Gradient utilization device for waste heat of air compressor

Abstract

The utility model discloses an air compressor waste heat gradient utilization device which comprises an air compressor waste heat recovery mechanism, a cooling tower, a hot water tank heating mechanism and a reverse osmosis water inlet heating mechanism. The air compressor waste heat recovery mechanism is composed of an air compressor body, a pipeline, an air compressor heat exchanger and a water circulation assembly. A first flow channel and a second flow channel are arranged in the heat exchanger to achieve heat exchange between lubricating oil or air and water. One end of the water circulation assembly is connected with the cooling tower, and the other end is connected with the hot water tank heating mechanism or the reverse osmosis inlet water heating mechanism; the reverse osmosis water inlet heating mechanism comprises a heat exchanger, the outlet end of the heating coil is connected with the heat exchanger through a cooling water inlet pipeline, and the heat exchanger is provided with an ultrafiltration water tank water outlet pipeline, a reverse osmosis water inlet pipeline and a cooling water outlet pipeline. Heat recovery of circulating cooling water of the air compressor is achieved, the running time of the cooling tower is shortened, heat energy is recycled, and meanwhile power consumption and water resource waste are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of air compressors, and particularly relates to a device for cascaded utilization of the waste heat of an air compressor. Background Art

[0002] When an air compressor works, only less than 20% of the input electric energy is converted into the internal energy of compressed air, and the remaining 80% is converted into heat energy. The high-temperature heat energy is taken away by circulating cooling water and cooled by air cooling through a cooling tower. The heat energy of the circulating cooling water of the air compressor is not effectively utilized, and the cooling tower still needs to consume electric energy for cooling. During the cooling process, water evaporation loss will also occur, and the higher the temperature, the greater the loss. Through actual detection, it is found that the return water temperature of the circulating cooling water of the air compressor is about 70°C. If the waste heat of the air compressor can be utilized, the operation of the cooling tower can be reduced, not only can the heat energy be fully utilized, but also water resources can be saved, achieving the purpose of energy conservation and carbon reduction.

[0003] In the prior art, the waste heat of the air compressor is used to heat the reverse osmosis inlet water, which ensures the water production rate of the reverse osmosis equipment in winter and utilizes the waste heat of the air compressor at the same time. However, the reverse osmosis equipment only has a heating requirement for the inlet water in winter, while the air compressor needs to operate all year round. During the time when the reverse osmosis equipment does not need to heat the inlet water, the waste heat of the air compressor is not effectively utilized and still needs to enter the cooling tower for cooling. Generally speaking, the existing problems are as follows: the waste heat of the air compressor is only used to heat the reverse osmosis inlet water, and the reverse osmosis inlet water has stable performance at about 20-25°C. In summer and autumn, the demand for the reverse osmosis inlet water is small or even non-existent; when the reverse osmosis equipment has no heating requirement, the waste heat of the air compressor is wasted; in summer, the environmental temperature is high, the waste heat of the air compressor is not utilized, and the heat of the circulating cooling water needs to be cooled by the cooling tower, resulting in waste of water resources and electric energy.

[0004] Therefore, it is urgent to design a device for cascaded utilization of the waste heat of an air compressor that meets the requirements. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide a device for cascaded utilization of the waste heat of an air compressor, which can make the waste heat of the air compressor be utilized to the greatest extent according to different users' heat energy requirements, solve the problem of mismatch between heat supply and heat demand in the prior art, fully utilize the waste heat of the air compressor, and achieve the purpose of energy conservation and consumption reduction.

[0006] The technical problem to be solved by the utility model is realized through the following technical solutions:

[0007] A device for cascaded utilization of the waste heat of an air compressor includes: an air compressor waste heat recovery mechanism, a cooling tower, a hot water tank heating mechanism, and a reverse osmosis inlet water heating mechanism, wherein:

[0008] The air compressor waste heat recovery mechanism includes: an air compressor body, pipelines, an air compressor heat exchanger, and a water circulation component. The air compressor heat exchanger is internally provided with a first flow channel and a second flow channel. The first flow channel is connected to the air compressor body through the pipeline. When lubricating oil or air flows in the pipeline, the lubricating oil or air can absorb the heat released by the air compressor body and exchange heat with the water in the second flow channel. The water circulation component includes: an air compressor water inlet pipeline and an air compressor water outlet pipeline. One end of the air compressor water inlet pipeline is connected to a cooling tower, and the other end is connected to one end of the second flow channel. One end of the air compressor water outlet pipeline is connected to the other end of the second flow channel away from the air compressor water inlet pipeline, and the other end is connected to the hot water tank heating mechanism or the reverse osmosis inlet water heating mechanism.

