A water-saving circulating cooling unit water resource utilization system

Abstract

The present invention discloses a water-saving circulating cooling unit water resource utilization system, which includes a water source treatment system, a front-end water use and drainage system, a wastewater deep concentration and reduction system, and a terminal water use and drainage system. Among them, the water source treatment system, the front-end water use and drainage system, the wastewater deep concentration and reduction system, and the terminal water use and drainage system are connected in sequence, and this system can achieve the efficient utilization of water resources in thermal power plants.

Description

Technical Field

[0001] The present invention belongs to the field of energy conservation and environmental protection in thermal power plants, and relates to a water-saving circulating cooling unit water resource utilization system. Background Art

[0002] Industrial enterprises are major water users in China. The total amount of water used and the water use efficiency directly affect the overall construction of a water-saving society in China. Through continuous technological reforms, the water use efficiency in China's industry has been greatly improved. Thermal power accounts for about 40% of industrial water use. The water-saving level of thermal power plants plays a crucial role in the formulation and implementation of the policies of thermal power plants. The efficient utilization of water resources in thermal power plants also has great economic, social and ecological benefits for power plants. At the same time, the improvement of the water-saving level of thermal power plants is also of great significance for alleviating the national water resource pressure and achieving various water resource management goals.

[0003] In 2017, among the 1363 units surveyed by the China Electricity Council, 775 units adopted circulating cooling, with an installed capacity of 272.79 million kW and a capacity ratio of 50.47%. Developing a water-saving circulating cooling unit water resource utilization system is of great significance for water conservation in the thermal power industry. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art and provide a water-saving circulating cooling unit water resource utilization system, which can achieve the efficient utilization of water resources in thermal power plants.

[0005] To achieve the above purpose, the water-saving circulating cooling unit water resource utilization system described in the present invention includes a source water treatment system, a front-end water intake and drainage system, a wastewater deep concentration and reduction system, and a terminal water intake and drainage system. Among them, the source water treatment system, the front-end water intake and drainage system, the wastewater deep concentration and reduction system, and the terminal water intake and drainage system are connected in sequence.

[0006] The source water treatment system includes a pretreatment system, a chemical water tank, a domestic and fire water tank, a circulating water system, and an industrial water tank;

[0007] The source water input pipeline is connected to the inlet of the pretreatment system, and the outlet of the pretreatment system is connected to the inlets of the chemical water tank, the domestic and fire water tank, the circulating water system, and the industrial water tank; the outlets of the chemical water tank, the domestic and fire water tank, the circulating water system, and the industrial water tank are connected to the front-end water intake and drainage system.

[0008] The front-end water intake and drainage system includes a boiler make-up water system, domestic water users, a fire protection water system, an industrial equipment cooling system, a water vapor circulation system, a greening system, a biological sewage treatment station, and an industrial wastewater treatment station; the wastewater deep concentration and reduction system includes a circulating water blowdown desalination system;

[0009] The inlet of the raw water input pipeline is connected to the inlet of the pretreatment system. The outlet of the pretreatment system is connected to the inlets of the chemical water tank, the domestic and fire water tank, the circulating water system, and the industrial water tank. The outlet of the chemical water tank is connected to the inlet of the boiler make-up water system. The waste water outlet of the boiler make-up water system is divided into three paths. The first path is connected to the backwash water and flushing water inlets of the pretreatment system. The second path is connected to the inlet of the desalination system for circulating cooling water blowdown. The third path is connected to the inlet of the industrial waste water treatment station. The demineralized water outlet of the boiler make-up water system is connected to the inlet of the steam-water circulation system. The polished regeneration waste water outlet of the steam-water circulation system is connected to the inlet of the industrial waste water treatment station. The boiler blowdown outlet of the steam-water circulation system is connected to the inlet of the circulating water system;

[0010] The outlet of the domestic and fire water tank is connected to the inlets of the domestic water users and the fire water system. The domestic sewage outlet of the domestic water users is connected to the inlet of the domestic sewage treatment station. The outlet of the domestic sewage treatment station is divided into two paths. One path is connected to the greening system, and the other path is connected to the circulating water system. The outlet of the industrial water tank is connected to the industrial equipment cooling system and the circulating water system.

