WO2023024627A1

WO2023024627A1 - Gas-fired steam-injection boiler for oilfield

Info

Publication number: WO2023024627A1
Application number: PCT/CN2022/095937
Authority: WO
Inventors: 陈军; 张乃峰; 赵学展; 马波; 肖刚; 杨斌; 尚庆军; 黄志宏; 张玥; 李勇; 陈超; 姜琳琳
Original assignee: 中国石油化工股份有限公司; 中国石油化工股份有限公司胜利油田分公司注汽技术服务中心
Priority date: 2021-08-26
Filing date: 2022-05-30
Publication date: 2023-03-02
Also published as: CN115930196A; CA3230235A1

Abstract

Disclosed in the present invention is a gas-fired steam-injection boiler for an oilfield, the gas-fired steam-injection boiler comprising a flue and a water supply pipeline, wherein the flue is provided with a radiation section (1) and a convection section (2), which are arranged in a flue gas flow direction. The water supply pipeline comprises a first pipe section, a second pipe section, and a third pipe section, wherein in the flue gas flow direction, the first pipe section is located at an upstream portion of the convection section (2), the second pipe section is located at a downstream portion of the convection section (2), and the third pipe section (3) is arranged between the first pipe section and the second pipe section; and in a water flow direction of the water supply pipeline, the second pipe section, the first pipe section and the third pipe section (3) are arranged in sequence. By using a flue gas condenser, the temperature of flue gas can be further reduced, and the latent heat of vaporization of steam in the flue gas is absorbed to form condensate water, such that the boiler efficiency is increased to 96% or more.

Description

Oilfield Gas Steam Injection Boiler

Cross References to Related Applications

This application claims the benefit of Chinese patent application 202110987125.8 filed on August 26, 2021, the contents of which are incorporated herein by reference.

technical field

The invention relates to the technical field of oilfield steam-injection boilers, in particular to an oilfield gas-fired steam-injection boiler.

Background technique

Existing oilfield steam injection boilers are usually horizontal once-through water tube boilers, which are mainly composed of a radiation section, a transition section connected to the tail of the radiation section, and a convection section arranged above the transition section. Among them, the inner wall of the radiation section is lined with aluminum silicate refractory fiber, and there are reciprocating coils, forming a spacious furnace in the middle; the convection section is a rectangular structure composed of light pipes and finned pipes; the transition section is connected to the radiation section. A semi-circular flue gas diversion passage connecting the convection section and the convection section has an axial dimension of about 1.3 meters and has no heat exchange function.

At present, the gas-fired steam injection boilers in use are large in size, mainly reflected in the axial length of the radiation section and the height of the flue gas outlet from the ground. The two directions are relatively large, which is not conducive to the flexible and flexible steam injection requirements of the heavy oil block.

Existing gas-fired boilers are transformed from oil-fired boilers, and the heat transfer surface is dominated by fuel oil combustion characteristics. After changing to natural gas fuel, the heat transfer characteristics and flue gas characteristics will change, which cannot meet the current high-efficiency and energy-saving requirements.

The heat-carrying mechanism of water vapor shows that the higher the steam dryness, the more heat it carries, and the more obvious the steam injection effect of heavy oil is. The once-through gas-fired boilers used in oil fields are restricted by the existing technology, and conventional water treatment cannot achieve direct dry operation.

Therefore, it is imminent to develop a new oilfield high-efficiency gas-fired steam injection boiler technology, and it is necessary to provide an oilfield gas-fired steam injection boiler to overcome the above defects.

Publication (announcement) number: CN101343989B, publication (announcement) date: 2012-08-22 is a high-dryness oilfield steam injection boiler and a high-dryness steam production method. The high-dryness oilfield steam injection boiler includes a radiation section, a convection section, and a transition section, as well as a furnace body, a feed water pump, and a steam-water separator; a steam superheater is fixedly installed in the furnace body between the convection section and the transition section; the convection section The water inlet of the inlet pipe is connected with the water outlet of the feed water pump, the water outlet of the inlet pipe of the convection section is connected with the water inlet at the upper end of the convection section; the steam inlet of the outlet pipe of the convection section is connected with the steam outlet at the lower end of the convection section, The steam outlet of the outlet pipe of the convection section communicates with the steam inlet of the radiation section. The invention has a reasonable and compact structure, is easy to use, can make the steam dryness reach 100%, and has a certain degree of superheat, and can meet the requirements of the steam injection process for the development of super heavy oil, thus greatly improving the efficiency of steam injection for the development of super heavy oil. Work efficiency, improve thermal efficiency, reduce energy consumption, and reduce production costs.

Publication (announcement) number: CN101551097A, publication (announcement) date: 2009-10-07 It relates to a steam injection boiler for producing high dry superheated steam, which consists of heat exchanger, radiation section, convection section, chimney, and water-installed steam-water separation It is composed of heater, superheater, furnace body, water supply pipeline, burner, electric heater, oil heater and flash tank. There is a burner in the front of the furnace body, a radiation section in the middle, and a convection section in the rear. The burner is connected to the electric heater and the oil heater respectively through wires and pipelines; a heat exchanger is installed outside the radiation section, and the outlet There is an external steam-water separator, the heat exchanger is connected to the feed water pump through the water supply pipeline, and the steam-water separator is respectively connected to the superheater and the flash tank through the pipeline; the lower part of the convection section is equipped with a superheater, and the upper part is equipped with a chimney; The radiation section and the convection section are respectively connected to the heat exchanger through pipelines. The invention is novel in structure, reasonable in design and reliable in operation. It can produce superheated steam with high dryness and high temperature, thereby improving the effect of heavy oil SAGD thermal recovery process.

