A kind of boat diesel engine combined desulfurization and denitration device and methodTechnical field
What the present invention relates to is a kind of marine exhaust pollutant emission control device, and what the present invention also relates to is a kind of marine exhaust pollutant emission control method.The Ship Power Equipment waste gas washing be specifically related to as meeting International Maritime Organization (IMO) ship exhaust emissions regulation removes the technology of SOx and NOx.
Background technology
According to IMOMARPOL73/78 pact supplemental provisions VI requirement, in Global Regional, from the year two thousand twenty January 1, Ship Power Equipment fuel oil sulfur content is low to moderate 0.5% from current 3.5%; And at sulfur oxides emissions control zone (SECA), from 1 day January in 2015, marine fuel oil sulfur content higher limit dropped to 0.1%; The TierIII standard that on January 1st, 2016, IMO will implement at discharged nitrous oxides control zone (NECA) about NOx emission.
Traditional marine exhaust pollutant post-processing approach technology is more ripe, and efficiency is higher, but the pollutant of removing is single, and waste gas treatment equipment volume and operating cost are all comparatively large, large on engine operation impact.
Combined desulfurization and denitration technology is the technology of a kind of collaborative reduction SOx and NOx discharge, by collaborative uses such as low-sulphur fuel technology, wet waste gas washing technology, SCR technology and EGR technology, as Low Sulfur Fuel Oil associating SCR technology, alternative fuel associating SCR technology, waste gas washing associating SCR technology and waste gas washing associating EGR technology etc.
Wherein, SCR technology utilizes catalytic reduction reaction that the NOx in marine exhaust is converted to N2and H2o, this technology requires strict to reaction temperature, temperature is too low is undertaken affecting reaction; SCR reaction unit is bulky, and take the more boats and ships useful space, operation and maintenance cost is also higher.EGR technology is by increasing working medium specific heat and reduction diesel engine intake oxygen concentration in cylinder, and effectively can reduce NOx generation amount, its volume, operation expense are all much smaller than SCR technology.
For reducing fuel cost, wet waste gas washing desulphurization technology obtains very high accreditation in marine exhaust emission control field.Wet waste gas washing technology to utilize in wash mill in alkaline detergent solution and SO in waste gas2, element sulphur is fixed in a liquid, thus reduces the SO of waste gas2discharge.
Disclose a kind of name in the patent document of number of patent application 201010540886.0 to be called " desulfurization denitration method of marine exhaust and treating apparatus ", adopt ozone, hydrogen peroxide and sodium chloride (nertralizer) to process the waste gas of marine diesel engine generation.Although nertralizer cheap and nonhazardous, in exhuast gas desulfurization denitrification process, EGT is higher, and the acid drops such as intermediate product sulfuric acid, nitric acid, hydrochloric acid easily flow in pipeline with waste gas, etching apparatus; And the N that ozone treating process and neutralisation treatment process generate2o5belong to inflammable and explosive noxious material with chlorine, there is larger potential safety hazard.
Disclose a kind of name in the patent document of number of patent application 201180036380.9 to be called " engine exhaust gas purification device ", during this plant running, the whole waste gas of first cleaning treatment engine, the waste gas part after cleaning imports circulation line and enters compressor through heat exchanger.Because the waste gas after washing is generally saturated or supersaturated gas, in EGR pipe road, EGT reduces easily generation corrosivity drop, after entering compressor, cylinder, adds corrosion and the wearing and tearing on the accurate coupling part surface of engine.
Disclose a kind of name in the patent document of number of patent application 201410059508.9 to be called " internal combustion engine, ERG and the method for EGR ", in the method, EGR is from before turbine, and exhaust gas pressure temperature is all higher.And the water-soluble desulfurization reaction temperature mentioned in method is lower, the waste gas therefore recycled needs to carry out cooling process before interpolation desulfurizing agent.On the one hand, exhaust air mass flow is comparatively large, and heat content is high, requires higher to the cooling effect of cooler; On the other hand, cycle gas is now high temperature and high pressure gas, and containing more utilisable energy, temperature-fall period can increase energy loss, reduces the thermal efficiency of engine.
Summary of the invention
The object of the present invention is to provide one that Marine Diesel Engine's Harmful Exhaust Emission can be made to meet IMO about the restriction of marine fuel oil sulfur content and discharged nitrous oxides requirement simultaneously, and EGR gas can be reduced to the corrosion of the parts such as compressor and cylinder sleeve and wearing and tearing, reduce the boat diesel engine combined desulfurization and denitration device of diesel engine energy loss simultaneously.The present invention also aims to provide a kind of boat diesel engine combined desulfurization and denitration method.
