CN103967648B - A kind of marine low speed diesel residual heat comprehensive recovery system - Google Patents

Abstract

The invention provides a waste heat comprehensive recovery system of a low-speed diesel engine of a ship. Including combined waste heat boiler system, power turbine power generation system, steam turbine power generation system, high temperature cooling water utilization heat exchange equipment and organic working medium steam turbine power generation system. The invention effectively recovers exhaust waste heat energy of the marine low-speed diesel engine by combining the waste heat boiler; effectively recovers the cylinder jacket cooling water of the marine low-speed diesel engine and the pressurized air air-cooled heat exchanger through the cylinder jacket water heat exchanger and the three-stage air-cooling heat exchanger The waste heat of the cooling water recovers the exhaust pressure energy of the diesel engine through the power turbine and the hot water energy of the boiler and the air-cooled heat exchanger recovered by the low-temperature working medium steam turbine, and converts it into electric energy, so as to comprehensively recover the waste heat of the main engine of the ship and significantly improve the thermal efficiency of the diesel engine , reduce ship EEDI energy consumption index.

Description

A comprehensive waste heat recovery system for marine low-speed diesel engines

technical field

The invention relates to a waste heat utilization system, in particular to a waste heat recovery system of a marine low-speed diesel engine.

Background technique

The energy issue has become a top priority issue in economic development. Ships are means of transportation with huge energy consumption. On the one hand, high energy consumption increases the operating cost of ships, and on the other hand, it also brings serious environmental problems to the operation of ships. How to effectively reduce ship energy consumption is a realistic and important issue. The International Maritime Organization (IMO) has adopted EEDI (Energy Efficiency Design Index, New Ship Energy Efficiency Design Index) as an index to evaluate the energy consumption of ship design. The low energy utilization efficiency of ships will not only face high fuel costs, but also Additional fines to compensate for damage to the environment. As the main power of the ship, the thermal efficiency of the diesel engine is close to 50%, but 50% of the energy is still taken away by the exhaust gas and cooling medium. If the heat from the main engine exhaust and cooling water can be used to generate electricity or provide steam as a heat source for auxiliary equipment, it can replace some auxiliary equipment and auxiliary boilers, and achieve energy saving and emission reduction effects. How to further utilize and excavate this part of waste heat is the problem to be solved by the present invention.

The ship main engine waste heat utilization systems developed by major ship main engine manufacturing companies all use conventional waste heat boilers, which are characterized in that the exhaust heat of the main engine is used to generate steam for reuse. But limited to the flue gas dew point temperature, in order to prevent low-temperature corrosion, the exhaust gas temperature of the waste heat boiler of the host waste heat utilization system is above 170°C, that is, the host waste heat utilization system only uses the energy of the exhaust temperature range of 170-300°C (about), The rest of the energy in the exhaust is released to the environment.

In the Chinese document with the publication number CN102777876A (published on November 14, 2012), a marine diesel generator set exhaust waste heat gas production system is disclosed. The system includes a hot well, boiler feed pump, steam drum, waste heat boiler, evaporator and preheater. It can effectively recover the waste heat of the exhaust gas of the marine power generation diesel engine. This technology is aimed at the utilization of exhaust waste heat of marine diesel generator sets, and does not involve the utilization of waste heat of main diesel engines of ships.

