CN116621369A - A system for the production, transmission, distribution and reuse of regenerated water into the heating network - Google Patents

Abstract

A system for producing, distributing and reusing regenerated water into the heating network, including an ultrafiltration UF unit, a two-stage reverse osmosis RO unit, and a vacuum electrochemical oxygen removal unit connected in sequence, and the ultrafiltration UF unit includes a connected self-cleaning unit. filter and ultrafiltration membrane, the two-stage reverse osmosis RO unit includes reverse osmosis low-pressure water inlet pump one, reverse osmosis low-pressure water inlet pump two and reverse osmosis membrane connected in sequence, and the vacuum electrochemical deoxygenation unit includes a connected vacuum An electrochemical deaerator and a deaeration pool, wherein an isolation bag is arranged in the deaeration pool. Based on the double-membrane method + vacuum electrochemical deoxidation process, the system performs advanced treatment on the effluent of traditional urban sewage plants to make it meet the water quality standards of the heating pipe network, so as to realize the use of the existing heating pipe network for reclaimed water Transmission and distribution, and there is no need to lay additional reclaimed water pipe network, thus reducing the construction of municipal pipe network.

Description

A system for the production, transmission, distribution and reuse of regenerated water into the heating network

technical field

The invention belongs to the technical field of sewage treatment, reclaimed water utilization and heating pipe network integration, and specifically relates to a system for producing, transporting, distributing and reusing regenerated water into a heating network.

Background technique

At present, the effluent quality of urban sewage treatment plants generally meets the first-class A standard or even higher, which is close to or exceeds the specification requirements for the design of the heating pipe network. If the effluent of the sewage plant is properly treated in depth, the hot water circulation pipeline in the urban heating system can be used as a pipeline platform for reclaimed water reuse, and the heating pipeline network can be rationally optimized and deployed. During the non-heating period, it can be used The existing heating pipe network transmits and distributes regenerated water without laying a new reclaimed water pipe network. During the heating period, regenerated water can be used as a supplementary water source for the heating pipe network and delivered to users for reuse after off-site water treatment and heat recovery .

The main task of the reclaimed water production process is desalination. At present, the methods commonly used for large-scale desalination include ion exchange, electrodialysis, reverse osmosis, and electrosorption. Among them, the ion exchange method is generally not used alone, the processing capacity of a single module of the electroadsorption method is small, and the guarantee rate of the effluent water quality of the electrodialysis method is not as high as that of reverse osmosis. Combining economy and stability, the reverse osmosis process is more suitable for advanced treatment of large-scale urban sewage treatment plant effluent. Since the reverse osmosis system has very strict requirements on the quality of influent water, the water source cannot be pumped directly, and ultrafiltration or microfiltration is required for pretreatment.

The conventional heating pipe network is a closed system. If reclaimed water is delivered to users, the whole system will become an open system, and air can easily enter the pipe network, resulting in an increase in dissolved oxygen content, which in turn leads to corrosion. Oxygen corrosion is the most common and serious corrosion phenomenon. The heating pipe network has strict standards for influent dissolved oxygen (requires DO≤0.1mg/L), and oxygen removal is one of the key steps to ensure the normal operation of the heating network. Vacuum electrochemical deaeration integrates vacuum, electricity and chemical deaeration methods. The effluent water quality is stable and the comprehensive cost is moderate. It is a superior deaeration method. The deaeration water storage device used in this deaeration method not only needs It is guaranteed to be isolated from the air, and the pressure in the water tank will not be boosted when the water tank enters the water, and the water tank will not be evacuated when the water is discharged, and the normal pressure is always maintained. For large-scale engineering applications, it is unrealistic to use a large number of finished deaeration water tanks. It is necessary to set up a deaeration tank with a concrete structure. Considering the influence of the structural beam, it is more appropriate to use a flexible insulation bag.

Contents of the invention

In view of the above problems, the purpose of the present invention is to provide a system for the production, distribution and reuse of regenerated water entering the heating network. This system is aimed at the regeneration of sewage in water-deficient cities in the north. Based on the current situation that has been fully utilized, based on the double-membrane method + vacuum electrochemical deoxidation process, the effluent of traditional urban sewage plants is subjected to advanced treatment to make it meet the water quality standards of the heating pipe network, so as to realize the utilization of existing heating The pipeline network is used for the transmission and distribution of recycled water, and there is no need to lay additional recycled water pipeline networks, thereby reducing the construction of municipal pipeline networks.