Publication (announcement) number: CN202660522U, publication (announcement) date: 2013-01-09 It relates to a high-dryness oilfield steam injection boiler, which belongs to the technical field of oilfield steam injection boilers; it includes double feedwater pumps, heat exchangers, steam-water separation Boiler and boiler; Boiler includes transition flue, convection evaporation section, secondary convection section, primary convection section and chimney; transition flue, convection evaporation section, secondary convection section, primary convection section and chimney are fixedly connected in sequence from bottom to top together; a burner communicating with the transition flue is fixedly connected to the outside of the transition flue; the water outlets of the double feed water pumps are fixedly connected together with the shell-side water inlet of the heat exchanger through the first pipeline. The utility model has a reasonable and compact structure and is easy to use. Through the combined use of double feed water pumps, heat exchangers, burners, transitional flues, convective evaporation sections, secondary convection sections, primary convection sections and chimneys, steam injection into single wells is realized. The purpose of large volume and high dryness of steam reaching the bottom of the well meets the requirements of SAGD development process.

The technical solutions, technical problems to be solved, and beneficial effects of the above disclosed technologies are all different from those of the present invention, or the technical fields or application occasions are different. For more technical features, technical problems to be solved and beneficial effects of the present invention, There is no technical inspiration in the above public technical documents.

Contents of the invention

The purpose of the present invention is to provide an oilfield gas-fired steam injection boiler for the above-mentioned defects in the prior art. The radiant section of the boiler is further segmented to solve the risk of overtemperature of the tube shell caused by the change of the temperature zone, so that scaling, The area where the over-temperature installation occurs is easy to monitor, and the combination of the third pipe section and the convection section is designed to reduce the thermal impact of the flue gas on the evaporation light pipe, and at the same time effectively improve the dryness of the steam. The use of the flue gas condenser can further reduce the temperature of the flue gas, absorb the latent heat of vaporization of the water vapor in the flue gas, form condensed water, and improve the efficiency of the boiler to more than 96%. Through the optimization of the heating surface and the design of the flue structure, the heat exchange ratio of the radiation section and the convection section is optimized to 5:5, and the heat exchange is more in line with the heat release characteristics of natural gas flames.

In order to achieve the above object, the present invention adopts the following technical solutions:

An oil field gas-fired steam injection boiler, comprising a radiation section, a convection section, and a condensation section arranged along the flue gas flow direction, wherein the convection section is provided with a convection section light tube and a convection section finned tube, and the convection section light tube A third pipe section is added between the finned tubes of the convection section, and the third pipe section is provided with evaporation light tubes and evaporation finned tubes, and the smoke passes through the radiation section, the convection section light pipes, the evaporation light pipes, and the evaporation fins in sequence Tubes, finned tubes in the convection section, heat exchange light tubes in the condensation section.

Optionally, the radiation section includes a radiation high-temperature section and a radiation low-temperature section arranged along the flue gas flow direction, and the radiation section is provided with a radiation high-temperature section light pipe located in the radiation high-temperature section and a radiation pipe located in the radiation low-temperature section. The light pipe in the radiation low temperature section, the heat exchange medium sequentially flows through the light pipe in the high temperature radiation section and the light pipe in the low temperature radiation section.

Optionally, it also includes a water tank. The feed water of the water tank passes through the heat exchange light tube in the condensation section, the deaerator, the light tube in the convection section, the finned tube in the convection section, the evaporating finned tube in the evaporation light tube, and the injector at the boiler steam outlet. steam pipes.

Optionally, a softener is provided on the connecting waterway between the water tank and the heat exchange light pipe of the condensation section.

Optionally, a plunger pump is provided on the connecting waterway between the deaerator and the light pipe in the convection section.

Optionally, the condensing section is provided with a condensing baffle, and the condensing baffle is located below the heat exchange light pipe of the condensing section, and the condensing baffle is also located above the light pipe of the convection section, and the condensing baffle is provided with a water receiving tank, and the edge of the water receiving tank has The drain port is connected to the recovery tank through the pipeline, and the recovery tank is connected to the water tank through the condensate recovery pump.

Optionally, the water path connected between the light pipe in the convection section and the light pipe in the evaporation section passes through the radiation section.

Optionally, the radiant high-temperature section adopts a single horizontal serpentine water-cooled wall, forming a cylindrical furnace in the middle; the radiant low-temperature section adopts a single horizontal serpentine water-cooled wall, forming a cylindrical furnace in the middle hearth.

Optionally, a 5:5 ratio of radiation and convection heat transfer is used.

On the other hand, this application adopts the following scheme:

An oil field gas-fired steam injection boiler, which includes a flue with a radiation section and a convection section arranged along the flue gas flow direction and a water supply pipeline, the water supply pipeline includes a first pipe section, a second pipe section and a third pipe section,

Wherein, in the flue gas flow direction, the first pipe section is located at the upstream part of the convection section, the second pipe section is located at the downstream part of the convection section, and the third pipe section is arranged between the first pipe section and the convection section. between the second pipe sections;

Wherein, in the water flow direction of the water supply pipeline, the second pipe section, the first pipe section and the third pipe section are arranged in sequence.

