CN110030548B - Modularized heat exchange device especially suitable for biomass combustion system - Google Patents
Modularized heat exchange device especially suitable for biomass combustion system Download PDFInfo
- Publication number
- CN110030548B CN110030548B CN201910297070.0A CN201910297070A CN110030548B CN 110030548 B CN110030548 B CN 110030548B CN 201910297070 A CN201910297070 A CN 201910297070A CN 110030548 B CN110030548 B CN 110030548B
- Authority
- CN
- China
- Prior art keywords
- heat exchange
- flue gas
- exchange device
- air
- biomass combustion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 34
- 239000002028 Biomass Substances 0.000 title claims abstract description 14
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 63
- 239000003546 flue gas Substances 0.000 claims abstract description 57
- 238000004140 cleaning Methods 0.000 claims abstract description 12
- 238000010438 heat treatment Methods 0.000 claims abstract description 10
- 239000010902 straw Substances 0.000 claims description 28
- 230000000694 effects Effects 0.000 claims description 10
- 238000007789 sealing Methods 0.000 claims description 10
- 239000000428 dust Substances 0.000 abstract description 20
- 238000001035 drying Methods 0.000 abstract description 18
- 238000010276 construction Methods 0.000 abstract description 5
- 238000000746 purification Methods 0.000 abstract description 5
- 238000000034 method Methods 0.000 abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 40
- 229910000831 Steel Inorganic materials 0.000 description 13
- 239000010959 steel Substances 0.000 description 13
- 235000013339 cereals Nutrition 0.000 description 12
- 238000004519 manufacturing process Methods 0.000 description 11
- 238000012546 transfer Methods 0.000 description 10
- 238000013461 design Methods 0.000 description 9
- 239000007789 gas Substances 0.000 description 9
- 239000002609 medium Substances 0.000 description 8
- 239000003245 coal Substances 0.000 description 7
- 238000002844 melting Methods 0.000 description 7
- 230000008018 melting Effects 0.000 description 7
- 239000003921 oil Substances 0.000 description 6
- 239000000446 fuel Substances 0.000 description 4
- 239000000779 smoke Substances 0.000 description 4
- 230000002528 anti-freeze Effects 0.000 description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000011707 mineral Substances 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- 239000012736 aqueous medium Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000011490 mineral wool Substances 0.000 description 2
- 238000013021 overheating Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Chemical compound [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 description 2
- CHWRSCGUEQEHOH-UHFFFAOYSA-N potassium oxide Chemical compound [O-2].[K+].[K+] CHWRSCGUEQEHOH-UHFFFAOYSA-N 0.000 description 2
- 229910001950 potassium oxide Inorganic materials 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000003566 sealing material Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- 235000004522 Pentaglottis sempervirens Nutrition 0.000 description 1
- 240000008042 Zea mays Species 0.000 description 1
- 235000005824 Zea mays ssp. parviglumis Nutrition 0.000 description 1
- 235000002017 Zea mays subsp mays Nutrition 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001722 carbon compounds Chemical class 0.000 description 1
- 239000004464 cereal grain Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 235000005822 corn Nutrition 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000001599 direct drying Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 229910001392 phosphorus oxide Inorganic materials 0.000 description 1
- 235000010333 potassium nitrate Nutrition 0.000 description 1
- 239000004323 potassium nitrate Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- VSAISIQCTGDGPU-UHFFFAOYSA-N tetraphosphorus hexaoxide Chemical compound O1P(O2)OP3OP1OP2O3 VSAISIQCTGDGPU-UHFFFAOYSA-N 0.000 description 1
- 238000012549 training Methods 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23B—METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
- F23B80/00—Combustion apparatus characterised by means creating a distinct flow path for flue gases or for non-combusted gases given off by the fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J3/00—Removing solid residues from passages or chambers beyond the fire, e.g. from flues by soot blowers
- F23J3/02—Cleaning furnace tubes; Cleaning flues or chimneys
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28G—CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS
- F28G1/00—Non-rotary, e.g. reciprocated, appliances
- F28G1/16—Non-rotary, e.g. reciprocated, appliances using jets of fluid for removing debris
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
- Air Supply (AREA)
Abstract
The invention relates to a modularized heat exchange method and a modularized heat exchange device which are particularly suitable for a biomass combustion system. Which includes several standardized heat exchange modules that can use various heat carrier mediums. The flue gas (6) flows in the heat exchange tube (8), and the heat exchange tube (8) is coaxially arranged between different heat exchange modules. This allows each heat exchange module to be operated using compressed air cleaning lances (30) to effectively clean dust from the heat exchange tubes. Since dust purification no longer has to be achieved by means of a high flow rate of the flue gas (6), it is possible to reduce the flue gas velocity and the power requirement of the induced draft fan. The invention is particularly suitable for the construction of systems for generating hot air by indirect heating, for example for the efficient generation of hot air above 100 ℃ when used for grain drying. The heat exchange device can be arranged along the vertical or horizontal direction according to the requirement, and the size and the length of the heat exchange device can be designed according to the requirement, so that the heat exchange device can realize very good performance.