In the patent document with the publication number CN103111172A (publication date: May 22, 2013), a system and method for waste heat recovery exhaust gas treatment of ship main engines are disclosed, including waste heat boilers, steam turbines, generators, carbon dioxide absorption towers, water pumps, water tanks, Horizontal ammonia synthesis tower, alkane cracker and air separator. It can not only efficiently utilize the waste heat of the main engine of the ship, but also absorb carbon dioxide in the exhaust gas and reduce carbon emissions. The technical solution is to use the air separator to separate the air into high-concentration oxygen and nitrogen. The high-concentration oxygen is burned in the waste heat boiler and the exhaust gas of the diesel engine to heat the boiler evaporator to generate high-temperature steam, which drives the steam turbine to generate electricity, and realizes the discharge of the marine main engine. Gas waste heat utilization; while high-concentration nitrogen and hydrogen produced by cracking alkanes are synthesized in the horizontal ammonia synthesis tower, and ammonia water is made into ammonium bicarbonate with carbon dioxide in the exhaust gas of diesel engines in the carbon dioxide absorption tower to realize carbon dioxide capture. The waste heat utilization involves waste heat boilers and steam turbines, but does not involve the waste heat utilization of the exhaust pressure of the ship's main diesel engine and the energy of air-cooled heat exchangers and cylinder jacket water.

In the patent document with the publication number CN102777221A (publication date: November 14, 2012), a waste heat power generation system for marine diesel generator sets based on the organic Rankine cycle is disclosed, including a waste heat boiler, an organic working medium expander, a reducer, Alternator, regenerator, condenser, organic working medium booster pump and evaporator installed in waste heat boiler. It can effectively recover the waste heat of the exhaust gas of the marine power generation diesel engine. This technology is aimed at the utilization of waste heat from the exhaust of marine diesel generator sets, and uses an organic working medium expander to generate electricity, without involving the utilization of waste heat from the main diesel engine of the ship.

In the article "Heat Balance Analysis of Exhaust Gas Heat Energy Recovery Device for Large Ship Main Engine" published in "Ship Engineering" 2009Vol.31, the working principle diagram system of foreign ship main engine Sulzer12RT2flex96C exhaust gas heat energy recovery system was introduced, and the heat balance analysis was carried out for the waste heat utilization system. The schematic diagram of Sulzer12RT2flex96C waste gas heat energy recovery system involves ship main engine exhaust waste heat boiler, double-pressure steam turbine and power turbine, but does not involve the combination of waste heat boiler organic working fluid evaporator and organic working medium steam turbine for power generation when the exhaust gas temperature is below 170 °C. unit.

The article "Research on Waste Heat Utilization Technology of Marine Diesel Engines" published in "Diesel Engine" (2012Vol.34) introduced a ship main engine MAN6S50ME-C waste heat utilization system, and carried out heat balance analysis on the waste heat utilization system. The waste heat utilization system consists of an ultra-low temperature exhaust waste heat boiler, a double-pressure steam turbine, a power turbine, and an organic working medium steam turbine generator set. The ultra-low temperature waste heat boiler consists of a high-pressure superheater, a high-pressure evaporator, a low-pressure evaporator and a water heater that recovers energy at an exhaust gas temperature below 170°C. The boiler flue gas outlet temperature is 95°C. Boiler feed water comes from the sump, flows through the jacket water heat exchanger of the main engine and the high-temperature section of the two-stage air cooler to be heated to 160°C, part of it directly enters the high-pressure boiler drum, and the other part is mixed with the feed water from the jacket water heat exchanger Enter the low pressure drum.

In the MAN6S50ME-C waste heat utilization system in this paper, the ultra-low temperature exhaust waste heat boiler uses the water heater to recover the energy of the exhaust gas below 170 °C for the use of the organic working fluid evaporator, and does not directly replace the organic working medium evaporator with the water heater. The total amount of boiler feed water is about 4t/h, and the energy of cylinder jacket water and high-temperature air of air cooler is not fully recovered. The power generation equipment in this article is a dual-pressure steam turbine, a power turbine, and an organic working medium steam turbine generator set, but it does not involve the modular design of the dual-pressure steam turbine generator set, power turbine generator set, and organic working medium steam turbine generator set, nor does it involve auxiliary systems , Waste heat utilization system control.