Optionally, the first pipe section is a convection section light pipe, and the second pipe section is a convection section finned pipe.

Optionally, the third pipe section includes evaporative light pipes and evaporative finned pipes arranged in the flow direction of the water supply pipeline, and in the direction of smoke flow in the convection section, the evaporative light pipes and evaporative finned pipes The evaporating finned tubes are arranged in sequence.

Optionally, the third pipe section is arranged in a region with a temperature of 800-900° C. in the convection section.

Optionally, the radiation section extends horizontally, an opening is provided on the upper side of the downstream end of the radiation section, and the convection section communicates with the upper side of the downstream end of the radiation section and extends vertically upward.

Optionally, the flue includes a condensation section extending vertically upward from the upper end of the convection section.

Optionally, the water supply pipeline includes a condensing section heat exchange light pipe arranged in the condensing section, and in the flow direction of the water supply pipeline, the condensing section heat exchange light pipe is located upstream of the second pipe section.

Optionally, a deaerator and a pressure pump are provided on the part of the water supply pipeline located between the heat exchange light tube of the condensation section and the second pipe section, and the water supply pipeline is located at the heat exchange section of the condensation section. A water tank and a softener are arranged on the upstream part of the light pipe.

Optionally, it also includes a condensation baffle located at the lower part of the condensation section and a water receiving tank located at the lower side of the condensation baffle, and the water receiving tank is connected to the recovery tank through a pipeline.

Optionally, the cross-sectional area of the connection between the lower port of the condensation section and the upper port of the convection section is larger than the cross-sectional area of the upper port of the condensation section, and the upper port of the condensation section is provided with a chimney.

Optionally, the water supply pipeline includes a radiant pipe section arranged in the radiant section, and in the water flow direction of the water supply pipeline, the second pipe section, the first pipe section, the radiant pipe section and the The third pipe segment is in sequence.

Optionally, the radiation section includes a radiation high-temperature section and a radiation low-temperature section arranged along the flue gas flow direction, and the radiation pipe section includes a radiation high-temperature section light pipe located in the radiation high-temperature section and a radiation tube located in the radiation low-temperature section. As for the light pipe in the low temperature section, in the flow direction of the water supply pipeline, the light pipe in the high temperature radiation section and the light pipe in the low temperature radiation section are arranged in sequence.

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

1. Design the combination of the third pipe section and the convection section to reduce the thermal impact of the flue gas on the third pipe section and effectively improve the steam dryness.

2. The flue gas condenser can further reduce the flue gas temperature, absorb the latent heat of vaporization of the water vapor in the flue gas, form condensed water, and improve the boiler efficiency to more than 96%.

3. Through the optimization of the heating surface and the design of the flue structure, the heat exchange ratio of the radiation section and the convection section is optimized to 5:5, and the heat exchange is more in line with the heat release characteristics of natural gas flames.

4. Through the combination of feed water preheating and flue gas condensation, the quality of feed water can be improved.

5. The radiant section is divided into partitions, and different materials can be set according to the flame temperature to solve the overtemperature risk of the tube and casing caused by the change of the flame temperature area of the low-nitrogen burner; the second is that the partition setting can more easily realize the uniform heat transfer control of the water-cooled wall ; The third is the partition setting, the steam area in the high temperature and low temperature area is moved backward as a whole, and the area where scaling and over-temperature safety occur is easier to monitor.

Description of drawings

Fig. 1 is a schematic structural view of an oilfield gas-fired steam injection boiler according to an embodiment of the present invention;

Fig. 2 is a schematic structural view of an oilfield gas-fired steam injection boiler according to another embodiment of the present invention.

Explanation of reference numerals: radiation section 1, convection section 2, third pipe section 3, condensation baffle 5, condensation section 4, recovery tank 6, condensed water recovery pump 7, water tank 8, softener 9, deaerator 10, Piston pump 11, radiation high temperature section 16, radiation low temperature section 17, radiation high temperature section light pipe 18, radiation low temperature section light pipe 19, convection section light pipe 21, evaporation light pipe 31, evaporation fin tube 32, convection section fin Pipe 22, heat exchange light pipe 41 in the condensation section.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1:

Please refer to Fig. 1 to Fig. 2, the present invention provides a kind of technical scheme:

An oil field gas-fired steam injection boiler, comprising a radiation section 1, a convection section 2, and a condensation section 4. The convection section is provided with a convection section bare tube 21 and a convection section finned tube 22. The convection section bare tube, convection section fin A third tube section 3 is added between the sheet tubes, and the third tube section is provided with an evaporating light tube 31 and an evaporating finned tube 31. Finned tubes 32, finned tubes 22 in the convection section, heat exchange light tubes 41 in the condensation section.

Further, it also includes a water tank 8, the feed water of the water tank sequentially passes through the heat exchange light pipe in the condensation section, the deaerator 10, the finned tube in the convection section, the light pipe in the convection section, the light evaporation pipe, the finned tube in the evaporation section, and the steam outlet of the boiler steam injection pipe. The medium dryness of the steam injection pipe at the steam outlet of the boiler is 90%.

