A control system for waste heat heating reverse osmosis feed water

Abstract

The utility model relates to industrial waste heat utilization technical field, concretely is a kind of control system of waste heat heating reverse osmosis water. Including condenser, cooling tower, heat exchanger, reverse osmosis water pipeline, reverse osmosis membrane device, temperature detection device, electrical control cabinet and control valve;The outlet of condenser, control valve, heat exchanger and the inlet of condenser are sequentially connected by pipeline;The outlet of condenser, cooling tower and the inlet of condenser are sequentially connected by pipeline;Reverse osmosis water pipeline, heat exchanger, temperature detection device and reverse osmosis membrane device are sequentially connected by pipeline;Temperature detection device, electrical control cabinet and control valve are connected by cable. Realized the utilization waste heat heating reverse osmosis water, solved the impact problem of reverse osmosis water temperature parameter fluctuation to reverse osmosis device, improved the operation stability and reliability of system.

Description

Technical Field

[0001] This utility model relates to the field of industrial waste heat utilization technology, specifically a control system for heating reverse osmosis water with waste heat. Background Technology

[0002] In recent years, reverse osmosis membrane technology has developed rapidly in the boiler feedwater treatment process of power plants. After treatment by reverse osmosis membrane, more than 97% of the salt and SiO2 in the water can be removed, as well as most of the calcium and magnesium components in the water, which greatly reduces the burden on subsequent desalination equipment.

[0003] However, the efficiency of reverse osmosis membrane devices is significantly affected by the temperature of the incoming water, especially in winter and early spring / late autumn when the water temperature is low, leading to increased water viscosity and a decrease in the water flux of the reverse osmosis membrane, resulting in reduced permeate production. Chinese Patent CN217490429U discloses "A device for increasing the temperature of reverse osmosis incoming water using waste heat from an air compressor." This system utilizes the waste heat from the air compressor's circulating cooling water to heat the water in the ultrafiltration tank to 25°C~30°C using a heating coil, which is then supplied to the reverse osmosis equipment for further processing. This device solves the problem of unstable reverse osmosis incoming water temperature, but it only mentions heating the water in the tank using a heating coil; it does not address how the system controls the water temperature to meet the requirements of the reverse osmosis incoming water. Utility Model Content

[0004] In order to overcome the shortcomings of the existing technology, this utility model provides a control system for heating reverse osmosis water with waste heat, which realizes the use of waste heat to heat reverse osmosis water, solves the problem of the impact of reverse osmosis water temperature parameter fluctuation on the reverse osmosis device, and improves the operational stability and reliability of the system.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A control system for heating reverse osmosis feed water using waste heat includes a condenser, a cooling tower, a heat exchanger, a reverse osmosis feed water pipeline, a reverse osmosis membrane unit, a temperature detection device, an electrical control cabinet, and control valves. The outlet of the condenser, the control valves, the heat exchanger, and the inlet of the condenser are connected sequentially by pipelines. The outlet of the condenser, the cooling tower, and the inlet of the condenser are connected sequentially by pipelines. The reverse osmosis feed water pipeline, the heat exchanger, the temperature detection device, and the reverse osmosis membrane unit are connected sequentially by pipelines.

[0007] The temperature detection device, electrical control cabinet, and control valve are connected by cables.

[0008] Furthermore, it also includes a power generation circulating water pipeline and a boiler; the power generation circulating water pipeline, condenser, and boiler are connected in sequence by pipelines.

[0009] Furthermore, the outlet of the heat exchanger is connected to the first branch pipe, the outlet of the cooling tower is connected to the second branch pipe, the first branch pipe and the second branch pipe merge into a main pipe, and the main pipe is connected to the inlet of the condenser.

[0010] Compared with the prior art, the present invention has at least the following technical effects or advantages:

[0011] 1. In this invention, cooling circulating water enters the condenser. After heat exchange, a portion of the cooled circulating water enters the heat exchanger through a control valve, while the remaining cooling circulating water is cooled in a cooling tower. Reverse osmosis water enters the heat exchanger, exits through a temperature detection device, and then enters the reverse osmosis membrane unit. The temperature detection device transmits a signal to the electrical control cabinet, which outputs a control valve opening signal to control the valve opening. By detecting the temperature of the heated reverse osmosis water, the amount of circulating cooling water entering the heat exchanger is controlled. This achieves the utilization of waste heat to heat the reverse osmosis water and controls the temperature of the heated reverse osmosis water within the range of 20℃ to 22℃. This solves the problem of the impact of reverse osmosis water temperature fluctuations on the reverse osmosis unit, improving the system's operational stability and reliability.