Description
Technical Field
The invention relates to a modularized heat exchange device which is particularly suitable for a biomass combustion system, wherein the device is formed by combining a plurality of heat exchange modules into one heat exchange device. The heat exchange module can be used for heating hot water, and can also be used for simultaneously heating a plurality of heat carrier mediums including hot oil. A particular example of application is the use of indirect heating to bring air to temperatures in excess of 100 ℃ and for grain drying.
Background
The flue gas in the tubes of a coal-fired steam boiler heat exchanger is typically designed to flow at high velocity to prevent ash buildup in the tubes. The relatively large dust particles generated by burning coal contain mineral substances, most of which are salts with higher melting points and friction effects, so that the purification of the heat exchange tube is facilitated. The flue gas of coal-fired boilers moves at a higher turbulence velocity than actually needed to obtain good heat transfer, which is why its induced draft fan often consumes more electrical energy.
The nanoscale fine dust generated by straw combustion does not have a friction purification effect, is generally charged and can be attached to the metal surface, even when the smoke moves at a high speed. For example, dust layers can be deposited on the wings of fans rotating up to 2800 rpm, which is not uncommon when fuelled with coal.
So far, no straw combustion system can well solve the problem of effective cleaning of the surface of a heat exchanger and design proper structural components. The integration of heat exchange modules into heat exchange devices, the mass and standardized manufacture of modular heat exchange devices with simplified designs at low prices is not seen in which country there is practical application.
The hot air of the traditional heat exchanger is generally subjected to heat exchange with one medium, and the practical application of utilizing one hot air source to act on several different mediums to realize heat exchange at the same time is not found.
In the field of feed and food processing, a number of indirectly heated hot air generators are used to dry plants, grain drying equipment, especially bulk drying products such as corn, often require an intensified heat source with a drying air temperature of more than 100 ℃. And it is relatively easy to realize the drying by directly using the fully combusted and discharged clean drying air.
If biomass is used as the fuel for indirect heating by a heat exchanger, high-temperature heat media such as steam or heat conducting oil must be used, the construction and operation of the biomass-type heat exchanger are far more expensive and complicated than those of a simple hot water boiler with the pressure of 95 ℃. Grain drying is often produced seasonally and it is difficult for operators to fully have the ability or qualification to operate complex steam boilers. Thermal oil media are expensive, prone to aging and are prone to environmental risks.
On the other hand, when the common thermodynamic system mainly using coal heats air by heat exchange through flue gas, the heat efficiency is often not high enough due to the fact that the temperature of the exhaust gas is too high.
There is often a risk of thermal blockage and damage to the heat exchange surfaces in heat exchangers made of heat-resistant steel, in which case open fires may enter the grain dryer and may cause fires. And because the straw flame is particularly long, the burning straw particles have a higher probability of causing fire disaster of the grain drying equipment. However, if the combustion temperature of the straw fuel is lowered due to this characteristic of the straw fuel, the sufficiency and efficiency of straw combustion are lowered. Straw combustion brings more dust to the heat exchanger than coal, which dust, in combination with unburned residual carbon compounds, becomes difficult to clean when attached to the heat exchanger. Thus, clean and complete combustion of straw is critical, but such complete clean combustion is not ensured to be fully achieved at combustion temperatures below 800 ℃.
In addition, chlorine in the straw has a strong corrosion effect and generally has a great influence on the performance of the steel. So far intensive cereal drying using biomass, in particular straw, as an energy source in agriculture has not been known.
Devices for drying grains using direct heating of natural gas or liquefied gas are common worldwide but expensive. Fuel oil is also used for indirect or direct (mostly illegal) drying, and only indirect drying is used with coal. Direct drying of cereal grains with biomass is not allowed in many countries.
