KR102117381B1 - Energy saving apparatus of a ship using waste heat - Google Patents

Abstract

Disclosed is a ship energy saving device. Energy saving device of the ship of the present invention, the low-temperature waste heat recovery system operating with an organic refrigerant having a lower boiling point than water as a working fluid; A waste heat recovery system for generating electric power using exhaust gas discharged from a ship engine as a working fluid; And a feed water heat exchanger that heats the water supplied to the heat exchanger with the organic refrigerant in a condenser of the low and medium temperature waste heat recovery system to drive the steam turbine of the waste heat recovery system.

Description

Energy saving device for ships using waste heat from organic refrigerants {ENERGY SAVING APPARATUS OF A SHIP USING WASTE HEAT}

The present invention relates to an energy-saving device for a ship, and more particularly, an energy-saving device for a ship using waste heat discarded by a condenser of a low-temperature waste heat recovery system operating with an organic refrigerant having a lower boiling point than water as a working fluid. It is about.

In general, about 50% of the thermal energy generated by burning fuel in a propulsion or power generation engine of a ship is used for propulsion or power generation, respectively, but almost all of the rest is cooled through heat exchange to the form of exhaust gas or engine cooling water. It is consumed in the form of being discharged to the outside through the back. The heat discharged in this form cannot be converted into a form useful for the propulsion or power generation of the engine, and can be said to be wasted heat, and thus it is called waste heat.

Therefore, if some of the waste heat discharged to the outside can be recovered and recycled as useful energy, fuel can be saved as much as possible, and thus, it can greatly contribute to reducing the total energy consumed by the ship.

As a result, in recent years, there is a need for a high-efficiency ship or an eco-friendly ship capable of saving energy by recovering some of the waste heat discharged to the outside. In the field of ships, gas turbines (or power turbines) that use high-temperature exhaust gas emitted from the engine as a working fluid for several years ago and part of the steam generated by using the heat of high-temperature exhaust gas are used as working fluid. A so-called waste heat recovery system (WHRS) is applied to additionally install steam turbines to produce electricity.

In recent years, ships operating at low speed have increased the number of ship owners who demand to reduce fuel costs. Therefore, when the ship is operated at low speed, the engine output uses only 30% to 50% of the maximum power.

If the engine is operated at such a low load, the exhaust gas temperature is low, so the existing waste heat recovery device using high-temperature heat cannot function properly. In other words, gas turbines and steam turbines of the conventional waste heat recovery device were able to recover heat only from heat sources of about 250 degrees Celsius or higher, thereby producing electrical energy. Have no problems.

Incidentally, the waste heat recovery device of a conventional ship recovers a relatively high temperature of the heat energy that is wasted, thereby producing electric power, so that when the engine is operated at a high load, it can recover a large amount of heat to produce electric power, but the engine is low. When operating under load, the temperature of the exhaust gas, that is, the waste heat is relatively low, thereby reducing the utility of power generation.

Therefore, a device capable of operating with a medium or low temperature waste heat of about 100 degrees to 250 degrees Celsius as a heat source is required, and such a device has been filed and registered by the applicant of the Korean Registered Patent Publication No. 10-1328401 (2013.11.06 ).

That is, the medium and low temperature waste heat recovery device is a turbine cycle that operates using an organic refrigerant having a lower boiling point than water as a working fluid, and is commonly referred to as an ORC (Organic Rankine Cycle) device. Because it uses an organic refrigerant with a lower boiling point than water, it can operate at a temperature lower than that of a steam turbine that uses water as a working fluid, and it can produce electric energy using waste heat of 250 degrees Celsius or less generated from ships. .

The above-described embodiment is limited to supplying and using the waste heat that is wasted from the ship as an evaporator of the medium and low temperature waste heat recovery device, and there is no discussion about the heat source of the organic refrigerant that is discarded as it is during condensation in the condenser. That is, the organic refrigerant, which is the working fluid supplied to the condenser of the low-temperature waste heat recovery device, is condensed by fresh water of about 36 degrees supplied to the condenser. In this process, all the heat of the organic refrigerant is discarded by the fresh water. .

Korean Patent Registration No. 10-1328401 (Daewoo Shipbuilding & Marine Engineering Co., Ltd.) 2013.11.06

Therefore, the technical problem to be achieved by the present invention is to enable the heat exchanger to exchange heat with the organic refrigerant in the condenser of the low and medium temperature waste heat recovery system to supply the heat supplied to the heat exchanger to drive the steam turbine of the waste heat recovery system. It is to provide an energy saving device for a ship that can be saved.