Further, a softener 9 is provided on the connecting waterway between the water tank and the heat exchange light pipe of the condensation section.

Further, a plunger pump 11 is provided on the connecting waterway between the deaerator and the light pipe in the convection section. The medium temperature in this section of the waterway is 60 degrees.

Further, the condensing section is provided with a condensing baffle, the condensing baffle is located below the heat exchange light pipe of the condensing section, and the condensing baffle is located above the light pipe of the convection section at the same time, the condensing baffle is provided with a water receiving tank, and the edge of the water receiving tank has a drain port , the drain port is connected to the recovery tank 6 through a pipeline, and the recovery tank is connected to the water tank through a condensate recovery pump 7 .

Further, the water path connected between the convection section light pipe and the evaporation light pipe passes through the radiation section.

Further, the radiant section adopts a single horizontal serpentine water-cooled wall, forming a cylindrical furnace in the middle.

Further, the ratio of radiation convection heat exchange is 5:5.

In conjunction with Fig. 1, it can be seen that the embodiment of the present invention is: the new type of high-efficiency gas-fired steam injection boiler for oilfields, including a radiation section, a convection section and a condensation section; wherein, the flue gas flow direction is the radiation section, the convection section Light tube, evaporation light tube, evaporation finned tube, convection section finned tube, condensation section light tube. The third pipe section is installed between the light pipe area of the convection section and the finned pipe area of the convection section, and is arranged along the axial direction of the radiation section. The condensation section is located directly above the convection section.

The core idea of the embodiment of the present invention is: use the flue gas condenser to further reduce the temperature of the flue gas, absorb the latent heat of vaporization of the water vapor in the flue gas, form condensed water, and improve the efficiency of the boiler to more than 96%; through the optimization of the heating surface and the flue gas The structural design optimizes the heat transfer ratio of the radiation section and the convection section to 5:5, and the heat transfer is more in line with the heat release characteristics of natural gas flames; the feedwater quality is improved by combining feedwater preheating and flue gas condensation. At the same time, the size of the overall boiler is shortened by 2-3 meters, which reduces the weight of the steam injection boiler and facilitates the transportation of the steam injection boiler.

In the present invention, the third pipe section is arranged between the bare pipe area and the finned pipe area of the convection section, and the low-temperature water in the light pipe area of the convection section absorbs heat to reduce the thermal impact of the flue gas on the bare pipe of the third pipe section, and at the same time effectively increase the dryness of the steam .

The invention adopts the flue gas condenser to further reduce the temperature of the flue gas, absorb the latent heat of vaporization of the water vapor in the flue gas, form condensed water, and improve the efficiency of the boiler to more than 96%. At the same time, the volume of the flue gas shrinks after the flue gas condenses, reducing the flow resistance of the flue gas.

The present invention optimizes the heat exchange ratio of the radiation section and the convection section to 5:5 through the optimization of the heating surface and the design of the flue structure, and the heat exchange is more in line with the heat release characteristics of the natural gas flame.

The present invention improves the quality of feed water through the combination of feed water preheating and flue gas condensation. At the same time, the size of the overall boiler is shortened by 2-3 meters, which reduces the weight of the steam injection boiler and facilitates the transportation of the steam injection boiler.

The core points of the present invention include several aspects of heat exchange ratio balance design, flue gas condensation waste heat recovery design and flue gas preheating feed water deoxygenation design.

Balanced design of heat transfer ratio According to the characteristics of short combustion flame and small heat radiation of gas-fired steam injection boilers, the heat transfer ratio of the convection section and the radiation section is readjusted, and the heat exchange surface is arranged along the flow direction of the flue gas, which is the radiation section and the convection section. , Evaporation light tube, evaporation finned tube, convection section finned tube, condensation section light tube. The high-efficiency and high-dry gas-fired boiler changes the ratio of radiation and convection heat absorption of conventional boilers to 6:4, and adopts the ratio of radiation and convection heat transfer to 5:5, which is more suitable for the combustion characteristics of gas-fired boilers, and the entire heat transfer process on the flue gas side is more reasonable and efficient.

The flue gas condensation waste heat recovery design adds a heat exchange light tube in the condensation section at the end of the condensation section, and uses the flue gas to cool down to below 55°C through the shell side, and 90% of the steam in the natural gas flue gas forms condensed water to realize the latent heat recovery of the flue gas and improve the thermal efficiency of the boiler. Greater than 96%.

The flue gas preheating feed water deaeration design passes the softener outlet water into the flue gas condensation heat exchange area tube, and after exchanging heat with the flue gas, the temperature of the feed water rises by about 20°C, changing the oxygen partial pressure entering the vacuum deaerator , improve the deoxygenation effect of the boiler feed water, the feed water no longer needs to be added to meet the operating conditions. Feedwater steam process recycling, feedwater heating, deaeration, steam formation, reheating, and high-dryness steam generation process layout.

Example 2:

An oil field gas-fired steam injection boiler, comprising a radiation section 1, a convection section 2, and a condensation section 4, the convection section is provided with a convection section bare tube 22, a convection section finned tube 21, and the convection section bare tube, convection section finned tube A third tube section 3 is added between the sheet tubes, and the third tube section is provided with an evaporating light tube 31 and an evaporating finned tube 32. , finned tubes in the convection section, and heat exchange light tubes 41 in the condensation section.