[0009] The hot water tank heating mechanism includes a hot water tank and a heating coil. The air compressor water outlet pipeline is connected to the inlet end of the heating coil, and the outlet end of the heating coil is connected to the cooling tower or the reverse osmosis inlet water heating mechanism.

[0010] The reverse osmosis inlet water heating mechanism includes a heat exchanger. The outlet end of the heating coil is connected to the heat exchanger through a cooling water inlet pipeline. The heat exchanger is provided with an ultrafiltration water tank outlet pipeline, a reverse osmosis inlet water pipeline, and a cooling water outlet pipeline.

[0011] Preferably, a first water pump and related valves and a second water pump and related valves are provided on the air compressor water inlet pipeline, and the first water pump and related valves and the second water pump and related valves are connected in parallel.

[0012] Preferably, one end of the air compressor water inlet pipeline is connected to the cooling water tank of the cooling tower.

[0013] Preferably, a heat preservation layer is provided on the outer side of the hot water tank, and a liquid level sensor is provided inside the hot water tank. The liquid level sensor is used to detect the liquid level in the hot water tank.

[0014] Preferably, the hot water tank heating mechanism further includes: a hot water tank water inlet pipeline. One end of the hot water tank water inlet pipeline is connected to the hot water tank, and the other end is connected to a demineralized water tank. When the liquid level in the hot water tank is lower than the set low water level, the demineralized water tank replenishes water into the hot water tank through the hot water tank water inlet pipeline.

[0015] Preferably, the left and right ends of the cooling water inlet pipeline are respectively connected to the air compressor water outlet pipeline and the heat exchanger, and the outlet end of the heating coil is connected to the center of the cooling water inlet pipeline so that the water in the heating coil can enter the heat exchanger through the cooling water inlet pipeline.

[0016] Preferably, a plurality of valves are provided on the water inlet pipeline of the air compressor, and the valves are used to control the water flowing out of the air compressor waste heat recovery mechanism to enter the hot water tank heating mechanism or the reverse osmosis water inlet heating mechanism; a valve is provided on the connecting pipeline between the heating coil and the cooling water inlet pipeline.

[0017] Preferably, a third water pump and related valves are provided on the cooling water inlet pipeline.

[0018] Preferably, the cooling water outlet pipeline is communicated with the cooling water tank of the cooling tower.

[0019] Preferably, the air compressor waste heat recovery mechanism includes a plurality of air compressor bodies, a plurality of pipelines, a plurality of air compressor heat exchangers, and a plurality of water circulation components so as to form multiple sets of parallel devices.

[0020] The above technical solution of the present invention has the following beneficial effects:

[0021] (1) Through cascade utilization, the heat recovery of the circulating cooling water of the air compressor is realized, greatly reducing the operation time of the cooling tower, recovering and utilizing heat energy while reducing power consumption and waste of water resources;

[0022] (2) The operation time of the air compressor is basically the same as that of the boiler. After using the waste heat of the air compressor to increase the water temperature of the hot water tank, the consumption of steam after entering the deaerator is reduced;

[0023] (3) The inlet water temperature of the reverse osmosis equipment is stabilized at 20-25 °C. The stability of the working conditions makes the performance of the reverse osmosis equipment more stable, ensuring the relative stability of the water production quality and water production volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings incorporated in the specification and constituting a part of the specification illustrate embodiments of the present invention and, together with the description, are used to explain the principles of the present invention.

[0025] Figure 1 It is a schematic diagram of the air compressor waste heat cascade utilization device of the present invention.

[0026] Wherein: 1 - air compressor waste heat recovery mechanism, 11 - air compressor body, 12 - pipeline, 13 - air compressor heat exchanger, 14 - water circulation component, 141 - air compressor water inlet pipeline, 142 - first water pump and related valves, 143 - second water pump and related valves, 144 - air compressor water outlet pipeline, 2 - cooling tower, 3 - hot water tank heating mechanism, 31 - hot water tank, 32 - heating coil, 33 - hot water tank water inlet pipeline, 4 - reverse osmosis water inlet heating mechanism, 41 - third water pump and related valves, 42 - heat exchanger, 421 - cooling water inlet pipeline, 422 - cooling water outlet pipeline, 423 - ultrafiltration water tank water outlet pipeline, 424 - reverse osmosis water inlet pipeline. Detailed implementation manners

[0027] Various exemplary embodiments of the present utility model will now be described in detail with reference to the accompanying drawings. It should be noted that: unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present utility model.

