Ship steam rankine cycle system and condensate subcooling degree regulation method

Abstract

The present application relates to the field of ship power technology, and provides a ship steam Rankine cycle system and a condensate supercooling degree regulation method.The ship steam Rankine cycle system comprises a steam generating device, a steam turbine, a direct contact condenser and a cooler.The direct contact condenser comprises a condensing area and a condensate tank, the condensing area is provided with a condensate chamber, the condensate tank is provided with a condensate heating module, and the condensing area is communicated with the condensate tank.The condensate heating module comprises at least one heat exchange pipe layer, and in the case that the condensate heating module comprises multiple heat exchange pipe layers, the multiple heat exchange pipe layers are arranged in the condensate tank along a first direction.The condensate heating module is communicated with the steam generating device, and the condensing area is communicated with the steam turbine.The ship steam Rankine cycle system and the condensate supercooling degree regulation method provided by the present application can solve the defect that the condensate supercooling degree regulation is difficult in the ship steam Rankine cycle system of the prior art.

Description

Technical Field

[0001] This invention relates to the field of marine propulsion technology, and in particular to a marine steam Rankine cycle system and a method for controlling condensate subcooling. Background Technology

[0002] In marine propulsion systems, direct contact condensers are typically used for heat exchange. In existing direct contact condensers, condensate is ejected through nozzles, passes through baffles to form a thin water film, and the two sides of this water film directly contact the exhaust steam, condensing it. Maintaining the water film is crucial for the normal and stable operation of the direct contact condenser.

[0003] However, compared to land-based fixed platforms, offshore platforms experience more variable operating conditions and greater condenser load variations. If the designed cooling water is still used for cooling under low operating conditions, the condensate will become significantly overcooled. Increased subcooling leads to a corresponding increase in oxygen content in the condensate, accelerating corrosion of condensate feedwater pipelines and affecting the safety and reliability of the steam Rankine cycle. If the cooling water flow rate is reduced under low operating conditions, some valves need to be closed to maintain the water film morphology, resulting in a reduced cooling water pump flow rate, deviating from the designed operating conditions, increased vibration and noise, and limited adjustment capabilities. At the same time, to adapt to the condensation requirements of different operating conditions, more valves are needed to control the opening and closing of the nozzles, affecting both reliability and compactness. Furthermore, the closure of some nozzles will disrupt the uniformity of the water film distribution, making it difficult for some exhaust steam to fully contact the water film for condensation, thus affecting the condensation effect. By using exhaust steam generated by other equipment or fresh steam after desuperheating and depressurization to feed into the condensate tank of the condenser, the condensate can be further heated to near saturation temperature, thereby achieving the purpose of deoxygenation of the condensate. However, under low operating conditions and high subcooling, the required amount of steam is large, and the steam bubbling condensation generates a lot of noise. How to achieve low-noise and uniform deoxygenation has become the key to the design of direct contact condensers and ship propulsion systems.

[0004] In view of this, there is an urgent need for a ship steam Rankine cycle system and a method for controlling the subcooling of condensate to solve the above problems. Summary of the Invention

[0005] This invention provides a ship steam Rankine cycle system and a method for controlling condensate subcooling, which solves the problem of high difficulty in controlling condensate subcooling in existing ship steam Rankine cycle systems.

[0006] The present invention provides a marine steam Rankine cycle system, comprising: a steam generator, a steam turbine, a direct contact condenser, and a cooler;

[0007] The direct contact condenser includes a condensation zone and a condensate tank. The condensation zone is equipped with a condensate chamber, and the condensate tank is equipped with a condensate heating module. The condensation zone is connected to the condensate tank.

[0008] The condensate heating module includes at least one heat exchange tube layer. When the condensate heating module includes multiple heat exchange tube layers, the multiple heat exchange tube layers are spaced apart in the condensate tank along a first direction. In two adjacent heat exchange tube layers, the outlet of the previous heat exchange tube layer is connected to the inlet of the next heat exchange tube layer.

[0009] The steam inlet of the steam turbine is connected to the steam outlet of the steam generating device, the steam inlet of the condensate heating module is connected to the steam outlet of the steam generating device, the condensation zone is connected to the steam outlet of the steam turbine, the condensate outlet of the condensate tank is connected to the condensate inlet of the cooler, the condensate outlet of the condensate tank is connected to the steam generating device, and the condensate outlet of the cooler is connected to the condensate chamber.

[0010] According to the Rankine cycle system for ship steam provided by the present invention, the heat exchange tube layer includes an intermediate manifold, and heat exchange tube groups are respectively provided on both sides of the intermediate manifold.

[0011] According to the Rankine cycle system for ship steam provided by the present invention, the intermediate manifold includes a first pipe section and a second pipe section, the heat exchange tube group includes multiple heat exchange tubes, the inlet of the heat exchange tube is connected to the first pipe section, and the outlet of the heat exchange tube is connected to the second pipe section.

[0012] The ship steam Rankine cycle system provided by the present invention further includes a jet pump and a condensate pump;

[0013] The condensate outlet of the condensate tank is connected to the condensate inlet of the jet pump, and the condensate outlet of the condensate heating module is connected to the working water inlet of the jet pump.

[0014] The outlet of the jet pump is connected to the inlet of the condensate pump, and the outlet of the condensate pump is connected to the inlet of the cooler.

[0015] According to the Rankine cycle system for marine steam provided by the present invention, the direct contact condenser further includes a gas distribution zone, in which a gas distribution mechanism is provided, the steam outlet of the steam turbine is connected to the gas distribution zone, and the gas distribution zone is connected to the condensation zone.

[0016] According to the Rankine cycle system for marine steam provided by the present invention, the direct contact condenser further includes a non-condensable gas recovery module, the non-condensable gas recovery module includes an air extraction device, and the air inlet of the air extraction device is connected to the air distribution zone.

[0017] According to the ship steam Rankine cycle system provided by the present invention, the non-condensable gas recovery module further includes a condensate drain device, the outlet end of the air extraction device is connected to the condensate drain device, and the condensate drain device is connected to the condensate tank.

[0018] The ship steam Rankine circulation system provided by the present invention further includes a bubbling pipe, one end of which is located in the condensate tank, and the end of the bubbling pipe located in the tank is provided with a plurality of bubbling nozzles.

[0019] According to the ship steam Rankine cycle system provided by the present invention, a control valve is provided on the pipeline connecting the steam generator and the condensate tank.

[0020] Another aspect of the present invention provides a method for controlling the condensate subcooling of a ship steam Rankine cycle system as described in any of the preceding claims, comprising:

[0021] Obtain the operating condition information of the ship's steam Rankine cycle system;

[0022] When the ship's steam Rankine cycle system is in the first operating condition, part of the steam generated by the steam generator is controlled to be introduced into the condensate heating module, and the bubbling pipe is controlled to blow heating gas into the condensate tank to heat the condensate in the condensate tank to the set temperature.

[0023] When the ship's steam Rankine cycle system is in the second operating condition, the bubbling pipe is controlled to blow heating gas into the condensate tank to heat the condensate in the tank to the set temperature.

[0024] The Rankine cycle steam system and condensate subcooling control method provided by this invention address the issue of insufficient condensate subcooling in low-temperature operation. When the system operates under low-temperature conditions, the turbine generates relatively little exhaust steam, which is insufficient to heat the condensate to the set temperature in the condensation zone directly contacting the condenser. In this case, a portion of the steam generated by the steam generator can be introduced into the condensate heating module. The multi-stage heat exchange tubes in the condensate heating module heat the condensate in the condensate tank in stages, achieving the set subcooling, reducing the oxygen content in the condensate, preventing cavitation of components such as the condensate pump, and achieving low-noise, simple subcooling regulation. When the system operates under medium- to high-temperature conditions, the turbine generates more exhaust steam. In the condensation zone directly contacting the condenser, the exhaust steam alone is sufficient to heat the condensate to near the set temperature. In this case, desuperheating and depressurization steam or exhaust steam bubbling heating of the condensate can then be used to maintain the required condensate subcooling.

[0025] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a ship steam Rankine cycle system provided in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of a direct contact condenser in a ship steam Rankine cycle system provided in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the first-stage heat exchanger tube layer in a ship steam Rankine cycle system provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the secondary heat exchanger tube layer in a ship steam Rankine cycle system provided in an embodiment of the present invention;

[0031] Figure 5 This is a schematic flowchart of the condensate subcooling control method provided in an embodiment of the present invention.

[0032] Figure label:

[0033] 1. Steam generator; 2. Steam turbine; 3. Direct contact condenser; 301. Gas distribution zone; 302. Condensation zone; 303. Condensate tank; 304. Condensate chamber; 305. Primary heat exchanger tube layer; 306. Secondary heat exchanger tube layer; 307. Exhaust device; 308. Drainage device; 4. Cooler; 5. Jet pump; 6. Condensate pump; 7. Bubble tube; 8. Control valve; 9. Feed water pump; 10. Heat exchanger tube assembly. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0036] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions 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 one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0037] Overview of existing technologies:

[0038] The propulsion system is a crucial component of a ship, providing essential propulsion and electrical power. The Rankine cycle is a common type of marine propulsion system, and the condenser is one of the most critical components. It condenses the exhaust steam from the turbine using a cooling medium (usually cooling water), and then transports the condensate to the steam generator via condensate and feedwater transport modules, thus completing the entire cycle. Compared to land-based Rankine cycles, offshore platform propulsion systems have higher requirements for compactness, safety, and stealth. Traditional shell-and-tube condensers are bulky and heavy, occupying significant valuable compartment space, and the heat exchange tubes are susceptible to corrosion due to exhaust steam scouring. Direct-contact condensers, which condense exhaust steam through direct contact between cooling water and shell-and-tube heat exchangers, offer advantages such as high heat transfer coefficient, small size and weight, and high safety and reliability, making them highly suitable for marine platform propulsion systems.

[0039] When the condenser of a ship's power system operates under low-condition conditions, partially closing nozzles to reduce cooling water volume is employed. This process requires controlling a large number of valves, leading to difficulties in control, limited adjustment range, complex control strategies, and reduced safety and reliability. Furthermore, the cooling water pump experiences increased vibration and noise during low-condition operation, and the uneven liquid film distribution makes complete condensation of exhaust steam difficult. Conversely, directly using fresh steam or desuperheated / depressurized steam for bubbling and deaeration during low-condition operation results in high steam consumption and strong vibration and noise from bubbling and bubble collapse. This invention proposes a ship steam Rankine cycle system and a method for controlling condensate subcooling, which utilizes fresh steam / exhaust steam in a cascaded manner to heat the condensate in the condensate tank of the condenser.

[0040] The following is combined with Figures 1 to 5 This invention describes the ship steam Rankine cycle system and the method for controlling condensate subcooling provided by the present invention.

[0041] like Figure 1 As shown, the present invention provides a ship steam Rankine cycle system, comprising: a steam generator 1, a steam turbine 2, a direct contact condenser 3, and a cooler 4;

[0042] The direct contact condenser 3 includes a condensation zone 302 and a condensate tank 303. The condensation zone 302 is provided with a condensate chamber 304, and the condensate tank 303 is provided with a condensate heating module. The condensation zone 302 is connected to the condensate tank 303.

[0043] The condensate heating module includes at least one heat exchange tube layer. When the condensate heating module includes multiple heat exchange tube layers, the multiple heat exchange tube layers are spaced apart in the condensate tank 303 along the first direction. In two adjacent heat exchange tube layers, the outlet of the previous heat exchange tube layer is connected to the inlet of the next heat exchange tube layer.

[0044] The steam inlet of the steam turbine 2 is connected to the steam outlet of the steam generator 1, the steam inlet of the condensate heating module is connected to the steam outlet of the steam generator 1, the condensate zone 302 is connected to the steam outlet of the steam turbine 2, the condensate outlet of the condensate tank 303 is connected to the condensate inlet of the cooler 4, the condensate outlet of the condensate tank 303 is connected to the steam generator 1, and the condensate outlet of the cooler 4 is connected to the condensate chamber 304.

[0045] The condensate chamber 304 can be arranged in direct contact with the condenser water chamber. In the water chamber, the cooling water sprayed from the nozzle passes through the baffle plate and forms a vertically descending liquid film. The liquid film is distributed throughout the water chamber. During the downward flow of steam, it comes into direct contact with the liquid film and condenses.

[0046] The Rankine cycle steam system and condensate subcooling control method provided by this invention address the following issues: When the system operates under low conditions, the exhaust steam generated by turbine 2 is insufficient. In the condensation zone 302 directly contacting condenser 3, the condensate cannot be heated to the set temperature. In this case, a portion of the steam generated by steam generator 1 can be introduced into the condensate heating module. The multi-stage heat exchange tubes in the condensate heating module can heat the condensate in the condensate tank 303 in stages, achieving the set subcooling, reducing the oxygen content in the condensate, preventing cavitation of components such as the condensate pump 6, and achieving low-noise, simple subcooling regulation. When the system operates under medium to high conditions, the exhaust steam generated by turbine 2 is more abundant. In the condensation zone 302 directly contacting condenser 3, the exhaust steam alone is sufficient to heat the condensate to a temperature close to the set temperature. In this case, desuperheating and depressurization steam or exhaust steam bubbling heating of the condensate can then be used to maintain the required condensate subcooling.

[0047] In this embodiment of the invention, the heat exchange tube layer includes an intermediate manifold, and heat exchange tube groups 10 are respectively provided on both sides of the intermediate manifold. After a portion of the high-temperature steam generated by the steam generator 1 is introduced into the condensate heating module, the steam enters the heat exchange tube group of the heat exchange tube layer and exchanges heat with the condensate in the condensate tank 303, thereby heating the condensate and reducing the subcooling of the condensate.

[0048] Specifically, in this embodiment, the condensate heating module includes two heat exchange tube layers: a primary heat exchange tube layer 305 and a secondary heat exchange tube layer 306. The primary heat exchange tube layer 305 is located above the secondary heat exchange tube layer 306 (in this case, the first direction is vertical). Steam mainly undergoes steam condensation heating in the primary heat exchange tube layer 305. After steam condensation heating, high-pressure condensate with a certain temperature and grade enters the secondary heat exchange tube layer 306 and exchanges heat with the condensate in the condensate tank 303.

[0049] It is foreseeable that in some embodiments, the condensate heating module may include only one heat exchange tube layer, or it may include three or more heat exchange tube layers, depending on actual needs. This invention does not make any specific limitations on this.

[0050] like Figure 2 and Figure 3As shown in a specific embodiment of the present invention, the intermediate manifold includes a first pipe section and a second pipe section. The heat exchange tube group 10 includes multiple heat exchange tubes. The inlet end of the heat exchange tube is connected to the first pipe section, and the outlet end of the heat exchange tube is connected to the second pipe section. In each heat exchange tube layer, after steam enters the first pipe section, it enters each heat exchange tube located on both sides of the first pipe section, and then enters the second pipe section from the outlet end of each heat exchange tube, and enters the intermediate manifold of the next stage heat exchange tube layer 305 (at this time, the steam may condense into a liquid phase, forming high-pressure condensate) or is discharged. The steam exchanges heat with the condensate in the condensate tank 303 in a wall-to-wall manner in the heat exchange tube, thereby heating the condensate.

[0051] like Figure 2 and Figure 3 As shown in this embodiment, each heat exchange tube in the heat exchange tube group 10 is U-shaped, and each heat exchange tube on both sides can cover the cross section of the condensate tank 303 to achieve the technical effect of fully exchanging heat with the condensate.

[0052] In some embodiments, the heat exchange tubes in the heat exchange tube group 10 may be configured in other shapes, such as coil structures, according to the specific cross-sectional shape of the condensate tank 303 (usually square or circular), so as to cover the entire cross-section of the condensate tank 303.

[0053] In this embodiment, the uppermost primary heat exchange tube layer 305 uses circular channels, and the diameter of the heat exchange tubes in the primary heat exchange tube layer 305 is larger than the diameter of the heat exchange tubes in the secondary heat exchange tube layer 306. This prevents excessive heat exchange from causing condensate to supercool and boil on the surface of the heat exchange tubes. The principle is that because the primary heat exchange tube layer 305 uses thicker tubes with poorer heat exchange efficiency, its heat exchange capacity is limited, and it is less likely to cause severe supercooling and boiling during the heating of condensate.

[0054] In this embodiment, in each heat exchange tube group 10 of each heat exchange tube layer, the inner diameter of the outer heat exchange tube is larger than that of the inner heat exchange tube. Since the steam travels a longer path in the outer heat exchange tube and a shorter path in the inner heat exchange tube, this arrangement ensures a uniform steam flow rate in the heat exchange tube, thereby improving the heat exchange effect.

[0055] Furthermore, in this embodiment, the diameter of each heat exchange tube in the secondary heat exchange tube layer 306 is smaller than the diameter of each heat exchange tube in the primary heat exchange tube layer 305. Since the secondary heat exchange tube layer 306 mainly contains condensate, its heat exchange capacity is significantly reduced compared to the condensation phase change in the primary heat exchange tube layer. Therefore, reducing the diameter of the heat exchange tubes in the secondary heat exchange tube layer 306 enhances the heat exchange method and improves the heat exchange effect.

[0056] In this embodiment of the invention, the ship's steam Rankine cycle system further includes a jet pump 5 and a condensate pump 6; the condensate outlet of the condensate tank 303 is connected to the condensate inlet of the jet pump 5, and the condensate outlet of the condensate heating module is connected to the working water inlet of the jet pump 5; the outlet of the jet pump 5 is connected to the inlet of the condensate pump 6, and the outlet of the condensate pump 6 is connected to the inlet of the cooler 4. By heating the condensate in the upper layer of the condensate tank 303 using the condensate heating module, the condensate temperature in the condensate tank 303 is significantly increased, reducing the subcooling of the condensate. After the new steam is heated by the condensate heating module, it condenses into lower temperature and higher pressure condensate, which is then further pressurized by the jet pump 5, increasing the condensate pressure at the inlet of the condensate pump 6, thereby reducing the risk of cavitation damage to the condensate pump 6.

[0057] like Figure 1 As shown in this embodiment of the invention, the direct contact condenser 3 further includes a gas distribution zone 301, which is equipped with a gas distribution mechanism. The steam outlet of the turbine 2 is connected to the gas distribution zone 301, and the gas distribution zone 301 is connected to the condensation zone 302. Specifically, the gas distribution mechanism includes multiple spaced gas distribution plates, which can evenly distribute the exhaust steam sent from the steam outlet of the turbine 2 into the condensation zone 302 to achieve a better direct contact heat exchange effect. In the condensation zone 302, the cooling water film in the condensate chamber 304 and the cooling water film sprayed from the nozzles connected to the cooler 4 directly contact and condense. The condensed water is collected in the condensate tank 303.

[0058] like Figure 1 As shown in this embodiment of the invention, the direct contact condenser 3 further includes a non-condensable gas recovery module. The non-condensable gas recovery module includes an extraction device 307, the inlet of which is connected to the gas distribution zone 301. Since the exhaust steam sent out from the steam outlet of the turbine 2 contains some non-condensable gases, by setting up the non-condensable gas recovery module, the extraction device 307 can be used to discharge the non-condensable gases (and some steam) accumulated in the upper space of the gas distribution zone 301 into the compartment.

[0059] In some embodiments, a small condenser may be provided inside the extraction device 307 to condense the vapor mixed in the non-condensable gas and prevent the vapor from entering the chamber.

[0060] like Figure 1 As shown, in a further embodiment of the present invention, the non-condensable gas recovery module further includes a condensate drain device 308. The outlet end of the extraction device 307 is connected to the condensate drain device 308, and the condensate drain device 308 is connected to the condensate tank 303. By setting the condensate drain device 308, steam and water can be identified, thereby achieving the purpose of automatically blocking steam and draining water, so as to discharge condensate into the condensate tank 303.

[0061] like Figure 1As shown, in this embodiment of the invention, the ship's steam Rankine cycle system also includes a bubbling tube 7. One end of the bubbling tube 7 is located inside the condensate tank 303, and the end of the bubbling tube 7 inside the tank is equipped with multiple bubbling nozzles. Specifically, in this embodiment, the bubbling tube 7 is located below the condensate heating module (specifically below the secondary heat exchange tube layer 306). When the system is running under high operating conditions, the turbine 2 generates a large amount of exhaust steam. In the condensation zone 302 that directly contacts the condenser 3, the exhaust steam generated by the turbine 2 alone is sufficient to heat the condensate to a temperature close to the set temperature (usually the saturation temperature). At this time, desuperheating and depressurization steam or exhaust steam is introduced into the condensate tank 303 through the bubbling tube 7 to bubble and heat the condensate, which can meet the requirement of maintaining the subcooling of the condensate.

[0062] like Figure 1 As shown in this embodiment of the invention, a control valve 8 is provided on the pipeline connecting the steam generator 1 and the condensate tank 303. When the system is detected to be in a low operating condition, the control valve 8 on the pipeline connecting the steam generator 1 and the condensate tank 303 can be opened to allow some of the steam generated by the steam generator 1 to be introduced into the condensate heating module to heat the condensate in the condensate tank 303.

[0063] In some embodiments, a pressure detection device and a temperature detection device may be installed on the pipeline connecting the steam generator 1 and the condensate tank 303 to monitor the pressure of the steam entering the condensate tank 303. A temperature detection device may also be installed in the condensate system to detect the subcooling of the condensate by detecting the condensate temperature.

[0064] As can be seen from the above description of the embodiments, the ship steam Rankine cycle system provided by the present invention has at least the following advantages:

[0065] (1) It can comprehensively utilize new steam and / or exhaust steam to heat the condensate in the condensate tank 303, replacing the scheme of directly contacting the nozzle of the condenser 3 by adjusting the valve. Under the premise of maintaining the subcooling of the condensate tank 303, it eliminates the complex valve control, reduces the volume occupied by the valve, and at the same time, the control is simple and the safety and reliability are improved. At the same time, by adopting this scheme, the cooling water pumps such as the condensate pump 6 can be maintained at the design operating conditions, avoiding the cooling water pumps such as the condensate pump 6 from operating off-center, and reducing the vibration and noise of the cooling water pumps such as the condensate pump 6.

[0066] (2) By setting up a direct contact condenser 3, it is possible to prevent fresh steam from being directly discharged into the condensate tank 303, thereby avoiding bubbling noise caused by a huge pressure difference. At the same time, the high-pressure condensate formed after the fresh steam is condensed is used to eject the condensate at the outlet of the condensate tank 303 of the direct contact condenser 3, further increasing the condensate pressure and reducing the cavitation risk of the condensate pump 6;

[0067] (3) The opening of the electric regulating valve is controlled by the regulating valve opening controller on the new steam branch. Under the design conditions, the valve is completely closed to improve the system conversion efficiency. Under the unfavorable conditions, the valve is opened to provide new steam as needed and avoid excessive steam.

[0068] The following describes the condensate subcooling control method provided by the present invention. The condensate subcooling control method described below can be referred to in correspondence with the ship steam Rankine cycle system described above.

[0069] like Figure 5 As shown, the present invention also provides a method for controlling the condensate subcooling of a ship steam Rankine cycle system based on the above embodiments, comprising:

[0070] S510. Obtain the operating condition information of the ship's steam Rankine cycle system;

[0071] S520. When the ship's steam Rankine cycle system is in the first operating condition, part of the steam generated by the steam generator 1 is controlled to be introduced into the condensate heating module, and the bubbling pipe 7 is controlled to blow heating gas into the condensate tank 303 to heat the condensate in the condensate tank 303 to the set temperature; when the ship's steam Rankine cycle system is in the second operating condition, the bubbling pipe 7 is controlled to blow heating gas into the condensate tank 303 to heat the condensate in the condensate tank 303 to the set temperature.

[0072] It should be noted that the first operating condition mentioned above specifically refers to the low operating condition, and the second operating condition mentioned above specifically refers to the medium-high operating condition. In the specific implementation process, the operating condition information of the steam Rankine cycle system can be obtained through [the relevant method / mechanism].

[0073] The condensate subcooling control method provided by this invention will be specifically described below based on the aforementioned ship steam Rankine cycle system. Please refer to... Figures 1 to 4 .

[0074] When the system is running under design conditions (medium-high operating conditions), the electric regulating valve on the high-temperature and high-pressure new steam branch (the pipeline connecting the steam generator 1 and the condensate heating module) is closed. The high-temperature and high-pressure steam generated by the steam generator 1 flows into the steam turbine 2, where it does work and converts internal energy into kinetic energy to provide propulsion power and electricity for the entire ship. The exhaust steam from the steam turbine 2 after doing work flows into the direct contact condenser 3. After being evenly distributed by the distribution plate set in the gas distribution area 301, it enters the condensation area 302 of the direct contact condenser 3. In the condensation area 302, the exhaust steam directly contacts and condenses with the cooling water film sprayed from the condenser water chamber and the nozzle connected to the cooler 4. The condensed water is collected in the condensate tank 303. The desuperheating and depressurization steam or exhaust steam bubbling into the condensate tank 303 by the bubble tube 7 heats the condensate to the required subcooling degree. The condensate then flows out through the condensate outlet of the condensate tank 303, passing sequentially through the jet pump 5 (which is not working at this time and only serves a circulation function) and the condensate pump 6. After that, most of the condensate flows into the cooler 4 through the cooling water branch pipe. Under the action of the cooler 4, the condensate is cooled and then flows into the condenser water chamber as cooling water. A small portion of the condensate is further pressurized by the feed water pump 9 and flows into the steam generator 1 to generate steam in the steam generator 1.

[0075] When operating conditions deviate from the design conditions, such as when the power system is running at low operating conditions, relying solely on desuperheated and depressurized steam or exhaust steam bubbling heating is insufficient to meet the requirements for heating the condensate in the condensate tank 303 and regulating the subcooling. At this time, the electric regulating valve on the high-temperature, high-pressure new steam branch (the pipeline connecting the steam generator 1 and the condensate heating module) is opened, allowing some of the high-temperature, high-pressure new steam generated by the steam generator 1 to be introduced into the condensate heating module located in the condensate tank 303. This steam then heats the condensate in the upper layer of the condensate tank 303 through the primary heat exchange tube layer 305 (primarily for steam condensation heating) and the secondary heat exchange tube layer 306 (primarily for water / water heat exchange). Simultaneously, desuperheated and depressurized steam or exhaust steam bubbles through the bubbling pipe 7 in the lower layer of the condensate tank 303 to further regulate the condensate subcooling. The high-pressure condensate formed after the high-temperature, high-pressure new steam condenses is introduced into the working water inlet of the jet pump 5 to eject the condensate flowing directly out of the condenser 3 outlet, increasing the condensate pressure and reducing the cavitation risk of the condensate pump 6.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ship steam Rankine cycle system, characterized in that, include: Steam generators, steam turbines, direct contact condensers, and coolers; The direct contact condenser includes a condensation zone and a condensate tank. The condensation zone is equipped with a condensate chamber, and the condensate tank is equipped with a condensate heating module. The condensation zone is connected to the condensate tank. The condensate heating module includes at least one heat exchange tube layer. When the condensate heating module includes multiple heat exchange tube layers, the multiple heat exchange tube layers are spaced apart in the condensate tank along a first direction. In two adjacent heat exchange tube layers, the outlet of the previous heat exchange tube layer is connected to the inlet of the next heat exchange tube layer. The steam inlet of the steam turbine is connected to the steam outlet of the steam generating device, the steam inlet of the condensate heating module is connected to the steam outlet of the steam generating device, the condensation zone is connected to the steam outlet of the steam turbine, the condensate outlet of the condensate tank is connected to the condensate inlet of the cooler, the condensate outlet of the condensate tank is connected to the steam generating device, and the condensate outlet of the cooler is connected to the condensate chamber.

2. The ship steam Rankine cycle system according to claim 1, characterized in that, The heat exchange tube layer includes an intermediate manifold, and heat exchange tube groups are respectively provided on both sides of the intermediate manifold.

3. The ship steam Rankine cycle system according to claim 2, characterized in that, The intermediate manifold includes a first pipe section and a second pipe section, and the heat exchange tube group includes multiple heat exchange tubes. The inlet of the heat exchange tube is connected to the first pipe section, and the outlet of the heat exchange tube is connected to the second pipe section.

4. The ship steam Rankine cycle system according to claim 1, characterized in that, It also includes jet pumps and condensate pumps; The condensate outlet of the condensate tank is connected to the condensate inlet of the jet pump, and the condensate outlet of the condensate heating module is connected to the working water inlet of the jet pump. The outlet of the jet pump is connected to the inlet of the condensate pump, and the outlet of the condensate pump is connected to the inlet of the cooler.

5. The ship steam Rankine cycle system according to claim 1, characterized in that, The direct contact condenser also includes a gas distribution zone, in which a gas distribution mechanism is provided. The steam outlet of the steam turbine is connected to the gas distribution zone, and the gas distribution zone is connected to the condensation zone.

6. The ship steam Rankine cycle system according to claim 5, characterized in that, The direct contact condenser also includes a non-condensable gas recovery module, which includes an air extraction device, the air inlet of which is connected to the air distribution area.

7. The ship steam Rankine cycle system according to claim 6, characterized in that, The non-condensable gas recovery module also includes a water-draining device. The outlet of the extraction device is connected to the water-draining device, and the water-draining device is connected to the condensate tank.

8. The ship steam Rankine cycle system according to claim 1, characterized in that, It also includes a bubbling tube, one end of which is located inside the condensate tank, and the end of the bubbling tube inside the tank is provided with multiple bubbling nozzles.

9. The ship steam Rankine cycle system according to claim 1, characterized in that, A control valve is installed on the pipeline connecting the steam generator and the condensate tank.

10. A method for controlling the condensate subcooling of a ship steam Rankine cycle system according to any one of claims 1 to 9, characterized in that, include: Obtain the operating condition information of the ship's steam Rankine cycle system; When the ship's steam Rankine cycle system is in the first operating condition, part of the steam generated by the steam generator is controlled to be introduced into the condensate heating module, and the bubbling pipe is controlled to blow heating gas into the condensate tank to heat the condensate in the condensate tank to the set temperature. When the ship's steam Rankine cycle system is in the second operating condition, the bubbling pipe is controlled to blow heating gas into the condensate tank to heat the condensate in the tank to the set temperature.

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