Further, it also includes a water tank 8, the feed water of the water tank sequentially passes through the heat exchange light pipe in the condensation section, the deaerator 10, the finned tube in the convection section, the light pipe in the convection section, the light evaporation pipe, the finned tube in the evaporation section, and the steam outlet of the boiler steam injection pipe. The outlet water temperature of the water tank is normal temperature 25 degrees. The medium dryness of the steam injection pipe at the steam outlet of the boiler is 90%.

Example 3:

An oil field gas-fired steam injection boiler, comprising a radiation section 1, a convection section 2, and a condensation section 4. The convection section is provided with a convection section bare tube 21 and a convection section finned tube 22. The convection section bare tube, convection section fin A third tube section 3 is added between the sheet tubes, and the third tube section is provided with an evaporating light tube 31 and an evaporating finned tube 32. , finned tubes in the convection section, and heat exchange light tubes 41 in the condensation section.

Example 4:

Referring to Fig. 2 to Fig. 3, the present invention provides a technical solution:

An oil field gas-fired steam injection boiler, which includes a flue with a radiation section 1 and a convection section 2 arranged along the flue gas flow direction and a water supply pipeline, the water supply pipeline includes a first pipe section, a second pipe section and a third pipe section Pipe section,

Wherein, in the flue gas flow direction, the first pipe section is located at the upstream part of the convection section 2, the second pipe section is located at the downstream part of the convection section 2, and the third pipe section 3 is arranged at the first between a pipe section and said second pipe section;

Wherein, in the water flow direction of the water supply pipeline, the second pipe section, the first pipe section and the third pipe section 3 are arranged in sequence.

In the third pipe section (or it can be called the evaporation pipe section), most of the liquid water is converted into steam, wherein the proportion of steam is very high (for example, higher than 80%), and has a relatively high dryness; in this scheme The third section of the pipe is the last part of the heat exchange between the water supply pipe and the flue, so that high-dryness steam is formed for use.

Among them, the water (and gradually generated steam) in the water supply pipeline passes through the second pipe section, the first pipe section and the third pipe section in sequence, and the flue gas exchanges heat with the first pipe section, the third pipe section and the second pipe section in sequence .

Since the formation of steam in the water supply pipeline is mainly concentrated in the third pipe section, and the third pipe section is set in the convection section 2 whose temperature is lower than that of the radiant section 1, therefore, compared with the scheme in which the third pipe section is set in the radiant section , the higher temperature flue gas can cause excessive impact on the pipeline, so as to better protect the pipeline of the third pipeline section.

Certainly, other pipelines may be included besides the first pipeline section, the third pipeline section and the second pipeline section, which will be further explained below.

Wherein, the first pipe section is a light pipe 21 in the convection section, and the second pipe section is a finned pipe 22 in the convection section. That is to say, the flue gas first exchanges heat with the light tube 21 of the convection section, and then exchanges heat with the finned tube 22 of the convection section.

Wherein, the third pipe section includes evaporative light tubes 31 and evaporative finned tubes 32 arranged in the flow direction of the water supply pipeline, and in the direction of flue gas flow in the convection section 2, the evaporative light tubes 31 and evaporating finned tubes 32 are arranged in sequence. The water supply flows through the evaporating light tube 31 and the evaporating finned tube 32 successively, and the flue gas also exchanges heat with the evaporating light tube 31 and the evaporating finned tube 32 in turn. The lower temperature fluid (water and steam) in the tube is heat exchanged, and then the lower temperature flue gas exchanges heat with the higher temperature fluid (water and steam) in the finned tube to better protect The third pipe section.

Wherein, the radiating section 1 extends horizontally, an opening is provided on the upper side of the downstream end of the radiating section 1 , and the convection section 2 communicates with the upper side of the downstream end of the radiating section 1 and extends vertically upward.

In addition, the flue includes a condensation section 4 extending vertically upward from the upper end of the convection section 2 .

Wherein, the water supply pipeline includes a condensing section heat exchange light pipe 41 arranged in the condensing section 4, and in the flow direction of the water supply pipeline, the condensing section heat exchange light pipe 41 is located upstream of the second pipe section . The water supply can first exchange heat with the flue gas in the condensation section 4 in the heat exchange light pipe 41 of the condensation section, so as to realize preliminary preheating of the water supply.

In addition, a deaerator 10 and a pressure pump 11 are provided on the part of the water supply pipeline located between the heat exchange light pipe 41 of the condensation section and the second pipe section, and the water supply pipeline is located at the heat exchange tube 41 of the condensation section. A water tank 8 and a softener 9 are arranged on the upstream part of the heat-optical pipe 41 . The water tank 8 can store the supply water, and the softener 9 is used to soften the supply water. After the supply water is preheated, the oxygen in it is removed by the deaerator 10 , and the flow power is provided by the pressure pump 11 .