[0028] Figure 1 It is a schematic diagram of the device for cascaded utilization of the waste heat of an air compressor of the present utility model. Figure 1 The arrows on each pipeline (loop) in [the figure] indicate the flow direction of the fluid (lubricating oil, air, or water). As shown in the figure: a device for cascaded utilization of the waste heat of an air compressor includes: an air compressor waste heat recovery mechanism 1, a cooling tower 2, a hot water tank heating mechanism 3, and a reverse osmosis feed water heating mechanism 4. The following will be described in detail:

[0029] The air compressor waste heat recovery mechanism 1 includes: an air compressor body 11, a pipeline 12, an air compressor heat exchanger 13, and a water circulation assembly 14. A first flow channel and a second flow channel are arranged inside the air compressor heat exchanger 13. The first flow channel is connected to the air compressor body 11 through the pipeline 12. When the lubricating oil or air flows in the pipeline 12, the lubricating oil or air can absorb the heat released by the air compressor body 11 and exchange heat with the water in the second flow channel; the water circulation assembly 14 includes: an air compressor water inlet pipeline 141 and an air compressor water outlet pipeline 144. One end of the air compressor water inlet pipeline 141 is connected to the cooling tower 2, and the other end is connected to one end of the second flow channel; one end of the air compressor water outlet pipeline 144 is connected to the other end of the second flow channel away from the air compressor water inlet pipeline 141, and the other end is connected to the hot water tank heating mechanism 3 or the reverse osmosis feed water heating mechanism 4;

[0030] The hot water tank heating mechanism 3 includes a hot water tank 31 and a heating coil 32. The air compressor water outlet pipeline 144 is connected to the inlet end of the heating coil 32, and the outlet end of the heating coil 32 is connected to the cooling tower 2 or the reverse osmosis feed water heating mechanism 4;

[0031] The reverse osmosis feed water heating mechanism 4 includes a heat exchanger 42. The outlet end of the heating coil 32 is connected to the heat exchanger 42 through a cooling water inlet pipeline 421. An ultrafiltration water tank outlet pipeline 423, a reverse osmosis feed water pipeline 424, and a cooling water outlet pipeline 422 are arranged on the heat exchanger 42.

[0032] Further, a first water pump and related valves 142 and a second water pump and related valves 143 are arranged on the air compressor water inlet pipeline 141. The first water pump and related valves 142 and the second water pump and related valves 143 are connected in parallel to achieve one standby while one is in use.

[0033] Further, one end of the air compressor water inlet pipeline 141 is connected to the cooling water tank of the cooling tower 2.

[0034] Further, a heat preservation layer is provided outside the hot water tank 31, and a liquid level sensor is provided inside the hot water tank 31. The liquid level sensor is used to detect the liquid level of the liquid in the hot water tank 31. The hot water tank heating mechanism 3 further includes: a hot water tank water inlet pipeline 33. One end of the hot water tank water inlet pipeline 33 is connected to the hot water tank 31, and the other end is communicated with the demineralized water tank. When the liquid level in the hot water tank 31 is lower than the set low water level, the demineralized water tank replenishes water into the hot water tank 31 through the hot water tank water inlet pipeline 33.

[0035] Further, the left and right ends of the cooling water inlet pipeline 421 are respectively communicated with the air compressor outlet pipeline 144 and the heat exchanger 42. The outlet end of the heating coil 32 is connected to the center of the cooling water inlet pipeline 421 so that the water in the heating coil 32 enters the heat exchanger 42 through the cooling water inlet pipeline 421. A plurality of valves are provided on the air compressor outlet pipeline 144. The valves are used to control the water flowing out of the air compressor waste heat recovery mechanism 1 to selectively enter the hot water tank heating mechanism 3 or the reverse osmosis inlet water heating mechanism 4; a valve is provided on the connecting pipeline between the heating coil 32 and the cooling water inlet pipeline 421.

[0036] Further, a third water pump and related valves 41 are provided on the cooling water inlet pipeline 421; the cooling water outlet pipeline 422 is communicated with the cooling water tank of the cooling tower 2.

[0037] Further, the air compressor waste heat recovery mechanism 1 includes a plurality of air compressor bodies 11, a plurality of pipelines 12, a plurality of air compressor heat exchangers 13 and a plurality of water circulation components 14 so as to form multiple sets of parallel devices.

[0038] When the air compressor is running, the first water pump and related valves 142 are opened. The water in the cooling water tank of the cooling tower 2 passes through the second flow channel of the air compressor heat exchanger 13. The internal energy of the lubricating oil in the first flow channel is transferred to the water by heat conduction, the lubricating oil is cooled, and the water is heated.

