Water quality modification process adopting pressure temperature control closed reaction

Abstract

The invention discloses a water quality modification process adopting an under-pressure temperature control closed reaction, relates to the technical field of gas field water treatment, and aims to solve the problems that water cannot be treated under the same dosage condition due to extremely high ferrous ion content or relatively high oxide content of existing gas field produced water, and the water quality is relatively low compared with the conventional produced water treatment dosage. The method solves the technical problem that the conventional water treatment effect can be achieved with difficulty only when the dosage is increased by 5-10 times or even higher, and comprises the following steps: S1, lifting raw water; abnormal gas field produced water is stably lifted to a heat exchange system from the storage or source position by means of a raw water lifting pump, it is ensured that the operation parameters of the raw water lifting pump adapt to the process requirements, the factors such as pipeline resistance and height difference can be effectively overcome, and the process continuity is guaranteed; s2, heat exchange; and a waste heat utilization and heat energy recovery mechanism is designed in the heat exchange system. The device and the method have the advantage of realizing water quality modification treatment on the gas field produced water.

Description

Technical Field

[0001] The invention relates to the technical field of gas field water treatment, and more specifically to a water quality modification process using a pressurized temperature-controlled closed reaction. Background Art

[0002] The main business of gas field natural gas processing plants includes raw gas technology, ethane recovery and gas field water treatment. Affected by fracturing, foam drainage and other mining engineering measures and stratum lithology, gas field produced water generally has problems such as large water quality fluctuations, difficulty in meeting treatment standards, and high costs. The produced water type of gas fields is mainly CaCl2, and also has NaHCO3, Na2SO4 and other water types. It has the characteristics of "six highs and one low" of high mineralization, high hardness, high suspended matter and sediment, high corrosiveness, high condensate oil, high methanol, and low pH.

[0003] At present, when the treatment plant treats the produced water of the gas field, some gas gathering stations will produce gas field produced water with high oxide or high ferrous ion due to the influence of circulating well opening (remaining fracturing return fluid is carried out of the well irregularly) and foaming operation. In the early stage of the reagent test, it was found that some of the water had extremely high ferrous ion content or high oxide content, resulting in the inability to treat the water body under the same dosage conditions. Compared with the dosage of conventional produced water treatment, the dosage needs to be increased by 5 to 10 times or even higher to barely achieve the treatment effect of conventional water. At the same time, it causes the floating speed of the slag to be slow, the size of the flotation equipment is designed to be larger, and more dosing sludge is produced, which puts a burden on the sludge system. In order to solve the problem of the influence of high oxidation / reduction substances and high organic matter in the produced water of the gas field on the subsequent produced water purification, in view of this, we propose a water quality modification process using a closed reaction with pressure and temperature control. Summary of the invention

[0004] The purpose of the present invention is to provide a water quality modification process using a pressurized temperature-controlled closed reaction to solve the technical problem that some of the existing gas field produced water has an extremely high ferrous ion content or a high oxide content, resulting in the inability to treat the water under the same dosage conditions. Compared with the conventional produced water treatment dosage, the dosage needs to be increased by 5 to 10 times or even higher to barely achieve the conventional water treatment effect.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a water quality modification process using a pressurized temperature-controlled closed reaction, comprising the following steps:

[0006] S1, raw water lifting;

[0007] The raw water lift pump is used to stably lift the produced water from the abnormal gas field from its storage or source to the heat exchange system, ensuring that the operating parameters of the raw water lift pump are adapted to the process requirements, and can effectively overcome factors such as pipeline resistance and height difference to ensure process continuity;

[0008] S2, heat exchange;

[0009] Design waste heat utilization and heat energy recovery mechanisms in the heat exchange system. The treated water first undergoes the first-stage heat exchange with the local methanol heat energy or waste heat steam. The heat exchange efficiency is ensured by reasonably controlling the heat exchange area, flow rate and temperature difference, and the waste heat energy is recovered to the maximum extent. After the first-stage heat exchange, the treated water continues to undergo the second-stage heat exchange with the reactor produced water to improve the heat energy utilization rate.