In addition, the oilfield gas-fired steam injection boiler also includes a condensation baffle 5 located at the lower part of the condensation section 4 and a water receiving tank located at the lower side of the condensation baffle 5 , and the water receiving tank is connected to the recovery tank 6 through a pipeline. The condensing baffle 5 can change the direction of the flue gas, promote the flue gas to scour the tube bundle horizontally, absorb the latent heat of vaporization of the water vapor in the flue gas, further reduce the temperature of the flue gas, form condensed water, and improve the efficiency of the boiler to more than 96%. After the water vapor condenses, the volume of the flue gas shrinks, reducing the flow resistance of the flue gas. Recycling condensed water through the sink can also reduce costs. The recovery tank 6 is communicated with the water tank 8 to deliver water to the water tank 8 for reuse.

Wherein, the cross-sectional area of the connection between the lower port of the condensation section 4 and the upper port of the convection section 2 is larger than the cross-sectional area of the upper port of the condensation section 4, and the upper port of the condensation section 4 is provided with a chimney. The chimney part can be used as the chimney effect area 15 of flue gas hot pressing.

In addition, the water supply pipeline includes a radiant pipe section arranged in the radiant section 1. In the water flow direction of the water supply pipeline, the second pipe section, the first pipe section, the radiant pipe section and the first pipe section The three pipe sections 3 are arranged in sequence. The water supply passes through the first pipe section, the radiant pipe section and the third pipe section sequentially, wherein the water supply exchanges heat with the flue gas in the radiant section in the radiant pipe section to absorb a large amount of heat.

Further, the radiation section 1 includes a radiation high-temperature section 16 and a radiation low-temperature section 17 arranged along the flue gas flow direction, and the radiation pipe section includes a radiation high-temperature section light pipe 18 located in the radiation high-temperature section 16 and a radiation pipe located in the radiation high-temperature section 16. The light pipes 19 of the radiation low temperature section in the low temperature section 17, in the flow direction of the water supply pipeline, the light pipes 18 of the high temperature radiation section and the light pipes 19 of the low temperature section of radiation are arranged in sequence. Referring to Fig. 3, the radiation high temperature section 16 is located upstream of the radiation low temperature section 17, and its flue gas temperature is relatively higher. The water supply first passes through the radiation high temperature section 16 and then passes through the radiation low temperature section 17. The water supply of section light pipe 18 basically does not form steam, but begins to form steam in the radiation low temperature section light pipe 19. In this structure, the radiation low temperature section 17 has lower requirements on the material of the pipe fittings than the radiation high temperature section 16, and can be used at a lower cost. Low fittings.

Among them, the pipe fittings respectively corresponding to the radiation section 1, the convection section 2, and the condensation section 4 are arranged in the furnace of the flue, exposed to the flue gas environment, and exchange heat with the flue gas therein.

Example 5:

An oil field gas-fired steam injection boiler, comprising a radiation section 1, a convection section 2, and a condensation section 4 arranged along the flue gas flow direction, the convection section 2 is provided with a convection section light tube 21 and a convection section finned tube 22, the A third pipe section 3 is added between the convection section light pipe and the convection section finned pipe. The third pipe section 3 is provided with an evaporation light pipe 31 and an evaporation finned pipe 32. The smoke passes through the radiation section and the convection section light pipe in turn. , evaporating light tube, evaporating finned tube, convection section finned tube, and condensing section heat exchange light tube 41 .

In addition, the radiation section 1 includes a radiation high-temperature section 16 and a radiation low-temperature section 17 arranged along the flue gas flow direction, and the radiation section is provided with a radiation high-temperature section light pipe 18 located in the radiation high-temperature section 16 and a radiation pipe located in the radiation The light pipe 19 in the radiation low temperature section of the low temperature section 17, the heat exchange medium flows through the light pipe 18 in the high temperature radiation section and the light pipe 19 in the low temperature radiation section in sequence, and the flue gas passes through the light pipe 18 in the high temperature radiation section and the light pipe 19 in the low temperature radiation section in sequence. The light pipe 19 of the radiation low temperature section.

As shown in Figure 3, in the radiation section 1, the flue gas flows through the high-temperature radiation section 16 and the low-temperature radiation section 17 in sequence, that is, reaches the light pipe 18 of the high-temperature radiation section and the light pipe 19 of the low-temperature radiation section in sequence; the heat exchange medium is, for example, the following The water in the water tank described above sequentially passes through the light pipe 18 of the high-temperature radiation section and the light pipe 19 of the low-temperature radiation section to absorb the heat energy in the radiation section 1; The temperature of the heat medium is relatively lower than the temperature of the heat exchange medium in the light pipe 19 of the radiation low temperature section, wherein, when the heat exchange medium is water, the light pipe 18 of the radiation high temperature section can be positioned in the radiation section 1 so that the water therein Less than or equal to the vaporization critical temperature, water vapor does not appear in the light pipe 18 of the radiation high-temperature section, and the radiation low-temperature section 19 is positioned so that the water therein continues to absorb heat to form water vapor, that is, the light pipe where water vapor begins to form is concentrated in the radiation Downstream location of segment 1.