According to an aspect of the present invention, a low-temperature waste heat recovery system operated using an organic refrigerant having a lower boiling point than water as a working fluid; A waste heat recovery system for generating electric power using exhaust gas discharged from a ship engine as a working fluid; And a water heat exchanger for heat-exchanging the water supplied to the heat exchanger with the organic refrigerant in the condenser of the low and medium temperature waste heat recovery system for driving the steam turbine of the waste heat recovery system.

The feed water heat exchanger may include a branch line that branches off from the leading line of the heat exchanger and passes through the condenser and then returns to the leading line; And a direction control valve provided in an intersection region of the branch line and the leading line to supply the water supply to the heat exchanger by bypassing the condenser or the condenser.

In addition to the feed water heat exchanger, fresh water may be supplied to the condenser to compensate for the insufficient cooling capacity of the organic refrigerant.

A cooling water circulation system for supplying waste heat of the cooling water to the evaporator of the medium and low temperature waste heat recovery system may be further provided.

An engine scavenging cooling unit provided on a line between the feed water heat exchange part and the heat exchanger to heat the feed water flowing into the heat exchanger may be further included.

It may further include an exhaust gas recirculation system for recirculating a portion of the exhaust gas and supplying it to the engine, but exchanging the exhaust gas and the feed water in a front end line of the heat exchanger.

A control unit may be further provided on the exhaust line of the exhaust gas to supply the exhaust gas to either the waste heat recovery system or the exhaust gas recirculation system.

The waste heat recovery system includes: a gas turbine that is directly driven by the exhaust gas discharged from the engine and provides a driving force to rotate a generator; A steam turbine interlocked with the gas turbine and providing a driving force for rotating the generator by the provided steam; A condenser for condensing steam discharged from the steam turbine; A vacuum degassing unit that removes dissolved oxygen from the condensed water by vacuum; A heat exchanger feed pump for pumping the degassed water from the vacuum degassing unit; And a heat exchanger that heats the feed water exchanged in the condenser and the exhaust gas discharged from the engine to generate steam for driving the steam turbine.

The exhaust gas recirculation system includes a scrubber for removing impurities contained in the exhaust gas discharged from the engine; A cooler that cools the exhaust gas supplied to the scrubber; And a blower blowing the exhaust gas cooled so that the exhaust gas cooled in the cooler is supplied from a supercharger and mixed with scavenging air flowing into the engine to be supplied to the engine.

The cooler may include: a first cooler that primarily cools the exhaust gas by mutually exchanging the exhaust gas discharged from the scrubber and the feed water circulated in the waste heat recovery system; And a second cooler for secondarily cooling the exhaust gas by mutually exchanging the exhaust gas discharged from the first cooler and a liquid separate from the water supply.

In addition, according to another aspect of the present invention, the waste heat wasted from the condenser of the low-temperature and low-temperature waste heat recovery system operating with an organic refrigerant having a lower boiling point than water as the working fluid, and the exhaust gas discharged from the engine of the ship as the working fluid An energy-saving device for a ship, characterized in that it is used as a heat source for heating the feed water supplied to the heat exchanger of the waste heat recovery system for producing electric power.

Embodiments of the present invention can maximize the waste heat recovery by saving heat by maximizing waste heat recovery by allowing heat exchanged with the organic refrigerant in the condenser of the low and medium temperature waste heat recovery system to supply the heat supplied to the heat exchanger to drive the steam turbine of the waste heat recovery system. .

1 is a conceptual diagram schematically showing an energy saving device of a ship using waste heat of an organic refrigerant according to a first embodiment of the present invention.
FIG. 2 is a view showing the operation of FIG. 1 schematically showing a process in which the water supply of the waste heat recovery system is supplied through a condenser of a medium and low temperature waste heat recovery device.
FIG. 3 is a view showing the operation of FIG. 1 schematically showing a process in which the water supply of the waste heat recovery system is supplied by bypassing the condenser of the medium and low temperature waste heat recovery device.
4 is a conceptual diagram schematically showing an energy saving device of a ship using waste heat of an organic refrigerant according to a second embodiment of the present invention.
5 is a conceptual view schematically showing an energy saving device of a ship using waste heat of an organic refrigerant according to a third embodiment of the present invention.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the contents described in the accompanying drawings, which illustrate preferred embodiments of the present invention.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings. The same reference numerals in each drawing denote the same members.

1 is a conceptual diagram schematically showing a device for saving energy of a ship using waste heat of an organic refrigerant according to a first embodiment of the present invention.

