Steam type lithium bromide absorption refrigerator

Abstract

The utility model discloses a steam type lithium bromide absorption refrigerator, which particularly relates to the field of new energy refrigeration, and comprises a generator which comprises a low-temperature regenerator and a high-temperature regenerator and is used for heating lithium bromide dilute solution through external heat supply steam to generate refrigerant steam; and the condenser is connected with the generator and used for condensing the refrigerant steam into refrigerant water, and the condenser is further externally connected with an air extractor. Industrial waste heat or power plant steam is efficiently used as a driving heat source, absorption-desorption circulation of lithium bromide-water working medium pairs is combined, steam parameters are dynamically adjusted through a pressure reducing valve and a temperature compensator, a fluctuating heat source is adapted, and stable output of low-temperature cooling capacity is achieved; refrigeration energy consumption and carbon emission can be remarkably reduced, and the energy efficiency, stability and environmental adaptability of the lithium bromide absorption refrigerator are remarkably improved through the innovative integrated structural design, the multi-stage steam adjusting technology and the intelligent control system.

Description

Steam-type lithium bromide absorption chiller Technical Field

[0001] This utility model relates to the field of new energy refrigeration technology, and more specifically, to a steam-type lithium bromide absorption chiller. Background Technology

[0002] With the advancement of the "dual carbon" goals, traditional coal-fired power plants face severe challenges such as low energy efficiency and high carbon emissions. Existing industrial park cooling systems largely rely on electrically driven chillers, which, while technologically mature, have high operating costs and exacerbate grid load. Furthermore, a large amount of waste heat (such as flue gas and steam) generated during power generation by coal-fired units is not effectively utilized, resulting in energy waste.

[0003] Lithium bromide absorption refrigeration technology, as a heat-driven refrigeration method, is widely used in the industrial field due to its energy-saving and environmentally friendly characteristics. While traditional electrically driven compression refrigeration units offer high refrigeration efficiency, they are entirely dependent on electricity, resulting in high operating costs and increased grid load. In contrast, absorption refrigeration technology can utilize low-grade heat energy (such as industrial waste heat and waste steam) to drive the refrigeration cycle, offering significant energy-saving advantages.

[0004] The existing technology has the following problems:

[0005] 1. Poor heat source adaptability: Existing lithium bromide units have strict requirements for steam parameters (pressure, temperature), making it difficult to match with fluctuating heat sources;

[0006] 2. Low energy efficiency: Traditional designs show a significant drop in coefficient of performance (COP) under low load conditions, resulting in insufficient heat utilization.

[0007] 3. Complex structure: The low integration of multiple components such as the absorber and generator results in a large size and difficult maintenance;

[0008] 4. Weak resistance to crystallization: Lithium bromide solutions are prone to crystallization at low temperatures or high concentrations, affecting system stability.

[0009] To address the aforementioned issues, there is an urgent need for a high-efficiency, compact, and interference-resistant steam-type lithium bromide absorption chiller. Summary of the Invention

[0010] In order to overcome the above-mentioned defects of the prior art, the embodiments of this utility model provide a steam-type lithium bromide absorption chiller. The technical problem to be solved by the present invention is: how to improve the existing cycle refrigeration technology with lithium bromide absorption refrigeration technology.

[0011] To achieve the above objectives, this utility model provides the following technical solution: a steam-type lithium bromide absorption chiller, comprising:

[0012] The generator, including a low-temperature regenerator and a high-temperature regenerator, is used to heat a dilute lithium bromide solution with externally supplied heating steam to produce refrigerant vapor;

[0013] A condenser, connected to the generator, is used to condense refrigerant vapor into refrigerant water, and the condenser is also externally connected to an air extraction device.

[0014] An evaporator, connected to the condenser via a U-shaped tube, is used to evaporate refrigerant water under low pressure and absorb heat to generate chilled water.

[0015] An absorber, connected to the evaporator, is used to absorb refrigerant vapor through a concentrated lithium bromide solution to form a dilute solution;

[0016] A solution heat exchanger, including a high-temperature heat exchanger and a low-temperature heat exchanger, connects a generator and an absorber and is used to preheat dilute solutions and cool concentrated solutions.