Boat diesel engine combined desulfurization and denitration device of the present invention comprises turbocharger, unidirectional stop valve, Venturi scrubber, cooler, washer, air blast, triple valve, scrubbing tower and cleaning solution baffle-box; The blast pipe of boat diesel engine is connected with turbine in turbocharger, turbine outlet is communicated with the entrance of unidirectional stop valve and triple valve, Venturi scrubber is communicated with unidirectional stop valve and cooler, cooler outlet is connected by pipeline with washer entrance, washer outlet air blast, blower export directly connects the compressor inlet in turbocharger, and unidirectional stop valve, Venturi scrubber, cooler, washer and air blast form diesel exhaust denitration path A; Two outlet washing tower inlets of triple valve and scrubbing tower export pipeline, form diesel exhaust desulfurization path B; Venturi scrubber, washer, scrubbing tower are connected with cleaning solution baffle-box respectively.
Boat diesel engine combined desulfurization and denitration device of the present invention can also comprise:
1, the pipeline be connected with cleaning solution baffle-box at scrubbing tower arranges the first NaOH solution supply point.
2, the pipeline be connected with cleaning solution baffle-box at Venturi scrubber arranges the second NaOH solution supply point.
3, the pipeline be connected with cleaning solution baffle-box at washer arranges the 3rd NaOH solution supply point.
4, described cleaning solution baffle-box is connected with wastewater treatment module, and when cleaning solution washability is not enough, cleaning solution baffle-box discharges cleaning solution to wastewater treatment module.
Boat diesel engine combined desulfurization and denitration method of the present invention comprises the steps:
(1) portion produced after boat diesel engine fuel combustion, through the denitration path A at unidirectional stop valve place, after treatment, imports cylinder; Remaining waste gas, through desulfurization path B, after washing desulphurization, enters ambient air, and the exhaust gas flow ratio of denitration path A and desulfurization path B that flows through is by air compressor control;
(2) waste gas in denitration path A, after unidirectional stop valve, enters Venturi scrubber; Cleaning solution sprays into from Venturi scrubber, mixes with waste gas, removes the particle in waste gas; Cooler reduces EGT and removes SO to NaOH washing liquid2preference temperature; Cycle gas removes SO in washer2and particle; Washer is with demister, and the droplet in removing waste gas, avoids the formation of acid drop; Waste gas, by improving cycle gas pressure, is pressed into turbocharger by air blast;
(3) waste gas in desulfurization path B, through triple valve, enters scrubbing tower, and in tower, cleaning solution cleaning, removes the SO in waste gas2and particle, be then disposed in ambient air;
(4) when Used in Diesel Engines Low Sulfur Fuel Oil, regulating three-way valve, by scrubbing tower bypass; Washer is out of service simultaneously, starts Venturi scrubber and cooler, removes particle and cooling, made the NOx emission satisfy regulatory requirement of engine by EGR to the EGR gas in denitration path A;
(5) cleaning solution is sodium hydroxide solution, and the cleaning solution of scrubbing tower, Venturi scrubber and washer all derives from cleaning solution baffle-box, and circulates use.
The present invention proposes method and the device of boat diesel engine combined desulfurization and denitration.That one can make Marine Diesel Engine's Harmful Exhaust Emission meet IMO about the restriction of marine fuel oil sulfur content and discharged nitrous oxides requirement simultaneously, and EGR gas can be reduced to the corrosion of the parts such as compressor and cylinder sleeve and wearing and tearing, reduce efficiency of waste gas desulfurization denitration method and the equipment of diesel engine energy loss simultaneously.
The present invention propose boat diesel engine combined desulfurization and denitration method compared with prior art advantage be:
(1) this combined desulfurization and denitration system is using NaOH as washing agent, the SO of energy efficient removal cycle gas2.
(2) waste gas starts circulation after turbine, and the energy of waste gas itself is farthest utilized, ensure that the effective power of diesel engine; Exhaust gas pressure after diesel engine turbine and temperature are all less, reduce the design difficulty of recirculating line.
(3) diesel exhaust is through Venturi scrubber and washer process, thoroughly removes the particle in waste gas, decreases waste gas to the corrosion of compressor and cylinder sleeve and wearing and tearing, extends the service life of compressor and cylinder sleeve.