Disclosure of Invention
Simple and economical cleaning of adhering dust on the surface of the heat exchanger is also the primary and most important task in the construction of straw combustion systems. Because the dust adhesion cannot be completely prevented even if the flue gas flows at a high speed, the heat exchanger dust purification is urgently required to be a low-energy-consumption, easy-to-implement construction design concept.
The invention allows for simultaneous heating of several different heat carrier mediums with only one flue gas stream, which can then be used in combination for design purposes.
The design of the heat exchange modules for different heat media should be capable of standardized and perfect combination, so that an automated production can be well achieved for low cost manufacturing.
In the application of the invention, the straw can be used as fuel, heat-resistant steel materials are not used, high-temperature heat mediums such as water vapor or hot oil are not used, and hot air with the temperature exceeding 100 ℃ is generated through indirect heating. The energy conversion efficiency is high, the fire risk is greatly reduced, and the heat energy burden born by various building materials is not excessive.
It is also important for the producer that expensive and complex monitoring of the hot air generating device is not required.
The invention aims to realize the heat exchange purpose by forming a modularized heat exchange device by a plurality of heat exchange modules, and coaxial heat exchange pipes are arranged between the heat exchange modules so as to enable flue gas generated by a straw combustion system to flow.
In the modularized heat exchange device, heat exchange pipes with different heat exchange pipe diameters and different pipe lengths are required to be configured according to different thermal performance performances, and the heat exchange pipes of all the heat exchange modules are coaxially arranged. Thus, the heat exchange modules may be placed vertically or horizontally with respect to each other, and the flue gas flows through all the heat exchange modules in a straight line.
The structure allows dust on the inner surfaces of the heat exchange pipes of all the heat exchange modules to be completely cleaned through compressed air flow, so that dust removal and purification are not borne by flue gas flow, the flue gas speed can be reduced, the energy consumption can be reduced for a fan, and the size of the heat exchanger can be controlled as required.
The heat exchange modules can be designed for different heat media, and the heat media can be water-glycol mixture or liquid such as hot oil, or gas such as air, so that different heat exchange modules can heat various heat media simultaneously.
If only the aqueous medium is heated, several standard heat exchange modules can be arranged perpendicular or parallel to each other, which reduces the production costs of the heat exchanger.
If the flue gas of the heat exchanger is first passed through a heat exchanger module with heat transfer oil or air as medium, a heat exchanger module with water as medium can be followed in order to achieve a lower exhaust flue gas temperature.
If it is desired to produce hot air at a temperature exceeding 100c, for example for grain drying or the like, more than 3 different heat exchange module combinations may be arranged according to the invention. Firstly, the flue gas flows through the flue gas-water heat exchange module, the temperature of the flue gas is reduced to below 680 ℃ which can be borne by steel, and 90 ℃ hot water generated by heat exchange flows through the air-water heat exchange module to preheat initial cold air to about 65 ℃, and the preheated air flows through the flue gas-air heat exchange module and is further heated to a required temperature, such as 115 ℃.
In order to improve the efficiency, the flue gas-air heat exchange module can be switched to another flue gas-water heat exchange module, and the heat transfer capacity of the unit area of the flue gas-air heat exchange module is higher than that of the flue gas-air heat exchange module, so that lower exhaust emission temperature can be obtained. In areas where the temperature is lower during winter grain drying, the second flue gas-water heat exchange module may also be replaced with a flue gas-air heat exchange module. Modular heat exchange devices allow manufacturers to design the structure based on the characteristics of the location of the heat exchange device.
By reducing the flue gas temperature in the first flue gas-water module, no special high price high temperature resistant steel is needed for the subsequent flue gas-air heat exchange module manufacture.
Dust produced by the combustion of coal contains oxides of salts, is generally poorly water soluble and has a melting point well above 1000 ℃. The risk of coal burning forming a melt layer on the surface of the heat exchanger is thus not great. While most of the dust is water-soluble salt oxide when the straw burns, a large part of the oxide is melted at a lower temperature, such as phosphorus oxide with a melting point of 340 ℃ or potassium nitrate with a melting point of 334 ℃, the dust generated by burning the straw also contains potassium oxide with a melting point of 770 ℃, and the like, and the potassium oxide and the like are required to be melted at a higher temperature.