As shown in this figure, the energy-saving device 1 of the ship according to the present embodiment is a low-temperature waste heat recovery system 100 operating with an organic refrigerant having a lower boiling point than water as a working fluid, and an engine of a ship (E) the waste heat recovery system 200 for generating power by using the exhaust gas discharged from the working fluid, and the water supplied to the heat exchanger 280 for driving the steam turbine 220 of the waste heat recovery system 200 A condenser 140 of the medium and low temperature waste heat recovery system 100 includes a feed water heat exchanger 300 for heat exchange with an organic refrigerant, and a main flow channel 410 through which cooling water for cooling the engine E flows, and the medium and low temperature waste heat recovery A cooling water circulation system 400 for supplying waste heat of cooling water to the evaporator 110 of the system 100 is provided.

The medium and low temperature waste heat recovery system 100 is a turbine cycle operated by using an organic refrigerant having a lower boiling point than water as a working fluid, and is also commonly referred to as an organic Rankine Cycle (ORC).

In this embodiment, the medium and low temperature waste heat recovery system 100 can use an organic refrigerant having a lower boiling point than water, for example, R 134a, so it can operate at a lower temperature than a steam turbine using water as a heat source. Electric energy can be produced by using waste heat around 100 ℃.

In addition, in this embodiment, engine cooling water (Jacket Cooling Fresh Water), a heat source having a lower temperature than steam used in ships, is used as a heat source and heat transfer material to evaporate the organic refrigerant, which is the working fluid of the medium and low temperature waste heat recovery system 100. It has the advantage of saving the fuel of the overall energy consumed on the ship.

Referring now to the low-temperature waste heat recovery system 100 in detail, the low-temperature waste heat recovery system 100 evaporates the organic refrigerant through heat exchange with cooling water delivered from the engine E, as shown in FIG. 1. The evaporator 110, the turbine 120 rotated through the organic refrigerant evaporated by the evaporator 110, the generator 130 interlocking with the rotation of the turbine 120 to produce power, and the turbine 120 ) Condenser 140 to cool and liquefy the organic refrigerant from the condenser, pump 150 to compress the condensed organic refrigerant from the condenser 140 and provide it to the evaporator 110, and turbine from the evaporator 110 It includes a conduit 160 to form a circulation path of the organic refrigerant to the 120 and the condenser 140 and the pump 150.

In this embodiment, the heat source that is the cooling water supplied from the engine E has a temperature of about 80 ° C., but as will be described later, the temperature rises to about 86 ° C. while passing through the dumping condenser unit 440, and the engine scavenging cooling unit ( 450), the temperature rises to about 106 ℃. The heat source, which is the cooling water having the increased temperature, drops about 80 ° C. after heat exchange with the evaporator 110.

In addition, the medium and low temperature waste heat recovery system 100 is characterized in that, as with other turbine systems, the higher the temperature difference between the high temperature portion heated in the evaporator 110 and the low temperature portion cooled in the condenser 140, the higher the efficiency. That is, the higher the temperature of the high-temperature portion that flows into the evaporator 110 and transfers heat to the evaporator 110, and the lower the temperature of the low-temperature portion that flows into the condenser 140 and condenses the organic refrigerant, the higher the efficiency.

The waste heat recovery system 200 generates electric power by using high-temperature exhaust gas discharged from the engine E as a direct working fluid or using a part of the steam generated by using high-temperature exhaust gas as a working fluid. Plays a role.

The waste heat recovery system 200 in this embodiment, as shown in Figure 1, the gas turbine 210 and the gas turbine 210, which is directly driven by the exhaust gas discharged from the engine E to provide a driving force to rotate the generator, gas The steam turbine 220 which is connected to the turbine 210 and provides a driving force for rotating the generator by steam provided from the heat exchanger 280 described later, and a condenser 230 that condenses the steam discharged from the steam turbine 220. ), A water supply pump 240 for pumping the water condensed from the condenser 230, and a water supply line pumped and discharged from the water supply pump 240, and the water supply is transferred to a vacuum degassing unit 260 to be described later or a condenser It includes a control valve 250 for opening and closing the condensate discharge line to be circulated to 230, and a vacuum degassing unit 260 in which condensate condensed in the condenser 230 is stored. Reference numeral T is a water supply tank, and the vacuum degassing unit 260 may be a vacuum degassing tank that removes dissolved oxygen from the water supplied by vacuum.

In addition, in the present embodiment, the waste heat recovery system 200 includes a heat exchanger water supply pump 270 for pumping water stored in the water supply tank 260 in the direction of the water supply heat exchanger 300 to be described later, as shown in FIG. 1. , Heat exchanger 280 to heat the heat exchanged in the heat exchanger feed pump 270 and the exhaust gas discharged from the engine E to generate steam for driving the steam turbine 220, and heat exchanger 280 It includes a steam separator 290 for separating the steam and water from the steam generated in the.