[0017] The steam regulating module, including a pressure reducing valve and a temperature compensator, is used to regulate the pressure and temperature of the input steam. The pressure reducing valve of the steam regulating module is selected to be suitable for a steam pressure range of 0.3-1.6MPa, and the temperature compensator controls the steam temperature error to ≤±2℃ through indirect water spray cooling technology.

[0018] In a preferred embodiment, an absorbent pump II is connected between the high-temperature heat exchanger and the low-temperature heat exchanger, and an absorbent pump I is connected between the absorber and the high-temperature regenerator; a refrigerant pump is connected between the evaporator and the generator.

[0019] In a preferred embodiment, the output end of the steam regulating module is connected to a steam pipe that passes through the high-temperature regenerator, and the steam pipe is also connected to a steam trap and a heat recovery unit, with a condensate outlet at the end of the steam pipe.

[0020] In a preferred embodiment, the absorber is also externally connected to a serpentine cooling water pipe, and a lithium bromide-water binary solution is used as the working fluid to complete the refrigeration cycle, wherein water is used as the refrigerant and lithium bromide is used as the absorbent.

[0021] In a preferred embodiment, the refrigerant channel of the evaporator adopts a spiral coil design, and the outer wall of the coil is provided with a fin structure with a fin density of 8-12 fins / cm to enhance heat exchange efficiency.

[0022] In a preferred embodiment, the absorber is provided with a jet booster, which includes a high-speed nozzle with a nozzle orifice diameter of 0.5-1.2 mm, a jet speed of ≥20 m / s, a solution atomization particle size of ≤50 μm, and the high-speed nozzle is made of tungsten carbide material with a hardness of ≥90 HRA and a wear resistance life of ≥10,000 hours.

[0023] In a preferred embodiment, both the high-temperature heat exchanger and the low-temperature heat exchanger are configured as plate heat exchangers, with the plate surfaces coated with a nano-ceramic coating, and the heat exchange efficiency is ≥85%.

[0024] The technical effects and advantages of this utility model are as follows:

[0025] This invention utilizes industrial waste heat or power plant steam as a driving heat source, combined with an absorption-desorption cycle of lithium bromide-water working fluid, and dynamically adjusts steam parameters through a pressure reducing valve and temperature compensator to adapt to fluctuating heat sources, achieving stable output of low-temperature cooling capacity. It is suitable for scenarios with waste steam resources such as industrial parks and power plants, and can significantly reduce refrigeration energy consumption and carbon emissions. Through innovative integrated structural design, multi-stage steam regulation technology and intelligent control system, it significantly improves the energy efficiency, stability and environmental adaptability of lithium bromide absorption chillers. Its compact design and anti-crystallization capability are particularly suitable for industrial waste heat recovery scenarios, providing an efficient technical solution for energy conservation and emission reduction. Attached Figure Description

[0026] Figure 1 is a schematic diagram of the overall structure of the refrigeration unit of this utility model.

[0027] The attached diagram is labeled as follows: 1 Low-temperature regenerator, 2 High-temperature regenerator, 3 Condenser, 4 Evaporator, 5 Refrigerant pump, 6 Absorbent pump I, 7 Steam trap, 8 Heat recovery unit, 9 High-temperature heat exchanger, 10 Absorbent pump II, 11 Low-temperature heat exchanger, 12 Vacuum extraction device, 13 Absorber, 14 Steam regulating module. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] This utility model provides a steam-type lithium bromide absorption chiller as shown in Figure 1, comprising:

[0030] The generator, including a low-temperature regenerator 1 and a high-temperature regenerator 2, is used to heat a dilute lithium bromide solution with externally supplied steam to generate refrigerant vapor. The solution boils in the generator, releasing refrigerant vapor (water vapor) to form a concentrated solution. The condenser 3, connected to the generator, is used to condense the refrigerant vapor into refrigerant water. The condenser 3 is also externally connected to an exhaust device 12. The refrigerant vapor enters the condenser 3 through a U-shaped tube and is condensed into liquid refrigerant water by cooling water. The refrigerant water enters the evaporator 4 after being depressurized by a throttling valve. The evaporator 4, connected to the condenser 3 through a U-shaped tube, is used to evaporate the refrigerant water under low pressure and absorb heat to generate chilled water. The refrigerant water evaporates under low pressure and absorbs heat to cool the refrigerant (such as chilled water) to the target temperature. The evaporated refrigerant vapor is sucked in by an absorber pump. A refrigerant pump 5 connects the evaporator 4 and the generator. The refrigerant channel of the evaporator 4 adopts a spiral coil design. The outer wall of the coil is equipped with a fin structure with a fin density of 8-12 fins / cm to enhance heat exchange efficiency.