As conceived above, the technical solution of the present invention is: a system for the production, distribution and reuse of regenerated water entering the heating network, which is characterized in that it includes sequentially connected ultrafiltration UF units, two-stage reverse osmosis RO units and vacuum electrochemical oxygen removal unit, the ultrafiltration UF unit includes a connected self-cleaning filter and an ultrafiltration membrane, and the two-stage reverse osmosis RO unit includes reverse osmosis low-pressure inlet pump one, reverse osmosis low-pressure inlet pump two and reverse osmosis membrane connected in sequence , the vacuum electrochemical deoxygenation unit includes a connected vacuum electrochemical deaerator and an oxygen removal pool, and an isolation bag is arranged in the oxygen removal pool.

Preferably, the outlet of the self-cleaning filter is connected to a drain, and the inlet is connected to a lift pump.

Preferably, the outlet of the ultrafiltration membrane is connected to a backwash wastewater tank.

Preferably, a security filter is installed between the first reverse osmosis low-pressure water inlet pump and the second reverse osmosis low-pressure water inlet pump.

Preferably, the outlet of the reverse osmosis membrane is connected to a concentrated water tank.

Preferably, the dissolved oxygen in the vacuum electrochemical deaerator is less than or equal to 12 mg/L, and the dissolved oxygen in the outlet water is less than or equal to 0.1 mg/L.

Preferably, an exhaust pipeline is provided on the top of the oxygen-removing pool to connect with the exhaust port of the isolation bag, and the pipeline leads to the outside.

The present invention has the following advantages and positive effects:

1. The present invention adopts the reverse osmosis (RO) process to desalinate the effluent of urban sewage treatment plants after conventional process treatment, the desalination rate can be maintained between 95% and 98%, the conductivity of the effluent is ≤100us/cm, and the total hardness of the effluent ≤20mg/L, effluent chlorine ion ≤10mg/L, which can meet the water quality requirements of most reclaimed water users;

2. The present invention uses a vacuum electrochemical process to deoxygenate the outlet water to meet the requirements of the heating pipe network for dissolved oxygen, DO≤0.1mg/L, and set up a deoxygenation pool to isolate the deoxygenated water from contact with the outside air and meet the storage capacity requirements;

3. The present invention adopts a flexible isolation bag as a measure to prevent secondary dissolved oxygen. An exhaust pipeline is arranged on the top of the deoxygenation pool to be connected to the exhaust port of the isolation bag. The pipeline leads to the outside, and the inside of the isolation bag is air. The outside of the capsule is water. When the liquid level drops, the pressure of the deoxygenated water pool drops, and the air enters the capsule from the pipeline, so that the deoxygenated water pool maintains a normal pressure state and is isolated from the air at the same time, thus effectively solving the pipeline problem in the process of transporting and distributing regenerated water. Mesh corrosion problem.

4. In the present invention, the effluent from the sewage plant will be properly treated as regenerated water as the replenishment water source of the heating pipe network, and the regenerated water will be transported to the user, and then reused after the off-site water treatment and heat recovery, which can increase the reuse rate of urban regenerated water. It is of great significance to realize the sustainable recycling of water resources to make full use of the municipal heating pipe network.

Description of drawings

Figure 1 is a schematic diagram of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in Figure 1, the present invention provides a system for the production, distribution and reuse of regenerated water entering the heating network, which includes an ultrafiltration UF unit, a two-stage reverse osmosis RO unit, and a vacuum electrochemical oxygen removal unit connected in sequence. The filter UF unit includes a connected self-cleaning filter and an ultrafiltration membrane. The two-stage reverse osmosis RO unit includes a reverse osmosis low-pressure inlet pump one, a reverse osmosis low-pressure inlet pump two and a reverse osmosis membrane connected in sequence. The chemical deaeration unit includes a vacuum electrochemical deaerator and a deaeration water pool + isolation bag connected in sequence.

Preferably, the outlet of the self-cleaning filter is connected to a drain, and the inlet is connected to a lift pump.

Preferably, the outlet of the ultrafiltration membrane is connected to a backwash wastewater tank.

Preferably, a security filter is installed between the first reverse osmosis low-pressure water inlet pump and the second reverse osmosis low-pressure water inlet pump.

Preferably, the outlet of the reverse osmosis membrane is connected to a concentrated water tank.

Preferably, the dissolved oxygen in the vacuum electrochemical deaerator is less than or equal to 12 mg/L, and the dissolved oxygen in the outlet water is less than or equal to 0.1 mg/L.

Preferably, an exhaust pipeline is provided on the top of the oxygen-removing pool to connect with the exhaust port of the isolation bag, and the pipeline leads to the outside.

