DE2003926A1 - Ship propulsion system - Google Patents

Description

Ship propulsion system The invention relates to a propulsion system for Ships, especially a steam generator for ships with a re. or reheater and the means for regulating the flow of combustion gas passing through said reheater.

The reheating of the steam between different turbine stages is widely recognized as a desirable measure of achievement for today's power plants required high efficiencies recognized. The application of the reheating principle However, a ship's propulsion system is associated with certain factors that are associated with stationary ones Attachments usually do not occur. One of these factors is in marine propulsion common processes, reheating and part of the steam cycle Reverse, when maneuvering and operating the ship ii port.

The one intended for superheating or intermittent superheating of the steam The heat exchanger surface is usually located in a zone where the flue gas operating temperatures are well above the usual limit values for the design temperatures for the metals. However, such use is made possible by the metal cooling effect that results from the fact that steam flows through the tubes of this heat exchanger. One Difficulty arises when reversing, maneuvering and operating of the ship in port when no steam is flowing through the reheater, so that a condition occurs in which the pipe metal temperatures exceed the permissible design limits exceed if no remedial action is taken through joint measures. One One way to overcome this difficulty is to use the reheater in to arrange one of two parallel flue gas flues and regulating flaps to connect that the reheater of hot combustion gases is painted while not in use. This arrangement is known from US Patent 3,280,559.

With the current state of the art, it is costly and frequent impractical to shut off and regulate one. hot and corrosive medium such as boiler flue gas to provide a gas-tight flap. The invention is subject to others are based on the task of protecting a tubular reheater in such a way that that you have an intermediate superheater upstream of a sufficiently large heat exchange surface is used to set the flue gas temperature before the gas enters the reheater to be reduced to sufficiently safe permissible limit values. This heat exchange surface can consist of pipes carrying saturated steam, with which the winch one between the superheater flue gas pass and the reheater flue gas pass arranged first Flue gas ducts are disguised.

An important nerkial of the arrangement with the pipes carrying saturated steam is the formation of an open beam space. Because the heat transfer in this room through Radiation occurs, it is primarily a function of the temperature in the radiation space incoming flue gases and not a function of the gas flow rate, as is the case with Heat transition through touch is the case. With a given boiler output the heat absorption of the radiant space is therefore essentially constant, irrelevant whether the reheater is bypassed or not. this in turn means that the blasting space is the flue gas temperature when bypassing of the reheater. much more effectively because it reduces the amount of the reheater inflowing flue gas is then reduced to a minimum (namely the amount which corresponds to the leakage of the regulating flap). In this way the reheater can be protected against overheating when bypassing the l @ u @@ gases while at the same time a certain additional heat potential ii flue gas available for normal operation stands.

Another task of the invention is to control the Superheated steam temperature by using a saturated steam heat exchange surface instead to enable a superheater surface to regulate the flue gas temperature and thereby protecting the reheater.

If in a steam generator the general disclosed by the applicant Execution part of the superheater surface is arranged in the reheater flue gas duct this part of the superheater remains practically out of operation when reversing, which effectively reduces the superheater area exposed to the combustion gases will.

Since the required superheater surface is basically dependent on the supplied Depending on the amount of fuel, this would mean that with the same fuel throughput with regard to the effective superheater area and the total heat absorption when reversing and forward movement of the ship there are considerable differences. Apparently this would regulate the superheated steam temperature over the entire load range of the Make the unit extremely difficult to operate.

Another object of the invention is to provide an effective and constant operation of the unit in all Operating modes thereby to achieve that the main part of the Eko heating surface is the total flow of combustion gases is exposed. This main part can make up 95 percent or more of the total Eko heating surface include and to increase the heat transfer from pipes with an enlarged heat transfer surface exist. The remaining part of the Eko surface can consist of smooth tubes that in the other flue gas flue provided for bypassing the reheater are arranged. The main task of these pipes is to reduce the flue gas temperature to less than about 10,000 Fahrenheit to the regulating flaps located in the flue gas flow to protect. With this Eko arrangement, the temperature of the feed water remains on dar boiler drum for a given fuel throughput regardless of the respective Operating mode almost constant.