The setting of the radiation high-temperature section 16 and the radiation low-temperature section 17, that is, the selection of the respective areas of the radiation high-temperature section light pipe 18 and the radiation low-temperature section light pipe 19 needs to be based on the heat absorption and evaporation of water, according to the specific boiler structure and related calculations The radiation high-temperature section light pipe 18 and the radiation low-temperature section light pipe 19 are arranged in a suitable area, so that the water entering the radiation high-temperature section light pipe 18 will not evaporate to form steam (below the evaporation critical temperature), but only in the radiation low-temperature section light Steam is formed in pipe 19. In simple terms, the division of the radiation high-temperature section 16 and the radiation low-temperature section 17 is based on the state of water (whether steam is formed) flowing through the radiation high-temperature section light pipe 18 and the radiation low-temperature section light pipe 19 .

Referring to Figure 3, it simply shows the arrangement of the light pipe 18 in the high-temperature radiation section and the light pipe 19 in the low-temperature radiation section. , and does not cross back and forth between the radiation high temperature section 16 and the radiation low temperature section 17 .

Further, it also includes a water tank 8, and the feed water of the water tank passes through the heat exchange light tube in the condensation section, the deaerator 10, the finned tube in the convection section, the light tube in the convection section, the light tube in the high-dry section, and the finned tube in the high-dry section , The steam injection pipeline of the steam outlet of the boiler. The outlet water temperature of the water tank is normal temperature 25 degrees. The medium dryness of the steam injection pipe at the steam outlet of the boiler is 90%.

Further, the water path connected between the convection section light pipe and the evaporation light pipe passes through the radiation section. That is, the waterway passes through the light pipe 18 of the high-temperature radiation section and the light pipe 19 of the low-temperature radiation section in sequence.

Further, the radiant high-temperature section 16 adopts a single horizontal serpentine water-cooled wall, forming a cylindrical furnace in the middle; the radiant low-temperature section 17 adopts a single horizontal serpentine water-cooled wall, forming a cylinder in the middle Shaped furnace; the outlet of the condensation section is connected to a tail chimney, and the internal flue of the tail chimney forms a flue gas hot-press chimney effect area to form a negative pressure suction environment, wherein the temperature of the flue gas entering the tail chimney is 56 degrees.

Further, the ratio of radiation convection heat exchange is 5:5.

Combining with Figure 3, it can be seen that the embodiment of the present invention is: the new type of high-efficiency gas-fired steam injection boiler for oilfields includes a radiation section, a convection section and a condensation section, and the radiation section includes a radiation high-temperature section arranged along the flue gas flow direction 16 and a radiation low-temperature section 17, the radiation section is provided with a radiation high-temperature section light pipe 18 located in the radiation high-temperature section 16 and a radiation low-temperature section light pipe 19 located in the radiation low-temperature section 17; wherein the flue gas flows The directions are the light pipe 18 in the high temperature radiation section, the light pipe 19 in the low temperature radiation section, the light pipe in the convection section, the light pipe in the evaporation section, the finned tube in the evaporation section, the finned tube in the convection section, and the light pipe in the condensation section. The third pipe section is installed between the light pipe area of the convection section and the finned pipe area of the convection section, and is arranged along the axial direction of the radiation section. The condensation section is located directly above the flue gas effect area.

The core idea of the embodiment of the present invention is: the radiation section is divided into the radiation high temperature section 16 upstream of the flue gas flow direction and the radiation low temperature section 17 downstream, the light pipe 18 of the high temperature radiation section and the light pipe 19 of the low temperature radiation section are respectively at different temperatures The area makes it easier to control the heat exchange of the water wall. The low temperature area of the heat exchange fluid in the tube is concentrated in the upstream and the high temperature area is concentrated in the downstream. Different tube and shell materials can be used; the flue gas condenser is used to further reduce the flue gas temperature, absorb the latent heat of vaporization of the water vapor in the flue gas, form condensed water, and improve the boiler efficiency to more than 100%; through the optimization of the heating surface and the design of the flue structure , the heat transfer ratio of the radiation section and the convection section is optimized to 5:5, and the heat exchange is more in line with the heat release characteristics of the natural gas flame; the feedwater quality is improved through the combination of feedwater preheating and flue gas condensation. At the same time, the size of the overall boiler is shortened by 2-3 meters, which reduces the weight of the steam injection boiler and facilitates the transportation of the steam injection boiler.

In the present invention, the third pipe section is arranged between the bare pipe area and the finned pipe area of the convection section, and the low-temperature water in the light pipe area of the convection section absorbs heat, thereby reducing the thermal impact of the flue gas on the bare pipe of the high-dry section, and effectively improving the dryness of the steam at the same time .

The present invention optimizes the heat exchange ratio of the radiation section and the convection section to 5:5 through the optimization of the heating surface and the design of the flue structure, and the heat exchange is more in line with the heat release characteristics of the natural gas flame. At the same time, through three different forms of depressurization during the flue gas flow process, the tail flue gas resistance is reduced.

The core points of the present invention include three aspects: design of heat exchange ratio balance, flue gas condensation waste heat recovery design, and flue gas preheating feed water deoxygenation design.

The flue gas temperature at the outlet of the condensation section is higher than that of the air at the chimney outlet, and the thermal pressure forms the chimney effect zone. The entire tail flue forms a negative pressure suction environment to reduce the flow resistance of flue gas.

The flue gas condensation waste heat recovery design adds a heat exchange light tube in the condensation section at the end of the condensation section, and uses the flue gas to cool down to below 55°C through the shell side, and 90% of the steam in the natural gas flue gas forms condensed water to realize the latent heat recovery of the flue gas and improve the thermal efficiency of the boiler. Greater than 100%.