The organic working medium steam turbine power generation system in the MAN6S50ME-C waste heat utilization system in this paper is composed of an evaporator, an organic working medium steam turbine, a condenser and a generator. The hot water heated by the boiler water heater to 140°C flows through the evaporator to generate high-temperature and high-pressure organic working medium steam, which enters the organic working medium steam turbine to do work, and drives the generator to generate electricity. The organic working fluid is isobutane. In addition, the ultra-low temperature exhaust waste heat boiler water heater and the organic working medium steam turbine generator set are arranged in an independent circuit, which also limits the recovery and utilization of cylinder jacket water and air cooler waste heat. The cylinder jacket water and air cooler organic working medium heat exchanger are not involved.

Contents of the invention

The purpose of the present invention is to provide a ship low-speed diesel engine waste heat comprehensive recovery system that can effectively improve the energy utilization efficiency of the ship's low-speed diesel engine power system.

The purpose of the present invention is achieved like this:

Including combined waste heat boiler system, power turbine power generation system, steam turbine power generation system, high temperature cooling water utilization heat exchange equipment and organic working medium steam turbine power generation system;

The combined waste heat boiler system is composed of a conventional waste heat boiler section and an organic working medium evaporator section, a vertical flue with a bypass flue, and a water tube forced circulation boiler with a horizontally placed enhanced heat exchange heating surface;

Diesel engine exhaust is divided into two paths in the diesel engine gas collection box and flows through the turbocharger and the power turbine power generation system respectively. After being mixed, the two parts of exhaust gas flow through the conventional waste heat boiler section and the organic working medium evaporator section of the combined waste heat boiler system in turn. , and discharged into the atmosphere through the outlet flue of the combined waste heat boiler;

The cylinder liner cooling water of the diesel engine is cooled by the liner water heat exchanger, and the sump is used as the source of circulating water. The circulating water passes through the liner water heat exchanger after being boosted by the feed water pump. One way enters the high-temperature heat exchanger of the sectional air-cooled heat exchanger, and the other one directly mixes with a part of the effluent water of the sectional air-cooled heat exchanger and then enters the conventional waste heat boiler section, and the effluent of the sectional air-cooled heat exchanger The other part is directly exported;

The steam generated by the conventional waste heat boiler section is supplied to the steam turbine of the steam turbine power generation system, and the exhaust steam after doing work enters the condenser, and after being condensed, it is boosted by the condensate pump to the water collection tank;

The organic working fluid evaporator section forms a cycle with the organic working fluid steam turbine power generation system.

The present invention may also include:

1. The segmented air-cooled heat exchanger is a three-stage air-cooled heat exchanger, which includes a high-temperature heat exchanger, a medium-temperature heat exchanger and a low-temperature heat exchanger, and also includes a cylinder liner connected in parallel with the cylinder liner water heat exchanger Water organic working medium preheater, the organic working medium coming out of the organic working medium steam turbine power generation system enters the medium temperature heat exchanger after passing through the jacket water organic working medium preheater and then enters the organic working medium evaporator section.

2. The conventional waste heat boiler section is a two-pressure boiler, namely saturated steam and superheated steam. The outlet of the superheated evaporator is connected to the high-pressure steam drum for temperature control. The branch pipe on the saturated steam inlet pipeline of the superheater is connected to the superheated steam outlet pipe of the superheater. The desuperheater on the road is connected.

3. The turbo-generator set is a double-pressure steam-enhancing condensing type steam-turbine-generator set, and its dual-pressure steam-enhancing condensing type steam turbine body, deceleration device and auxiliary equipment are integrated on a common base with the third generator, and the condenser set down.

4. The power turbine, the second gearbox and the second generator of the power turbine generator set are integrated on a common base, the lubrication and cooling system is placed below, and the power turbine, the second gearbox and the second generator are provided by the same oil station Centralized oil supply, the inlet of the power turbine is connected to the exhaust header of the diesel engine through pipelines, the exhaust outlet of the power turbine is connected to the flue gas inlet of the combined waste heat boiler through pipelines, and the intake control valve group of the power turbine consists of three valves and two The three valves are emergency bypass valve, quick closing valve and flow adjustment bypass valve. The emergency bypass valve is connected with the first throttle pressure reducer, and the flow adjustment bypass valve is connected with the second throttle pressure reducer.

