Low-temperature waste heat refrigeration type cooling circulating water energy-saving and water-saving system and method

Abstract

The invention discloses an energy-saving and water-saving system and method for cooling a circulating water device through low-temperature waste heat refrigeration, the system comprises main components such as a cooling tower, a surface air cooler, a spraying system, a coil pipe type heat exchanger and a lithium bromide refrigerator, and recycling of low-temperature waste heat and energy-saving and water-saving of cooling circulating water are achieved by integrating the components. Specifically, according to the system, low-temperature waste heat generated in the production process is converted into low-temperature chilled water through a lithium bromide refrigerating machine, the chilled water exchanges heat with air entering a cooling tower through a coil pipe type heat exchanger, the air temperature is reduced, the temperature difference between cooling circulating water and the air is increased, and the cooling efficiency is improved. And meanwhile, the surface air cooler at the top of the cooling tower condenses and captures evaporated cooling circulating water by using chilled water, so that the loss of cooling water is reduced. According to the method, the production efficiency is improved, the operation cost is reduced, a new thought is provided for recycling of low-temperature waste heat, and the method has wide application prospects and popularization value.

Description

Technical Field

[0001] The present invention relates to the technical field of cooling tower cooling circulating water systems, in particular to a low-temperature waste heat refrigeration type cooling circulating water energy-saving and water-saving system, and also to an energy-saving and water-saving method for using low-temperature waste heat refrigeration for a cooling circulating water device. Background Art

[0002] In the process industry, cooling towers are important heat exchange equipment and are widely used to reduce the temperature of circulating water. In summer, cooling towers use evaporation to transfer heat through the contact between water and air to achieve heat exchange. Limited by the ambient wet-bulb temperature, the temperature difference between the inlet and outlet water of the cooling tower is small, and the ideal edge temperature cannot be reached, which may cause the DCS unit to alarm and affect production safety and economic benefits. Therefore, lowering the wet-bulb temperature of the incoming air and increasing the temperature difference between the air and the cooling circulating water can effectively improve the cooling efficiency and reduce the power consumption of the cooling circulating water pump. At the same time, a large amount of low-temperature waste heat cannot be used in process industrial production, and there is a lack of available heat sinks, so a large amount of low-temperature waste heat is wasted. During the operation of the cooling tower, a large amount of cooling circulating water is evaporated into the atmosphere, resulting in a waste of circulating water.

[0003] Therefore, in response to the above problems, we propose an energy-saving and water-saving method and system for low-temperature waste heat refrigeration for cooling circulating water devices. Summary of the invention

[0004] To this end, the present invention provides a low-temperature waste heat refrigeration cooling water energy-saving and water-saving system to solve the above-mentioned problems in the prior art. The purpose is to reduce the incoming air temperature, collect and utilize low-temperature waste heat, and reduce the evaporation loss of cooling circulating water. In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: According to the first aspect of the present invention, a low-temperature waste heat refrigeration cooling water energy-saving and water-saving system,

[0005] The system includes a cooling tower, a surface cooler, a spray system, a cooling filler, a coil heat exchanger, and a water collection tank stacked in sequence from top to bottom;

[0006] The side of the water collection tank is connected to the cooling water tank through a pipeline;

[0007] The cooling water pool is connected to the spray system through a pipeline connected in series with a cooling circulating water pump and a heat exchanger;

[0008] The coil heat exchanger is connected with the surface cooler and the lithium bromide refrigerator through pipelines to form a loop.

[0009] Furthermore, the pipeline between the surface cooler and the lithium bromide refrigerator is a chilled water outlet pipeline.

[0010] Furthermore, the pipeline between the heat exchanger and the spray system is a cooling circulating water inlet pipeline.

[0011] Furthermore, the pipe between the coil heat exchanger and the lithium bromide refrigerator is a chilled water inlet pipe.

[0012] Furthermore, the pipe between the water collecting tank and the cooling water tank is a cooling circulating water return pipe.

[0013] Furthermore, the input end of the lithium bromide refrigerator is a waste heat inlet.

[0014] Furthermore, the output end of the lithium bromide refrigerator is a waste heat outlet.