Another object of the invention is to regulate the intermediate steam temperature by regulating the amount of gas flowing through the reheater, dies is achieved through selective setting of the other resp.

Bypassing flue gas inlet of the first contact flue gas flue arranged Regulating flaps reached. These flaps are for a. effective regulation of duroh designed the bypass flowing flue gas. On the other hand, it is provided that the flaps on the double superheater flue gas pass are always either fully open or are completely closed, since their only job is to prevent that the reheater when driving backwards, when maneuvering or during operation of the ships in port is smeared with flue gases. These flaps are therefore necessary as closures and not as Regulating flaps with inevitable Scheme trained.

In the drawings, Fig. 1 is a schematic side view in FIG Section along the line 1-1 in Fig. 2 of an improved steam generator for a Marine propulsion, Fig. 2 is a. schematic plan view in section along the line 2-2 in Fig. 1.

Figures 1 and 2 show a boiler bearing 10, consisting of the front wall 11, the rear wall 12 and the side walls 13 and 14. The boiler storage 10 is enclosed by the casing 15 and the insulation 16. The boiler storage 10 is divided into a combustion chamber 17, a superheater flue gas 18, a first contact flue 19, a reheater flue 20 and one second contact flue 21. The combustion chamber 17 is ton the side wall 13 and parts of the front wall 11 and the rear wall 12 and a partition wall 22 defined. With the exception of part of the partition wall 22, which does not offset an intermediate section arranged pipes To form an inlet provided with a pipe curtain 23 in the superheater flue 18, and the part of the front wall 11, in which the openings 24 for the (not shown) burner are attached, acts the ones surrounding the combustion chamber 17 wind around closed drilling walls. The tubes forming the combustion chamber bottom 34, the partition wall 22 and the side wall 13 begin in the lower collector 25 and end in the steam drum 26. The tubes in the combustion chamber part the front wall 11 begin at the lower collector 27 and end in the upper one @collectors 28 and 29, @ie are connected to the ramp drum 26 via riser pipes 3 @. The leadership of the prenn chamber part of the (not the installed) rear wall 12 is the same as the ear guide the front wall 11, each with the difference, there are no openings in the corner wall available.

@er @ superheater-kauchgaszug 1 @ contains the entire @ superheater- @ heat exchange area, which is made up of vertical, essentially U-shaped and bent over the whole Br @ ite @es @auchgaszuges distributed @ ears 35 composed and together @ ekundär-oberhitzer 36, a tertiary-oberbitzer 37 and a primary superheater 38 exists, which in this order are consecutive in the direction of the gas flow are switched. The parts of the front wall that define the @ superheater @ also gas flue 11 and the rear wall 12 consist of tubes with a wide pitch, the distances are filled with fins 39 between the individual tubes. The pipes in the superheater flue gas part of the front wall 11 begin at the lower header 40 and end in the steam drum 26. The pipe routing of the superheater flue gas pass part of the rear wall (not shown) 12 resembles the ear guide of the front wall 11, but with the difference that in the rear wall doors 41 for entry into the exhaust gas lanes between the upper heater tube bundles are pre-gang. @er overheater - @@ auchgaszug 18 has an inclined floor 42 feuerfestor @uskleid auf. The floor 42 also serves as the ceiling of the @ ammler antechamber 43. The first contact flue 19 is in the gas flow direction after the @ superheater flue 18 arranged. The flues 18 and 19 are through the partition wall 44 separated from one another, which have an intermediate section with tubes arranged in an offset manner to form a flue gas inlet 45 into the first one with a pipe curtain Has contact flue 19. The superheater flue 18 contains an as Tubular curtain formed transverse wall 16, which is primarily used to suspend the tertiary superheater 37 by means of the support brackets 47 is used. The primary superheater 38 and the secondary superheater 36 are suspended from the partition walls 44 and 22 with similar support brackets.

The first contact flue 19 is a vertical, elongated one Train running between the superheater flue 18 and the reheater flue 20 and is arranged laterally adjacent to these trains and from parts of the front and rear pipe wall 11 and 12 respectively and the partition walls 44 and 48 is defined. the Partition 48 includes a lower section with staggered tubes through the one provided with a pipe curtain inlet 50 into the reheater flue gas pass 20 is formed, while two intermediate sections of staggered tubes form the pipe curtains 51 and 52 at the flue gas inlet 45 in the partition wall 44. Min Feed water preheater (Eko) 49 is arranged between the pipe curtains 51 and 52 and consists of serpentine tubes arranged horizontally in the first contact flue 19 76, the pipe ends at the headers 60 resp.

61 are attached. The tubes of the partitions 44 and 40 begin in FIG the lower drum 53 and end in the steam drum 26. The first contact flue gas draft part the tubes forming the front wall 11 begin in the lower header 54 and end in the upper collector 55. The pipe guide of the first contact flue gas draft part the rear wall 12 (not shown) is similar to the guide of the front wall 11.

The upper outlet part 32 of the first located above the collector 55 Contact flue gas 19 is defined by the casing 15 and contains a Flap 5C at inlet 57 of the second contact flue 21. The partition 44 is given away with a door 59 for entry into the collector antechamber space 43.

The reheater flue gas pass 20 is a vertical, elongated one Train that adjoins the first contact flue 19 and runs parallel to it. The reheater flue gas flue 20 ton of the partition wall 48, the side wall, is defined 14 and parts of the front wall 11 and the rear wall 12. The reheater flue gas pass 20 includes a reheater 62 made of coiled tubes 75, these tubes Form several separate tube bundles and across the width of the flue gas passage are arranged. The pipe ends are attached to the headers 63 and 64, respectively. The pipes in the reheater flue gas part of the front wall 11 begin at the bottom Collector 65 and ends at the upper collector 55. The pipe routing of the reheater flue gas pass part the rear wall 12 (not shown) is similar to the pipe guide of the front wall 11. The outlet part 33 of the reheater flue gas flue located above the collector 55 20 is defined by the casing 15 and includes a flap 66 at the entrance 57 of the second contact flue 21.

The @wide contact flue 21 is a vertical, elongated Train that is above the outlets of the first contact flue and the reheater flue arranged and over flaps 56 resp.

66 is associated with these outlets. The second touch flue 21 is defined by walls formed by the formwork 15, and contains a main feedwater preheater (Eko) 67 made of serpentine tubes 74, wherein these tubes form several separate tube bundles and span the width of the flue gas flue are arranged. The Hohrenden flow into dei Sanmler 68 and 69.

Downpipes 70 connect the steam drum to all of the inlet headers the combustion chamber walls, e.g. with the collectors 25 and 27 and the lower drum 53. In addition connect the feed tube 71, the lower drum 53 with the front wall collectors 40, 54 and 65 and with similarly arranged collectors of the rear wall. The steam drum 26 contains the steam separator 72. For the sake of clarity, the connecting Steam piping between drum 26 and the various superheater headers 73 is omitted from the illustration.

When the ship is moving forward normally, the steam-water mixture increases of the steam generator unit following @ eg @ line regulated amount of feed water fed into the inlet collector 68 of the main feedwater preheater 67 and at Combustion gases flow through the coiled pipes 74 on the @eg to the outlet collector 69 heated. The heated feed water is then passed through pipelines (not shown) the collector 60 fed to the bypass 49 and when flowing through the coiled pipes 76 further heated by combustion gases on the way to the outlet collector 61. at another arrangement occurs heated feed water from the Main feed water preheater 67 into collector 61 of the bypass feed water preheater 49 on and off the collector 60. Make flow through the bypass feed water heater 49 is the heated feed water through a feed line (not shown) conventionally fed into the steam drum 26 to a predetermined water level to maintain.

There is a natural cycle through which the water flows into the steam drum 26 in the circuit through the downpipes 70 to the lower drum 53, to the inlet headers 25 and 27 etc.

and from the lower drum through the supply duct 71 to the inlet headers 40, 54 and 65 and to similarly arranged collectors on the rear wall. That from the above-mentioned lower drum and the mentioned entry collectors escaping water is heated and turns into a steam-water mixture, while it is through the tubes of the front wall 11 and the rear wall 12, the side walls 13 and 14 and the partitions 22, 44 and 48 and the pipe curtain 46 rises. That Steam-water mixture is dir @ kt from the partitions and side walls and over the Outlet headers 28, 29 and 55 returned to the steam drum 26 through the riser pipes 30. When entering the steam drum 26, the steam-water mixture passes through the separators 72. The water exiting from the separators 72 goes into the water out of the drum 26 and enters the downpipes 70 from there to again in the Circuit m get. The saturated steam emerging from the separators 72 is passed through Primary scrubber 77 and secondary scrubber 78 passed and after leaving the steam drum 26 through suitable (not pipelines shown, to go through the primary, secondary and tertiary superhiters 38, 36 and 37 one after the other. These superheater parts are connected one after the other and can be placed between the outlet of the primary superheater 38 and the inlet of the secondary superheater 36 (not included) cooler for regulating the steam temperature. The one from the tertiary superheater 37 escaping superheated steam is introduced into the high-pressure turbine (not shown). The Dupf emerging from the high pressure turbine is controlled by suitable (not shown) Pipelines to the reheater inlet header 63 led to when flowing through of the pipes 75 are reheated ru, and exits the reheater outlet header 64 from, through suitable (not shown) Rchrleitung the with reheating working low pressure turbine to be supplied.

The path of the combustion gases is as follows; Fuel and combustion air are inserted through the burner openings 24. After they have some of their heat content to the water wall pipes used to cool the combustion chamber 17, the gases pass through the opening 23 into the superheater flue 18, where they heat to the superheater and saturated steam conducting wall surfaces. From the flue 18 the gases enter the first contact flue 19 through the opening 45, we the gas flow can be divided into two partial flows, one of which according to is directed down to the opening 50 and to part of the water wall pipes of the flue gas 19 gives off heat. The other gas flow is at the curtain tubes 51, 52 and 31 and the feed water heater 49 over up to exit 32 and directed to the flap 56, with these heat-absorbing surfaces and the neighboring Parts of the pipe walls of the flue gas duct carrying saturated steam 19 give off heat. The gases exiting into the reheater flue gas pass 20 are at the reheater 62 and the curtain tubes 31 through the outlet 33 up to the flap 66 steered, with the reheater 62 and the saturated steam conducting pipe wall surfaces Heat is given off. Whenever steam flows through the reheater 20, is located the flap 66 is in the fully open position. The steam temperature at the reheater outlet is achieved by regulating the flap 56 and the resulting change in the gas flow rate to the flue gas flue 20 and controlled by the reheater 63. Closing the Flap 56 has the consequence that a larger amount of smoke gas through the inlet opening 30 flows into the flue gas flue 20 @@, which results in a constant steam throughput Increase in the intermediate steam temperature leads. The opposite effect occurs when the amount of smoke gas is reduced. those emerging from the gas passages 32 and 33 Flue gases flow together through the second contact flue gas duct 21 in dn the feed water flowing through @ so da feed water preheater 67 gives off heat will.

When the ship is moving backwards normally, the steam-water cycle differs from operation during normal forward travel to the extent that that from the tertiary superheater 37 emerging steam of a (not shown) high-pressure condensation turbine is supplied, which is usually referred to as a reverse turbine act the direction of rotation of which corresponds to the direction of rotation of the turbine used for forward travel is opposite. Since in this operating mode there is usually no steam through the When the reheater flows, the steam emerging from the reversing door becomes condensed and returned to the (not shown) Kendensatsystem as Feed water to be used for the boiler.

The path taken by the combustion gases when the ship is moving backwards take, differs from that when driving forward in that essentially all gases exiting the superheater flue 18 through the first contact flue 19 up to the flap 56 and from there further through the second contact flue 21 can be steered. In this operating mode, in which there is no steam through the reheater 62 flows, the flap 66 is closed and the flap 56 is completely open, fle that the flow of combustion gases in and through the reheater flue 20 is essentially shut off.

Since the medium to be controlled is a hot, corrosive one Gas with a temperature up to 1000 degrees Fahrenheit is economical impossible, a gas-tight shut-off valve suitable for the appropriate operation to build. Therefore, for practical reasons, the flap 66 is expected to be Leaks are more than 10 percent of the total gas flow in the closed position suspended. Similar Krwägungen inside the flap 54 lead to the fact that the first contact flue gas @ ug 19 with a sufficiently large heat-absorbing, saturated steam-leading Pipe wall surface was provided to the temperature of the entering in the flue 20 Gases to less than 1000 degrees Fahrenheit, being a Impermeability of more than 20 percent of the total gas flow was assumed.

The flue gas temperature remains the same under all normal operating conditions on flaps 56 and 66 within acceptable limits for the flap metal temperature.

A specific embodiment of a ship steam generator according to the invention with reheating could be operated under the conditions given in Table I. will.

TABLE I OUTPUT MORMAL REVERSE Superheated steam lb / hr 166 200 210 000 Intermediate steam lb / hr 162 800-STEAM TEMPERATURE Superheater outlet temperature ° F 1 000 1,000 reheater outlet temperature ° F 950-SMOKE GAS WEIGHTS Total flue gas lb / hr 238 300 255 820 loading of the superheater 238 300 255 820 loading of the reheater 190 700 51 200 Actuation of the reheater bypass 47 600 204 620 GUEST TEMPERATURE Chamber outlet ° F 2350 2380 By-pass feed water preheater inlet 1070 1135 bypass feed water heater outlet 693 880 Bypass flap entry 685 850 Reheater outlet 710 970 Reheater flap inlet 705 950 Main feed water preheater inlet 700 860 Main feed water preheater outlet 320 335 FEED WATER TEMPERATURE Feed water preheater inlet 0F 280 280 Main feed water preheater outlet 420 475 bypass feed water preheater exit 450 535

Claims (7)

Patent claims 1. Schifi drive system, characterized in that that either superheated steam (superheated steam) and intermediate steam (reheated Steam) from a drive turbine for forward travel and only superheated steam from a drive turbine for reverse travel, further identified by the X combination of the drive system with a steam generating, superheating and inter-superseating Unit, in detail consisting of: winches with boiler tubes that support a boiler form partitions with boiler tubes, through which the boiler storage is divided into a combustion chamber, a superheater gas flue, which is adjacent to the side of the combustion chamber and at its inlet end has an opening to the combustion chamber which extends over extends the entire width and the greater part of the height of the combustion chamber, one Reheater gas cable and a vertical, elongated first contact gas cable, the one between the superheater throttle cable and the reheater throttle cable and on the side is arranged adjacent to these trains and arranged so that it is the entire from the superheater gas flue can absorb the amount of gas escaping, this first Throttle cable with a gas outlet part, which extends to the lower end of the reheater gas cable opens towards, and another gas outlet part for bypassing the gases around the Has reheater throttle cable, Firing devices for the combustion chamber, a bundle of vertically arranged superheater tubes with return bends in the overheater gas flue, an economizer or preheater in the other part mentioned above of the first convection gas flue, a bundle of reheater tubes in the reheater gas flue, which form the entire reheater heating surface, a second convection gas flue, which is set up so that it draws the gas directly from the reheater and gases emerging from the mentioned other part of the first convection gas flue can accommodate another economizer or preheater in the second convection throttle, this preheater for conducting the liquid flow with the former Preheater is connected and the greater part of the total economizer heating surface forms, and damping means for regulating the from the mentioned other part of the first convection gas flue and gas flow emerging from the reheater gas flue. 2. Ship propulsion system according to claim 1, characterized in that that the damping means from a first set of dampers at the outlet of the reheater gas cable and a second set of dampers at the exit of the top of the first convection throttle cable exist. 3. Ship propulsion system according to claim 2, characterized in that that the first set of dampers is fully open and the second set of dampers is using is used to reduce the gas flow between the reheater gas pass and the first convection gas pass to be proportioned when intermediate steam is supplied to the drive turbine for forward travel will. 4. Ship propulsion system according to claim 2, characterized in that that the first saturated damper is fully closed and the second set of damper is open is when only superheated steam is fed to the drive turbine for reversing. 5. Ship propulsion system according to claim 1, characterized in that that the other economizer is connected in series with the first-mentioned economizer, so that the medium flows through both economizers in succession. 6. ship propulsion systems according to claim 5, characterized in that that the flow through the first-mentioned economizer in indirect, heat-absorbing, There is a parallel flow reference to the gases. 7. Ship propulsion system according to claim 5, characterized in that that the flow through the first-mentioned economizer is directly, heat absorbing, Parallel flow relationship with the G @ sen is.