And in this embodiment, the heat exchanger 280 may be provided in multiple stages to improve heat exchange efficiency.

The water supply heat exchanger 300 is provided in a line between the heat exchanger water supply pump 270 and the heat exchanger 280, as shown in FIG. 1, and supplied to the heat exchanger 280 for driving the steam turbine 220. It serves to exchange heat with the organic refrigerant in the condenser 140 of the medium and low temperature waste heat recovery system 100.

The conventional method, that is, a method of supplying fresh water, which is cooling water in order to condense organic refrigerant in a condenser, has been forced to discard the heat source of the organic refrigerant. For reference, the temperature of fresh water supplied to condense the condenser is about 36 degrees.

However, in this embodiment, the water supplied to the heat exchanger 280 for driving the steam turbine 220 (about 27 to 30 degrees lower than the temperature of the fresh water of about 36 degrees supplied to the cooling water of the condenser 140) Prepared to exchange heat with the organic refrigerant in the condenser 140 of the low and medium temperature waste heat recovery system 100 through the feed water heat exchange unit 300.

As a result, the waste heat of the organic refrigerant discarded from the condenser 140 of the low and medium temperature waste heat recovery system 100 can be recovered, thereby maximizing the recovery of waste heat and saving energy.

In this embodiment, the feed water heat exchanger 300 is branched from the leading line of the heat exchanger 280 and passes through the condenser 140 of the low and medium temperature waste heat recovery system 100, as shown in FIG. Directional control valve to be supplied to the heat exchanger 280 by bypassing the condenser 140 or the condenser 140 provided in the crossing region of the branch line 310 and the branch line 310 and the leading line returning to 320).

The direction control valve 320 of the water supply heat exchange unit 300, a line connecting the heat exchanger water supply pump 270 and the heat exchanger 280, as shown in Figure 1, a pair may be provided spaced apart. Among the pair of directional control valves 320, the directional control valve 320 disposed closest to the heat exchanger water supply pump 270 supplies the water supplied from the heat exchanger water supply pump 270 to a condenser 140 or a condenser 140. Bypass to serve to supply to the heat exchanger (280). The rest of the direction control valve 320 may serve to prevent the water supply bypassing the condenser 140 from flowing back to the condenser 140.

In this embodiment, the direction control valve 320 may be a three-way valve, and the three-way valve may be an electronic control valve operated by an electrical signal. Also, the direction control valve 320 disposed closest to the heat exchanger 280 may be a check valve.

On the other hand, in the present embodiment, if the organic refrigerant is not sufficiently cooled due to a lack of cooling capability of the water supplied from the water heat exchanger 300, the efficiency or equipment problem of the low and medium temperature waste heat recovery system 100 may occur.

To prevent this problem, the present embodiment provides a separate line through which condenser 140 flows about 36 degrees of fresh water, and exchanges fresh water and organic refrigerant supplied through a separate line to compensate for a lack of cooling capacity of water. It can increase the stability of the system.

In addition, fresh water flowing through a separate line, water flowing through the branch line 310, and a line flowing through an organic refrigerant may be provided as independent lines that are not merged with each other.

The cooling water circulation system 400 cools the engine E by circulating a heat source that is cooling water. As shown in FIG. 1, the engine E and the main flow passage 410 are connected to the engine E and pass through the engine E. The jacket cooler 420 that cools the cooling water, which is a heat source, and the main coolant 410 that connects the jacket cooler 420 and the engine E to the engine coolant 420 that is cooled by the jacket cooler 420 are provided in the engine ( E) the cooling water pump 430 pumped, and the heat source provided from the cooling water circulation system 400 is exchanged with the dumping steam delivered from the ship's steam system to be transferred to the low and medium temperature waste heat recovery system 100 In the turbocharger (TC) of the engine (E), the dumping condenser unit (440) that raises the temperature of the cooling water and condenses the heat-exchanged dumping steam and the cooling water whose temperature is increased by heat exchange in the dumping condenser unit (440) It includes an engine scavenging cooling unit 450 that heats the supplied scavenged air to further increase the temperature of the coolant delivered to the low and medium temperature waste heat recovery system 100 and cools the heat exchanged scavenged air.

The engine E of the cooling water circulation system 400 may use a heat engine such as a two-stroke diesel engine and may be a main engine driving a ship.

The dumping condenser unit 440 of the cooling water circulation system 400 serves to condense the remaining steam used in the vessel with low-temperature cooling water to condense into water.