[0011] The terminal water discharge system includes a desulfurization system, a coal conveying system, an ash and slag removal system, a desulfurization waste water treatment and zero discharge system, a coal water treatment system, and a slag overflow water treatment system;

[0012] The outlet of the circulating water system is connected to the inlet of the desalination system for circulating cooling water blowdown. The outlets of the circulating water system, the desalination system for circulating cooling water blowdown, and the industrial waste water treatment station are combined through pipes and connected to the inlets of the desulfurization system, the coal conveying system, and the ash and slag removal system; The outlet of the desulfurization system is connected to the desulfurization waste water treatment and zero discharge system. The coal conveying system is connected to the coal water treatment system. The ash and slag removal system is connected to the slag overflow water treatment system.

[0013] The pretreatment system uses the lime softening process to treat the raw water.

[0014] The industrial waste water treatment station uses the neutralization - coagulation clarification - filtration process to collect and treat industrial waste water.

[0015] The domestic sewage treatment station is an aerated biological filter or a membrane bioreactor.

[0016] The coal water treatment system is an integrated coagulation clarification filtration device or an electrocoagulation device.

[0017] The slag overflow water treatment system uses the clarification and heat exchange processes to treat the slag overflow water.

[0018] The present invention has the following beneficial effects:

[0019] When the water-saving circulating cooling unit water resource utilization system described in the present invention is specifically operated, the source water is treated in the pretreatment system and then sent into the front-end water use and drainage system as make-up water for boilers, domestic water, fire-fighting water, water for industrial equipment cooling systems, and greening water. Then, it is treated by the wastewater deep concentration and reduction system and finally sent into the terminal water use and drainage system as water for desulfurization systems, coal conveying systems, and ash and slag removal systems, establishing a water-saving circulating cooling unit water resource utilization network to achieve wastewater reuse and full utilization of water resources. Moreover, the system is simple and clear, and is convenient for adjustment and supervision during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to enable those skilled in the art of this technology to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present invention disclosure. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concepts disclosed in the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0022] The structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are only exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0023] Referring to Figure 1 , the water-saving circulating cooling unit water resource utilization system described in the present invention includes a source water treatment system, a front-end water use and drainage system, a wastewater deep concentration and reduction system, and a terminal water use and drainage system;

[0024] Among them, the raw water treatment system includes a pretreatment system, a chemical water tank, a domestic and fire water tank, a circulating water system, and an industrial water tank; the front-end water supply and drainage system includes a boiler make-up water system, domestic water users, a fire water system, an industrial equipment cooling system, a water-vapor circulation system, a greening system, a biological sewage treatment station, and an industrial wastewater treatment station. The wastewater deep concentration and reduction system includes a circulating water blowdown desalination system. The terminal water supply and drainage system includes a desulfurization system, a coal conveying system, an ash and slag removal system, a desulfurized wastewater treatment and zero discharge system, a coal water treatment system, and a slag overflow water treatment system;

[0025] The raw water input pipeline is connected to the inlet of the pretreatment system. The outlet of the pretreatment system is connected to the inlets of the chemical water tank, the domestic and fire water tank, the circulating water system, and the industrial water tank. The outlet of the chemical water tank is connected to the inlet of the boiler make-up water system. The wastewater outlet of the boiler make-up water system is divided into three paths. Among them, the first path is connected to the backwash water and flushing water inlets of the pretreatment system, the second path is connected to the inlet of the circulating water blowdown desalination system, and the third path is connected to the inlet of the industrial wastewater treatment station. The demineralized water outlet of the boiler make-up water system is connected to the inlet of the water-vapor circulation system. The refined treatment regeneration wastewater outlet of the water-vapor circulation system is connected to the inlet of the industrial wastewater treatment station. The boiler blowdown outlet of the water-vapor circulation system is connected to the inlet of the circulating water system;