[0012] 2. In this invention, the circulating water for power generation enters the condenser for cooling. After cooling, the condensed circulating water is treated and then reintroduced into the boiler, achieving efficient closed-loop utilization of the circulating water (boiler feedwater). The condenser condenses the steam after it has done work into pure condensate. This water undergoes a rigorous purification process to remove trace impurities and corrosion products before being returned to the boiler as feedwater. This design greatly improves water resource utilization efficiency, requiring only a small amount of replenishment water to maintain operation and significantly reducing water consumption. Simultaneously, it ensures extremely high water quality entering the boiler, effectively preventing scaling and corrosion, and guaranteeing the safe, efficient, and long-life operation of the boiler. Furthermore, it recovers the heat from the condensate and the valuable pure water itself, enhancing the economic efficiency and environmental friendliness of the entire power plant operation.

[0013] 3. The outlet of the heat exchanger of this utility model is connected to the first branch pipe, and the outlet of the cooling tower is connected to the second branch pipe. The first and second branch pipes merge into a main pipe, which is connected to the inlet of the condenser. The cooling circulating water from the heat exchanger merges with the cooling circulating water cooled by the cooling tower and re-enters the condenser. This mixing buffers the fluctuations in the cooling tower outlet water temperature caused by environmental factors, helping to maintain the stability of condenser operation. In addition, by adjusting the ratio of the two water flows, the total flow rate and temperature entering the condenser can be flexibly controlled, enhancing the system's ability to adapt to different loads and environmental changes, ultimately achieving water and energy savings and improving the overall economic efficiency of operation. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure and process principle of this utility model.

[0015] In the diagram: 1. Condenser; 2. Cooling tower; 3. Heat exchanger; 4. Reverse osmosis membrane unit; 5. Control valve; 6. Temperature detection device; 7. Electrical control cabinet; 8. Power generation circulating water; 9. Cooling circulating water; 10. Reverse osmosis inlet water; 11. Boiler; 12. Power generation circulating water pipeline; 13. Reverse osmosis inlet water pipeline. Detailed Implementation

[0016] The embodiments of this utility model are described in detail below. To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0017] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] In the description of this utility model, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0021] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0022] like Figure 1 As shown, a control system for heating reverse osmosis feed water with waste heat includes a condenser 1, a cooling tower 2, a heat exchanger 3, a reverse osmosis membrane device 4, a control valve 5, a temperature detection device 6, an electrical control cabinet 7, a boiler 11, a power generation circulating water pipeline 12, and a reverse osmosis feed water pipeline 13.

[0023] The power generation circulating water pipeline 12 is connected to the first inlet of condenser 1, and the first outlet of condenser 1 is connected to the boiler 11 pipeline, realizing the efficient closed-loop utilization of power generation circulating water (boiler feedwater). Condenser 1 condenses the steam after it has done work into pure condensate. This water undergoes rigorous purification by a fine treatment system to remove trace impurities and corrosion products before being returned to boiler 11 as feedwater. This design greatly improves water resource utilization efficiency, requiring only a small amount of supplemental water to maintain operation and significantly reducing water consumption. Simultaneously, it ensures extremely high water quality entering the boiler, effectively preventing scaling and corrosion, and guaranteeing the safe, efficient, and long-life operation of the boiler. Furthermore, it recovers the heat from the condensate and the valuable pure water itself, enhancing the economic efficiency and environmental friendliness of the entire power plant operation.

[0024] The second outlet of condenser 1 is connected to the first inlet pipe of heat exchanger 3, and a control valve 5 is installed on the connected pipe. The second outlet of condenser 1 is connected to the inlet pipe of cooling tower 2. The first outlet of heat exchanger 3 is connected to the first branch pipe, and the outlet of cooling tower 2 is connected to the second branch pipe. The first branch pipe and the second branch pipe merge into a main pipe, which is connected to the second inlet of condenser 1. The cooling circulating water from heat exchanger 3 merges with the cooling circulating water cooled by cooling tower 2 and re-enters condenser 1. This mixing buffers the temperature fluctuations of the cooling tower 2 outlet water caused by environmental factors, helping to maintain the operational stability of condenser 1. In addition, by adjusting the ratio of the two water flows, the total flow rate and temperature entering condenser 1 can be flexibly controlled, enhancing the system's ability to adapt to different loads and environmental changes, ultimately achieving water and energy savings and improving the overall economic efficiency of operation.