Although all of the above embodiments use Fig. 1 to Fig. 3, as those skilled in the art can clearly know, there is no need to provide a separate drawing to represent, as long as the missing parts or structural features in the embodiment are in the drawing Just remove it. This is clear to those skilled in the art. Of course, the embodiment with more parts is only the optimal embodiment, and the embodiment with fewer parts is the basic embodiment, but it can also realize the basic purpose of the invention, so all of these are within the protection scope of the present invention.

All the components themselves that are not discussed in this application, and the connection methods of each component in this application belong to the known technology in the technical field, and will not be repeated. Such as welding, threaded connection, etc.

In the present invention, the term "plurality" refers to two or more, unless otherwise clearly defined. The terms "installation", "connection", "connection", "fixed" and other terms should be interpreted in a broad sense, for example, "connection" can be fixed connection, detachable connection, or integral connection; "connection" can be directly or indirectly through an intermediary. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear" etc. is based on the orientation shown in the drawings Or positional relationship is only for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the referred device or unit must have a specific direction, be constructed and operated in a specific orientation, and therefore, should not be construed as a limitation of the present invention.

In the description of this specification, descriptions of the terms "one embodiment", "some embodiments", "specific embodiments" and the like mean that specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in the present invention In at least one embodiment or example of . In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

An oilfield gas-fired steam injection boiler is characterized in that it includes a flue and a water supply pipeline with a radiation section (1) and a convection section (2) arranged along the flue gas flow direction, and the water supply pipeline includes a first pipe section, the second pipe section and the third pipe section,

Wherein, in the flue gas flow direction, the first pipe section is located at the upstream part of the convection section (2), the second pipe section is located at the downstream part of the convection section (2), and the third pipe section (3 ) is disposed between the first pipe section and the second pipe section;

Wherein, in the water flow direction of the water supply pipeline, the second pipe section, the first pipe section and the third pipe section (3) are arranged in sequence.
The oilfield gas-fired steam injection boiler according to claim 1, characterized in that, the first pipe section is a smooth pipe (21) in the convection section, and the second pipe section is a finned pipe (22) in the convection section.
The oilfield gas-fired steam injection boiler according to claim 1, characterized in that, the third pipe section (3) includes evaporating light pipes (31) and evaporating finned pipes ( 32), and in the flue gas flow direction of the convection section (2), the evaporation light tube (31) and the evaporation finned tube (32) are arranged in sequence.
The oil-field gas-fired steam injection boiler according to claim 1, characterized in that, the third pipe section (3) is arranged in an area with a temperature of 800-900°C in the convection section (2).
The oilfield gas-fired steam injection boiler according to any one of claims 1-4, characterized in that, the radiant section (1) extends horizontally, and an opening is provided on the upper side of the downstream end of the radiant section (1), so The convection section (2) communicates with the upper side of the downstream end of the radiation section (1) and extends vertically upward.
The oilfield gas-fired steam injection boiler according to claim 5, characterized in that the flue includes a condensation section (4) extending vertically upward from the upper end of the convection section (2).
The oilfield gas-fired steam injection boiler according to claim 6, characterized in that, the water supply pipeline includes a heat exchange light tube (41) in the condensation section (4) arranged in the condensation section (4), and in the water flow direction of the water supply pipeline Above, the heat exchange light pipe (41) of the condensation section is located upstream of the second pipe section.
The oilfield gas-fired steam injection boiler according to claim 7, characterized in that, the water supply pipeline is provided with a deaerator on the part between the heat exchange light tube (41) of the condensation section and the second pipe section (10) and a pressure pump (11), the water supply pipeline is provided with a water tank 8 and a softener 9 on the part upstream of the heat exchange light pipe (41) of the condensation section.
The oilfield gas-fired steam injection boiler according to any one of claims 6-8, characterized in that it also includes a condensation baffle (5) located at the lower part of the condensation section (4) and a condensation baffle ( 5) The water receiving tank on the lower side, the water receiving tank is connected to the recovery tank (6) through a pipeline.
The oilfield gas-fired steam injection boiler according to any one of claims 5-9, characterized in that the cross-sectional area of the connection between the lower port of the condensation section (4) and the upper port of the convection section (2) is greater than The flow cross-sectional area of the upper port of the condensing section (4), the upper port of the condensing section (4) is provided with a chimney.
The oil-field gas-fired steam injection boiler according to any one of claims 1-10, characterized in that, the water supply pipeline includes a radiant pipe section arranged in the radiant section (1), and the water flow in the water supply pipeline Directionally, the second pipe section, the first pipe section, the radiant pipe section and the third pipe section (3) are arranged in sequence.
The oilfield gas-fired steam injection boiler according to claim 11, characterized in that, the radiant section (1) includes a radiant high-temperature section (16) and a radiant low-temperature section (17) arranged along the flue gas flow direction, and the radiant pipe section Comprising a radiation high-temperature section light pipe (18) located in the radiation high-temperature section (16) and a radiation low-temperature section light pipe (19) located in the radiation low-temperature section (17), in the water flow direction of the water supply pipeline, The light pipes (18) of the radiation high temperature section and the light pipes (19) of the radiation low temperature section are arranged in sequence.