[0026] The outlet of the domestic and fire water tank is connected to the inlets of domestic water users and the fire water system. The domestic sewage outlet of domestic water users is connected to the inlet of the domestic sewage treatment station. The outlet of the domestic sewage treatment station is divided into two paths. One path is connected to the greening system, and the other path is connected to the circulating water system. The outlet of the industrial water tank is connected to the industrial equipment cooling system and the circulating water system. The outlet of the circulating water system is connected to the inlet of the circulating water blowdown desalination system. The outlets of the circulating water system, the circulating water blowdown desalination system, and the industrial wastewater treatment station are combined through pipelines and then connected to the inlets of the desulfurization system, the coal conveying system, and the ash and slag removal system; the outlet of the desulfurization system is connected to the desulfurized wastewater treatment and zero discharge system. The coal conveying system is connected to the coal water treatment system. The ash and slag removal system is connected to the slag overflow water treatment system.

[0027] The working process of the present invention is as follows:

[0028] The source water enters the pretreatment system for treatment and then separately enters the chemical water tank, industrial fire water tank, circulating water system and industrial water tank. Among them, the water output from the chemical water tank enters the boiler make-up water system. The wastewater output from the boiler make-up water system is divided into three paths. The first path enters the pretreatment system as backwash water and flushing water. The second path enters the circulating water blowdown desalination system as reverse osmosis concentrate water. The third path enters the industrial wastewater treatment station as regeneration wastewater. The demineralized water output from the boiler make-up water system enters the steam-water circulation system. The polished treatment regeneration wastewater output from the steam-water circulation system enters the industrial wastewater treatment station. The boiler blowdown water output from the steam-water circulation system enters the circulating water system. The water output from the raw water fire water tank is divided into two paths. One path enters the domestic water users as domestic water, and the other path enters the fire water system as fire protection water. The domestic sewage output from the domestic water users enters the domestic sewage treatment station for treatment. The clear water output from the domestic sewage treatment station enters the circulating water system as greening water. The concentrated water output from the biological sewage treatment station enters the circulating water system. The water output from the circulating water system is divided into two paths. One path enters the circulating water blowdown desalination system, and the other path is mixed with the concentrated water output from the circulating water blowdown desalination system and the wastewater output from the industrial wastewater treatment station and then enters the desulfurization system, coal conveying system and ash and slag removal system.

[0029] The desulfurization system generates desulfurization wastewater and enters the desulfurization wastewater and zero discharge system; the coal water generated by the coal conveying system is treated by the coal water treatment system and recycled in this system; the slag water generated by the ash and slag removal system is treated by the slag overflow water treatment system and recycled in this system.

[0030] Construct a dynamic water balance of the water resource utilization system for a water-saving circulating cooling unit:

[0031] 1. Water volume balance model of the source water treatment system

[0032] Source water flow Q1 + backwash water and flushing water flow Q12 of the boiler make-up water system = water production volume Q2 of the pretreatment system + sludge discharge loss S1 of the pretreatment system;

[0033] 2. Water volume balance model of the front-end water use and drainage system

[0034] Water production volume Q2 of the pretreatment system = water inlet volume Q3 of the chemical water tank + water inlet volume Q4 of the domestic and fire water tank + fresh water make-up volume Q5 of the circulating water system;

[0035] Water inlet volume Q3 of the chemical water tank + water production volume Q25 of the circulating water blowdown desalination system = water inlet volume Q6 of the boiler make-up water system = wastewater volume Q10 of the boiler make-up water system + demineralized water volume Q11;

[0036] The waste water volume Q10 of the boiler make-up water system = backwash water flushing water flow Q12 + reverse osmosis concentrated water volume Q13 + regeneration waste water volume Q14;

[0037] The demineralized water volume Q11 = polished treatment regeneration waste water volume Q15 + boiler blowdown water volume Q16 + steam and water loss S2;

[0038] The regeneration waste water volume Q14 of the boiler make-up water system + the polished treatment regeneration waste water volume Q15 = the influent water volume Q18 of the industrial waste water treatment station;

[0039] The influent water volume Q4 of the domestic and fire fighting water tank = domestic water volume Q7 + fire fighting water consumption Q8 = domestic water volume Q7 + fire fighting water system leakage loss S4;

