Waste heat recovery power generation system for dual-fuel power dredging ship

Abstract

The waste heat recovery power generation system comprises a heat conduction oil furnace, an oil-water heat exchanger, an expansion water tank, a hot water pump, an evaporator, a main machine high-temperature water preheater, a working medium pump, a working medium storage tank, a cooler and an expansion power generator. The heat-conducting oil furnace and the oil-water heat exchanger form a heat-conducting oil circulation module, the oil-water heat exchanger, the expansion water tank, the hot water pump and the evaporator form a hot water circulation module, and the evaporator, the host high-temperature water preheater, the working medium pump, the working medium storage tank, the cooler and the expansion generator form an organic Rankine cycle power generation module. Through control of the hot water circulation module, the cooling water circulation module and the organic Rankine cycle power generation module, waste heat can be fully and efficiently utilized, and the problem that waste heat in the dual-fuel power dredging ship is recycled and used for power generation is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of heat recovery devices, and in particular relates to a waste heat recovery power generation system for a dual-fuel powered dredging vessel. Background Art

[0002] Driven by the trend of "carbon neutrality and carbon peak", in order to meet the increasingly stringent global emission standards, it is necessary to further improve the energy efficiency of ships, use leading energy-saving and emission-reduction technologies to reduce fuel consumption, pollutant emissions and greenhouse gas emissions, so making good use of the waste heat energy of ship diesel engines is an important means. In the past, recovering the waste heat discharged by the engine and using it for heating ship heavy oil was an important means of utilizing waste heat in ordinary ships.

[0003] Dual-fuel powered dredging vessels can use clean fuels and have the characteristics of a large number of engines, large installed power, complex and changeable working conditions, and small layout space. However, when using clean fuels, there is no need to heat the heavy oil, and the heating required for life is also very small, resulting in a large amount of recovered waste heat that can only be discarded, and even a special cooling system must be used for additional cooling, resulting in greater energy waste. Utility Model Content

[0004] In view of the problems existing in the prior art, the utility model provides a waste heat recovery power generation system for a dual-fuel powered dredging vessel. The hot water circulation, waste heat recovery power generation and cooling water circulation are adjusted in real time according to the status of the waste heat recovery power generation system to achieve full and efficient utilization of waste heat, thus solving the problem of recovering waste heat in a dual-fuel powered dredging vessel and using it for power generation.

[0005] The technical solution adopted by the utility model to solve the technical problem is: a waste heat recovery power generation system for dual-fuel powered dredging ships, including a thermal oil furnace, an oil-water heat exchanger, an expansion water tank, a hot water pump, an evaporator, a main engine high-temperature water preheater, a working fluid pump, a working fluid storage tank, a cooler, and an expansion generator; the thermal oil furnace and the oil-water heat exchanger constitute a thermal oil circulation module, the oil-water heat exchanger, the expansion water tank, the hot water pump, and the evaporator constitute a hot water circulation module, and the evaporator, the main engine high-temperature water preheater, the working fluid pump, the working fluid storage tank, the cooler, and the expansion generator constitute an organic Rankine cycle power generation module;

[0006] The hot oil outlet of the thermal oil furnace is connected to the hot oil inlet of the oil-water heat exchanger, and the hot oil outlet of the oil-water heat exchanger is connected to the hot oil inlet of the thermal oil furnace;

[0007] The hot water outlet of the oil-water heat exchanger is connected to the hot water inlet of the evaporator, the hot water outlet of the evaporator is respectively connected to the hot water inlet of the hot water pump and the expansion water tank through a three-way valve, and the hot water outlet of the hot water pump is connected to the hot water inlet of the oil-water heat exchanger;

[0008] The working medium outlet of the evaporator is connected to the working medium inlet of the expansion generator via a one-way valve, the working medium outlet of the expansion generator is connected to the working medium inlet of the cooler, the working medium outlet of the evaporator is connected to the working medium inlet of the cooler via a bypass valve, the working medium outlet of the cooler is connected to the working medium inlet of the working fluid storage tank, the working medium outlet of the working fluid storage tank is connected to the working medium inlet of the working fluid pump, the working medium outlet of the working fluid pump is connected to the working medium inlet of the main engine high-temperature water preheater, and the working medium outlet of the main engine high-temperature water preheater is connected to the working medium inlet of the evaporator.