[0015] Furthermore, the cooling tower is a trapezoidal structure with a cross-section gradually increasing from top to bottom.

[0016] Further, the nozzle of the spray system is arranged toward the cooling filler.

[0017] According to a second aspect of the present invention, a method for achieving energy and water saving using any system of the first aspect of the present invention comprises the following steps:

[0018] Step S100: First, a large amount of low-temperature waste heat generated in process industrial production is sent to a lithium bromide refrigerator, where the low-temperature waste heat transfers heat to a lithium bromide aqueous solution, which exchanges heat with chilled water through evaporation and condensation to achieve the purpose of cooling;

[0019] Step S200, then, the cooled chilled water is transported to the coil heat exchanger, and the air temperature is lowered through air heat exchange, thereby increasing the temperature difference between the cooling circulating water sprayed by the spray system and the air entering the cooling tower. The cooling circulating water sprayed by the spray system is collected by the water collection tank and then enters the cooling water tank for further circulation;

[0020] Step S300, finally, the coil heat exchanger sends the chilled water to the surface cooler at the top of the cooling tower, so that the evaporated cooling circulating water is cooled and condensed into the water collection tank, and the chilled water is then sent back to the lithium bromide refrigerator to continue circulating, and the residual heat is sent out of the lithium bromide refrigerator.

[0021] The present invention has the following advantages:

[0022] 1. This scheme reduces the temperature of the air entering the cooling tower and increases the temperature difference between the air and the cooling circulating water by adding lithium bromide refrigerators, coil heat exchangers and other devices. When the temperature difference increases, the required cooling circulating water flow rate decreases, reducing the power consumption of the cooling circulating water pump, and has a significant energy-saving effect. The power saving rate is more than 20%. At the same time, it reduces the possibility of DCS unit alarm due to failure to reach the card edge temperature, thereby improving the safety of the system.

[0023] 2. This solution adds a surface cooler on the top of the cooling tower and uses lithium bromide refrigeration machine to cool and condense the evaporated cooling circulating water, which then flows back to the water collection tank and continues to circulate, thereby reducing the loss of cooling circulating water and reducing the system operating cost.

[0024] 3. This scheme uses low-temperature waste heat for refrigeration, which not only recycles a large amount of low-temperature waste heat and improves the cooling effect of the cooling tower, but also recycles the waste heat resources that lack available heat sinks in the production process, thereby improving production efficiency and reducing cooling costs. At the same time, it provides a new recycling and utilization idea for similar waste heat resources in other industries.

[0025] 4. The main equipment involved in this plan, such as lithium bromide refrigerators, coil heat exchangers, and surface coolers, are all mature and standardized products on the market. They are simple to produce and assemble, with controllable costs, and have good promotion significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 An expanded structural diagram of a low-temperature waste heat refrigeration cooling circulating water energy-saving and water-saving system provided for some embodiments of the present invention.

[0027] In the figure, 1. Cooling tower; 2. Surface cooler; 3. Spray system; 4. Cooling filler; 5. Coil heat exchanger; 6. Cooling circulating water return pipe; 7. Cooling water tank; 8. Collection tank; 9. Cooling circulating water pump; 10. Waste heat inlet; 11. Waste heat outlet; 12. Chilled water inlet pipe; 13. Chilled water outlet pipe; 14. Cooling circulating water inlet pipe; 15. Lithium bromide refrigerator; 16. Heat exchanger. DETAILED DESCRIPTION

[0028] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] like Figure 1 As shown, a low-temperature waste heat refrigeration cooling circulating water energy-saving and water-saving system in the first aspect of the present invention,

[0031] The system includes a cooling tower 1, a surface cooler 2, a spray system 3, a cooling filler 4, a coil heat exchanger 5, and a water collection tank 8 which are stacked in sequence from top to bottom;

[0032] The side of the water collecting tank 8 is connected to the cooling water tank 7 through a pipeline;

[0033] The cooling water pool 7 is connected to the spray system 3 through a pipeline connected in series with a cooling circulating water pump 9 and a heat exchanger 16;

[0034] The coil heat exchanger 5 is connected to the surface cooler 2 and the lithium bromide refrigerator 15 through pipelines to form a loop.