[0025] The reverse osmosis water inlet pipe 13 is connected to the second inlet of the heat exchanger 3, and the second outlet of the heat exchanger 3 is connected to the pipe of the reverse osmosis membrane device 4. A temperature detection device 6 is installed on the connected pipe. The temperature detection device 6, the electrical control cabinet 7, and the control valve 5 are connected by cables.

[0026] The working principle and process of this utility model are as follows:

[0027] The exhaust steam from the power generation circulating water 8, passing through the power generation circulating water pipeline 12, enters the condenser 1 at a pressure of 0.004–0.006 MPa, a temperature of 29°C–36.2°C, and a specific enthalpy of 2553 kJ / kg–2566 kJ / kg. The cooling circulating water entering the condenser 1 has a temperature of 20°C–25°C. This cooling circulating water exchanges heat with the generator exhaust steam in the condenser, and the temperature of the cooling circulating water after the heat exchange is 25°C–30°C. The condensate from the power generation circulating water exhaust steam is treated and then supplied back to the boiler 11.

[0028] A portion of the cooled circulating water 9 after heat exchange enters heat exchanger 3. The temperature of the reverse osmosis water 10 entering heat exchanger 3 via reverse osmosis water pipe 13 fluctuates between 4℃ and 15℃. Generally, the water temperature is 4℃ to 8℃ in winter and 10℃ to 15℃ in summer. A detection point is set up to monitor the temperature of the heated reverse osmosis water. The collected temperature signal is transmitted to the electrical control cabinet 7 to determine if the temperature is within the reverse osmosis water temperature range of 20℃ to 22℃. If it is not within this range, the control valve 5 for cooling circulating water entering the heat exchanger is adjusted after PID calculation in the electrical control cabinet to regulate the flow of cooling circulating water into heat exchanger 3, ensuring that the heated reverse osmosis water temperature remains within the 20℃ to 22℃ range. The heated reverse osmosis water then enters the reverse osmosis membrane unit 4. The cooling circulating water that does not enter the heat exchanger 3 is cooled in the cooling tower 2 and merges with the cooling circulating water that comes out of the heat exchanger 3. Then it re-enters the condenser 1 to cool and exchange heat with the exhaust steam of the generator set.

[0029] In the above system, the waste heat of the power generation circulating water is used to replace the original steam heating of the reverse osmosis water, and the temperature of the heated reverse osmosis water is kept within the range of 20℃~22℃. This solves the problem of the impact of the reverse osmosis water temperature parameter fluctuation on the reverse osmosis membrane device 4, meets the production requirements of reverse osmosis membrane, improves the operational stability of the system, and reduces the system operating cost.

[0030] This invention controls the amount of circulating cooling water entering the heat exchanger by detecting the temperature of the heated reverse osmosis water, thereby utilizing waste heat to heat the reverse osmosis water and controlling the temperature of the heated reverse osmosis water within the range of 20℃ to 22℃. This solves the problem of the impact of reverse osmosis water temperature parameter fluctuations on the reverse osmosis device and improves the operational stability and reliability of the system.

[0031] Example 1:

[0032] During summer operation, the pressure of the 100t / h power generation circulating water 8 exhaust steam entering condenser 1 is 0.006MPa, the temperature is 36.2℃, and the specific enthalpy is 2566kJ / kg; the 10000m³ of steam entering condenser 1... 3 The temperature of the cooling circulating water 9 is 25℃. The cooling circulating water 9 exchanges heat with the exhaust steam of the power generation circulating water 8 in the condenser 1. After the heat exchange, the temperature of the cooling circulating water 9 is 30℃. After the exhaust steam of the power generation circulating water 8 exchanges heat and condenses, it becomes 35℃ circulating water. After treatment, it is supplied to the boiler 11 for use.

[0033] The 30°C cooling circulating water 9 from condenser 1, of which 350m³ 3 Cooling circulating water at a rate of / h enters heat exchanger 3; in summer, 200m³ / h... 3The reverse osmosis water 10 has a temperature of 15℃ and enters the heat exchanger 3 to exchange heat with the cooling circulating water. The temperature of the reverse osmosis water 10 after heat exchange is 23℃. The heated reverse osmosis water 10 passes through the temperature detection device 6, which transmits the collected temperature signal of the heated water to the electrical control cabinet 7.