Because the temperature of the heat exchange tube of the general steam boiler rarely exceeds 300 ℃, the danger of dust melting and forming a solid layer is avoided when the straw is burnt. However, the temperature of the heat exchange steel pipe is higher in the flue gas-air-flue gas exchange process, for example, the temperature of the heat exchange steel pipe can reach 500 ℃ when the temperature of the flue gas is 900 ℃ and the temperature of the air is 100 ℃. This temperature is already too high for ordinary steels, so there is a risk of problems with the molten mineral. It is necessary to control the flue gas temperature to below 680 c during straw combustion so that it is ensured that the heat exchange steel tube temperature is below 400 c, which is the temperature that the steel tube can withstand and avoid melting of minerals.
For safety, the flue gas input temperature is monitored, and if necessary, the flue gas temperature can be timely reduced by adding cold air into the cyclone post-combustion chamber.
The flue gas injection heat exchanger modules are connected with each other, and can be stacked one above the other to enable the flue gas to flow vertically or arranged one behind the other to enable the flue gas to flow horizontally. All heat exchange tubes are coaxially arranged in line with each other.
When the temperature of the flue gas is reduced, in order to keep the flow rate of the flue gas, the diameter of the heat exchange tube can be gradually reduced along with the flow direction of the flue gas like the common practice of a steam boiler.
By selecting the diameter of the heat exchange tube, a small section of the heat exchange tube of the rear heat exchange module can be inserted into the heat exchange tube of the front heat exchange module.
Hot water from the flue gas-water heat exchange module may be pumped to the water-air heat exchange module.
In the practice of the invention, the heat exchange tube channels may be accessed through a sealing cap or fire door that contains a device that enables cleaning of the flue gas side heat exchange surface using a compressed air lance during system operation. The sealing cover or the fireproof door comprises a fireproof inner cover and a sealing outer cover arranged above. The sealing cap or fire door can be opened upward or sideways to release the internal pressure, which is accomplished conveniently by first releasing the internal and external pressure differential by opening a small vent flap on the upper cap.
The inner cover is provided with a conduit which is arranged therein and is connected with the heat exchange tube, the hand-held compressed air spray gun can be conveniently inserted into the heat exchange tube through the conduit, and the dust of the compressed air can be removed from the heat exchange tube through spraying.
Since there is a risk of frost with water as a heat medium, an antifreeze can be added to the water if necessary, and the water cycle must be closed to prevent water loss due to evaporation. The pressure of the aqueous medium is kept to be less than 0.1MPa just like the cooling system of the automobile engine, so that the pressure monitoring is avoided.
If the pressure is as high as 0.6MPa as in solar systems, the temperature is also above 100 ℃, which, while compensating for the reduced heat transfer capacity, must comply with higher legal regulatory requirements.
Drawings
FIG. 1 is a side view of a heat exchange device for producing hot water
FIG. 2 is a side view of an upright heat exchange device for generating hot air
Fig. 3 is a bird's eye view of the heat exchanger device according to fig. 2.
FIG. 4 is a top cover interior design that can be cleaned using compressed air
FIG. 5 is a perspective view of a circulating heat exchanger for generating hot air
FIG. 6 is a cross-sectional view of the heat exchange device according to FIG. 5
FIG. 7 is a view of the flue gas supply of the heat exchange device according to FIG. 5
FIG. 8 is a cross-sectional view of a heat exchange module with heat exchange tubes
In the figure: 1-smoke-water heat exchange module, 2-smoke-water heat exchange module, 3-smoke-water heat exchange module, 4-smoke inlet end, 5-smoke release end, 6-smoke, 7-exhaust gas, 8-heat exchange tube, 9-stretching ring, 10-sealing material, 11-smoke-water heat exchange module, 12-smoke-air heat exchange module, 13-smoke-water heat exchange module, 14-pump, 15-water-air heat exchange module, 16-pump, 17-water-air heat exchange module, 18-air, 19-axial fan, 20-air, 21-straw combustion system, 22-straw bundle, 23-straw loading device, 24-cyclone post combustion chamber, 25-dust collection chamber, 26-induced draft fan, 27-chimney, 28-inner cover, 29-guiding pipe, 30-compressed air cleaning spray gun, 31-upper cover, 32-ventilation valve plate, 33-flue gas-water heat exchange module, 34-flue gas-air heat exchange module, 35-flue gas-air heat exchange module, 36-water-air heat exchange module, 37-pump, 38-pipeline, 39-air deflector, 40-steel structure house, 41-heat insulation layer, 42-fireproof door, 43-temperature sensor, 44-electric control air baffle, 45-safety flap, 46-electromagnet, 47-mineral wool, 48-supporting plate with wind dividing function, 49-supporting plate without wind dividing function, 50-end socket supporting plate, 51-end socket supporting plate.