[0035] The technical effects achieved by the above embodiments are:

[0036] 1. This scheme reduces the temperature of the air entering the cooling tower and increases the temperature difference between the air and the cooling circulating water by adding lithium bromide refrigerators, coil heat exchangers and other devices. When the temperature difference increases, the required cooling circulating water flow rate decreases, reducing the power consumption of the cooling circulating water pump, and has a significant energy-saving effect. The power saving rate is more than 20%. At the same time, it reduces the possibility of DCS unit alarm due to failure to reach the card edge temperature, thereby improving the safety of the system.

[0037] 2. This solution adds a surface cooler on the top of the cooling tower and uses lithium bromide refrigeration machine to cool and condense the evaporated cooling circulating water, which then flows back to the water collection tank and continues to circulate, thereby reducing the loss of cooling circulating water and reducing the system operating cost.

[0038] 3. This scheme uses low-temperature waste heat for refrigeration, which not only recycles a large amount of low-temperature waste heat and improves the cooling effect of the cooling tower, but also recycles the waste heat resources that lack available heat sinks in the production process, thereby improving production efficiency and reducing cooling costs. At the same time, it provides a new recycling and utilization idea for similar waste heat resources in other industries.

[0039] 4. The main equipment involved in this plan, such as lithium bromide refrigerators, coil heat exchangers, and surface coolers, are all mature and standardized products on the market. They are simple to produce and assemble, with controllable costs, and have good promotion significance.

[0040] Example 2

[0041] like Figure 1 As shown, a low-temperature waste heat refrigeration type cooling circulating water energy-saving and water-saving system includes all the contents of Example 1. In addition, the pipeline between the surface cooler 2 and the lithium bromide refrigerator 15 is a chilled water outlet pipeline 13.

[0042] Optionally, the pipeline between the heat exchanger 16 and the spray system 3 is a cooling circulating water inlet pipeline 14 .

[0043] Optionally, the pipeline between the coil heat exchanger 5 and the lithium bromide refrigerator 15 is a chilled water inlet pipeline 12.

[0044] Optionally, the pipe between the water collecting pool 8 and the cooling water pool 7 is a cooling circulating water return pipe 6 .

[0045] Optionally, the input end of the lithium bromide refrigerator 15 is the waste heat inlet 10 .

[0046] Optionally, the output end of the lithium bromide refrigerator 15 is a waste heat outlet 11 .

[0047] Example 3

[0048] like Figure 1 As shown, a low-temperature waste heat refrigeration type cooling circulating water energy-saving and water-saving system includes all the contents of Example 2. In addition, the cooling tower 1 is a trapezoidal structure with a gradually increasing cross-section from top to bottom.

[0049] Optionally, the nozzle of the spray system 3 is arranged toward the cooling filler 4 .

[0050] Example 4

[0051] like Figure 1 As shown, a method for energy saving and water saving using low temperature waste heat refrigeration for a cooling circulating water device includes all the contents of Embodiments 1 to 3, including the following steps:

[0052] First, a large amount of low-temperature waste heat generated in process industrial production is sent to the lithium bromide refrigerator 15 through the waste heat inlet 10. The low-temperature waste heat transfers heat to the lithium bromide aqueous solution in the lithium bromide refrigerator 15. The lithium bromide aqueous solution exchanges heat with the chilled water through the evaporation and condensation process to achieve the purpose of cooling.

[0053] Next, the cooled chilled water is sent to the coil heat exchanger 5 through the chilled water inlet pipe 12, and the air temperature is lowered through air heat exchange, thereby increasing the temperature difference between the cooling circulating water sprayed by the spray system 3 and the air entering the cooling tower 1. The cooling circulating water sprayed by the spray system 3 is collected by the collecting tank 8 and then enters the cooling water tank 7 for further circulation.

[0054] Finally, the coil heat exchanger 5 sends the chilled water to the surface cooler 2 at the top of the cooling tower, so that the evaporated cooling circulating water cools down and condenses into the water collection tank 8, and the chilled water is then sent back to the lithium bromide refrigerator 15 through the chilled water outlet pipe 13 to continue circulating. The waste heat is sent out of the lithium bromide refrigerator 15 through the waste heat outlet 11.