[0034] Since this temperature is 20℃~22℃ higher than the reverse osmosis inlet water temperature, the control valve 5 for the cooling circulating water entering the heat exchanger 3 needs to be adjusted after PID calculation within the electrical control cabinet 7 to reduce the flow rate of cooling circulating water into the heat exchanger 3 to 280m³. 3 / h; at this time, 200m at 15℃ 3 / h reverse osmosis water 10 enters the heat exchanger to exchange heat with the cooling circulating water. The temperature of the reverse osmosis water after heat exchange is 21.5℃. After adjustment, the temperature of the heated reverse osmosis water is in the range of 20℃~22℃.

[0035] The heated reverse osmosis water 10 enters the reverse osmosis membrane unit 4; the cooling circulating water that does not enter the heat exchanger is cooled to 25°C in the cooling tower 2 and merges with the cooling circulating water coming out of the heat exchanger 3, and then re-enters the condenser to cool and exchange heat with the exhaust steam of the generator set.

[0036] Example 2:

[0037] During winter operation, the pressure of the exhaust steam from the power generation circulating water 8 entering condenser 1 is 0.004 MPa, the temperature is 29℃, and the specific enthalpy is 2553 kJ / kg; the 10000m³ of steam entering condenser 1... 3 The temperature of the cooling circulating water 9 is 20℃. The cooling circulating water 9 exchanges heat with the exhaust steam of the power generation circulating water 8 in the condenser 1. After the heat exchange, the temperature of the cooling circulating water 9 is 25℃. After the exhaust steam of the power generation circulating water 8 exchanges heat and condenses, it becomes 28℃ circulating water. After treatment, it is supplied to the boiler 11 for use.

[0038] The 25°C cooling circulating water 9 from condenser 1 contains 600m³ of water. 3 Cooling circulating water at a rate of / h enters heat exchanger 3; in winter, 200m³ / h... 3 The reverse osmosis water 10 has a temperature of 5℃ and enters the heat exchanger 3 to exchange heat with the cooling circulating water. The temperature of the reverse osmosis water after heat exchange is 18.5℃. The heated reverse osmosis water 10 passes through the temperature detection device 6, which transmits the collected temperature signal of the heated water to the electrical control cabinet 7.

[0039] Since this temperature is below the reverse osmosis inlet water temperature range of 20℃~22℃, the control valve 5 for the cooling circulating water entering the heat exchanger needs to be adjusted after PID calculation in the electrical control cabinet 7 to increase the cooling circulating water flow rate into the heat exchanger 3 to 700m³.3 / h; at this time, 200m at 5℃ 3 The reverse osmosis water enters the heat exchanger and exchanges heat with the cooling circulating water. The temperature of the reverse osmosis water after heat exchange is 20.7℃.

[0040] After adjustment, the temperature of the heated reverse osmosis water is in the range of 20℃~22℃. The heated reverse osmosis water enters the reverse osmosis membrane unit 4; the cooling circulating water that does not enter the heat exchanger is cooled to 20℃ in the cooling tower 2, and then merges with the cooling circulating water coming out of the heat exchanger 3, and then re-enters the condenser to cool and exchange heat with the exhaust steam of the generator set.

[0041] The scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. A control system for heating reverse osmosis feed water using waste heat, characterized in that: This includes condensers, cooling towers, heat exchangers, reverse osmosis water supply pipes, reverse osmosis membrane units, temperature detection devices, electrical control cabinets, and control valves; The outlet of the condenser, the control valve, the heat exchanger and the inlet of the condenser are connected in sequence by pipelines. The outlet of the condenser, the cooling tower and the inlet of the condenser are connected in sequence by pipes; The reverse osmosis water supply pipe, heat exchanger, temperature detection device and reverse osmosis membrane device are connected in sequence by pipes; The temperature detection device, electrical control cabinet, and control valve are connected by cables.

2. The control system for waste heat heating reverse osmosis feed water according to claim 1, characterized in that: It also includes a power generation circulating water pipeline and a boiler; the power generation circulating water pipeline, condenser and boiler are connected in sequence by pipelines.

3. The control system for waste heat heating reverse osmosis feed water according to claim 1, characterized in that: The outlet of the heat exchanger is connected to the first branch pipe, the outlet of the cooling tower is connected to the second branch pipe, the first branch pipe and the second branch pipe merge into a main pipe, and the main pipe is connected to the inlet of the condenser.

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