[0039] The heated water is connected to the inlet end of the heating coil 32 installed in the hot water tank 31 through the air compressor outlet pipeline 144, and the waste heat of the air compressor is used to heat the water in the hot water tank 31 to realize the first-stage utilization of the waste heat of the air compressor.

[0040] The outlet end of the heating coil 32 enters the heat exchanger 42 through the connecting cooling water inlet pipeline 421. An ultrafiltration water tank outlet pipeline 423 is also connected to the heat exchanger 42. Through the heat exchanger 42, the surplus heat absorbed by the hot water tank is used to heat the outlet water of the ultrafiltration water tank to realize the second-stage utilization of the waste heat of the air compressor. After heat exchange, the cooling water is further cooled and is connected to the cooling tower 2 through the cooling water outlet pipeline 422. After the outlet water of the ultrafiltration water tank is heat-exchanged, the temperature is raised to the set temperature and enters the reverse osmosis device through the reverse osmosis inlet pipeline 424 for further treatment.

[0041] To ensure that the water discharged from the ultrafiltration water tank is heated to the set temperature of 20°C, a third water pump and related valves 41 are installed on the cooling water inlet pipeline 421. The water pump is controlled by a frequency converter to adjust the cooling water inlet flow rate and control the reverse osmosis inlet water temperature in the reverse osmosis inlet pipeline 424. When the temperature exceeds 20°C, the cooling water flow rate into the heat exchanger 42 is reduced, and the remaining cooling water is directly connected to the cooling tower 2 through a pipeline.

[0042] In winter when the ambient temperature is low, after the hot water tank absorbs part of the heat, the waste heat of the air compressor is not sufficient to heat the reverse osmosis inlet water to the set temperature of 20°C. At this time, through valve switching, the air compressor outlet pipeline 144 is directly connected to the cooling water inlet pipeline 421 and is preferentially used to heat the reverse osmosis inlet water.

[0043] A liquid level sensor is provided in the hot water tank 31. The liquid level sensor can detect the liquid level of the hot water tank 31, and the hot water tank is connected to the demineralized water tank. When the liquid level is lower than the set low water level, the demineralized water tank replenishes water to the hot water tank through the hot water tank inlet pipeline 33; when the liquid level is replenished to the set high water level, the hot water tank inlet pipeline 33 stops water intake.

[0044] A temperature sensor is also provided in the hot water tank 31 to monitor the water temperature in the hot water tank in real time. A heat preservation layer is added outside the hot water tank 31 to play a role in heat preservation and insulation, preventing the heat of the water in the hot water tank 31 from dissipating quickly. The water in the hot water tank enters the deaerator for deaeration and then is supplied to the boiler for use. Increasing the water temperature in the hot water tank is beneficial to reducing energy consumption.

[0045] During actual use, the waste heat utilization of the air compressor is adjusted according to the operation of the reverse osmosis equipment to maximize the waste heat utilization of the air compressor. In winter when the ambient temperature is low, the operation of the reverse osmosis equipment is preferentially ensured, the reverse osmosis inlet water temperature is raised to about 20°C to ensure the normal operation of the reverse osmosis equipment, and the excess heat enters the hot water tank to raise the water temperature of the hot water tank through the heating coil. In other seasons, when the reverse osmosis equipment has little or no demand for heat, the waste heat of the air compressor first enters the hot water tank. After the hot water tank absorbs the heat, it is then used to heat the reverse osmosis inlet water through the heat exchanger. At this time, the set value of the reverse osmosis inlet water temperature can be adjusted to 25°C, and the outlet water temperature of the air compressor circulating cooling water is effectively reduced and finally enters the cooling tower for further cooling to the set value (such as 26°C).

[0046] After two-stage utilization, the outlet water temperature of the air compressor circulating cooling water is effectively reduced, effectively reducing the energy waste and water evaporation loss during the operation of the cooling tower. At the same time, the water temperature of the hot water tank is increased, reducing the steam consumption after entering the deaerator, achieving the purpose of energy conservation and consumption reduction. The reverse osmosis inlet water temperature is stable at 25°C in spring, summer and autumn and stable at 20°C in winter, ensuring the stable operation of the reverse osmosis equipment.

[0047] Although the present utility model has been disclosed above by way of embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make various different selections and modifications without departing from the spirit and scope of the present utility model. Therefore, the protection scope of the present utility model is defined by the claims and their equivalent forms.