[0031] Absorber 13, connected to evaporator 4, is used to absorb refrigerant vapor through a concentrated lithium bromide solution to form a dilute solution. An absorbent pump I6 connects absorber 13 to high-temperature regenerator 2. The concentrated solution mixes with an intermediate solution from the generator and is atomized and sprayed through a jet booster. After absorbing refrigerant vapor, the solution becomes a dilute solution and is returned to the generator via absorbent pump I6. Absorber 13 is also externally connected to a serpentine cooling water pipe. A binary solution of lithium bromide and water is used as the working fluid to complete the refrigeration cycle, with water as the refrigerant and lithium bromide as the absorbent. An jet booster, including high-speed nozzles, is installed inside absorber 13. The nozzle orifice diameter is 0.5-1.2mm, the spray speed is ≥20m / s, the solution atomization particle size is ≤50μm, the high-speed nozzle is made of tungsten carbide material, the hardness is ≥90HRA, and the wear resistance life is ≥10000 hours; the solution heat exchanger includes a high-temperature heat exchanger 9 and a low-temperature heat exchanger 11, and an absorbent pump II 10 is connected between the high-temperature heat exchanger 9 and the low-temperature heat exchanger 11, which connects the generator and the absorber 13 for preheating dilute solutions and cooling concentrated solutions. Both the high-temperature heat exchanger 9 and the low-temperature heat exchanger 11 are plate heat exchangers, and the surface of the plates is coated with a nano-ceramic coating, with a heat exchange efficiency of ≥85%;

[0032] The steam regulating module 14 includes a pressure reducing valve and a temperature compensator, which are used to regulate the pressure and temperature of the input steam. The pressure reducing valve of the steam regulating module is selected to be suitable for a steam pressure range of 0.3-1.6MPa. The temperature compensator controls the steam temperature error to ≤±2℃ through indirect water spray cooling technology. The output end of the steam regulating module 14 is connected to a steam pipe that passes through the high-temperature regenerator 2. The steam pipe is also connected to a steam trap 7 and a heat recovery unit 8. A condensate outlet is provided at the end of the steam pipe. The steam regulating module 14 achieves wide-range steam pressure adaptation (0.3-1.6MPa) and improves the heat source utilization rate.

[0033] It is equipped with a control system that integrates a PLC controller and sensors to monitor solution concentration, temperature and steam flow in real time and adjust operating parameters. The control system includes, but is not limited to, concentration sensors, temperature sensors and pressure sensors. Sensor data is used to dynamically adjust the opening of the steam valve and the speed of the solution pump through the PLC controller. The control system integrates a remote monitoring module and supports communication with the host computer via Modbus TCP or LoRa protocol to realize remote operation and maintenance and data interaction.

[0034] The improvement in COP for traditional models using this solution is 1.10% + 1.35% + 22.7% in volume (m²). 3 8.55.1-40% Annual failure rate; 30.9-70% Cooling capacity fluctuation range: ±10% ±3%-70% surface

[0035] Working principle of this utility model:

[0036] Referring to Figure 1 in the instruction manual, external steam, after being regulated to stable parameters (pressure 0.3-1.6 MPa, temperature ≥150℃) by a pressure reducing valve and a temperature compensator, enters the coil-type heat exchanger inside the generator to heat a dilute lithium bromide solution (concentration approximately 60%). The solution boils upon heating, releasing refrigerant vapor (water vapor). The concentrated solution (concentration ≥65%) is cooled by a high-temperature heat exchanger 9 and a low-temperature heat exchanger 11 before being transported to the absorber 13. The refrigerant vapor enters the condenser 3 and condenses into liquid refrigerant water (temperature approximately 35℃) under the action of circulating cooling water. Subsequently, it is depressurized through a U-tube to a low-pressure environment (approximately 0.8 kPa) in the evaporator 4. Evaporator 4 is sprayed with evaporator to absorb heat from the refrigerant and generate chilled water at 7-12℃, which outputs cooling capacity. The evaporated refrigerant vapor is drawn into the absorber 13 by the pump. Inside the absorber 13, the concentrated solution and the intermediate solution are mixed and then atomized and sprayed by the jet enhancer to form a high specific surface area liquid film that absorbs the refrigerant vapor and generates a dilute solution (concentration reduced to 58-60%). The dilute solution is sent back to the generator by the absorbent pump I6 to complete the cycle. During the process, the intelligent control system monitors the solution concentration, temperature and vapor flow in real time, dynamically adjusts the valve opening and pump speed to maintain COP≥1.3, and automatically dilutes the solution when the concentration exceeds the limit through the anti-crystallization bypass to ensure continuous and stable operation of the system.

[0037] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0038] Secondly: The accompanying drawings of the embodiments disclosed in this utility model only involve the structures involved in the embodiments disclosed in this utility model. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this utility model can be combined with each other.

[0039] Finally: The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A steam-type lithium bromide absorption chiller, characterized in that, include: The generator, including a low-temperature regenerator (1) and a high-temperature regenerator (2), is used to heat a dilute lithium bromide solution with externally supplied heating steam to generate refrigerant vapor; A condenser (3) is connected to the generator and is used to condense refrigerant vapor into refrigerant water. The condenser (3) is also connected to an external air extraction device (12). An evaporator (4) is connected to the condenser (3) through a U-tube and is used to evaporate refrigerant water under low pressure and absorb heat to generate chilled water. An absorber (13) is connected to the evaporator (4) and is used to absorb refrigerant vapor through a concentrated lithium bromide solution to form a dilute solution. A solution heat exchanger includes a high-temperature heat exchanger (9) and a low-temperature heat exchanger (11) and is connected to the generator and the absorber (13). It is used to preheat the dilute solution and cool the concentrated solution. A steam regulating module (14) includes a pressure reducing valve and a temperature compensator and is used to regulate the pressure and temperature of the input steam.

2. The steam-type lithium bromide absorption chiller according to claim 1, characterized in that: An absorbent pump II (10) is connected between the high-temperature heat exchanger (9) and the low-temperature heat exchanger (11), and an absorbent pump I (6) is connected between the absorber (13) and the high-temperature regenerator (2); a refrigerant pump (5) is connected between the evaporator (4) and the generator.

3. The steam-type lithium bromide absorption chiller according to claim 1, characterized in that: The output end of the steam regulating module (14) is connected to a steam pipe that passes through the high-temperature regenerator (2), and the steam pipe is also connected to a steam trap (7) and a heat recovery unit (8). The end of the steam pipe is provided with a condensate outlet.

4. The steam-type lithium bromide absorption chiller according to claim 1, characterized in that: The absorber (13) is also connected to a serpentine cooling water pipe, and uses a "lithium bromide-water" binary solution as the working fluid to complete the refrigeration cycle, wherein water is used as the refrigerant and lithium bromide is used as the absorbent.

5. The steam-type lithium bromide absorption chiller according to claim 1, characterized in that: The refrigerant channel of the evaporator (4) adopts a spiral coil design, and the outer wall of the coil is provided with a fin structure with a fin density of 8-12 fins / cm.

6. The steam-type lithium bromide absorption chiller according to claim 1, characterized in that: The absorber (13) is equipped with a jet booster, which includes a high-speed nozzle with a nozzle orifice diameter of 0.5-1.2 mm, a jet speed of ≥20 m / s, and a solution atomization particle size of ≤50 μm.

7. The steam-type lithium bromide absorption chiller according to claim 1, characterized in that: Both the high-temperature heat exchanger (9) and the low-temperature heat exchanger (11) are plate heat exchangers with nano-ceramic coatings on the surface of the plates.

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