In this embodiment, the dumping condenser unit 440, as shown in Figure 1, the first condenser module 441 and the first condenser module 441 to increase the temperature of the cooling water by heat exchange between the cooling water and the dumping steam A second condenser module 442 that cools and condenses the heat-exchanged dumping steam through, and is provided in a rear line of the first condenser module 441 to flow cooling water to the first condenser module 441 or the first condenser module 441 ) Is provided in the front line of the first directional control valve 443 and the first condenser module 441 to prevent the fresh water passing through from flowing in the direction of the main flow path 410, and the cooling water passing through the first condenser module 441. The second water that prevents the fresh water supplied to flow to the engine scavenging cooling unit 450 or to cool the dumping steam from the second condenser module 442 to the first condenser module 441 or the engine scavenging cooling unit 450. And a direction control valve 444.

In this embodiment, the first direction control valve 443 and the second direction control valve 444 may be three-way valves.

Hereinafter, the operation state of the dumping condenser unit 440 will be briefly described by classifying it as an operation or a non-operation of the medium and low temperature waste heat recovery system 100.

When the medium and low temperature waste heat recovery system 100 is operated, the cooling water supplied from the main flow path 410 includes a first directional control valve 443, a first condenser module 441, and a second directional control valve 444. It is supplied to the evaporator 110 of the medium and low temperature waste heat recovery system 100 via the engine scavenging cooling unit 450.

At this time, the first directional control valve 443 may flow only the first condenser module 441 and the second directional control valve 444 may flow cooling water only to the engine scavenging cooling unit 450.

When the medium and low temperature waste heat recovery system 100 is not operated, since the cooling water does not flow in the direction of the dumping condenser unit 440, the steam supplied to the first dumping condenser module is not directly exchanged with the cooling water, and is directly supplied to the second condenser module 442 do. In this case, condensation of dumping steam may be performed by fresh water supplied to the second condenser module 442.

In addition, primary condensation of dumping steam may occur in the first condenser module 441 by fresh water supplied to the first condenser module 441 by the second directional control valve 444 and the first directional control valve 443. It might be. That is, the line connected to the second condenser module 442 and the line through which fresh water flows is connected to the second direction control valve 444, and the line connected to the second condenser module 442 and the line from which fresh water is discharged is the first direction control valve. Connected to (443), a portion of fresh water flowing into the second condenser module 442 is supplied to the first condenser module 441 through the second directional control valve 444, and discharged from the first condenser module 441 The fresh water may be discharged through a line connected to the second condenser module 442 through the first direction control valve 443.

The engine scavenging cooling unit 450 exchanges heat from the dumping condenser unit 440 with the scavenging air supplied from the turbocharger TC of the engine E to heat the heat-cooled coolant to the medium and low temperature waste heat recovery system 100. It further increases the temperature of the delivered coolant and serves to cool the scavenged air that has been exchanged.

That is, in the present exemplary embodiment, the temperature of the heat source transferred to the evaporator 110 is further increased by additionally raising the temperature of the heat source delivered to the evaporator 110 of the low and medium temperature waste heat recovery system 100 by the engine scavenging cooling unit 450. Since it can be raised to about 106 ° C, it is possible to improve the efficiency of the medium and low temperature waste heat recovery system 100.

In this embodiment, the engine scavenging cooling unit 450 heat exchanges the scavenging air supplied from the turbocharger and the cooling water whose temperature has increased through the dumping condenser unit 440, as shown in FIG. The first stage module 451 for raising the temperature, the second stage module 452 for cooling the scavenging air passing through the first stage module 451, and the rear and front lines of the first stage module 451 A third directional control valve that is provided in each of the middle and low temperature waste heat recovery system 100 to prevent dry running of the first stage module 451 by supplying fresh water to the first stage module 451 453 and a fourth directional control valve 454.

In this embodiment, the third direction control valve 453 and the fourth direction control valve 454 may be three-way valves.

Hereinafter, the operation state of the engine scavenging cooling unit 450 will be briefly described by classifying it as an operation or a non-operation of the medium and low temperature waste heat recovery system 100.

When the medium and low temperature waste heat recovery system 100 is operated, the cooling water supplied from the first condenser module 441 includes a third direction control valve 453, a first stage module 451, and a fourth direction control valve 454. ) And is supplied to the evaporator 110 of the low and medium temperature waste heat recovery system 100.

At this time, the third direction control valve 453 may flow only cooling water to the first stage module 451 and the fourth direction control valve 454 only to the evaporator 110.

When the medium and low temperature waste heat recovery system 100 is not operated, since the cooling water does not flow to the first stage module 451, the first stage module 451 is dry without cooling water due to high temperature scavenging (about 200 ° C) supplied. Running may occur.