[0055] In the description of the present invention, it is to be understood that the terms “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0056] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0057] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0059] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

[0060] In the description of this specification, the description with reference to the terms "embodiment one", "embodiment two", "example", "specific example", or "some examples" means that the specific method, device or feature described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, methods, devices or features described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0061] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-temperature waste heat refrigeration cooling circulating water energy-saving and water-saving system, characterized in that: The system comprises a cooling tower (1), a surface cooler (2), a spray system (3), a cooling filler (4), a coil heat exchanger (5), and a water collection tank (8) which are stacked in sequence from top to bottom; The side of the water collecting tank (8) is connected to the cooling water tank (7) through a pipeline; The cooling water pool (7) is connected to the spray system (3) through a pipeline connected in series with a cooling circulating water pump (9) and a heat exchanger (16); The coil heat exchanger (5) is connected to the surface cooler (2) and the lithium bromide refrigerator (15) through pipelines to form a loop.

2. The low-temperature waste heat refrigeration cooling circulating water energy-saving and water-saving system according to claim 1 is characterized in that: The pipeline between the surface cooler (2) and the lithium bromide refrigerator (15) is a chilled water outlet pipeline (13).

3. The low-temperature waste heat refrigeration cooling circulating water energy-saving and water-saving system according to claim 1 is characterized in that: The pipeline between the heat exchanger (16) and the spray system (3) is a cooling circulating water inlet pipeline (14).

4. The low-temperature waste heat refrigeration cooling circulating water energy-saving and water-saving system according to claim 1 is characterized in that: The pipeline between the coil heat exchanger (5) and the lithium bromide refrigerator (15) is a chilled water inlet pipeline (12).

5. The low-temperature waste heat refrigeration type cooling circulating water energy-saving and water-saving system according to claim 1 is characterized in that: The pipeline between the water collecting pool (8) and the cooling water pool (7) is a cooling circulating water return pipeline (6).

6. The low-temperature waste heat refrigeration cooling circulating water energy-saving and water-saving system according to claim 1 is characterized in that: The input end of the lithium bromide refrigerator (15) is the waste heat inlet (10).

7. The low-temperature waste heat refrigeration cooling circulating water energy-saving and water-saving system according to claim 6 is characterized in that: The output end of the lithium bromide refrigerator (15) is a waste heat outlet (11).

8. The low-temperature waste heat refrigeration type cooling circulating water energy-saving and water-saving system according to claim 1 is characterized in that: The cooling tower (1) is a trapezoidal structure with a cross-section that gradually increases from top to bottom.

9. The low-temperature waste heat refrigeration type cooling circulating water energy-saving and water-saving system according to claim 1, characterized in that: The nozzle of the spray system (3) is arranged toward the cooling filler (4).

10. A method for achieving energy and water conservation using the system of any one of claims 1 to 9, characterized in that: The following steps are involved: Step S100, first, a large amount of low-temperature waste heat generated in process industrial production is sent to a lithium bromide refrigerator (15), and the low-temperature waste heat transfers heat to a lithium bromide aqueous solution in the lithium bromide refrigerator (15), and the lithium bromide aqueous solution exchanges heat with chilled water through evaporation and condensation processes, thereby achieving the purpose of cooling; Step S200, then, the cooled chilled water is transported to the coil heat exchanger (5), and the air temperature is lowered through air heat exchange, thereby increasing the temperature difference between the cooling circulating water sprayed by the spray system (3) and the air entering the cooling tower (1). The cooling circulating water sprayed by the spray system (3) is collected by the water collection tank (8) and then enters the cooling water tank (7) for further circulation; Step S300. Finally, the coil heat exchanger (5) sends the chilled water to the surface cooler (2) at the top of the cooling tower (1), so that the evaporated cooling circulating water is cooled and condensed and enters the water collection tank (8). The chilled water is then sent back to the lithium bromide refrigerator (15) to continue circulating, and the residual heat is sent out of the lithium bromide refrigerator (15).

Images