[0009] Furthermore, the working medium of the organic Rankine cycle power generation module is an organic working fluid, and the heat energy of the organic working fluid is a heat source from wastewater and exhaust gas of a main diesel engine of a ship power generation.

[0010] Furthermore, a temperature regulating valve is provided on the hot oil inlet pipeline of the oil-water heat exchanger.

[0011] Furthermore, a temperature regulating valve is provided on the hot water inlet pipeline of the evaporator.

[0012] Furthermore, the cooling water inlet and outlet of the cooler are connected to a cooling water pump.

[0013] Furthermore, the wastewater and exhaust gas heat source inlet and outlet of the main engine high-temperature water preheater are connected to the cylinder jacket cooling water pipeline of the ship's main diesel engine for power generation.

[0014] The beneficial effects of the utility model are:

[0015] 1. The organic Rankine cycle power generation module in the waste heat recovery power generation system of the utility model is driven by an organic working fluid, and multiple organic Rankine cycle power generation modules can share the heat source of wastewater and exhaust gas of multiple main engines, and the layout position of the organic Rankine cycle power generation module is independent of the exhaust gas pipeline of the diesel engine of the dredging ship and the position of the exhaust gas boiler, and can be arranged at any suitable position. At the same time, the organic Rankine cycle power generation module has a compact structure, small size, and small space occupation, and has little impact on the overall layout of the dredging ship.

[0016] 2. The organic Rankine cycle power generation module in the waste heat recovery power generation system of the utility model is separated from the main engine and will not have any impact on the operation of the main engine. At the same time, the organic Rankine cycle power generation module can recover low-grade heat sources. Therefore, even if the main engine operates at a low load and the exhaust gas temperature generated is low, the organic Rankine cycle power generation module can be driven, which is suitable for the complex and changeable working conditions of dredging ships and has good adaptability to working conditions.

[0017] 3. The working medium in the organic Rankine cycle power generation module in the waste heat recovery power generation system of the utility model is stable and maintenance-free throughout its life; the heat transfer oil in the heat transfer oil circulation module of the utility model does not have phase change, is not corrosive, has good sealing, and is easy to manage and maintain.

[0018] 4. The utility model can adjust the hot water circulation, waste heat recovery power generation and cooling water circulation in real time according to the state of the waste heat recovery power generation system, so as to fully and efficiently utilize the waste heat, and solve the problem of waste heat recovery and power generation in dual-fuel powered dredging vessels. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A structural diagram of a waste heat recovery power generation system for a dual-fuel powered dredging vessel provided in an embodiment of the utility model;

[0020] Figure 2 A flow chart of a control method for a waste heat recovery power generation system for a dual-fuel powered dredging vessel provided in an embodiment of the utility model.

[0021] In the figure: 1. Thermal oil boiler; 2. Oil-water heat exchanger; 3. Expansion water tank; 4. Hot water pump; 5. Three-way valve; 6. Evaporator; 7. Main engine high-temperature water preheater; 8. Working fluid pump; 9. Bypass valve; 10. Check valve; 11. Cooler; 12. Expansion generator; 12. Working fluid storage tank. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail in combination with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0023] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Example

[0026] See also Figure 1 The present embodiment provides a waste heat recovery power generation system for a dual-fuel powered dredging vessel, comprising a thermal oil furnace 1, an oil-water heat exchanger 2, an expansion water tank 3, a hot water pump 4, a three-way valve 5, an evaporator 6, a main engine high-temperature water preheater 7, a working fluid pump 8, a bypass valve 9, a check valve 10, a cooler 11, an expansion generator 12, and a working fluid storage tank 13; the thermal oil furnace 1 and the oil-water heat exchanger 2 constitute a thermal oil circulation module, the oil-water heat exchanger 2, the expansion water tank 3, the hot water pump 4, the three-way valve 5, and the evaporator 6 constitute a hot water circulation module, and the evaporator 6, the main engine high-temperature water preheater 7, the working fluid pump 8, the bypass valve 9, the check valve 10, the cooler 11, the expansion generator 12, and the working fluid storage tank 13 constitute an organic Rankine cycle power generation module.