(4) waste gas circulated, after washing, adds water vapour content in waste gas, effectively improves the specific heat of engine intake mixing air, is conducive to the generation and the discharge that reduce NOx in cylinder.
(5) this combined desulfurization and denitration device arranges demister in washer, and the water droplet be mingled with in removing waste gas, effectively prevent the destruction of water droplet to oil film.
(6) in order to ensure the safety of boat diesel engine, unidirectional stop valve and triple valve being set in pipeline, when guaranteeing combined desulfurization and denitration system malfunctions/or safeguard, not affecting boat diesel engine and normally working.
Accompanying drawing explanation
Fig. 1 is the structural representation of boat diesel engine combined desulfurization and denitration device of the present invention.
Detailed description of the invention
Illustrate below and the present invention is described in more detail.
Composition graphs 1, the device of boat diesel engine combined desulfurization and denitration of the present invention comprises turbocharger 2, unidirectional stop valve 3, Venturi scrubber 4, cooler 5, washer 6, air blast 7, triple valve 8, scrubbing tower 9 and cleaning solution baffle-box 10; Diesel engine 1 blast pipe is connected with turbine in turbocharger, turbine outlet is communicated with unidirectional stop valve and triple valve, Venturi scrubber is communicated with unidirectional stop valve and cooler, cooler outlet is connected by pipeline with washer entrance, washer outlet air blast, blower export directly connects the compressor inlet in turbocharger, and unidirectional stop valve, Venturi scrubber, cooler, washer and air blast form diesel exhaust denitration path A; Triple valve is communicated with washing tower inlet and scrubbing tower export pipeline, forms diesel exhaust desulfurization path B.
Venturi scrubber in described denitration path A is connected with cleaning solution baffle-box, cleaning solution flows to Venturi scrubber from cleaning solution baffle-box, the fresh NaOH solution of supply on the way, the cleaning solution in Venturi scrubber after scrubbing exhaust gas, comes back to cleaning solution baffle-box by pipeline.
Washer in described denitration path A is connected with cleaning solution baffle-box, and cleaning solution flows to washer from cleaning solution baffle-box, the fresh NaOH solution of supply on the way, and the cleaning solution in washer after scrubbing exhaust gas, comes back to cleaning solution baffle-box by pipeline.
Scrubbing tower in described desulfurization path B is connected with cleaning solution baffle-box, and cleaning solution flows to scrubbing tower from cleaning solution baffle-box, the fresh NaOH solution of supply on the way, and the cleaning solution in scrubbing tower after scrubbing exhaust gas, comes back to cleaning solution baffle-box by pipeline.
Described cleaning solution baffle-box is connected with wastewater treatment module, and when cleaning solution washability is not enough, cleaning solution baffle-box discharges cleaning solution to wastewater treatment module.
For reaching the object of combined desulfurization and denitration, the waste gas that boat diesel engine is discharged is through following process process:
(1) portion produced after boat diesel engine fuel combustion, through the denitration path A at unidirectional stop valve place, after treatment, imports cylinder; Remaining most of waste gas, through desulfurization path B, after washing desulphurization, enters ambient air, and the exhaust gas flow ratio of denitration path A and desulfurization path B that flows through is by air compressor control.
(2) waste gas in denitration path A, after unidirectional stop valve, enters Venturi scrubber; Cleaning solution sprays into from Venturi scrubber, mixes with waste gas, removes the particle in waste gas; Cooler reduces EGT and removes SO to NaOH washing liquid2preference temperature; Cycle gas thoroughly removes SO in washer2and particle; Washer, with demister, to remove the droplet in waste gas, avoids the formation of acid drop; Air blast is by improving cycle gas pressure, and waste gas press-in is to compressor (turbocharger) the most at last.
(3) waste gas in desulfurization path B, through triple valve, enters scrubbing tower, and in tower, cleaning solution cleaning, removes the SO in waste gas2and particle, be then disposed in ambient air.
(4) when Used in Diesel Engines Low Sulfur Fuel Oil, only need consider whether NOx emission meets IMO emission request.Now adjustable triple valve, by scrubbing tower bypass; Washer is out of service simultaneously, starts Venturi scrubber and cooler, removes particle and cooling, made the NOx emission satisfy regulatory requirement of engine, and reduce plant energy consumption by EGR the EGR gas in denitration path A.