In this case, the temperature of the coolant stagnated in the first stage module 451 of the engine scavenging cooling unit 450 is continuously elevated by the high-temperature compressed scavenging air supplied through the supercharger TC to exceed the boiling point, and the steam It can cause the pressure of the line to rise.

Of course, since a safety valve (not shown) for pressure discharge is installed, the pressure does not rise above a certain pressure, but it is not preferable if a safety valve designed to operate in an emergency is operated frequently.

In addition, since cooling of scavenging air is not performed in the first stage module 451 of the engine scavenging cooling unit 450, the second stage module 452 for cooling scavenged air may be burdened, and in some cases scavenged air The cooling may not be performed as desired, which may affect engine performance.

In the present exemplary embodiment, dry running of the first stage module 451 may be prevented by fresh water supplied to the first stage module 451 by the third direction control valve 453 and the fourth direction control valve 454. . That is, the line connected to the second stage module 452 and the line through which fresh water flows is connected to the fourth direction control valve 454, and the line connected to the second stage module 452 and the line from which fresh water is discharged is the third direction control valve. Connected to (453), a portion of fresh water flowing into the second stage module 452 is supplied to the first stage module 451 through the fourth direction control valve 454, and discharged from the first stage module 451 The fresh water can be discharged through a line connected to the second stage module 452 through the third direction control valve 453.

On the other hand, the cooling water circulation system 400 according to the present embodiment does not supply the cooling water discharged from the engine E to the dumping condenser unit 440, that is, by bypassing the medium and low temperature waste heat recovery system 100, the jacket cooler ( It further includes a control valve 470 provided on the bypass line 460 to be supplied to the 420, and a temperature sensor 480 provided on the main line behind the jacket cooler 420.

This embodiment is provided with a temperature sensor 480 in the main flow path 410 of the rear end of the jacket cooler 420, that is, when the temperature at this point rises excessively, that is, the engine scavenging cooling unit in the medium and low temperature waste heat recovery system 100 If all of the heat of the coolant whose temperature is raised through 450 is not absorbed, the control valve 470 may be opened to allow the coolant to flow through the bypass line 460.

FIG. 2 is a view showing the operation of FIG. 1 and schematically showing a process in which the water supply of the waste heat recovery system is supplied through a condenser of a medium and low temperature waste heat recovery device, and FIG. 3 is an operation state diagram of FIG. It is a diagram schematically showing the process of supplying by bypassing the condenser of the medium and low temperature waste heat recovery device.

When the medium and low temperature waste heat recovery system 100 and the waste heat recovery system 200 are operating, the organic refrigerant flowing into the condenser 140 of the low and medium temperature waste heat recovery system 100 requires condensation in the condenser 140, but this implementation The example does not need to supply a separate fresh water as a condensation heat source of the organic refrigerant, as shown in Figure 2, the organic refrigerant as the feed water supplied from the waste heat recovery system 200 to the condenser 140 through the water supply heat exchanger 300 Can condense.

That is, since the heat of the organic refrigerant, which is conventionally discarded by the condenser 140, can be used as a heating heat source of the water supply supplied through the water supply heat exchanger 300, energy can be saved by maximizing waste heat recovery.

In addition, when the organic refrigerant is not sufficiently cooled due to a lack of cooling capability of the water supplied from the water heat exchanger 300, the efficiency of the medium and low temperature waste heat recovery system 100 may be reduced or equipment problems may occur.

To prevent this problem, the present embodiment provides a separate line through which condenser 140 flows about 36 degrees of fresh water, and exchanges fresh water and organic refrigerant supplied through a separate line to compensate for a lack of cooling capacity of water. It can increase the stability of the system.

On the other hand, when the medium and low temperature waste heat recovery system 100 is not operating, since the waste heat cannot be obtained from the condenser 140, the water supplied from the heat exchanger water supply pump 270, as shown in FIG. 3, the condenser 140 Bypass is directly supplied to the heat exchanger 280.

4 is a conceptual diagram schematically showing an energy saving device of a ship using waste heat of an organic refrigerant according to a second embodiment of the present invention.

The energy saving device (1a) of the ship according to this embodiment is not the line connected to the engine scavenging cooling unit (450, see FIG. 1) disclosed in the first embodiment to the medium and low temperature waste heat recovery system 100, Figure 4 As shown, there is a difference from the first embodiment in that it is provided on the line between the water supply heat exchanger 300 and the heat exchanger 280.

In this case, since the scavenging air is a high temperature of about 200 ° C., the engine scavenging cooling unit 450 can heat the feed water before the heat exchanger 280, thereby reducing the load on the heat exchanger 280. In addition, there is an advantage that the water supply can be pre-heated additionally regardless of whether the medium and low temperature waste heat recovery system 100 is operated.