[0010] It can also be designed into three-stage series connection according to the actual heat energy situation. The third stage heat exchange uses heat medium to ensure the stability and safety of the heat medium and can accurately adjust the heat input.

[0011] A spiral plate heat exchanger is used, and the flow velocity in the flow channel is 1.2 times the conventional design value. A spoiler column is set to break the laminar flow state and promote the formation of turbulence, improve the heat transfer coefficient and solve the problem of precipitated material blockage, ensuring the long-term stable operation of the heat exchange system.

[0012] S3, reactor treatment;

[0013] The heated water to be treated enters the pressurized temperature-controlled reactor, where heat transfer oil, steam or electric heating provide additional heat energy. The heating is switched according to the working conditions and energy supply conditions to provide a stable and suitable temperature environment for the water modification reaction, thereby promoting physical and chemical reactions of substances in the water to achieve water quality modification.

[0014] The reactor volume is designed according to the time required for the reaction. The effective reaction time of water with high ferrous oxide content is at least 5-10 minutes.

[0015] The reactor adopts a pressurized closed structure, and the tank body is a carbon steel lined enamel structure, which reduces sewage corrosion, prolongs equipment life and reduces maintenance costs;

[0016] A cyclone separator is installed at the non-condensable gas discharge port of the reactor to separate water droplets carried in the gas to ensure the purity of the discharged gas and the stable operation of the system;

[0017] A regular drain valve is set at the bottom of the reactor to discharge the concentrate according to the cycle or water quality conditions to keep the water quality stable and ensure the continuous and efficient reaction;

[0018] S4, heat recovery;

[0019] The modified treated water carries the remaining heat back to the front heat exchange system for heat energy reuse. Reasonable pipeline layout and flow control ensure effective heat transfer between treated water and water to be treated, recover waste heat, reduce energy consumption, improve energy utilization efficiency and realize heat energy recycling;

[0020] S5, subsequent processing;

[0021] The treated water after thermal energy utilization enters the subsequent treatment system and undergoes deep treatment such as flotation, sedimentation, filtration, and disinfection according to water quality requirements and discharge standards to ensure that the final effluent water quality meets the standards and can be safely discharged or reused.

[0022] Preferably, it also includes an external circulation pump system step;

[0023] An external circulation pump system is set up to extract water from the pressurized temperature-controlled reactor and combine it with the external heat source system for circulation spraying. A spray port is set at the top of the reactor to ensure uniform water spraying, so that the dissolved gas in the water can fully escape, achieve uniform water treatment and uniform temperature in the tank, and improve reaction efficiency and quality.

[0024] Preferably, the external circulation pump has a suitable flow rate and head to ensure that water can circulate smoothly between the inside of the reactor and the external heat source.

[0025] Preferably, the method further comprises a liquid level control step;

[0026] A liquid level transmitter is installed on the pressurized temperature-controlled reactor to monitor the liquid level changes in real time, and a flow control valve is installed on the water production pipeline. The liquid level meter and the flow control valve work together through interlocking control. The flow control valve opening is automatically adjusted according to the liquid level changes to control the water production flow rate and maintain the stability of the liquid level in the tank, thereby ensuring the effective reaction volume and time and ensuring that the reaction is carried out under stable liquid level conditions.

[0027] Preferably, the interlocking control accuracy of the liquid level transmitter and the flow control valve should meet specific standards to ensure stable liquid level control.

[0028] Preferably, the method further comprises a temperature control step;

[0029] The design temperature of the reactor is 1-2°C higher than the temperature required for hydrolysis or pyrolysis of the target substance. A temperature transmitter is installed on the third-stage circulating heat exchange spray pipe to monitor the water temperature in real time. The temperature transmitter cooperates with the flow control valve or electric heater on the heat exchange medium supply pipe through interlocking control. The flow control valve opening or the electric heater power is automatically adjusted according to the water temperature deviation to accurately control the heat exchange medium supply to maintain the required temperature of the reactor and temperature stability, thereby ensuring the effect and consistency of the water quality modification reaction.

[0030] Preferably, the interlock control response time between the temperature transmitter and the flow control valve or the electric heater should be within a specific range to ensure accurate temperature control.