Detailed Description
According to fig. 1, a heat exchange device for producing only hot water is presented. The flue gas-water heat exchange device consists of independent flue gas-water heat exchange modules (1, 2, 3), a flue gas inlet end (4) and a flue gas release end (5). The flue gas (6) enters the flue gas inlet end (4) and leaves the flue gas release end (5) as exhaust gas (7). The flue gas-water heat exchange modules (1, 2, 3) comprise heat exchange tubes (8) with different diameters, the diameters of the heat exchange tubes (8) in the next heat exchange module become smaller along the flue gas flowing direction, and the heat exchange tubes (8) of the next heat exchange module (2, 3) can be inserted into a small section in the heat exchange tubes of the previous heat exchange module (1, 2).
The heat exchange modules (1, 2, 3) are connected to each other and to the flue gas inlet end (4) and the flue gas discharge end (5) by means of a tension ring (9) with sealing material (10).
The vertical stacking of such heat exchange modules (1, 2, 3) requires the construction of a tall cyclone afterburner (24) that allows for long residence times of the flue gases. The operator can clean the heat exchange tube (8) conveniently from above using the compressed air cleaning gun (30) as shown in fig. 4.
Only one heat exchanger device, in particular for producing hot water, is proposed here, which is entirely composed of simple components, the production process being easily automated and standardized, and all of this being advantageous for a reduction in production costs.
In fig. 2 is shown a heat exchange device for generating hot air by indirect heating, for example for grain drying. The device comprises 3 heat exchange modules (11, 12, 13) through which the flue gas (6) flows. The first of these is a flue gas-water heat exchange module (11) which has only short heat exchange tubes (8). The second is a flue gas-air heat exchange module (12), and the third is another flue gas-water heat exchange module (13). The heat exchange tubes of each heat exchange module are tapered in diameter so as to maintain a sufficiently high gas turbulence velocity to achieve good heat transfer.
The warm water of the heat exchange module (11) is sent into the water-air heat exchange module (15) through a pump (14) according to the design. The hot water of the heat exchange module (12) is fed by a pump (16) to a water-air heat exchange module (17). Cold air (18) fed from the axial fan (19) flows through the heat exchange modules (15, 17) and is heated to above 70 ℃, after which the hot air continues to flow through the flue gas-air heat exchange module (12) and reaches a temperature above 100 ℃ as drying air (20).
The whole system is composed of only ordinary steel. The maximum operating temperature of the low-pressure water as heat carrier medium is not higher than 95 ℃, so that the pressure does not have to be monitored by law. Even when the hot air temperature exceeds 100 ℃, there is no risk of formation of a soot coating on the heat exchanger surface, nor is there a need to use expensive high temperature heat carrier medium, since there is no material from high temperatures.
The heat exchanger with the modularized structure is suitable for mass production and low cost production.
Fig. 3 further illustrates the system from a top view. The cross-section of the heat exchange module (12) shows the heat exchange tube (8), the flue gas (6) comes from the straw combustion system (21), and the straw bales (22) are put into the straw combustion system (21) by the straw loading device (23). The flue gas (6) enters the cyclone post-combustion chamber (24) to complete clean combustion, so that tar or carbon can be safely prevented from depositing on the heat exchange tube.
The exhaust gas (7) leaves the heat exchange module (12) and enters the dust collection chamber (25), and then is sent to the chimney (27) through the induced draft fan (26). The speed of the induced draft fan (26) can be regulated and controlled through frequency conversion to meet the requirements of users, in particular to a grain dryer. The system configuration can also be optimized to achieve optimal heat transfer by changing the flue gas velocity in the heat pipes (8) according to relevant criteria.
Figure 4 shows how dust deposits of the heat exchange tubes (8) are cleaned from the upper part of the flue gas inlet end (4). The inner cover (28) is provided with a guide tube (29), and the compressed air cleaning spray gun (30) can be properly inserted into the heat exchange tube (8) through the guide tube (29). The sealing cover (31) is opened into the region of the inner cover (28), but the vent flap (32) must be opened to release the pressure before opening the sealing cover (31). The system provides the operator with a working platform, which arrangement allows for a very economical realization of a complete cleaning of the heat exchange tubes (8) while the system is in continuous operation.