5. The organic steam turbine body, the fourth gear box, the fourth generator, the condenser, the liquid collection tank, the organic working medium feed water booster pump and auxiliary systems of the organic working medium turbogenerator set are integrated on a common base.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The combined waste heat boiler is adopted, which can recover more exhaust energy when the exhaust temperature is below 170°C, expanding the range of waste heat utilization and the available waste heat.

(2) The combination of the organic working fluid evaporator in the combined waste heat boiler and the organic working fluid steam turbine generator set converts low-grade heat energy into high-grade electrical energy.

(3) The combined waste heat boiler is adopted, and the pollutants carried in the flue gas, such as NOx, SOx and CO ₂ , etc., combine with the condensed water in the tail flue of the combined waste heat boiler to form corresponding acids, and along with the condensed water from the discharge pipe discharge, which is conducive to emission control.

(4) The parameter matching of diesel engine, power turbine and combined waste heat boiler is realized to the greatest extent.

(5) The organic combination of power turbine, steam turbine, organic working medium steam turbine power generation system and combined waste heat boiler can realize the comprehensive utilization of waste heat from low-speed diesel engines in ships.

Description of drawings

Fig. 1 is a schematic diagram of the first embodiment of the waste heat comprehensive recovery system of the marine low-speed diesel engine of the present invention.

Fig. 2 is a schematic diagram of the second embodiment of the waste heat comprehensive recovery system of the marine low-speed diesel engine of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment, the ship low-speed diesel engine waste heat comprehensive recovery system of the present invention is further described:

The purpose of the invention is to improve the energy utilization efficiency of the marine low-speed diesel engine power system. In order to achieve this purpose, the guiding ideology of the overall scheme of the present invention is put forward by fully considering the utilization of the energy of the exhaust gas of the ship's low-speed diesel engine below 170°C, and comprehensively improving the waste heat utilization potential of the ship's main diesel engine.

The ship low-speed diesel engine waste heat utilization system of the present invention is mainly composed of the following parts: a combined waste heat boiler system for recovering ship low-speed diesel engine exhaust waste heat, a power turbine power generation system for using split exhaust energy to do work, a steam turbine power generation system for using steam to do work, The high-temperature cooling water of the low-speed diesel engine of the ship uses heat exchange equipment and an organic working medium steam turbine power generation system that uses low-quality energy to do work. These parts of the system are connected by pipelines, and the working medium circulates among them, which constitutes the transfer and recovery process of the waste heat energy of the entire low-speed diesel engine power system of the ship.

The low-speed marine diesel engine waste heat utilization system can be applied to a marine low-speed diesel engine power system with power above 9,000kW in consideration of cost and benefit. The waste heat utilization system utilizes the energy of the ship's low-speed diesel engine exhaust, air cooler and cylinder jacket water in the form of power generation.

The exhaust temperature of the low-speed diesel engine of the ship mentioned above is to increase the exhaust temperature of the current high-power low-speed diesel engine appropriately by modifying the timing of the diesel engine and re-matching the diesel engine supercharger under the premise of basically not reducing the performance of the diesel engine, so that when the power of the diesel engine is greater than 50%. , can provide exhaust energy for the power turbine power generation system, while the diesel turbocharger can still work stably in the full range of working conditions, and at the same time improve the utilization rate of waste heat of the boiler.

The combined waste heat boiler 10 is a water tube forced circulation boiler with a vertical flue with a bypass flue, which is composed of a conventional waste heat boiler section 12 and an organic working medium evaporator section 11, and has a horizontally placed enhanced heat exchange heating surface. The conventional waste heat boiler section 12 and the organic working medium evaporator section 11 are arranged separately or combined waste heat boilers are arranged integrally. The organic working fluid evaporator tube bundle is made of corrosion-resistant steel.