[0027] The hot oil outlet of the thermal oil furnace 1 is connected to the hot oil inlet of the oil-water heat exchanger 2 , and the hot oil outlet of the oil-water heat exchanger 2 is connected to the hot oil inlet of the thermal oil furnace 1 .

[0028] The hot water outlet of the oil-water heat exchanger 2 is connected to the hot water inlet of the evaporator 6, and the hot water outlet of the evaporator 6 is connected to the hot water inlet of the hot water pump 4 and the expansion water tank 3 through a three-way valve 5. There are two hot water pumps, one for use and one for backup. The hot water outlet of the hot water pump 4 is connected to the hot water inlet of the oil-water heat exchanger 2.

[0029] The working medium outlet of the evaporator 6 is connected to the working medium inlet of the expansion generator 12 via a one-way valve 10, and the working medium outlet of the expansion generator 12 is connected to the working medium inlet of the cooler 11. The working medium outlet of the evaporator 6 is connected to the working medium inlet of the cooler 11 via a bypass valve 9. When the thermal parameters of the working medium do not meet the working requirements of the expansion generator 12 or the expansion generator 12 is not working, the bypass valve 9 takes effect. The working medium outlet of the cooler 11 is connected to the working medium inlet of the working fluid storage tank 13, and the working medium outlet of the working fluid storage tank 12 is connected to the working medium inlet of the working fluid pump 8. There are two working fluid pumps, one for use and one for backup. The working medium outlet of the working fluid pump 8 is connected to the working medium inlet of the main engine high-temperature water preheater 7, and the working medium outlet of the main engine high-temperature water preheater 7 is connected to the working medium inlet of the evaporator 6.

[0030] Specifically, the working medium of the organic Rankine cycle power generation module is an organic working fluid, and the heat energy of the organic working fluid is a heat source from wastewater and exhaust gas of a main diesel engine of a ship power generation.

[0031] The hot oil inlet pipeline of the oil-water heat exchanger 2 is provided with a temperature regulating valve.

[0032] The hot water inlet pipeline of the evaporator 6 is provided with a temperature regulating valve.

[0033] The cooling water inlet and outlet of the cooler 11 are connected to a cooling water pump.

[0034] The waste water and waste gas heat source inlet and outlet of the main engine high temperature water preheater 7 are connected to the cylinder jacket cooling water pipeline of the ship's main diesel engine.

[0035] The control method of the waste heat recovery power generation system is divided into three stages: hot water circulation module control, cooling water circulation module control, and organic Rankine cycle power generation module control;

[0036] The hot water circulation module controls: controls the start and stop of the hot water pump 4, and controls the flow of the heat transfer oil entering the hot water circulation module through the thermostatic valve arranged on the hot oil inlet pipeline of the oil-water heat exchanger 2;

[0037] The cooling water circulation module controls: controlling the start and stop of the cooling water pump of the cooler 11, and starting the cooling water circulation before the organic Rankine cycle power generation module operates;

[0038] The organic Rankine cycle power generation module controls: controlling the start-up, unit run-up, unit grid connection and grid operation of the organic Rankine cycle power generation module; when the hot water circulation module and the cooling water circulation module are running, the organic Rankine cycle power generation module starts; when the waste heat recovery power generation system parameters meet the expansion generator run-up requirements, the expansion generator runs up and reaches the rated speed; after receiving the grid connection request, the expansion generator 12 automatically synchronizes and realizes grid connection; the expansion generator 12 automatically takes load after being grid-connected.

[0039] When the operating load of the ship's main diesel engine decreases, the exhaust waste heat and cylinder water waste heat of the ship's main diesel engine will decrease accordingly, causing the temperature of the heat transfer oil to drop. The waste heat recovery power generation system will monitor the temperature of the heat transfer oil in real time, and automatically reduce the opening of the thermostatic valve on the hot oil inlet pipeline of the oil-water heat exchanger according to the drop in the temperature of the heat transfer oil, thereby reducing the flow of heat transfer oil entering the hot water circulation module; when the amount of waste heat recovery decreases, the waste heat recovery power generation system will automatically reduce the amount of power generated.