By adopting the method, the cleaning problem of the heat exchange tube is solved, the design of the heat exchange tube and the heat exchange surface is only carried out around how to realize good heat transfer, and the flue gas flow does not need to bear cleaning tasks, so that the speed of the flue gas flow can be obviously reduced, and the pressure loss of the system and the electric power consumption of the induced draft fan are obviously reduced.
However, the arrangement according to fig. 2 and 3 has certain limitations when a higher performance representation of the heat exchange system is required. The vertically arranged heat exchange device may become too high, the straw combustion also requires 2 continuous cyclone post-combustion chambers (24), and the flue gas (6) may become fed near the bottom of the ground, which is more suitable for large horizontal heat exchange module combinations.
Fig. 5 shows such a horizontal heat exchange device, in which in zone I is a flue gas-water heat exchange module (33), in zone II is a flue gas-air heat exchange module (34), in zone III is 2 sections, one is a flue gas-air heat exchange module (35), the other is a water-air heat exchange module (36), and the water-air heat exchange module (36) is connected to the flue gas-water heat exchange module (33) by a pump (37) and a pipe (38). The flue gas is guided to pass through a supporting plate (48) with a wind dividing effect and a supporting plate (49) without the wind dividing effect through an air deflector (39) after entering the heat exchange device, and the supporting plate (48) with the wind dividing effect and the supporting plate (49) without the wind dividing effect are used for supporting the heat exchange tube (8) and overcoming vibration of the flue gas when passing through the heat exchange tube (8).
This arrangement has only one water circulation and is particularly suitable for cold areas where half of the year is winter and most of the grain drying is done in winter. Typically very cold air achieves a sufficiently low exhaust gas emission temperature only upon inefficient gas-to-gas heat exchange. After entering the heat exchange module (35), the air (18) is guided by the air deflector (39) to repeatedly pass through the flue gas-air heat exchange module (35) and simultaneously pass through the water-air heat exchange module (36) twice, and at the moment, the air which is already close to 70 ℃ repeatedly passes through the flue gas-air heat exchange module (34) and receives required heat, and the temperature can reach 120 ℃ at the highest.
As can be seen from the cross-section of the flue gas-air heat exchange module (34), the heat exchange module cross-section is rectangular, with the air (20) passing through the heat exchange tube bundle in a horizontal direction, as shown in fig. 6. The entire heat exchange module is enclosed by a steel structure house (40) having a thick insulating layer (41) for reducing heat loss.
In this application, 3300kW of heat is used for generating flue gas, and 162 heat exchange tubes with the length of 6m are arranged at the flue gas-air heat exchange modules (34, 35), wherein the diameter of the heat exchange tubes of the heat exchange modules (34) is 108mm, and the diameter of the heat exchange tubes of the heat exchange modules (35) is 89mm.
In fig. 7, the entry of flue gas (6) into the flue gas-water heat exchange module (33), the fire door (42) with the cleaning tool guide tube (29) and the sealing upper cover (31) with the vent flap (32) are shown in more detail.
In order to safely prevent overheating, a channel for the intake of fresh air is provided at the end of the cyclone post-combustion chamber. For precise regulation of the temperature of the flue gas (6), a control device is provided with a temperature sensor (43) which allows fresh air to be sucked in via an electrically controlled air baffle (44) for cooling the flue gas (6).
Furthermore, a safety flap (45) with an electromagnet (46) is provided, which automatically drops and introduces cold air in the event of extreme overheating of the system or a power failure.
Fig. 8 shows a cross-sectional view of the junction of two heat exchange modules. The heat exchange tube (8) of the rear heat exchange module penetrates through the seal head supporting plate (50) and is inserted into a small section of the heat exchange tube of the front heat exchange module penetrating through the seal head supporting plate (51), and mineral wool (47) is filled between the two heat exchange module seal head supporting plates (50, 51) before assembly.
The antifreeze may be added to the heat transfer medium water in a metered amount, but changes in fluidity, heat transfer and heat transfer capacity resulting from the addition of the antifreeze must be accounted for in calculating and reading all system components.
In the practice of the present invention, all of the facilities related to air management, water expansion, thermal expansion, sealing, and speed control pumps may be realized in good engineering practice.