[0031] Preferably, the method further comprises a pressure control step;

[0032] A pressure transmitter is installed on the pressurized temperature-controlled reactor to monitor pressure changes in real time, and a pressure regulating valve is set on the non-condensable gas discharge pipeline. The pressure transmitter and the pressure regulating valve work together through interlocking control. The opening of the pressure regulating valve is automatically adjusted according to the pressure change to control the amount of non-condensable gas escaping from the external drainage to achieve pressure system balance. The reactor control pressure is determined by the saturated water vapor pressure corresponding to the maximum reaction temperature, ensuring that the pressure in the reactor is within a safe, stable and appropriate range to provide a good pressure environment for the reaction.

[0033] Preferably, the method further comprises a flow control step;

[0034] A flow meter is installed on the outlet pipe of the water inlet lift pump to detect the pump outlet flow in real time, and a flow regulating valve is installed at the rear end of the flow meter. The flow meter and the flow regulating valve operate in coordination through interlocking control. According to the set stable operating flow, the flow regulating valve opening is automatically adjusted to control the lift pump outlet flow, and a continuous and stable flow of incoming water is achieved. This is conducive to the stable operation of the heat exchange system, and ensures the effective reaction time of the pressurized temperature control reactor, and realizes the effective and stable operation of heat recovery and temperature control reaction.

[0035] Preferably, the interlocking control between the pressure transmitter and the pressure regulating valve should have high reliability to ensure stable pressure control.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. The present invention designs a waste heat utilization and heat energy recovery mechanism, fully utilizes local methanol heat energy or waste heat steam for primary heat exchange, and then performs secondary heat exchange with reactor produced water, and is designed into a three-stage series heat exchange according to actual conditions, which greatly improves energy utilization. Compared with the existing technology, this cascade utilization of heat energy can significantly reduce energy consumption and achieve sustainable energy utilization, and solves the problem that some of the existing gas field produced water has extremely high ferrous ion content or high oxide content, resulting in the inability to treat the water under the same dosage conditions. Compared with the conventional produced water treatment dosage, the dosage needs to be increased by 5 to 10 times or even higher to barely achieve the conventional water treatment effect.

[0038] 2. The pressurized temperature-controlled reactor of the present invention can flexibly provide heat energy from a variety of heat sources, such as heat transfer oil, steam or electric heating, etc., and can be selected and switched according to different working conditions and energy supply conditions to ensure a stable and suitable temperature environment for water modification reactions. At the same time, the design temperature of the reactor is scientifically set to be 1-2°C higher than the required temperature according to the hydrolysis or pyrolysis characteristics of the target substance, and the supply of the heat exchange medium is accurately controlled through the intelligent interlocking control of the flow control valve or electric heater on the heat exchange medium supply pipeline with a high sensitivity temperature transmitter to maintain the required temperature of the reactor and the continuous stability of the temperature. Compared with the existing technology, this precise temperature control can effectively avoid incomplete reactions or side reactions caused by temperature fluctuations, and improve the controllability of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0040] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings of the specification.

[0041] A water quality modification process using a pressurized temperature-controlled closed reaction comprises the following steps:

[0042] S1, raw water lifting;

[0043] The raw water lift pump is used to stably lift the produced water from the abnormal gas field from its storage or source to the heat exchange system, ensuring that the operating parameters of the raw water lift pump are adapted to the process requirements, and can effectively overcome factors such as pipeline resistance and height difference to ensure process continuity;

[0044] S2, heat exchange;

[0045] Design waste heat utilization and heat energy recovery mechanisms in the heat exchange system. The treated water first undergoes the first-stage heat exchange with the local methanol heat energy or waste heat steam. The heat exchange efficiency is ensured by reasonably controlling the heat exchange area, flow rate and temperature difference, and the waste heat energy is recovered to the maximum extent. After the first-stage heat exchange, the treated water continues to undergo the second-stage heat exchange with the reactor produced water to improve the heat energy utilization rate.

[0046] It can also be designed into three-stage series connection according to the actual heat energy situation. The third stage heat exchange uses heat medium to ensure the stability and safety of the heat medium and can accurately adjust the heat input.