In the present invention, the effluent from a certain urban sewage treatment plant in the north is lifted by a water inflow lift pump and then enters the system after being treated by a conventional process. After being purified by a self-cleaning filter, it enters the ultrafiltration membrane, and the wastewater generated by the ultrafiltration membrane is discharged into the backwash wastewater. pool, and then drained away with the wastewater in the factory area. Part of the ultrafiltration water is used for chemical cleaning water, and the other part passes through the reverse osmosis low-pressure water pump 1, security filter, and reverse osmosis high-pressure inlet pump 2 in turn to enter the subsequent reverse osmosis membrane, and the reverse osmosis membrane The concentrated water produced is discharged into the concentrated water pool, and then discharged with the wastewater in the factory area or subjected to advanced treatment of the concentrated water, and the regenerated water enters the vacuum electrochemical deaerator of the vacuum electrochemical deaeration unit for deaeration, and deaeration through the deaerator The final deoxygenated water is transported to the deoxygenated water pool + isolation bag, as a measure to prevent secondary dissolved oxygen in the vacuum system, so that the stored water is isolated from the atmosphere, and at the same time maintains a normal pressure state. The deaeration pool is a concrete structure constructed in combination with the civil engineering form of a sewage treatment plant when the vacuum electrochemical deaerator is used in a large-scale project, and a flexible isolation bag is arranged inside it.

In the present invention, after the effluent of urban sewage treatment plant is subjected to advanced treatment by double-membrane method (ultrafiltration membrane and reverse osmosis membrane) and vacuum electrochemical deaerator, it can meet the water quality standard of the heating pipe network and at the same time meet the Specific reclaimed water users need for water quality, enter the heating pipe network, the pH value of the double-membrane method is about 3 to 5, add sodium hydroxide to adjust the pH value to 9 during the project operation, and the concentration of the original drug in the storage tank is 30% .

During the heating season, recycled water can replace tap water to replenish the heating pipe network. At the same time, the heating pipe network can also be used to transport reclaimed water to users. There is a large temperature difference between the return water temperature (20°C-50°C) and the reclaimed water outlet temperature (about 15°C) of the reclaimed water pipeline for transmission and distribution. In order to achieve the heat balance of the pipe network system and avoid the loss of heat sources, fully consider the hydraulic power of the heating network and the reclaimed water transmission and distribution Features, during the heating period, it can be reused after being treated by the off-site water treatment system + heat source recovery system. During the non-heating period, the idle heating pipe network can be used to transport and distribute recycled water to other users for industry, landscaping, car washing, toilet flushing, etc.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (7)

1. A heat supply network access reclaimed water production, transmission and distribution and recycling system is characterized in that: the ultrafiltration UF unit comprises a self-cleaning filter and an ultrafiltration membrane which are communicated, wherein the two sections of reverse osmosis RO units comprise a reverse osmosis low-pressure water inlet pump I, a reverse osmosis low-pressure water inlet pump II and a reverse osmosis membrane which are communicated in sequence, the vacuum electrochemical deoxidization unit comprises a vacuum electrochemical deoxidizer and a deoxidization pond which are communicated, and an isolation bag is arranged in the deoxidization pond.

2. The system for producing, delivering and recycling reclaimed water by using a heat supply network according to claim 1, wherein the system is characterized in that: and the outlet of the self-cleaning filter is communicated with the drainage ditch, and the inlet of the self-cleaning filter is connected with the lifting pump.

3. The system for producing, delivering and recycling reclaimed water by using a heat supply network according to claim 1, wherein the system is characterized in that: and the outlet of the ultrafiltration membrane is connected with a backwashing wastewater tank.

4. The system for producing, delivering and recycling reclaimed water by using a heat supply network according to claim 1, wherein the system is characterized in that: and a cartridge filter is arranged between the first reverse osmosis low-pressure water inlet pump and the second reverse osmosis low-pressure water inlet pump.

5. The system for producing, delivering and recycling reclaimed water by using a heat supply network according to claim 1, wherein the system is characterized in that: and the outlet of the reverse osmosis membrane is connected with a concentrated water tank.

6. The system for producing, delivering and recycling reclaimed water by using a heat supply network according to claim 1, wherein the system is characterized in that: the water inlet dissolved oxygen of the vacuum electrochemical deaerator is less than or equal to 12mg/L, and the water outlet dissolved oxygen is less than or equal to 0.1mg/L.

7. The system for producing, delivering and recycling reclaimed water by using a heat supply network according to claim 1, wherein the system is characterized in that: the top of the deoxidizing water tank is provided with an exhaust pipeline connected with the exhaust port of the isolating bag, and the pipeline is communicated with the outside.