Claims

1. A device for utilizing waste heat from an air compressor in stages, characterized in that: include: An air compressor waste heat recovery mechanism (1), a cooling tower (2), a hot water tank heating mechanism (3) and a reverse osmosis water inlet heating mechanism (4), wherein: The air compressor waste heat recovery mechanism (1) comprises: an air compressor body (11), a pipeline (12), an air compressor heat exchanger (13) and a water circulation component (14); a first flow channel and a second flow channel are arranged inside the air compressor heat exchanger (13); the first flow channel is connected to the air compressor body (11) through the pipeline (12); when lubricating oil or air flows in the pipeline (12), the lubricating oil or air can absorb the heat released by the air compressor body (11) and exchange the heat with the water in the second flow channel; The water circulation component (14) comprises: an air compressor water inlet pipeline (141) and an air compressor water outlet pipeline (144); one end of the air compressor water inlet pipeline (141) is connected to the cooling tower (2), and the other end is connected to one end of the second flow channel; one end of the air compressor water outlet pipeline (144) is connected to one end of the second flow channel away from the air compressor water inlet pipeline (141), and the other end is connected to the hot water tank heating mechanism (3) or the reverse osmosis water inlet heating mechanism (4); The hot water tank heating mechanism (3) comprises a hot water tank (31) and a heating coil (32), the air compressor water outlet pipeline (144) is connected to the inlet end of the heating coil (32), and the outlet end of the heating coil (32) is connected to the cooling tower (2) or the reverse osmosis water inlet heating mechanism (4); The reverse osmosis water inlet heating mechanism (4) comprises a heat exchanger (42); the outlet end of the heating coil (32) is connected to the heat exchanger (42) via a cooling water inlet pipeline (421); and the heat exchanger (42) is provided with an ultrafiltration water tank outlet pipeline (423), a reverse osmosis water inlet pipeline (424) and a cooling water outlet pipeline (422).

2. The air compressor waste heat cascade utilization device according to claim 1, characterized in that: The air compressor water inlet pipeline (141) is provided with a first water pump and related valves (142) and a second water pump and related valves (143), and the first water pump and related valves (142) and the second water pump and related valves (143) are connected in parallel.

3. The air compressor waste heat cascade utilization device according to claim 1, characterized in that: One end of the air compressor water inlet pipeline (141) is connected to the cooling water tank of the cooling tower (2).

4. The air compressor waste heat cascade utilization device according to claim 1, characterized in that: A heat-insulating layer is arranged on the outside of the hot water tank (31), and a liquid level sensor is arranged inside the hot water tank (31), wherein the liquid level sensor is used to detect the liquid level of the liquid in the hot water tank (31).

5. The air compressor waste heat cascade utilization device according to claim 4, characterized in that: The hot water tank heating mechanism (3) further comprises: a hot water tank water inlet pipeline (33), one end of the hot water tank water inlet pipeline (33) being connected to the hot water tank (31) and the other end being connected to a desalted water tank; when the liquid level in the hot water tank (31) is lower than a set low water level, the desalted water tank replenishes water into the hot water tank (31) through the hot water tank water inlet pipeline (33).

6. The air compressor waste heat cascade utilization device according to claim 1, characterized in that: The left and right ends of the cooling water inlet pipeline (421) are respectively connected to the air compressor outlet pipeline (144) and the heat exchanger (42), and the outlet end of the heating coil (32) is connected to the center of the cooling water inlet pipeline (421) so that the water in the heating coil (32) can enter the heat exchanger (42) through the cooling water inlet pipeline (421).

7. The air compressor waste heat cascade utilization device according to claim 1, characterized in that: A plurality of valves are provided on the air compressor water outlet pipeline (144), and the valves are used to control the water flowing out of the air compressor waste heat recovery mechanism (1) to enter the hot water tank heating mechanism (3) or the reverse osmosis water inlet heating mechanism (4); a valve is provided on the connecting pipeline between the heating coil (32) and the cooling water inlet pipeline (421).

8. The air compressor waste heat cascade utilization device according to claim 1, characterized in that: The cooling water inlet pipeline (421) is provided with a third water pump and related valves (41).

9. The air compressor waste heat cascade utilization device according to claim 1, characterized in that: The cooling water outlet pipeline (422) is connected to the cooling water tank of the cooling tower (2).

10. The air compressor waste heat cascade utilization device according to claim 1, characterized in that: The air compressor waste heat recovery mechanism (1) comprises a plurality of air compressor bodies (11), a plurality of pipelines (12), a plurality of air compressor heat exchangers (13) and a plurality of water circulation components (14) so ​​as to form a plurality of parallel devices.

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