[0047] A spiral plate heat exchanger is used, and the flow velocity in the flow channel is 1.2 times the conventional design value. A spoiler column is set to break the laminar flow state and promote the formation of turbulence, improve the heat transfer coefficient and solve the problem of precipitated material blockage, ensuring the long-term stable operation of the heat exchange system.

[0048] S3, reactor treatment;

[0049] The heated water to be treated enters the pressurized temperature-controlled reactor, where heat transfer oil, steam or electric heating provide additional heat energy. The heating is switched according to the working conditions and energy supply conditions to provide a stable and suitable temperature environment for the water modification reaction, thereby promoting physical and chemical reactions of substances in the water to achieve water quality modification.

[0050] The reactor volume is designed according to the time required for the reaction. The effective reaction time of water with high ferrous oxide content is at least 5-10 minutes.

[0051] The reactor adopts a pressurized closed structure, and the tank body is a carbon steel lined enamel structure, which reduces sewage corrosion, prolongs equipment life and reduces maintenance costs;

[0052] A cyclone separator is installed at the non-condensable gas discharge port of the reactor to separate water droplets carried in the gas to ensure the purity of the discharged gas and the stable operation of the system;

[0053] A regular drain valve is set at the bottom of the reactor to discharge the concentrate according to the cycle or water quality conditions to keep the water quality stable and ensure the continuous and efficient reaction;

[0054] S4, heat recovery;

[0055] The modified treated water carries the remaining heat back to the front heat exchange system for heat energy reuse. Reasonable pipeline layout and flow control ensure effective heat transfer between treated water and water to be treated, recover waste heat, reduce energy consumption, improve energy utilization efficiency and realize heat energy recycling;

[0056] S5, subsequent processing;

[0057] The treated water after thermal energy utilization enters the subsequent treatment system and undergoes deep treatment such as flotation, sedimentation, filtration, and disinfection according to water quality requirements and discharge standards to ensure that the final effluent water quality meets the standards and can be safely discharged or reused.

[0058] It also includes the step of an external circulation pump system; an external circulation pump system is set up to extract water from the inside of the pressurized temperature-controlled reactor and combine it with the external heat source system for circulation spraying, a spray port is set at the top of the reactor to ensure uniform spraying of water, so that the dissolved gas in the water can fully escape to achieve uniformity of water treatment and uniformity of temperature in the tank, improve reaction efficiency and quality, and the external circulation pump has a suitable flow rate and head to ensure that water can circulate smoothly between the inside of the reactor and the external heat source.

[0059] It also includes a liquid level control step; a liquid level transmitter is installed on the pressurized temperature-controlled reactor to monitor the liquid level changes in real time, a flow control valve is installed on the water production pipeline, and the liquid level meter and the flow control valve work together through interlocking control. The flow control valve opening is automatically adjusted according to the liquid level changes to control the water production flow rate to maintain the stability of the liquid level in the tank, ensure the effective reaction volume and time, and ensure that the reaction is carried out under stable liquid level conditions. The interlocking control accuracy of the liquid level transmitter and the flow control valve should meet specific standards to ensure stable liquid level control.

[0060] It also includes a temperature control step; the design temperature of the reactor is 1-2°C higher than the temperature required for hydrolysis or pyrolysis of the target substance, and a temperature transmitter is installed on the third-stage circulating heat exchange spray pipe to monitor the water temperature in real time. The temperature transmitter and the flow control valve or electric heater on the heat exchange medium supply pipe are coordinated through interlocking control. The flow control valve opening or the electric heater power is automatically adjusted according to the water temperature deviation to accurately control the heat exchange medium supply to maintain the required temperature of the reactor and temperature stability, thereby ensuring the effect and consistency of the water quality modification reaction. The interlocking control response time of the temperature transmitter and the flow control valve or electric heater should be within a specific range to ensure precise temperature control.