5 is a conceptual diagram schematically showing an energy saving device of a ship using waste heat of an organic refrigerant according to a third embodiment of the present invention.

The energy saving device 1b of the ship according to the present embodiment includes the above-described medium and low temperature waste heat recovery system 100, waste heat recovery system 200, and the feed water heat exchanger 300, exhaust gas recirculation system 500 and control unit 600.

In the exhaust gas recirculation system 500, when the ship according to the present embodiment operates the ECA (Emission Control Area), the exhaust gas recirculated by recirculating the exhaust gas discharged from the engine E is supplied from the supercharger TC It serves to reduce the generation of NOx by being supplied to the engine E with scavenging.

Specifically, most of the NOx is generated when combustion is performed at a high temperature in the combustion chamber of the engine E. In general, as the concentration of oxygen increases, the combustion temperature also increases. That is, since the concentration of oxygen and the combustion temperature are in a proportional relationship, if the concentration of oxygen supplied to the combustion chamber can be reduced, NOx production can be reduced as a result. This has a beneficial advantage in terms of responding to regulations for IMO Tier III (NOx emissions) that will be applied from 2016, i.e., regulations to reduce NOx emissions to the level required when operating ECA.

In the present embodiment, the exhaust gas recirculation system 500 is burned in the engine E, and a part of the exhaust gas having little oxygen is mixed with scavenging air supplied from the supercharger TC and supplied to the engine E, thereby reducing the oxygen during combustion. By reducing the concentration, NOx production is reduced by a decrease in combustion temperature.

Referring now to the exhaust gas recirculation system 500 in detail, the exhaust gas recirculation system 500, as shown in Figure 1, a scrubber for removing impurities contained in the high-temperature exhaust gas discharged from the engine (E) (510), the cooler 520 to cool the high-temperature exhaust gas from which impurities have been removed from the scrubber 510, and the exhaust gas cooled from the cooler 520 is supplied from the supercharger TC and flows into the engine E A blower (530, blower) that blows cooled exhaust gas to be mixed with scavenging air to be supplied to the engine (E), and a line that connects the blower (230) and the engine (E) to open and close this line Includes valve 540.

In this embodiment, the exhaust gas recirculation system 500 may be driven only when the ECA is operated by the control unit 600 to be described later, and may not be driven outside the ECA.

This embodiment can also be cooled with low-temperature cooling water, and heats the heat of the exhaust gas wasted from the cooler 520 and the water circulated in the waste heat recovery system 200 to exchange the temperature of the condensate supplied to the heat exchanger 280. In order to increase, the cooler 520 may be manufactured in two steps.

In this embodiment, the cooler 520, as shown in Figure 5, the exhaust gas discharged from the scrubber 510 and the condensate circulated in the waste heat recovery system 200 mutually heat exchange to cool the exhaust gas primarily In addition, the first cooler 521 to increase the temperature of the condensed water discharged, and the second cooler (2) to cool the exhaust gas by heat exchange between the exhaust gas and the condensed water discharged from the first cooler 521 522).

In this embodiment, since the flow rate of the cooling water supplied to the cooler 520 can be reduced in addition to the above-described advantages, the power consumption can be further reduced according to the flow rate reduction.

The control unit 600, the exhaust gas recirculation system 500 to minimize the generation of NOx when the ship according to this embodiment operates the ECA (Emission Control Area) where the emission of exhaust gas containing NOx is restricted ), And when the ship operates outside the ECA, exhaust gas is supplied to the waste heat recovery system 200 to reduce energy used in the ship.

That is, the control unit 600 is provided in the exhaust line of the exhaust gas to control the exhaust gas discharged from the engine E to be supplied to either the waste heat recovery system 200 or the exhaust gas recirculation system 500 in an area such as ECA. It serves to enable the ship to operate selectively.

In this embodiment, the control unit 600, as shown in Figure 5, is provided in the exhaust gas exhaust line connecting the gas turbine 210 of the engine E and the waste heat recovery system 200, the exhaust gas exhaust line A first valve 610 for opening and closing, and a second valve 620 provided in the exhaust gas discharge line connecting the engine E and the scrubber 510 of the exhaust gas recirculation system 500 to open and close the exhaust gas discharge line Includes.

In this embodiment, the first valve 610 and the second valve 620 may be proportional control valves controlled by electrical signals.

Meanwhile, the exhaust gas discharged from the engine E and not supplied to the waste heat recovery system 200 and the exhaust gas recirculation system 500 is transferred to the heat exchanger 280 through the supercharger TC as shown in FIG. 5. It can be supplied and used for generating steam.