[0040] Domestic water volume Q7 + tap water volume Q9 = domestic water user consumption S3 + domestic sewage volume Q17;

[0041] Domestic sewage volume Q17 = treated domestic sewage reuse for greening water volume Q20 + treated domestic sewage reuse for circulating water system water volume Q19;

[0042] The fresh water make-up volume Q5 of the circulating water system + the treated domestic sewage reuse for circulating water system water volume Q19 + boiler blowdown water volume Q16 = the evaporation and wind loss S5 of the circulating water system + the circulating water blowdown water volume Q21;

[0043] The circulating water blowdown water volume Q21 = the circulating water blowdown water volume to the desalination system Q22 + the direct reuse water volume Q23 of the circulating water blowdown;

[0044] 3. Water volume balance model of the waste water deep concentration and reduction system

[0045] The influent water volume Q24 of the circulating water blowdown desalination system = the circulating water blowdown water volume to the desalination system Q22 + the reverse osmosis concentrated water volume Q13 of the boiler make-up water system = the produced water volume Q25 of the circulating water blowdown desalination system + the concentrated water volume Q26 of the circulating water blowdown desalination system + the sludge loss water volume S6 of the circulating water blowdown desalination system;

[0046] 4. Water volume balance model of the terminal water use and drainage system

[0047] The water volume Q18 of the industrial waste water treatment station + the concentrated water volume Q26 of the circulating water blowdown desalination system + the direct reuse water volume Q23 of the circulating water blowdown = the make-up water volume Q27 of the desulfurization system + the make-up water volume Q28 of the coal conveying system + the make-up water volume Q29 of the ash and slag removal system;

[0048] The make-up water volume Q27 of the desulfurization system = the evaporation loss water volume Q30 of the desulfurization system + the desulfurization waste water volume Q31.

[0049] Example 1

[0050] In the actual application process, a supporting facility corresponding to the present invention is established in the power plant to realize the treatment and reuse of water. For example, a 2×600MW circulating cooling unit.

[0051] There is a pretreatment system with a capacity of 2×1250 m 3 / h, which uses the lime softening process to treat reclaimed municipal water.

[0052] There is an industrial wastewater treatment station with a capacity of 100 m 3 / h, which adopts the neutralization - coagulation clarification - filtration process to collect and treat industrial wastewater, and treats about 30 m 3 / h of industrial wastewater.

[0053] There is a domestic sewage treatment station with a capacity of 30 m 3 / h, which adopts a biological - based treatment process such as an aerated biological filter or a membrane bioreactor to collect and treat domestic wastewater, and treats about 13 m 3 / h of domestic wastewater.

[0054] A wastewater deep concentration and reduction system is built to treat 368 m 3 / h of circulating water blowdown. The sodium hydroxide - sodium carbonate secondary softening + reverse osmosis process is used, and the water production is 220 m 3 / h. Among them, 160 m 3 / h is used as the water source for the boiler make - up water system, 60 m 3 / h is replenished into the circulating water system, 148 m 3 / h of concentrated water and 30 m 3 / h of industrial wastewater are used as the make - up water for the desulfurization, coal conveying, and slag removal terminal water use systems.

[0055] There is a coal water treatment system with a capacity of 2×20 m 3 / h, which adopts an integrated coagulation clarification and filtration device or an electro - flocculation device. The treated coal - containing wastewater is reused for flushing and is in a closed - loop cycle.

[0056] There is a slag overflow water treatment system with a capacity of 2×300 m 3 / h, which adopts a clarification and heat exchange process. The treated slag overflow water is in a closed - loop cycle.

[0057] There is a desulfurization wastewater treatment and zero - discharge treatment system with a capacity of 24 m 3 / h to achieve zero discharge of high - salt wastewater.

[0058] Before the transformation, the fresh water intake was 2544 m 3 / h. After the transformation, the fresh water intake is 1813 m 3 / h, and the water intake per unit of generated electricity is 1.51 m 3 / (MW·h), the fresh water intake is reduced by 28.7%, and about 4 million tons of fresh water intake can be saved annually.