The heat exchange device is completely suitable for being fuelled by straw, and can be built in almost any size. All components are easy to manufacture and process without expensive materials. The required temperature of the heat medium can be obtained safely, the technical risk is hardly caused, the monitoring can be avoided, personnel can operate without receiving much training, and the product has long service life and low manufacturing cost.
Claims (7)
1. The modularized heat exchange device particularly suitable for the biomass combustion system comprises a heat exchange tube, a heat carrier medium, a pump, a pipeline and a fan, wherein flue gas (6) generated by the straw combustion system flows into the heat exchange tube (8) of the heat exchange module and is fixed by a supporting plate (48) with a wind dividing effect and a supporting plate (49) without the wind dividing effect, and the supporting plate (48) with the wind dividing effect is matched with an air deflector (39) to finish air diversion; the heat exchange device is characterized in that different heat exchange modules (1, 2,3, 11, 12, 13, 33, 34, 35) are coaxially connected with each other by using the same number of heat exchange tubes (8) and are arranged in a straight line.
2. A modular heat exchange device, in particular for a biomass combustion system, according to claim 1, characterized in that the heat exchange module is designed for heating different heat media.
3. A modular heat exchange device, in particular for biomass combustion systems, according to claim 1, characterized in that the flue gas inlet end (4) is arranged in the front section of the heat exchange device and the flue gas discharge end (5) is arranged in the rear section of the heat exchange device.
4. A modular heat exchange device, particularly for biomass combustion systems, according to claim 1, characterized in that the heat exchange tubes (8) of the rear heat exchange module are reduced in diameter so that they are inserted into a small section of the heat exchange tubes of the front heat exchange module.
5. A modular heat exchange device, particularly adapted for biomass combustion systems, according to claim 1, characterized in that the flue gas inlet end (4) is sealed by a fire door (42), the fire door (42) comprising an inner cover (28) and a sealing upper cover (31).
6. A modular heat exchange device, particularly adapted for biomass combustion systems, according to claim 3, characterized in that the sealing upper cover (31) comprises a vent flap (32).
7. A modular heat exchange device, particularly suitable for biomass combustion systems, according to claim 3, characterized in that the inner cover (28) or the fire door (42) comprises a guide tube (29) for inserting a compressed air cleaning lance (30), the guide tube (29) being coaxially connected to the heat exchange tube (8).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910297070.0A CN110030548B (en) | 2019-04-01 | 2019-04-01 | Modularized heat exchange device especially suitable for biomass combustion system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910297070.0A CN110030548B (en) | 2019-04-01 | 2019-04-01 | Modularized heat exchange device especially suitable for biomass combustion system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110030548A CN110030548A (en) | 2019-07-19 |
| CN110030548B true CN110030548B (en) | 2024-06-25 |
Family
ID=67238285
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910297070.0A Active CN110030548B (en) | 2019-04-01 | 2019-04-01 | Modularized heat exchange device especially suitable for biomass combustion system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110030548B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6681839B1 (en) * | 2001-02-23 | 2004-01-27 | Brent A. Balzer | Heat exchanger exchange-tube cleaning lance positioning system |
| CN102522583A (en) * | 2011-12-31 | 2012-06-27 | 中国东方电气集团有限公司 | Heat exchange system |
| CN107860022A (en) * | 2017-11-28 | 2018-03-30 | 西安交通大学 | One kind becomes flue cross section tubular air preheater |
| CN108592661A (en) * | 2018-06-29 | 2018-09-28 | 惠州市溶科环保科技有限公司 | A kind of Efficient high-temperature gas heat exchanger |
| CN212178848U (en) * | 2019-04-01 | 2020-12-18 | 黑龙江赫尔特生物质能源发展有限公司 | Modularized heat exchange device especially suitable for biomass combustion system |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1556813A (en) * | 1976-08-12 | 1979-11-28 | Stelrad Group Ltd | Modular heat exchangers with a common flue |