(5) for reducing equipment volume, improving cleaning solution desulfuration efficiency and utilization rate, the cleaning solution in device is sodium hydroxide solution, and the cleaning solution of scrubbing tower, Venturi scrubber and washer all derives from cleaning solution baffle-box, and circulates use.
The blast pipe of diesel engine 1 is connected to the turbine of turbocharger 2, and turbine outlet pipeline is two tunnels, and a road is denitration path A, and another road is desulfurization path B.
Described denitration path A, unidirectional stop valve 3 is communicated with turbine outlet and Venturi scrubber 4, Venturi scrubber 4 is communicated with cooler 5, and then be communicated with washer 6, washer 6 connects air blast 7, and air blast 7 export pipeline is connected with the compressor of turbocharger 2 after converging with diesel engine 1 fresh air inlet pipeline; Venturi scrubber 4 in denitration pipeline A is connected with cleaning solution baffle-box 10 respectively with washer 6, forms cleaning solution closed circuit, and on respective connecting pipeline, is respectively equipped with alkali lye supply place II and III.
Described denitration path A, under normal circumstances, from turbine waste gas out, through unidirectional stop valve 3, enter Venturi scrubber 4, after thoroughly removing most of particle and part SOx wherein, enter cooler 5 and reduce temperature, then enter washer 6, remove the SOx in waste gas and particle wherein, and after the water droplet in demist removing waste gas, through blower, after fresh air mixes in diesel engine 1 air inlet pipeline, enter the compressor in turbocharger 2, compressedly enter cylinder, participate in burning; When denitration path A break down/or safeguard time, close unidirectional stop valve 3, cut out denitration path A, waste gas discharged through desulfurization path B, guarantee diesel engine 1 normally work.
Described desulfurization path B, is made up of triple valve 8 and scrubbing tower 9, and three interfaces of triple valve 8 are connected with scrubbing tower 9 export pipeline with turbine outlet, scrubbing tower 9 entrance respectively; Scrubbing tower 9 is connected by pipeline with cleaning solution baffle-box 10, forms cleaning solution closed circuit, and is furnished with alkali lye supply place I thereon.
Described desulfurization path B, under normal circumstances, waste gas enters scrubbing tower 9 entrance through triple valve 8, removes after particle wherein through washing desulphurization, enters ambient air from scrubbing tower 9 outlet; When scrubbing tower break down/or safeguard time, switch three-way valve 8, from turbine waste gas out, after triple valve 8, is directly bypassed to ambient air, ensures that diesel engine 1 can normally run.
The exhausted air quantity of described denitration path A is controlled by air blast 7.
Described boat diesel engine waste gas combined desulfurization and denitration device, when Used in Diesel Engines Low Sulfur Fuel Oil, scrubbing tower 9 is out of service, by switch three-way valve 8, by scrubbing tower 9 bypass; Washer 6 is out of service simultaneously.
Described boat diesel engine waste gas combined desulfurization and denitration device, the cleaning solution in scrubbing tower 9, Venturi scrubber 4 and washer 6 all derives from cleaning solution baffle-box 10, and circulates (shown in dotted line); The supply of NaOH alkali lye is carried out at I, II, III place respectively; Cleaning solution drains into wastewater treatment module after losing absorbability and processes.
Described boat diesel engine waste gas combined desulfurization and denitration device, for ensureing that waste gas joint processing system does not affect the safe operation of boat diesel engine, unidirectional stop valve 3 and triple valve 8 is provided with in pipeline, when denitration path A break down/or safeguard time, close unidirectional stop valve 3, engine exhaust flows out through triple valve 8; When scrubbing tower 9 break down/or safeguard time, switch three-way valve 8, makes exhaust gas bypass enter ambient air.
The description of aforesaid embodiment is provided for the purpose of illustration and description.That if it does not lie in limit or limit the disclosure.The independently element of specific embodiment or feature are not restricted to specific embodiment usually, but it can make use, for interchangeable and can be used in selected embodiment, even if its not display or describe in detail.It equally also can be changed in many ways.This type of change is not considered the disengaging disclosure, and this type of changes all will be included within the scope of the present disclosure.Should be appreciated that the ordinary skill of this area just design according to the present invention can make many modifications and variations without the need to creative work.Therefore, all technical staff in the art, all should by the determined protection domain of claims under this invention's idea on the basis of existing technology by the available technical scheme of logical analysis, reasoning, or a limited experiment.