside the second-stage generator 32 through a pipeline, and the two heat exchange tube bundles are respectively connected to the driving hot water inlet and the driving hot water outlet, and the seventh heat exchange tube bundle 621 inside the second-stage evaporator 62 and the sixth heat exchange tube bundle 611 inside the first-stage evaporator 61 are respectively connected to the cold water return inlet and the cold water supply outlet; the fourth heat exchange tube 511 inside the first-stage absorber 51 is respectively connected to the cooling water inlet and the fifth heat exchange tube 521 inside the second-stage absorber 52 through a pipeline, and the third heat exchange tube 411 inside the condenser 4 is respectively connected to the fourth heat exchange tube 511 inside the first-stage absorber 51, the fifth heat exchange tube 521 inside the second-stage absorber 52 and the cooling water outlet through a pipeline.

[0057] The driving hot water, as a high-temperature heat source, enters the first-stage heat exchange tube 311 and the second-stage heat exchange tube 321 inside the first generator 31 and the second generator 32 in turn, and performs heat exchange with the lithium bromide dilute solution on the vacuum side outside the tube in countercurrent, and uses the heat of the high-temperature hot water to heat the dilute solution, and after cooling, flows out of the second-stage generator 32 along the heat exchange tube; the two-stage generator device increases the cooling amplitude of the driving hot water in the generator, and the content of the lithium bromide concentrated solution generated on the vacuum side is also increased. At the same time, after being cooled by cooling water in the absorber (the ability of the lithium bromide solution to absorb water vapor is proportional to the concentration and inversely proportional to the temperature), the ability of the lithium bromide concentrated solution to absorb refrigerant vapor is enhanced. In order to spontaneously maintain the same working pressure of the refrigerant vapor flow pipeline between the absorbers and evaporators at each stage, the refrigerant water in the evaporators at each stage will increase its vaporization amount, absorb a large amount of heat from the cold water return water, and produce a large inlet and outlet water temperature difference between the cold water return water and the cold water supply water, so as to better achieve the purpose of cooling.

[0058] Since the inside of the unit is in a vacuum state, a low-pressure environment can be formed, so that the refrigerant water can evaporate at a low temperature. The refrigerant water is sprayed from the top in parallel through the drive of the refrigerant pump 2 into the first-stage evaporator 61 and the second-stage evaporator 62, and rapidly expands and vaporizes in the evaporator. The cold water return water passes through the seventh heat exchange tube bundle 621 inside the second-stage evaporator 62 and the seventh heat exchange tube bundle 611 inside the first-stage evaporator 61 in sequence, releasing the heat required for the evaporation of the refrigerant water in the evaporator step by step, reducing the heat loss in the cold water transportation process.

[0059] The cooling water pipeline passes through the fifth heat exchange tube bundle 521 inside the second-stage absorber 52, the fourth heat exchange tube bundle 511 inside the first-stage absorber 51 and the third heat exchange tube bundle 411 inside the condenser 4 in turn for heat exchange, cooling the lithium bromide solution on the vacuum side of the second-stage absorber 51 and the first-stage absorber 52, so that a larger inlet and outlet temperature difference is produced between the cold water return water and the cold water supply water, thereby better achieving the purpose of cooling, and continuing to cool the refrigerant vapor in the condenser 4 to generate refrigerant water that enters the refrigerant pipeline to continue the evaporation heat absorption cycle.

[0060] It can be seen that this unit adopts a two-stage generator, two-stage evaporator, two-stage absorber and single-stage condenser arranged in a left-right structure, which can produce a larger inlet and outlet water temperature difference for heating water or cooling water, while reducing the unit area.

[0061] Although the utility model is disclosed as above, the utility model is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the utility model. Therefore, the protection scope of the utility model shall be subject to the scope defined by the claims.

Claims

1. A high-efficiency hot water type lithium bromide absorption unit with left and right structural arrangement, characterized in that: The evaporator, absorber and generator all adopt two-stage heat exchange, and the condenser (4) adopts single-stage heat exchange. The unit mainly includes two independent solution circulation loops and a refrigerant pipeline. The first-stage generator (31) and the second-stage generator (32) are connected in series through the pipeline, the second-stage evaporator (62) and the first-stage evaporator (61) are connected in series through the pipeline, and the second-stage absorber (52), the first-stage absorber (51) and the condenser (4) are connected in series through the pipeline; the first-stage generator (31) and the second-stage generator (32) are arranged up and down, and are arranged on the left and right of the condenser (4) respectively, and the vacuum sides are connected; the first-stage evaporator (61) and the first-stage absorber (51) are arranged on the left and right, and the vacuum sides are connected; the second-stage evaporator (62) and the second-stage absorber (52) are arranged on the left and right, and the vacuum sides are connected.

2. The unit according to claim 1, characterized in that: The solution circulation loop is divided into a first-stage solution circulation loop and a second-stage solution circulation loop. The first-stage solution circulation loop mainly comprises a first-stage generator (31), a first-stage solution heat exchanger (71), a first-stage solution pump (11), a first-stage absorber (51) and pipelines; the second-stage solution circulation loop mainly comprises a second-stage generator (32), a second-stage solution heat exchanger (72), a second-stage solution pump (12), a second-stage absorber (52) and pipelines.

3. The unit according to claim 2, characterized in that: The first-stage solution circulation loop and the second-stage solution circulation loop are connected in parallel.

4. The unit according to claim 1, characterized in that: The condenser (4) is connected to the first-stage evaporator (61) through a pipeline, and the second-stage evaporator (62) is connected to the first-stage evaporator (61) and the refrigerant pump (2) through pipelines, respectively, to form a refrigerant pipeline.

5. The unit according to claim 4, characterized in that: The refrigerant pump (2) and the first-stage evaporator (61) and the second-stage evaporator (62) are connected in parallel to form a refrigerant water spray pipeline (15).

6. The unit according to claim 1, characterized in that: The second-stage generator (32) is arranged above the first-stage evaporator (61), and the condenser (4) is arranged above the first-stage absorber (51).

7. The unit according to claim 1, characterized in that: A first-stage generation-condensation liquid baffle (81) is arranged between the condenser (4) and the first-stage generator (31), a second-stage generation-condensation liquid baffle (82) is arranged between the condenser (4) and the second-stage generator (32), a first-stage evaporation-absorption liquid baffle (91) is arranged between the first-stage evaporator (61) and the first-stage absorber (51), and a second-stage evaporation-absorption liquid baffle (92) is arranged between the second-stage evaporator (62) and the second-stage absorber (52).

8. The unit according to claim 1, characterized in that: The condenser (4), the first-stage evaporator (61), and the second-stage evaporator (62) are all provided with a refrigerant tray at the bottom; the first-stage generator (31), the second-stage generator (32), the first-stage absorber (51), and the second-stage absorber (52) are all provided with a solution tray at the bottom.

9. The unit according to claim 1, characterized in that: The first-stage generator (31), the second-stage generator (32), the first-stage absorber (51), the second-stage absorber (52), the first-stage evaporator (61), the second-stage evaporator (62) and the condenser (4) are each a heat exchange chamber, and a plurality of rows of heat exchange tube bundles are installed in each heat exchange chamber, and each heat exchange tube bundle is composed of a plurality of heat exchange tubes placed horizontally.

10. The unit according to claim 1, characterized in that: Spray devices are provided above the heat exchange tubes of the first-stage generator (31), the second-stage generator (32), the first-stage absorber (51), the second-stage absorber (52), the first-stage evaporator (61) and the second-stage evaporator (62).

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