The feed water preheating of the combined waste heat boiler adopts the staged heating technology of cylinder jacket cooling water and pressurized air. The feed water preheater in the conventional waste heat boiler section 12 is composed of the jacket water heat exchanger 64 of the diesel engine and the high temperature heat exchanger 23 of the three-stage air cooler. The original pressurized air air-cooling heat exchanger of the diesel engine is redesigned into a three-stage air cooler of high temperature, medium temperature and low temperature. The high temperature heat exchanger of the air cooler is used for the feed water preheating of the conventional waste heat boiler section 12.

In the dual-pressure steam-admission condensing type steam turbine generator set 30, the body 31 of the dual-pressure steam-enrichment condensing type steam turbine, the deceleration device 32, the auxiliary equipment and the generator 33 are integrated on a common base, and the condenser 34 is placed below. Form a power generation module.

The power turbine generator set 40, its power turbine 41, gear box 42 and generator 43, including the air intake control valve group and other components are integrated on a common base, and the lubrication and cooling system is placed underneath to form a power generation module. Power turbines, gearboxes and generators are centrally supplied with oil from the same oil station. Single-stage power turbine or two-stage tandem power turbine integrated with gearbox. The inlet of the power turbine is connected with the exhaust header of the low-speed diesel engine through pipelines, and the exhaust outlet of the power turbine is connected with the flue gas inlet of the ultra-low temperature waste heat boiler through pipelines. The power turbine intake control valve group consists of three valves and two throttle reducers. The three valves are an emergency bypass valve 44 , a quick closing valve 45 and a flow regulating bypass valve 46 . The emergency bypass valve 44 is connected with the throttling pressure reducer 47 , and the flow regulating bypass valve 46 is connected with the throttling pressure reducer 48 . The quick-closing valve and flow regulating bypass valve control the power generation power of the power turbine to ensure that the exhaust pressure is the same as the exhaust pressure after the low-speed diesel engine supercharger, and the exhaust temperature of the power turbine meets the requirements of the mixed temperature of the exhaust gas of the main engine.

The organic working medium steam turbine generator set 50, its organic steam turbine body 51, gear box 52 and generator 53, condenser 54, liquid collection tank 55, organic working medium feed water booster pump 56 and auxiliary systems are integrated in a common On the base, a power generation module is formed. When the organic working medium R245fa is used, the working pressure of the organic working medium steam turbine is ～1.1MPa, and the exhaust pressure is 0.2～0.3MPa; when the organic working medium is R236 and R601a, the working pressure and exhaust pressure change accordingly. The organic working medium evaporator 11 is connected with the conventional waste heat boiler section to form a combined waste heat boiler, which directly recovers the energy of the low-speed diesel engine exhaust below 170°C; the organic working medium preheater consists of a three-stage air cooler medium temperature heat exchanger and a cylinder jacket It consists of a water-organic working medium preheater, which absorbs the energy of the air cooler and cylinder jacket water.