| DE2948201C2 (en) * | 1979-11-30 | 1985-09-26 | Degussa Ag, 6000 Frankfurt | Apparatus and method for periodically cleaning heat exchanger tubes from solid deposits and the use of this apparatus |
| DE19512939A1 (en) * | 1995-04-06 | 1996-10-10 | Harald Dr Ing Lorson | Hot gas cleaning of dust-laden flue gas from gas-fired power stations etc. |
| CN2789609Y (en) * | 2005-05-16 | 2006-06-21 | 中橡集团炭黑工业研究设计院 | Air preheater |
| US7921828B2 (en) * | 2008-03-20 | 2011-04-12 | GM Global Technology Operations LLC | Modulating flow through an exhaust gas recirculation cooler to maintain gas flow velocities conducive to reducing deposit build-ups |
| CN101769540A (en) * | 2008-12-31 | 2010-07-07 | 钟景武 | Straw fuel warm air air-conditioning heating device |
| CN101782340B (en) * | 2009-01-15 | 2013-06-12 | 王智慧 | Multi-stage type high-efficiency bellows waste heat recovery device |
| US9618273B2 (en) * | 2010-04-26 | 2017-04-11 | Claudio Filippone | Modular heat exchanger and conversion system |
| JP2017101902A (en) * | 2015-12-04 | 2017-06-08 | 株式会社クマガワ | Combustion furnace to be used for power generating system |
| CN205593409U (en) * | 2016-04-27 | 2016-09-21 | 成都融科能源环境工程有限公司 | A modular fluoroplastics gas heat exchanger for thermal power factory |
| CN208620881U (en) * | 2018-05-21 | 2019-03-19 | 南京宜热纵联节能科技溧阳有限公司 | A kind of Modular plate-type air cooler |
-
2019
- 2019-04-01 CN CN201910297070.0A patent/CN110030548B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6681839B1 (en) * | 2001-02-23 | 2004-01-27 | Brent A. Balzer | Heat exchanger exchange-tube cleaning lance positioning system |
| CN102522583A (en) * | 2011-12-31 | 2012-06-27 | 中国东方电气集团有限公司 | Heat exchange system |
| CN107860022A (en) * | 2017-11-28 | 2018-03-30 | 西安交通大学 | One kind becomes flue cross section tubular air preheater |
| CN108592661A (en) * | 2018-06-29 | 2018-09-28 | 惠州市溶科环保科技有限公司 | A kind of Efficient high-temperature gas heat exchanger |
| CN212178848U (en) * | 2019-04-01 | 2020-12-18 | 黑龙江赫尔特生物质能源发展有限公司 | Modularized heat exchange device especially suitable for biomass combustion system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110030548A (en) | 2019-07-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101484675B (en) | Indirect-fired gas turbine power plant | |
| US20100243228A1 (en) | Method and Apparatus to Effect Heat Transfer | |
| CN201652438U (en) | Straw-fueled in-flight burning furnace | |
| CN212178848U (en) | Modularized heat exchange device especially suitable for biomass combustion system | |
| CN107384455A (en) | Downdraft radiant tube biomass pyrolytic charcoal processing stove | |
| CN103822357A (en) | Horizontal pulverized coal organic heat carrier boiler | |
| CN210486063U (en) | Modularized boiler | |
| CN110030548B (en) | Modularized heat exchange device especially suitable for biomass combustion system | |
| RU2347147C2 (en) | Method of flue gas purification and heat utilisation and device for its implementation | |
| CN203478344U (en) | Multi-return-stroke reverse combustion heating furnace | |
| RU2213307C2 (en) | Water boiler | |
| CN104930526A (en) | Air curtain system for shock wave soot blowing | |
| CN203771690U (en) | Horizontal coal dust organic heat carrier boiler | |
| RU194770U1 (en) | Heat power plant for heat supply of mine workings and large-volume premises | |
| CN103851605A (en) | Granular fuel heating stove | |
| CN206191559U (en) | Waste heat recovery green hot water boiler | |
| CN208418788U (en) | Inner-rotary type straw direct burning boiler and biomass direct-fired cogeneration system | |
| CN1067730A (en) | Utilize flue gas and hot blast method and device for the heating heavy oil of thermal source | |
| CN101900418B (en) | Organic biomass heat carrier furnace | |
| CN112833383A (en) | Vertical biomass briquetting solid fuel boiler | |
| CN206682953U (en) | A kind of waste incinerator furnace wall cooling air system | |
| CN105465760B (en) | A kind of biomass steam generator | |
| CN113418302B (en) | Heat exchanger structure based on biomass hot blast stove is used | |
| WO2011156871A1 (en) | Indirectly fired gas turbine assembly | |
| CN208833018U (en) | The direct-fired device of low-temperature flue gas in a kind of pair of pipeline |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |