Power generation system using waste heat

Abstract

The present invention relates to a power generation system using waste heat. More specifically, a power generation system using waste heat is provided to prevent steam generated in a steam generation unit from being discarded after being condensed by a dump condenser without being fully consumed in steam consumption places by using excess steam to form an organic Rankine cycle unit so that electricity is generated using surplus steam, and including a decompression buffer tank unit provided in front of the organic Rankine cycle unit so that the generated excess steam is constantly and continuously supplied to the organic Rankine cycle unit, thereby enabling stable power generation.

Description

Power generation system using waste heat

[0001] The present invention relates to a power generation system using waste heat, and more specifically, to prevent steam generated in a steam generation unit from being condensed and discarded by a dump condenser without being fully used at a steam use location, an organic Rankine cycle is formed using excess steam to generate electricity with the surplus steam, and a decompression buffer tank is formed in front of the organic Rankine cycle unit so that the excess steam is supplied to the organic Rankine cycle unit in a constant and continuous manner, thereby providing a power generation system using waste heat that enables stable power generation.

[0002] Only about half of the heat energy generated by burning fuel in a ship's propulsion or power generation engine is used for propulsion or power generation, and the remaining heat is wasted as unused waste heat.

[0003] If the waste heat emitted to the outside can be recycled, it can not only significantly reduce the total energy consumed by the ship, but also reduce the carbon dioxide emitted by the ship. Therefore, research is currently underway on ways to utilize the waste heat emitted to the outside.

[0004] For example, in the shipbuilding industry, a waste heat recovery system (WHRS) is being applied to generate electricity by additionally installing a gas turbine that directly uses the high-temperature exhaust gas emitted from the engine as a working fluid, or a steam turbine that uses some of the steam generated by utilizing the heat of the high-temperature exhaust gas as a working fluid.

[0005] However, as more and more ship owners seek to reduce fuel costs by operating their vessels at lower speeds, problems are emerging with conventional power generation methods using waste heat recovery systems. This is because the engine output of slow-moving vessels is only 30 to 50% of maximum output. Consequently, the exhaust gas temperature from engines operating at low loads is low, making it difficult for conventional waste heat recovery systems, which require high temperatures, to function properly.

[0006] To solve these problems, the relevant industry has begun to focus on the development of organic Rankine cycle (ORC) devices.

[0007] An organic Rankine cycle device is a system that generates electricity through a closed cycle of evaporation, expansion, condensation, and compression using a fluid with a high vapor pressure by utilizing waste heat with a low energy level.

[0008] Specifically, the organic Rankine cycle device vaporizes a working fluid through a constant pressure heating process that absorbs heat from an external heat source in an evaporator, and when the pressure within the cycle device rapidly increases due to the vaporization, the increased pressure causes a turbine installed within the cycle to rotate.

[0009] During the adiabatic expansion process, the rotating turbine generates power by converting rotational kinetic energy into electrical energy, and the gas that drives the turbine and passes through it is returned to the condenser, where it undergoes a constant-pressure heat dissipation process in which it loses heat through heat exchange with an external heat source and is adiabatically compressed.

[0010] The liquefied working fluid is recirculated to the evaporator using a pump, and the organic Rankine cycle device can continuously produce electricity. The organic Rankine cycle device has the characteristic that the efficiency increases as the temperature of the external heat source on the high-temperature side increases and as the temperature of the external heat source on the low-temperature side decreases.

[0011] Figure 1 is a drawing showing an energy-saving ship (90) equipped with a conventional power generation device utilizing a temperature difference, which is disclosed in Korean Patent Publication No. 10-2011-0063935 (June 15, 2011).

[0012] An energy-saving vessel (90) equipped with a power generation device utilizing the above temperature difference is configured to include a heat engine (91) that is cooled by fresh water, a cooler (92) in which fresh water and seawater flow and exchange heat with each other, a warm water pipe (93) that connects the heat engine (91) and the cooler (92) and through which warm fresh water discharged from the heat engine (91) flows, a cold water pipe (94) that connects the heat engine (91) and the cooler (92) and through which cold fresh water discharged from the cooler (92) flows, a cold seawater pipe (95) that guides seawater introduced from the outside of the hull to flow to the cooler (92), a warm seawater pipe (96) through which seawater discharged after heat exchange with fresh water in the cooler (92) is discharged, and an organic Rankine cycle device (97) that generates electric power as a working fluid circulates through an evaporator, a turbine, a condenser, and a pump.

[0013] The above energy-saving ship (90) has the characteristic of saving fuel oil and reducing greenhouse gas emissions by installing an organic Rankine cycle device (97) in the cooling system of various heat engines of the ship, which generates electricity by repeating the vaporization and liquefaction process by repeatedly circulating an evaporator and a condenser using a working fluid that is easily vaporized at the same temperature as the high-temperature water of the main engine, auxiliary engine, and boiler drain cooler, and easily liquefied at the same temperature as the low-temperature water of the room temperature or cooler.

[0014] However, the conventional organic Rankine cycle device had a problem in that the turbine that produces electricity rotated quickly and then slowly repeatedly, resulting in uneven electrical energy production.

[0015] And on ships, the steam required for the ship is produced using the exhaust gas generated from the main engine. If less steam is produced than the amount used, additional steam can be produced using an auxiliary boiler. However, if more steam is produced than the amount used, the steam is forcibly cooled using a dump condenser to maintain the main steam line at a constant pressure. This process causes the problem of excess steam not being used but being discarded.

[0016] In particular, with the recent strengthening of environmental regulations and the use of ammonia mixed fuel engines as ship engines, there are fewer places to utilize the surplus steam generated on ships, and the amount of steam that is not consumed by users and is discarded is increasing.

[0017] Accordingly, the relevant industry is demanding the development of technology that can utilize the excess steam for power generation, while also ensuring that the turbines that produce electricity can rotate evenly to produce electricity stably.

[0018] (Patent Document 1) Korean Patent Publication No. 10-2011-0063935 (June 15, 2011)

[0019] The present invention has been devised to solve the above problems.

[0020] The purpose of the present invention is to provide a power generation system using waste heat that prevents steam produced in a steam generation unit from being condensed and discarded by a dump condenser without being fully used at the steam use site.

[0021] Another object of the present invention is to provide a power generation system using waste heat, which can use excess steam that is not used in a steam use site to form an organic Rankine cycle, thereby enabling the excess steam to be used for electricity generation.

[0022] Another object of the present invention is to provide a power generation system utilizing waste heat, which enables stable power generation by configuring a depressurization buffer tank section so that excess steam is supplied to an organic Rankine cycle section in a constant and continuous manner.

[0023] Another object of the present invention is to provide a power generation system utilizing waste heat, which forms a heat exchange section within a depressurized buffer tank section to apply heat to an organic refrigerant circulating in an organic Rankine cycle section with excess steam, thereby allowing the organic refrigerant to be vaporized.

[0024] Another object of the present invention is to provide a power generation system utilizing waste heat, which comprises a dump condenser section to recover and condense steam exceeding a set pressure from a pressure-reducing buffer tank section, and also allows condensate generated at a steam usage site to be collected in one place.

[0025] Another object of the present invention is to provide a power generation system utilizing waste heat, which comprises a steam recovery line section for moving steam discharged from a depressurization buffer tank section to a dump condenser section, and a steam branch line section for branching steam flowing through a steam supply line section to a dump condenser section, thereby recovering and condensing steam that is not used for power generation, thereby preventing an increase in pressure within the pipe.

[0026] Another object of the present invention is to provide a power generation system utilizing waste heat, which comprises a feed tank section so that condensate condensed by cooling in a dump condenser section can be collected in the feed tank section and stored in one place.

[0027] Another object of the present invention is to provide a power generation system utilizing waste heat, which comprises a condensate supply line part having one end connected to a feed tank part and the other end connected to a steam generation part, and a pump formed on the condensate supply line part to supply condensate to the steam generation part so that the condensate heated by engine waste heat is turned into steam, thereby recycling the condensed water and increasing system efficiency.

[0028] Another object of the present invention is to provide a power generation system utilizing waste heat, which allows an organic refrigerant having a high vapor pressure to flow within a closed line, an organic refrigerant line section, so that the organic refrigerant can evaporate even if the temperature of the steam is low, and the evaporated gas rotates an expander section to generate electricity through a power generation section.

[0029] Another object of the present invention is to provide a power generation system utilizing waste heat, which comprises a cooling section and a pump section within an organic Rankine cycle section so that vaporized organic refrigerant can be liquefied again and circulated.

[0030] Another object of the present invention is to provide a power generation system utilizing waste heat, which comprises a first organic refrigerant line connecting an expander section and a cooling section, and a regeneration section that exchanges heat with a second organic refrigerant line connecting the cooling section and a heat exchange section, thereby enabling maximum output while minimizing heat loss.

[0031] Another object of the present invention is to provide a power generation system utilizing waste heat, which increases system efficiency by utilizing low-temperature gas naturally vaporized during LNG transport for cooling, by enabling the cooling source used for cooling in the cooling section of the organic Rankine cycle section to be LNG boil-off gas (BOG) in addition to fresh water or sea water.

[0032] In order to achieve the above-mentioned purpose, the present invention is implemented by an embodiment having the following configuration.

[0033] According to one embodiment of the present invention, the present invention is characterized by including an organic Rankine cycle unit that generates power using thermal energy, and a waste heat supply line unit that is connected to the organic Rankine cycle unit and supplies waste heat to the organic Rankine cycle unit.

[0034] According to another embodiment of the present invention, the present invention is characterized in that the waste heat supply line section supplies waste heat to the organic Rankine cycle section through steam.

[0035] According to another embodiment of the present invention, the present invention is characterized in that the steam is surplus steam that is produced by a steam generating unit that generates steam using waste heat but is not consumed in the steam use location.

[0036] According to another embodiment of the present invention, the power generation system using the waste heat includes a steam supply line section for supplying steam produced in the steam generation section to the steam user, and the waste heat supply line section is characterized in that one end is connected to the steam supply line section and the other end is connected to the organic Rankine cycle section.

[0037] According to another embodiment of the present invention, the power generation system using waste heat is characterized in that it further includes a pressure reducing buffer tank section formed on the steam supply line section and located in front of the organic Rankine cycle section, and which keeps the pressure of the steam supplied to the organic Rankine cycle section constant at a set pressure.

[0038] According to another embodiment of the present invention, the present invention is characterized in that the decompression buffer tank section includes a heat exchange section that applies heat to the organic refrigerant circulating in the organic Rankine cycle section to vaporize it.

[0039] According to another embodiment of the present invention, the power generation system using the waste heat is characterized in that it includes a dump condenser section that recovers and condenses steam exceeding the set pressure from the decompression buffer tank section.

[0040] According to another embodiment of the present invention, the power generation system using waste heat is characterized in that it includes a steam recovery line section, one end of which is connected to the depressurization buffer tank section and the other end of which is connected to the dump condenser section, and moves steam discharged from the depressurization buffer tank section to the dump condenser section.

[0041] According to another embodiment of the present invention, the power generation system using waste heat is characterized in that it includes a steam branch line section, one end of which is connected to the steam supply line section and the other end of which is connected to the dump condenser section, and which branches steam flowing through the steam supply line section to the dump condenser section.

[0042] According to another embodiment of the present invention, the power generation system using the waste heat is characterized in that it includes a feed tank section connected to the dump condenser section and receiving and storing condensate from the dump condenser section.

[0043] According to another embodiment of the present invention, the power generation system using waste heat is characterized in that it includes a condensate supply line unit, one end of which is connected to the feed tank unit and the other end of which is connected to the steam generation unit, and which supplies the condensate stored in the feed tank unit to the steam generation unit.

[0044] According to another embodiment of the present invention, the organic Rankine cycle section includes an organic refrigerant line section through which an organic refrigerant flows, and the organic refrigerant line section is characterized in that the organic refrigerant passes through the heat exchange section so as to be vaporized by the heat exchange section.

[0045] According to another embodiment of the present invention, the glass Rankine cycle unit comprises an expander unit that rotates by vaporized organic refrigerant, a power generation unit that is connected to the expander unit and generates electricity, a cooling unit that condenses the vaporized organic refrigerant discharged from the expander unit, and a pump unit that transfers the liquefied organic refrigerant discharged from the cooling unit to the heat exchange unit.

[0046] According to another embodiment of the present invention, the organic Rankine cycle unit further includes a regeneration unit that heat-exchanges a first organic refrigerant line connecting the expander unit and the cooling unit, and a second organic refrigerant line connecting the cooling unit and the heat exchange unit.

[0047] According to another embodiment of the present invention, the present invention is characterized in that the cooling unit condenses the vaporized organic refrigerant into boil-off gas (BOG).

[0048] The present invention can obtain the following effects through the combination and use of the configuration described above and the following examples.

[0049] The present invention has the effect of providing a power generation system utilizing waste heat, which prevents steam produced in a steam generation unit from being condensed and discarded by a dump condenser without being fully used in the steam usage location.

[0050] The present invention provides a power generation system utilizing waste heat, which enables the surplus steam to be used for electricity generation by constructing an organic Rankine cycle using the surplus steam that is not used at the steam use site.

[0051] The present invention has the effect of providing a power generation system utilizing waste heat that enables stable power generation by configuring a depressurization buffer tank section so that excess steam is supplied to an organic Rankine cycle section in a constant and continuous manner.

[0052] The present invention has the effect of providing a power generation system utilizing waste heat, which forms a heat exchange section within a depressurized buffer tank section and applies heat to an organic refrigerant circulating in an organic Rankine cycle section with excess steam, thereby allowing the organic refrigerant to be vaporized.

[0053] The present invention provides a power generation system utilizing waste heat, which comprises a dump condenser section to recover and condense steam exceeding a set pressure from a pressure-reducing buffer tank section, and also allows condensate generated at a steam use site to be collected in one place.

[0054] The present invention has the effect of providing a power generation system utilizing waste heat, which comprises a steam recovery line section for moving steam discharged from a depressurization buffer tank section to a dump condenser section, and a steam branch line section for branching steam flowing through a steam supply line section to a dump condenser section, thereby recovering and condensing steam that is not used for power generation, thereby preventing an increase in pressure within the pipe.

[0055] The present invention has the effect of providing a power generation system utilizing waste heat, which configures a feed tank section so that condensate condensed by cooling in a dump condenser section can be gathered into the feed tank section and stored in one place.

[0056] The present invention provides a power generation system utilizing waste heat, which comprises a condensate supply line section having one end connected to a feed tank section and the other end connected to a steam generation section, and a pump formed on the condensate supply line section to supply condensate to the steam generation section so that the condensate heated by engine waste heat is turned into steam, thereby recycling the condensed water and increasing system efficiency.

[0057] The present invention has the effect of providing a power generation system utilizing waste heat, which allows an organic refrigerant having a high vapor pressure to flow within a closed line, an organic refrigerant line section, so that the organic refrigerant can evaporate even when the temperature of the steam is low, and the evaporated gas rotates an expander section to generate electricity through a power generation section.

[0058] The present invention has the effect of providing a power generation system utilizing waste heat, which comprises a cooling section and a pump section within an organic Rankine cycle section, so that vaporized organic refrigerant can be liquefied again and circulated.

[0059] The present invention provides a power generation system utilizing waste heat that minimizes heat loss while enabling maximum output by configuring a regeneration unit that heat-exchanges a first organic refrigerant line connecting an expander unit and a cooling unit, and a second organic refrigerant line connecting a cooling unit and a heat exchange unit.

[0060] The present invention has the effect of providing a power generation system utilizing waste heat, which increases system efficiency by utilizing low-temperature gas naturally vaporized during LNG transport for cooling, by enabling the cooling source used for cooling in the cooling section of the organic Rankine cycle section to be LNG boil-off gas (BOG) in addition to fresh water or sea water.

[0061] Figure 1 is a drawing showing an energy-saving ship equipped with a conventional power generation device utilizing temperature difference.

[0062] FIG. 2 is a diagram illustrating a power generation system using waste heat according to one embodiment of the present invention.

[0063] FIG. 3 is a diagram illustrating an organic Rankine cycle unit according to one embodiment of the present invention.

[0064] FIG. 4 is a drawing illustrating an organic Rankine cycle section according to another embodiment of the present invention.

[0065] Figure 5 is a usage diagram of a power generation system using waste heat according to one embodiment of the present invention.

[0066] Figure 6 is a usage diagram of a power generation system using waste heat according to another embodiment of the present invention.

[0067] Hereinafter, preferred embodiments of a power generation system utilizing waste heat according to the present invention will be described in detail with reference to the attached drawings. In the following description of the present invention, if it is determined that a detailed description of a well-known function or structure may unnecessarily obscure the gist of the present invention, such detailed description will be omitted. Unless otherwise defined, all terms in this specification have the same general meaning as those skilled in the art to which the present invention pertains. If there is a conflict between the meaning of a term used in this specification and the meaning of the term, the definition used in this specification shall prevail.

[0068] The present invention relates to a power generation system (1) using waste heat, and in order to prevent steam generated in a steam generation unit from being condensed and discarded by a dump condenser without being fully used at a steam use location, an organic Rankine cycle is formed using excess steam to generate electricity with the surplus steam, and a pressure-reducing buffer tank is formed in front of the organic Rankine cycle unit so that excess steam is supplied to the organic Rankine cycle unit in a constant and continuous manner, thereby enabling stable power generation.

[0069] FIG. 2 is a drawing illustrating a power generation system (1) using waste heat according to one embodiment of the present invention. Referring to FIG. 2, the power generation system (1) using waste heat includes a steam generation unit (10), a depressurization buffer tank unit (20), an organic Rankine cycle unit (30), a dump condenser unit (40), a feed tank unit (50), and a fluid supply line unit (60).

[0070] The above steam generating unit (10) is a configuration that generates steam, and preferably refers to a boiler that produces steam. The steam generating unit (10) may be configured to produce steam using waste heat generated from the ship's engine and condensate supplied from a feed tank unit (50) to be described later. The steam produced in the steam generating unit (10) is supplied to steam users in various locations within the ship that require steam, and in this process, the present invention branches off excess steam toward a decompression buffer tank unit (20) to be described later, so that waste heat that is not fully used in the steam users and is discarded can be utilized for power generation.

[0071] The above-described decompression buffer tank unit (20) is formed on the steam supply line unit (61) to be described later, and, as shown in FIG. 2, is located in front of the organic Rankine cycle unit (30) to be described later, and refers to a configuration that keeps the pressure of the steam supplied to the organic Rankine cycle unit (30) constant at a set pressure. Preferably, the above-described decompression buffer tank unit (20) can constantly control the pressure of the steam supplied to the organic Rankine cycle unit (30) to be 7 bar. Therefore, when the pressure of the steam exceeds 7 bar, the excess portion can be supplied to the dump condenser unit (40) to be described later and condensed. Ultimately, the present invention configures the above-described decompression buffer tank unit (20) so that the excess steam is constantly and continuously supplied to the organic Rankine cycle unit (30) to be described later, thereby enabling stable power production. The above-described decompression buffer tank unit (20) includes a heat exchange unit (21).

[0072] The above heat exchange unit (21) refers to a configuration that applies heat to the organic refrigerant circulating in the organic Rankine cycle unit (30) described later to vaporize it, and can function as an evaporator. The present invention inserts the heat exchange unit (21) into the depressurization buffer tank unit (20) to apply heat to the organic refrigerant circulating in the organic Rankine cycle unit (30) with surplus steam, thereby allowing the organic refrigerant to vaporize.

[0073] The above organic Rankine cycle unit (30) is configured to generate electricity using thermal energy, and the present invention configures an organic Rankine cycle using excess steam that is not used in a steam usage location, thereby allowing the excess steam to be used for electricity generation. Preferably, the capacity of the organic Rankine cycle unit (30) can be adjusted according to the steam usage of the ship in consideration of efficiency and boiler operation. Referring to FIGS. 3 and 4, the organic Rankine cycle unit (30) includes an organic refrigerant line unit (31), an expander unit (32), a power generation unit (33), a cooling unit (34), a pump unit (35), and a regeneration unit (36).

[0074] The organic refrigerant line section (31) may be configured to have an organic refrigerant flowing therein, and may be configured to pass through the heat exchange section (21) so that the organic refrigerant is vaporized by the heat exchange section (21). The present invention allows an organic refrigerant having a high vapor pressure to flow within the organic refrigerant line section (31), which is a closed line, so that the organic refrigerant can vaporize even if the temperature of the steam is low, and the vaporized gas rotates the expander section (32) to be described later, thereby generating electricity through the power generation section (33). Referring to FIGS. 3 and 4, the organic refrigerant line section (31) includes a first organic refrigerant line (311) and a second organic refrigerant line (312).

[0075] The above first organic refrigerant line (311) refers to a configuration that connects the expander unit (32) and the cooling unit (34) to be described later. The organic refrigerant flowing on the first organic refrigerant line (311) is in a gaseous state before being cooled by the cooling unit (34) to be described later. In FIG. 3, the regeneration unit (36) to be described later is not configured, so there is no heat exchange between the first organic refrigerant line (311) and the second organic refrigerant line (312) to be described later. However, referring to FIG. 4, since the regeneration unit (36) to be described later is configured, heat exchange can be performed between the first organic refrigerant line (311) and the second organic refrigerant line (312) to be described later.

[0076] The second organic refrigerant line (312) is configured to connect the cooling unit (34) to be described later and the heat exchange unit (21), and as shown in FIG. 3, a pump unit (35) to be described later is configured on the second organic refrigerant line (312), so that the organic refrigerant that has become a liquid state by cooling by the cooling unit (34) to be described later can easily move toward the heat exchange unit (21) by the pump unit (35) formed on the second organic refrigerant line (312).

[0077] The above expander unit (32) is a power engine that receives kinetic energy from the flow of fluid and converts it into rotational force, and is configured to rotate by vaporized organic refrigerant. The expander unit (32) is connected to a power generation unit (33) described later, so that electricity can be generated by the rotational force of the organic refrigerant.

[0078] The above-mentioned power generation unit (33) refers to a configuration that is connected to the above-mentioned expander unit (32) and generates electricity. As the expander unit (32) rotates due to the fluid flow of the evaporated organic refrigerant, electricity is generated in the power generation unit (33) connected to the expander unit (32). According to the present invention, the waste heat of the remaining steam can be used to produce electricity required for ships, etc.

[0079] The cooling unit (34) above refers to a configuration that condenses the vaporized organic refrigerant discharged from the expander unit (32). The cooling source used for cooling in the cooling unit (34) of the organic Rankine cycle unit (30) may be fresh water or sea water, but preferably, by condensing the vaporized organic refrigerant with boil-off gas (BOG) of LNG, the low-temperature gas naturally vaporized during LNG transport can be utilized for cooling, thereby increasing system efficiency.

[0080] The above pump unit (35) refers to a configuration that transfers the liquefied organic refrigerant discharged from the cooling unit (34) toward the heat exchange unit (21). The present invention configures the cooling unit (34) and the pump unit (35) within the organic Rankine cycle unit (30) so that the vaporized organic refrigerant can be liquefied again and circulated.

[0081] The above regeneration unit (36) refers to a configuration that exchanges heat between the first organic refrigerant line (311) and the second organic refrigerant line (312). As described above, a relatively high-temperature gaseous organic refrigerant flows on the first organic refrigerant line (311), and this high-temperature gaseous organic refrigerant is in a state requiring cooling by the cooling unit (34). Conversely, a relatively low-temperature liquid-state organic refrigerant flows on the second organic refrigerant line (312), and this low-temperature liquid-state organic refrigerant is in a state requiring heating by the heat exchange unit (21). Therefore, if the temperature of the gaseous organic refrigerant is lowered before entering the cooling unit (34) and the temperature of the liquid-state organic refrigerant is raised before entering the heat exchange unit (21), maximum output can be achieved while minimizing heat loss, and system efficiency can be greatly increased. Accordingly, the present invention configures the regeneration unit (36) as shown in FIG. 4 so that the first organic refrigerant line (311) and the second organic refrigerant line (312) exchange heat, so that the organic refrigerant in a gaseous state before entering the cooling unit (34) can be precooled, and the organic refrigerant in a liquid state before entering the heat exchange unit (21) can be preheated.

[0082] The above dump condenser unit (40) refers to a configuration that recovers and condenses steam exceeding the set pressure from the pressure reduction buffer tank unit (20). Preferably, when the set pressure of 7 bar is exceeded, the surplus steam can flow toward the dump condenser unit (40). The present invention configures the dump condenser unit (40) to recover and condense steam exceeding the set pressure from the pressure reduction buffer tank unit (20), and also allows condensate, etc. generated at the steam usage site to be collected in one place.

[0083] The above feed tank section (50) is configured to be connected to the dump condenser section (40) and to receive and store condensate from the dump condenser section (40). The condensate condensed by cooling in the dump condenser section (40) is collected in the feed tank section (50) and stored in one place, and the feed tank section (50) is configured to provide the stored condensate to the steam generator section (10) by means of a condensate supply line section (65) to be described later.

[0084] The above fluid supply line section (60) is a configuration that collectively refers to a pipeline that transports a gaseous or liquid fluid. Referring to FIG. 5, the fluid supply line section (60) includes a steam supply line section (61), a waste heat supply line section (62), a steam recovery line section (63), a steam branch line section (64), and a condensate supply line section (65).

[0085] The above steam supply line unit (61) refers to a configuration that supplies steam produced in the steam generation unit (10) to the steam user. One side of the steam supply line unit (61) may be connected to the steam generation unit (10), and the other side of the steam supply line unit (61) may be connected to the steam user. A waste heat supply line unit (62), which will be described later, is connected to the steam supply line unit (61), so that surplus steam that is not fully used in the steam user can be branched off from the steam supply line unit (61) through the waste heat supply line unit (62).

[0086] The waste heat supply line unit (62) refers to a configuration that is connected to the organic Rankine cycle unit (30) and supplies waste heat to the organic Rankine cycle unit (30). Preferably, the waste heat supply line unit (62) may be configured to supply waste heat to the organic Rankine cycle unit (30) via steam. At this time, the steam refers to surplus steam that is produced by the steam generation unit (10) that generates steam using waste heat, but is not consumed in the steam use location. One side of the waste heat supply line unit (62) is connected to the steam supply line unit (61), and the other side is connected to the organic Rankine cycle unit (30).

[0087] The above steam recovery line section (63) is configured such that one side is connected to the decompression buffer tank section (20) and the other side is connected to the dump condenser section (40), and moves steam discharged from the decompression buffer tank section (20) to the dump condenser section (40). As described above, the decompression buffer tank section (20) always keeps the bar setting of the steam constant so that steady electricity can be produced in the organic Rankine cycle section (30). When a situation occurs where the set pressure value is exceeded, the surplus steam is transferred to the dump condenser section (40) through the steam recovery line section (63).

[0088] The above steam branch line section (64) is configured such that one side is connected to the steam supply line section (61) and the other side is connected to the dump condenser section (40), thereby branching the steam flowing through the steam supply line section (61) to the dump condenser section (40). The present invention configures the steam branch line section (64) to recover and condense steam that is not used for power generation, thereby preventing an increase in pressure within the pipe.

[0089] The above condensate supply line section (65) is configured such that one side is connected to the feed tank section (50) and the other side is connected to the steam generation section (10), and supplies the condensate stored in the feed tank section (50) to the steam generation section (10). The present invention configures the condensate supply line section (65) to supply condensate to the steam generation section (10) so that the condensate heated by engine waste heat is converted into steam, thereby recycling the condensed water and increasing system efficiency. Referring to Fig. 5, the condensate supply line section (65) includes a condensate pump section (651).

[0090] The above condensate pump unit (651) is formed on the condensate supply line unit (65) and refers to a configuration that allows the condensate flowing inside the condensate supply line unit (65) to move toward the steam generation unit (10). By means of the condensate pump unit (651), the condensate stored in the feed tank unit (50) can be easily transported to the steam generation unit (10).

[0091] FIG. 5 is a diagram showing the state of use of a power generation system (1) using waste heat according to one embodiment of the present invention, and FIG. 6 is a diagram showing the state of use of a power generation system (1) using waste heat according to another embodiment of the present invention. Hereinafter, with reference to FIGS. 5 and 6, the state of use of a power generation system (1) using waste heat according to the present invention will be described.

[0092] As illustrated in FIGS. 5 and 6, waste heat, which is the remaining heat energy generated by burning fuel in the engine (E) of the ship, can be used to produce steam in the steam generation unit (10). The steam generated in the steam generation unit (10) is supplied to steam-using locations in the ship that require steam through the steam supply line unit (61), and unused steam can be moved to the organic Rankine cycle unit (30) through the waste heat supply line unit (62).

[0093] A depressurized buffer tank (20) is formed in front of the organic Rankine cycle section (30) to supply a constant amount of steam at a constant pressure, so that the organic Rankine cycle section (30) can produce steady and stable power. A heat exchange section (21) is inserted into the depressurized buffer tank section (20), and the heat exchange section (21) functions as an evaporator for the organic Rankine cycle.

[0094] Steam that has completed heat exchange in the heat exchange unit (21) enters the dump condenser unit (40) through the steam recovery line unit (63) and is condensed, and the organic refrigerant that is heated and evaporated in the heat exchange unit (21) rotates the expander unit (32) in a gaseous state, and power is generated in the power generation unit (33) by the rotational force of the expander unit (32).

[0095] The organic refrigerant in the gas phase that is discharged by rotating the above expander section (32) enters the cooling section (34) and is cooled. Fresh water, sea water, or boil-off gas (BOG) of LNG can be used as a cooling source. The liquid organic refrigerant cooled by the cooling section (34) circulates while moving back toward the heat exchange section (21) through the pump section (35).

[0096] The organic Rankine cycle unit (30) may be additionally configured with a regeneration unit (36). The regeneration unit (36) exchanges heat between the first organic refrigerant line (311) and the second organic refrigerant line (312), thereby lowering the temperature of the organic refrigerant in a gaseous state before entering the cooling unit (34) and raising the temperature of the organic refrigerant in a liquid state before entering the heat exchange unit (21), thereby greatly increasing the system efficiency.

[0097] Meanwhile, the water condensed by the dump condenser section (40) moves to the feed tank section (50), where the condensate is collected and stored, and then moves to the steam generation section (10) through the condensate supply line section (65) to be used as water required to create steam.

[0098] The detailed description above is illustrative of the present invention. Furthermore, the above description illustrates and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. In other words, changes or modifications are possible within the scope of the inventive concept disclosed in this specification, the scope equivalent to the written disclosure, and / or the scope of technology or knowledge in the art. The written embodiments illustrate the best possible state for implementing the technical idea of ​​the present invention, and various modifications required for specific application fields and uses of the present invention are also possible. Therefore, the detailed description of the invention above is not intended to limit the present invention to the disclosed embodiments. Furthermore, the appended claims should be construed to include other embodiments.

Claims

1. An organic Rankine cycle section that generates electricity using thermal energy, A power generation system using waste heat, characterized in that it includes a waste heat supply line section connected to the organic Rankine cycle section and supplying waste heat to the organic Rankine cycle section.

2. In paragraph 1, A power generation system using waste heat, characterized in that the waste heat supply line section supplies waste heat to the organic Rankine cycle section through steam.

3. In paragraph 2, A power generation system using waste heat, characterized in that the above steam is surplus steam produced by a steam generation unit that generates steam using waste heat but is not consumed in the steam use location.

4. In paragraph 3, The power generation system using the above waste heat includes a steam supply line section that supplies steam produced in the steam generation section to the steam user, A power generation system using waste heat, characterized in that the waste heat supply line section is connected at one end to the steam supply line section and at the other end to the organic Rankine cycle section.

5. In paragraph 4, A power generation system using waste heat, characterized in that the system further includes a pressure reducing buffer tank formed on the steam supply line section and positioned in front of the organic Rankine cycle section to keep the pressure of steam supplied to the organic Rankine cycle section constant at a set pressure.

6. In paragraph 5, A power generation system using waste heat, characterized in that the above-mentioned depressurized buffer tank section includes a heat exchange section that applies heat to the organic refrigerant circulating in the organic Rankine cycle section to vaporize it.

7. In paragraph 5, A power generation system using waste heat, characterized in that the system includes a dump condenser section that recovers and condenses steam exceeding the set pressure from the depressurization buffer tank section.

8. In paragraph 7, A power generation system using waste heat, characterized in that the system includes a steam recovery line section, one end of which is connected to the depressurization buffer tank section and the other end of which is connected to the dump condenser section, and which moves steam discharged from the depressurization buffer tank section to the dump condenser section.

9. In paragraph 7, A power generation system using waste heat, characterized in that the system includes a steam branch line section, one end of which is connected to the steam supply line section and the other end of which is connected to the dump condenser section, and which branches steam flowing through the steam supply line section to the dump condenser section.

10. In paragraph 7, A power generation system using waste heat, characterized in that the system includes a feed tank section connected to the dump condenser section and receiving and storing condensate from the dump condenser section.

11. In paragraph 10, A power generation system using waste heat, characterized in that the system includes a condensate supply line section having one end connected to the feed tank section and the other end connected to the steam generation section, and supplying the condensate stored in the feed tank section to the steam generation section.

12. In paragraph 6, The above organic Rankine cycle section includes an organic refrigerant line section in which an organic refrigerant flows, A power generation system using waste heat, characterized in that the organic refrigerant line section passes through the heat exchange section so that the organic refrigerant is vaporized by the heat exchange section.

13. In paragraph 12, A power generation system using waste heat, characterized in that the glass Rankine cycle section includes an expander section that rotates by vaporized organic refrigerant, a power generation section that is connected to the expander section and generates electricity, a cooling section that condenses the vaporized organic refrigerant discharged from the expander section, and a pump section that transfers the liquefied organic refrigerant discharged from the cooling section to the heat exchange section.

14. In paragraph 13, A power generation system using waste heat, characterized in that the organic Rankine cycle section further includes a regeneration section that heat-exchanges a first organic refrigerant line connecting the expander section and the cooling section, and a second organic refrigerant line connecting the cooling section and the heat exchange section.

15. In paragraph 13, A power generation system using waste heat, characterized in that the cooling unit condenses the vaporized organic refrigerant into boil-off gas (BOG).

Images