[0059] The above are only examples of the implementation steps of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A water-saving circulating cooling unit water resource utilization system, characterized in that, it includes a water source treatment system, a front-end water intake and drainage system, a wastewater deep concentration and reduction system, and a terminal water intake and drainage system. Among them, the water source treatment system, the front-end water intake and drainage system, the wastewater deep concentration and reduction system, and the terminal water intake and drainage system are connected in series; The water source treatment system includes a pretreatment system, a chemical water tank, a domestic and fire water tank, a circulating water system, and an industrial water tank; The water source input pipeline is connected to the inlet of the pretreatment system, and the outlet of the pretreatment system is connected to the inlets of the chemical water tank, the domestic and fire water tank, the circulating water system, and the industrial water tank; the outlets of the chemical water tank, the domestic and fire water tank, the circulating water system, and the industrial water tank are connected to the front-end water intake and drainage system; The front-end water intake and drainage system includes a boiler make-up water system, domestic water users, a fire protection water system, an industrial equipment cooling system, a water and steam circulation system, a greening system, a biological sewage treatment station, and an industrial wastewater treatment station; the wastewater deep concentration and reduction system includes a circulating cooling water blowdown desalination system; The water source input pipeline is connected to the inlet of the pretreatment system, and the outlet of the pretreatment system is connected to the inlets of the chemical water tank, the domestic and fire water tank, the circulating water system, and the industrial water tank. The outlet of the chemical water tank is connected to the inlet of the boiler make-up water system. The wastewater outlet of the boiler make-up water system is divided into three paths. Among them, the first path is connected to the backwash water and flushing water inlets of the pretreatment system, the second path is connected to the inlet of the circulating cooling water blowdown desalination system, and the third path is connected to the inlet of the industrial wastewater treatment station. The demineralized water outlet of the boiler make-up water system is connected to the inlet of the water and steam circulation system. The fine treatment regeneration wastewater outlet of the water and steam circulation system is connected to the inlet of the industrial wastewater treatment station. The boiler blowdown outlet of the water and steam circulation system is connected to the inlet of the circulating water system; The outlet of the domestic and fire water tank is connected to the inlets of domestic water users and the fire protection water system. The domestic sewage outlet of domestic water users is connected to the inlet of the domestic sewage treatment station. The outlet of the domestic sewage treatment station is divided into two paths. One path is connected to the greening system, and the other path is connected to the circulating water system. The outlet of the industrial water tank is connected to the industrial equipment cooling system and the circulating water system.

2. The water-saving circulating cooling unit water resource utilization system according to claim 1, characterized in that, the terminal water intake and drainage system includes a desulfurization system, a coal conveying system, an ash and slag removal system, a desulfurized wastewater treatment and zero discharge system, a coal water treatment system, and a slag overflow water treatment system; The outlet of the circulating water system is connected to the inlet of the circulating cooling water blowdown desalination system. The outlets of the circulating water system, the circulating cooling water blowdown desalination system, and the industrial wastewater treatment station are combined through pipes and connected to the water inlets of the desulfurization system, the coal conveying system, and the ash and slag removal system; the water outlet of the desulfurization system is connected to the desulfurized wastewater treatment and zero discharge system. The coal conveying system is connected to the coal water treatment system. The ash and slag removal system is connected to the slag overflow water treatment system.

3. The water-saving circulating cooling unit water resource utilization system according to claim 1, characterized in that, the pretreatment system uses the lime softening process to treat the source water.

4. The water-saving circulating cooling unit water resource utilization system according to claim 1, characterized in that, the industrial wastewater treatment station uses the neutralization - coagulation clarification - filtration process to collect and treat industrial wastewater.

5. The water-saving circulating cooling unit water resource utilization system according to claim 1, characterized in that, the domestic sewage treatment station is an aerated biological filter or a membrane bioreactor.

6. The water-saving circulating cooling unit water resource utilization system according to claim 2, characterized in that, the coal water treatment system is an integrated coagulation clarification filtration device or an electrocoagulation device.

7. The water-saving circulating cooling unit water resource utilization system according to claim 2, characterized in that, the slag overflow water treatment system uses the clarification and heat exchange processes to treat the slag overflow water.

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