[0040] When the operating load of the ship's main diesel engine increases, the exhaust waste heat and cylinder water waste heat of the ship's main diesel engine will increase accordingly, causing the temperature of the heat transfer oil to rise. The waste heat recovery power generation system will monitor the temperature of the heat transfer oil in real time, and automatically increase the opening of the thermostatic valve on the hot oil inlet pipeline of the oil-water heat exchanger according to the increase in the temperature of the heat transfer oil, thereby increasing the flow of heat transfer oil entering the hot water circulation module; when the waste heat recovery amount increases, the waste heat recovery power generation system will automatically increase the power generation.

[0041] When the operating load of the ship's main diesel engine remains unchanged, the heat consumption of other heat users increases or decreases, which causes the temperature of the heat transfer oil to drop or rise accordingly. The waste heat recovery power generation system will also be automatically adjusted in the same way as above.

[0042] Specifically, when the operating load of the ship's main diesel engine remains unchanged, the heat consumption of other heat users increases, causing the temperature of the thermal oil to drop. The waste heat recovery power generation system will monitor the temperature of the thermal oil in real time, and automatically reduce the opening of the thermostatic valve on the hot oil inlet pipeline of the oil-water heat exchanger according to the drop in the temperature of the thermal oil, thereby reducing the flow of thermal oil entering the hot water circulation module; when the amount of waste heat recovery decreases, the waste heat recovery power generation system will automatically reduce the amount of power generated.

[0043] When the operating load of the ship's main diesel engine remains unchanged, the heat consumption of other heat users decreases, causing the temperature of the thermal oil to rise. The waste heat recovery power generation system will monitor the temperature of the thermal oil in real time, and automatically increase the opening of the thermostatic valve on the hot oil inlet pipeline of the oil-water heat exchanger according to the increase in the temperature of the thermal oil, thereby increasing the flow of thermal oil entering the hot water circulation module; when the amount of waste heat recovery increases, the waste heat recovery power generation system will automatically increase the power generation.

[0044] In this embodiment, in the organic Rankine cycle power generation module of the waste heat recovery power generation system for dual-fuel powered dredging vessels, hot water enters the evaporator 6 in the organic Rankine cycle power generation module, causing the circulating working medium to evaporate due to heat, generating steam of a certain pressure and temperature that enters the expansion generator 12, driving the expansion generator 12 to generate electricity; the expanded exhaust steam enters the condenser 11 and is cooled into a liquid state, and the liquid working medium enters the working fluid storage tank 13, is pressurized by the working fluid pump 8, and then circulates again after passing through the main engine high-temperature water preheater 7.

[0045] In this embodiment, the hot water circulation module of the waste heat recovery power generation system for dual-fuel powered dredging vessels is a closed cycle, and the temperatures of hot water entering and leaving the oil-water heat exchanger 2 are 125°C and 140°C respectively, and the system considers heat dissipation loss to be 2%.

[0046] In this embodiment, the cooling water circulation in the cooler 11 of the waste heat recovery power generation system for the dual-fuel powered dredging vessel is a closed cycle, and fresh water is used as the cooling water of the organic Rankine cycle power generation module. Fresh water is used to cool the working fluid, and seawater is used to cool the fresh water. Since seawater is highly corrosive and clogged with dirt, it needs to be regularly disassembled and flushed, so an independent fresh water circulation system is used. When the seawater heat exchanger needs maintenance, the organic Rankine cycle power generation module only needs to stop running without extracting the working fluid.

[0047] In this embodiment, Figure 2 As shown, the basic operation process of the control method for the waste heat recovery power generation system of the dual-fuel powered dredging vessel is as follows:

[0048] Starting, stopping and adjusting the hot water circulation module: The hot water circulation module receives instructions to start and stop the hot water pump 4, and controls the hot water flow in the hot water circulation module by adjusting the thermostatic valve set on the hot water inlet pipeline of the evaporator 6.

[0049] Starting and stopping the cooling water circulation module: The cooling water circulation module receives instructions to start and stop the cooling water pump of the cooler 11. The cooling water circulation module needs to be started before the organic Rankine cycle power generation module is operated.

[0050] Start-up of the organic Rankine cycle power generation module: When the hot water circulation module and the cooling water circulation module are running, the organic Rankine cycle power generation module meets the start-up conditions and can be started.