[0061] It also includes a pressure control step; a pressure transmitter is installed on the pressurized temperature-controlled reactor to monitor pressure changes in real time, a pressure regulating valve is set on the non-condensable gas discharge pipeline, the pressure transmitter and the pressure regulating valve work together through interlocking control, and the opening of the pressure regulating valve is automatically adjusted according to the pressure change to control the amount of non-condensable gas escaping from the external water to achieve pressure system balance. The reactor control pressure is determined by the saturated water vapor pressure corresponding to the maximum reaction temperature, ensuring that the pressure in the reactor is within a safe, stable and appropriate range to provide a good pressure environment for the reaction.

[0062] It also includes a flow control step: a flow meter is installed on the outlet pipe of the water inlet lift pump to detect the pump outlet flow in real time, a flow regulating valve is installed at the rear end of the flow meter, and the flow meter and the flow regulating valve are operated in coordination through interlocking control. According to the set stable operating flow, the flow regulating valve opening is automatically adjusted to control the lift pump outlet flow, so as to achieve a continuous and stable flow of incoming water. This is conducive to the stable operation of the heat exchange system, and ensures the effective reaction time of the pressurized temperature control reactor, so as to achieve effective and stable operation of heat recovery and temperature control reaction.

[0063] The interlocking control between the pressure transmitter and the pressure regulating valve should be highly reliable to ensure stable pressure control.

[0064] The embodiments of the present invention disclose preferred embodiments, but are not limited thereto. A person skilled in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. However, as long as they do not deviate from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A water quality modification process using a pressurized temperature-controlled closed reaction, characterized in that: The following steps are involved: S1, raw water lifting; The raw water lift pump is used to stably lift the produced water from the abnormal gas field from its storage or source to the heat exchange system, ensuring that the operating parameters of the raw water lift pump are adapted to the process requirements, and can effectively overcome factors such as pipeline resistance and height difference to ensure process continuity; S2, heat exchange; Design waste heat utilization and heat energy recovery mechanisms in the heat exchange system. The treated water first undergoes the first-stage heat exchange with the local methanol heat energy or waste heat steam. The heat exchange efficiency is ensured by reasonably controlling the heat exchange area, flow rate and temperature difference, and the waste heat energy is recovered to the maximum extent. After the first-stage heat exchange, the treated water continues to undergo the second-stage heat exchange with the reactor produced water to improve the heat energy utilization rate. It can also be designed into three-stage series connection according to the actual heat energy situation. The third stage heat exchange uses heat medium to ensure the stability and safety of the heat medium and can accurately adjust the heat input. A spiral plate heat exchanger is used, and the flow velocity in the flow channel is 1.2 times the conventional design value. A spoiler column is set to break the laminar flow state and promote the formation of turbulent flow, thereby improving the heat transfer coefficient and solving the problem of clogging by sediment, thus ensuring the long-term stable operation of the heat exchange system. S3, reactor treatment; The heated water to be treated enters the pressurized temperature-controlled reactor, where heat transfer oil, steam or electric heating provide additional heat energy. The heating is switched according to the working conditions and energy supply conditions to provide a stable and suitable temperature environment for the water modification reaction, thereby promoting physical and chemical reactions of substances in the water to achieve water quality modification. The reactor volume is designed according to the time required for the reaction. The effective reaction time of water with high ferrous oxide content is at least 5-10 minutes. The reactor adopts a pressurized closed structure, and the tank body is a carbon steel lined enamel structure, which reduces sewage corrosion, prolongs equipment life and reduces maintenance costs; A cyclone separator is installed at the non-condensable gas discharge port of the reactor to separate water droplets carried in the gas to ensure the purity of the discharged gas and the stable operation of the system; A regular drain valve is set at the bottom of the reactor to discharge the concentrate according to the cycle or water quality conditions to keep the water quality stable and ensure the continuous and efficient reaction; S4, heat recovery; The modified treated water carries the remaining heat back to the front heat exchange system for heat energy reuse. Reasonable pipeline layout and flow control ensure effective heat transfer between treated water and water to be treated, recover waste heat, reduce energy consumption, improve energy utilization efficiency and realize heat energy recycling; S5, subsequent processing; The treated water after thermal energy utilization enters the subsequent treatment system and undergoes deep treatment such as flotation, sedimentation, filtration, and disinfection according to water quality requirements and discharge standards to ensure that the final effluent water quality meets the standards and can be safely discharged or reused.