As described above, the present embodiment maximizes waste heat recovery by maximizing waste heat recovery by allowing heat exchanged with the organic refrigerant in the condenser of the low and medium temperature waste heat recovery system to supply heat supplied to the heat exchanger to drive the steam turbine of the waste heat recovery system. can do.

As described above, the present invention is not limited to the described embodiments, and it is obvious to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations will have to belong to the claims of the present invention.

1,1a, 1b: Ship's energy saving device 100: Medium and low temperature waste heat recovery system
110; Evaporator 120: turbine
130: generator 140: condenser
150: pump 160: pipeline
200: waste heat recovery system 210: gas turbine
220: steam turbine 230: condenser
240: water supply pump 250: control valve
260: water supply tank 270: heat exchanger water supply pump
280: heat exchanger 290: steam separator
300: feed water heat exchanger 310: branch line
320: Directional control valve 400: Cooling water circulation system
410: Main Euro 420: Jacket cooler
430: cooling water pump 440: dumping condenser unit
450: Engine scavenging cooling unit 460: Bypass line
470: control valve 480: temperature sensor
500: exhaust gas recirculation system 510: scrubber
520: cooler 530: blower
540: open / close valve 600: control unit
610: first valve 620: second valve
E: Engine TC: Supercharger

Claims (11)

A low temperature waste heat recovery system operated by using an organic refrigerant having a lower boiling point than water as a working fluid;
A waste heat recovery system for generating electric power using exhaust gas discharged from a ship engine as a working fluid;
A water supply heat exchanger for heat-exchanging the water supplied to the heat exchanger with the organic refrigerant in the condenser of the low and medium temperature waste heat recovery system for driving the steam turbine of the waste heat recovery system; And
A cooling water circulation system having a main flow path through which cooling water for cooling the engine flows and supplying waste heat of the cooling water to an evaporator of the low and medium temperature waste heat recovery system;
The cooling water circulation system includes a control valve provided on a bypass line to bypass the medium and low temperature waste heat recovery system and supplied to the jacket cooler, and a temperature sensor provided on the main flow path at the rear end of the jacket cooler;
The feed water heat exchanger may include a branch line branched from the tip line of the heat exchanger and passing through the condenser to return to the tip line; And
And a direction control valve provided at an intersection of the branch line and the leading line to supply the feed water to the heat exchanger by bypassing the condenser or the condenser. delete The method according to claim 1,
Energy saving device of the ship, characterized in that to supply the fresh water (fresh water) to the condenser separately from the water supply heat exchange portion to compensate for the insufficient cooling capacity of the organic refrigerant. delete The method according to claim 1,
Energy saving device of the ship further comprises an engine scavenging cooling unit provided on the line between the feed water heat exchange unit and the heat exchanger to heat the feed water flowing into the heat exchanger. The method according to claim 1,
An energy saving device for a ship, further comprising an exhaust gas recirculation system for recirculating a portion of the exhaust gas and supplying it to the engine, but exchanging the exhaust gas and the feed water in a front end line of the heat exchanger. The method according to claim 6,
Energy saving device of the ship further comprises a control unit provided in the exhaust line of the exhaust gas to supply the exhaust gas to either the waste heat recovery system or the exhaust gas recirculation system. The method according to claim 1,
The waste heat recovery system,
A gas turbine driven directly by the exhaust gas discharged from the engine to provide a driving force for rotating the generator;
A steam turbine interlocked with the gas turbine and providing a driving force for rotating the generator by the provided steam;
A condenser for condensing steam discharged from the steam turbine;
A vacuum degassing unit that removes dissolved oxygen from the condensed water by vacuum;
A heat exchanger feed pump for pumping the degassed water from the vacuum degassing unit; And
An energy saving device for a ship including a heat exchanger for generating steam for driving the steam turbine by exchanging the feed water heat-exchanged from the condenser and the exhaust gas discharged from the engine. The method according to claim 6,
The exhaust gas recirculation system,
A scrubber for removing impurities contained in the exhaust gas discharged from the engine;
A cooler that cools the exhaust gas supplied to the scrubber; And
Energy-saving device of the ship including a blower blowing the exhaust gas cooled so that the exhaust gas cooled in the cooler is supplied from a supercharger and mixed with scavenging air flowing into the engine to be supplied to the engine. The method according to claim 9,
The cooler,
A first cooler that primarily cools the exhaust gas by mutually exchanging heat between the exhaust gas discharged from the scrubber and the feed water circulated in the waste heat recovery system; And
Energy-saving device of the ship including a second cooler for secondary cooling of the exhaust gas by mutually exchanging the exhaust gas discharged from the first cooler and a liquid separate from the water supply. delete

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