The auxiliary system includes a jacket water organic working medium preheater 62, a jacket water heat exchanger 64 and a jacket water cooler 65, a group of regulating valves for flow, temperature and pressure control and regulation group, a steam turbine condensate sump 60 and a pump group 61, etc. It is characterized in that: the jacket water cooler 65 is the original jacket water cooler of the low-speed diesel engine; the jacket water organic working fluid preheater 62 and the jacket water heat exchanger 64 pass through pipelines and valves 63 and 67 The two are connected in series on the original liner water cooler 65 system loop of the main engine, and the heat exchange and liner water temperature control are realized by throttling or splitting; the control and adjustment valve groups 68, 69 and 72 control the cylinder The jacket water heat exchanger 64 and the high-temperature heat exchanger 23 of the three-stage air cooler are connected with the feed water of the low-pressure steam drum 16 to realize the mixing temperature and flow control of the feed water of the low-pressure steam drum 16; High-pressure steam drum and organic working medium evaporator flow regulating valve; by closing valves 63, 66 and 67, under low working conditions, the jacket water can be circulated in a small way without passing through the three heat exchangers, ensuring that the jacket water of the main engine maintains Working temperature: from 30% working condition, by closing the valve 73, the jacket water first flows through the jacket water organic working medium preheater 62 and the jacket water heat exchanger 64 of the waste heat utilization system to provide the required flow for the waste heat utilization system 80°C organic working medium undersaturated liquid and hot water; if the outlet temperature of the jacket water is still higher than the inlet temperature required by the cooling regulations of the main engine, it is controlled and adjusted through valves 66 and 74, and the jacket water flows through the original cylinder of the main engine. Enter the main engine after the jacket water cooler 65.

The first embodiment of the present invention will be further described below with reference to FIG. 1 .

The combined waste heat boiler consists of a conventional waste heat boiler section 12 and an organic working fluid evaporator section 11. It is a triple-pressure boiler; The energy of the exhaust gas temperature range of 100-170°C controls the exhaust outlet temperature of the combined waste heat boiler 10 at ~100°C and operates across the acid dew point. The conventional waste heat boiler section is a two-pressure boiler, that is, saturated steam and superheated steam, which are used for steam turbine power generation. Its feed water preheater is composed of the jacket water heat exchanger 64 of the diesel engine and the high temperature heat exchanger 23 of the three-stage air-cooled heat exchanger. . The outlet temperature of superheated steam is controlled by the desuperheating control of saturated steam in high pressure drum 17, which is realized by connecting the branch pipe 18 on the saturated steam inlet pipeline of superheater 15 with the desuperheater 19 on the superheated steam outlet pipeline of superheater. The organic working medium evaporator section 11 is integrated with the conventional waste heat boiler section 12 to generate 90-95°C organic working medium steam as the steam source of the organic working medium steam turbine generator set. The organic working medium preheater is replaced by a three-stage air cooling system. The medium temperature heat exchanger 22 of the heater and the jacket water organic working fluid preheater 62 are composed. Recover low-grade heat energy as much as possible to increase the power generation of the organic working medium steam turbine generator set.

The adjusted exhaust gas of the diesel engine flows through the supercharger and the power turbine respectively in two paths in the gas collecting tank of the diesel engine, and the exhaust gas entering the power turbine accounts for about 10% of the exhaust gas of the diesel engine. The outlet temperature of the power turbine exhaust is 20 to 30°C higher than the outlet temperature of the supercharger, and the exhaust gas of the power turbine is mixed with the exhaust temperature of the supercharger to increase the inlet temperature of the boiler flue gas. After the two parts of exhaust are mixed, they flow through the combined waste heat boiler high-pressure superheater 15, high-pressure evaporator 14, low-pressure evaporator 13 and organic working medium evaporator 11 in sequence, and are discharged into the atmosphere through the combined waste heat boiler outlet flue. at ~100°C.

Using the sump 60 as the circulating water source, after the feed water pump 61 boosts the pressure, the jacket water heat exchanger 64 raises the temperature to about 80°C, and then divides into two paths. All the way into the high-temperature heat exchanger 23 of the three-stage air-cooled heat exchanger 20, after the temperature is raised to about 160° C., the hot water is divided into three parts. The first part supplies high-temperature hot water to the outside of the system through the valve 71 for daily heating, and directly enters the sump 60 after heat exchange; the second part enters the high-pressure steam drum 17 through the flow regulating valve 70, and is boosted by the high-pressure hot water circulating pump , into the high-pressure evaporator 14 and high-pressure superheater 15 to be heated into superheated steam, and then enter the steam turbine 31 to do work after being cooled by the saturated steam; the third part controls the flow of the valve 72 and the other hot water of the jacket water heat exchanger 64, The flow rate is regulated by the valve 68. After mixing and releasing heat, hot water with a temperature of 138°C is formed and enters the low-pressure steam drum 16. After being boosted by the low-pressure hot water circulation pump, it flows to the low-pressure evaporator 13 to be heated to a saturated steam-water mixture, and then flows to the low-pressure steam drum. In the bag, the saturated steam separated from the steam-water of the low-pressure steam drum is supplied to the steam turbine 31 to make work. The exhausted steam after the work of the supplementary steam condensing steam turbine enters the condenser 34, and after being condensed, the pressure is boosted to the water collection tank 60 by the condensate pump 35.