2. The water quality modification process using a pressurized temperature-controlled closed reaction according to claim 1 is characterized in that: Also included are steps for an external circulation pump system; An external circulation pump system is set up to extract water from the pressurized temperature-controlled reactor and combine it with the external heat source system for circulation spraying. A spray port is set at the top of the reactor to ensure uniform water spraying, so that the dissolved gas in the water can fully escape, achieve uniform water treatment and uniform temperature in the tank, and improve reaction efficiency and quality.

3. The water quality modification process using a pressurized temperature-controlled closed reaction according to claim 2 is characterized in that: The external circulation pump has appropriate flow and head to ensure that water can circulate smoothly between the reactor and the external heat source.

4. The water quality modification process using a pressurized temperature-controlled closed reaction according to claim 1 is characterized in that: Also included is a liquid level control step; A liquid level transmitter is installed on the pressurized temperature-controlled reactor to monitor the liquid level changes in real time, and a flow control valve is installed on the water production pipeline. The liquid level meter and the flow control valve work together through interlocking control. The flow control valve opening is automatically adjusted according to the liquid level changes to control the water production flow rate and maintain the stability of the liquid level in the tank, thereby ensuring the effective reaction volume and time and ensuring that the reaction is carried out under stable liquid level conditions.

5. The water quality modification process using a pressurized temperature-controlled closed reaction according to claim 4 is characterized in that: The interlocking control accuracy of the liquid level transmitter and the flow control valve should meet specific standards to ensure stable liquid level control.

6. The water quality improvement process using a pressurized temperature-controlled closed reaction according to claim 1 is characterized in that: Also included is a temperature control step; The design temperature of the reactor is 1-2°C higher than the temperature required for hydrolysis or pyrolysis of the target substance. A temperature transmitter is installed on the third-stage circulating heat exchange spray pipe to monitor the water temperature in real time. The temperature transmitter cooperates with the flow control valve or electric heater on the heat exchange medium supply pipe through interlocking control. The flow control valve opening or the electric heater power is automatically adjusted according to the water temperature deviation to accurately control the heat exchange medium supply to maintain the required temperature of the reactor and temperature stability, thereby ensuring the effect and consistency of the water quality modification reaction.

7. The water quality modification process using a pressurized temperature-controlled closed reaction according to claim 6 is characterized in that: The interlock control response time between the temperature transmitter and the flow control valve or electric heater should be within a specific range to ensure accurate temperature control.

8. The water quality modification process using a pressurized temperature-controlled closed reaction according to claim 1 is characterized in that: Also included is a pressure control step; A pressure transmitter is installed on the pressurized temperature-controlled reactor to monitor pressure changes in real time, and a pressure regulating valve is set on the non-condensable gas discharge pipeline. The pressure transmitter and the pressure regulating valve work together through interlocking control. The opening of the pressure regulating valve is automatically adjusted according to the pressure change to control the amount of non-condensable gas escaping from the external drainage to achieve pressure system balance. The reactor control pressure is determined by the saturated water vapor pressure corresponding to the maximum reaction temperature, ensuring that the pressure in the reactor is within a safe, stable and appropriate range to provide a good pressure environment for the reaction.

9. The water quality improvement process for a pressurized temperature-controlled closed reaction according to claim 1, characterized in that: Also included is a flow control step; A flow meter is installed on the outlet pipe of the water inlet lift pump to detect the pump outlet flow in real time, and a flow regulating valve is installed at the rear end of the flow meter. The flow meter and the flow regulating valve operate in coordination through interlocking control. According to the set stable operating flow, the flow regulating valve opening is automatically adjusted to control the lift pump outlet flow, and a continuous and stable flow of incoming water is achieved. This is conducive to the stable operation of the heat exchange system, and ensures the effective reaction time of the pressurized temperature control reactor, and realizes the effective and stable operation of heat recovery and temperature control reaction.

10. The water quality modification process using a pressurized temperature-controlled closed reaction according to claim 8, characterized in that: The interlocking control between the pressure transmitter and the pressure regulating valve should be highly reliable to ensure stable pressure control.

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