In order to ensure the normal operation of the ship’s low-speed diesel engine system, the design of the jacket water cooling circuit considers that the jacket water organic working medium preheater 62 and the jacket water heat exchanger 64 are connected in parallel and then connected in series to the original jacket water cooler of the low-speed diesel engine On the system circuit of 65, the heat exchange and jacket water temperature control are realized by controlling the flow of the three through the switch of the pipeline and the valve; in low working conditions, by closing the valves 63, 66 and 67, and opening the valves 73 and 74, It can realize the small circulation of the jacket water without going through the three heat exchangers to ensure that the jacket water of the main engine maintains the working temperature; from 30% working condition, by closing the valve 73 and opening the valves 63, 66 and 67, the jacket water can be realized Through the jacket water organic working medium preheater 62, provide the required flow rate of 80°C liquid for the organic working medium evaporator; through the jacket water flow through the jacket water heat exchanger 64, provide the required flow rate of 80°C for the waste heat utilization system Hot water; if the outlet temperature of the jacket water is still higher than the inlet temperature required by the cooling regulations of the main engine, control and adjust it through valves 66 and 74 to ensure that the jacket water flows through the original jacket water cooler 65 of the main engine and then enters the main engine. The water temperature is controlled within the specified range.

The invention can maximize the recovery of the heat energy in the exhaust gas of the ship's low-speed diesel engine, the air cooler and the water in the cylinder jacket, and convert it into high-grade electric energy, which can achieve a good emission reduction effect.

Fig. 2 shows a second embodiment of the present invention. Compared with the first embodiment shown in FIG. 1 , the difference is that the organic working medium evaporator 11 of the combined waste heat boiler and the organic working medium turbogenerator set form an independent circuit. The organic working medium booster pump 56 is used as a system circulation pump to directly pump the supercooled organic working medium into the organic working medium evaporator of the combined boiler, eliminating the need for the medium temperature heat exchanger 22 of the air cooler of the diesel engine and the jacket water organic working medium preheater 62.

In addition, the air cooler is a double-stage air cooler, that is, the high temperature heat exchanger 23 and the low temperature heat exchanger 21 of the air cooler; the jacket water retains the jacket water heat exchanger 64 and the jacket water cooler 65 . Although the waste heat energy recovery rate of the air cooler and jacket water is lower than that of the system in Figure 1, the waste heat utilization system is relatively simple.

Claims (1)

1. a marine low speed diesel residual heat comprehensive recovery system, comprises combination afterheat boiler system, power turbine power generation system, turbine generating system, high-temperature cooling water utilizes heat transmission equipment and organic working medium turbine generating system; It is characterized in that:

Described combination afterheat boiler system is made up of conventional exhaust heat boiler section (12) and organic working medium vaporizer section (11), is three pressure boilers, conventional exhaust heat boiler section (12) utilizes the energy of exhaust temperature ranges 170 ~ 300 DEG C, organic working medium vaporizer section (11) utilizes the energy of exhaust temperature ranges 100 ~ 170 DEG C, makes the exhaust exit temperature of combination exhaust heat boiler (10) control running across acid dew point, conventional exhaust heat boiler section is two pressure boilers, i.e. saturated vapour and superheated vapor, for steam turbine power generation, conventional exhaust heat boiler section feed water preheater is made up of the jacket water heat exchanger (64) of diesel engine and the high-temperature heat-exchanging (23) of 3 stops air-cooled heat exchanger, superheated vapor outlet temperature controls to adopt HP steam drum (17) saturated steam attemperation to control, to be connected with the desuperheater (19) on superheater superheated vapor export pipeline by the branched pipe (18) on superheater (15) saturated vapour entrance pipe and to realize, organic working medium vaporizer section (11) is connected with conventional exhaust heat boiler section (12), produce the vapour source of 90-95 DEG C of organic working medium steam as organic working medium Turbo-generator Set, organic working medium preheater is by the mid temperature heat exchanger (22) of 3 stops air-cooled heat exchanger, jacket water organic working medium preheater (62) forms,

Diesel exhaust gas point two-way in diesel engine gas collecting box flows through pressurized machine and power turbine respectively, the air displacement entering power turbine accounts for 10% of diesel exhaust gas amount, power turbine exhaust exit temperature is higher than supercharger outlet delivery temperature 20 to 30 DEG C, after two-part exhaust mixing, flow through combination exhaust heat boiler high-pressure superheater (15), high pressure evaporator (14), low pressure evaporator (13) and organic working medium vaporizer (11) successively, and enter air through combination heat boiler outlet flue;

Collecting annulus (60) is as circulating water water source, two-way is divided into temperature is risen to 80 DEG C by jacket water heat exchanger (64) after feed water pump (61) boosting after, temperature is risen to 160 DEG C of after heat moisture and becomes three parts by the high-temperature heat-exchanging (23) that one tunnel enters 3 stops air-cooled heat exchanger (20), first portion supplies high-temperature-hot-water through the first valve (71) outside system, directly enters collecting annulus (60) after heat exchange, second portion enters HP steam drum (17) through flow control valve (70), after high pressure hot water circulating pump boosting, enter high pressure evaporator (14) and high-pressure superheater (15) is heated to form superheated vapor, after saturated steam attemperation, enter steam turbine (31) acting, Part III passes through another road hot water of (72) flow control of the second valve and jacket water heat exchanger (64), through the 3rd valve (68) regulating flow, form 138 DEG C of high-temperature-hot-waters after mixing heat release and enter low-pressure drum (16), and be heated to form saturated vapour aqueous mixtures by flowing to low pressure evaporator (13) after the boosting of low pressure hot water recycle pump, then flow in low-pressure drum, through the saturated vapour that low-pressure drum carbonated drink is separated, for steam turbine (31) filling acting, exhaust steam after the acting of filling condensing steam turbine enters condenser (34), collecting annulus (60) is boosted to by condensate pump (35) after being condensed,

Be connected on the system circuit of the original jacket water cooler (65) of low-speed diesel engine after jacket water organic working medium preheater (62) is in parallel with jacket water heat exchanger (64) again, realize heat exchange by the mode of the switch control rule three flow of pipeline and valve and jacket water water temperature controls; When low operating mode by closedown the 4th valve (63), the 5th valve (66) and the 6th valve (67), open the 7th valve (73) and the 8th valve (74), realize jacket water and carry out short circle without three heat exchangers; From 30% operating mode, by closing the 7th valve (73), open the 4th valve (63), the 5th valve (66) and the 6th valve (67), realize jacket water through stream jacket water organic working medium preheater (62), for organic working medium vaporizer provides the 80 DEG C of liquid requiring flow; Jacket water through stream jacket water heat exchanger (64), for bootstrap system provides the 80 DEG C of hot water requiring flow; If when jacket water outlet temperature still specifies higher than main frame cooling the inlet temperature required, undertaken controlling and regulating by the 5th valve (66) and the 8th valve (74), ensure jacket water flow through main frame original jacket water cooler (65) laggard enter the water temperature of main frame control in regulation scope.