[0051] Unit start-up: The organic Rankine cycle power generation module starts after receiving the start-up command. When the waste heat recovery power generation system parameters meet the expansion generator 12 start-up requirements, the expansion generator 12 starts after receiving the start-up command.

[0052] Grid connection of the unit: After the expansion generator 12 reaches the rated speed, it meets the grid connection requirements and sends a grid connection request. After receiving the grid connection request and being allowed, it automatically synchronizes and realizes grid connection.

[0053] On-grid operation control: When the expansion generator 12 is connected to the grid and stabilized, it can be loaded automatically or manually.

[0054] In this embodiment, the waste heat recovery power generation system sets the initial value of the heat transfer oil temperature to T0, and the waste heat recovery power generation system monitors the heat transfer oil temperature in real time to T1. When T1<T0, the heat transfer oil valve opening is automatically reduced to reduce the heat transfer oil flow rate entering the hot water circulation module. When the waste heat recovery amount decreases, the waste heat recovery power generation system will automatically reduce the power generation; when T1>T0, the heat transfer oil valve opening is automatically increased to increase the heat transfer oil flow rate entering the hot water circulation module. When the waste heat recovery amount increases, the waste heat recovery power generation system will automatically increase the power generation.

[0055] In this embodiment, when the auxiliary fuel oil boiler of the ship is running, the waste heat recovery power generation system will stop running. The waste heat recovery power generation system can be stopped manually, or the auxiliary fuel oil boiler operation signal can be given and the system automatically stops the waste heat recovery power generation system.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A waste heat recovery power generation system for a dual-fuel powered dredging vessel, characterized in that: It includes a thermal oil furnace, an oil-water heat exchanger, an expansion water tank, a hot water pump, an evaporator, a main engine high-temperature water preheater, a working fluid pump, a working fluid storage tank, a cooler, and an expansion generator; the thermal oil furnace and the oil-water heat exchanger constitute a thermal oil circulation module, the oil-water heat exchanger, the expansion water tank, the hot water pump, and the evaporator constitute a hot water circulation module, and the evaporator, the main engine high-temperature water preheater, the working fluid pump, the working fluid storage tank, the cooler, and the expansion generator constitute an organic Rankine cycle power generation module; The hot oil outlet of the thermal oil furnace is connected to the hot oil inlet of the oil-water heat exchanger, and the hot oil outlet of the oil-water heat exchanger is connected to the hot oil inlet of the thermal oil furnace; The hot water outlet of the oil-water heat exchanger is connected to the hot water inlet of the evaporator, the hot water outlet of the evaporator is respectively connected to the hot water inlet of the hot water pump and the expansion water tank through a three-way valve, and the hot water outlet of the hot water pump is connected to the hot water inlet of the oil-water heat exchanger; The working medium outlet of the evaporator is connected to the working medium inlet of the expansion generator via a one-way valve, the working medium outlet of the expansion generator is connected to the working medium inlet of the cooler, the working medium outlet of the evaporator is connected to the working medium inlet of the cooler via a bypass valve, the working medium outlet of the cooler is connected to the working medium inlet of the working fluid storage tank, the working medium outlet of the working fluid storage tank is connected to the working medium inlet of the working fluid pump, the working medium outlet of the working fluid pump is connected to the working medium inlet of the main engine high-temperature water preheater, and the working medium outlet of the main engine high-temperature water preheater is connected to the working medium inlet of the evaporator.

2. The waste heat recovery power generation system for a dual-fuel powered dredging vessel according to claim 1, characterized in that: The working medium of the organic Rankine cycle power generation module is an organic working fluid, and the heat energy of the organic working fluid is a heat source from wastewater and exhaust gas of a main diesel engine for ship power generation.

3. The waste heat recovery power generation system for a dual-fuel powered dredging vessel according to claim 1, characterized in that: A temperature regulating valve is arranged on the hot oil inlet pipeline of the oil-water heat exchanger.

4. The waste heat recovery power generation system for a dual-fuel powered dredging vessel according to claim 1, characterized in that: A temperature regulating valve is arranged on the hot water inlet pipeline of the evaporator.

5. The waste heat recovery power generation system for a dual-fuel powered dredging vessel according to claim 1, characterized in that: The cooling water inlet and outlet of the cooler are connected to a cooling water pump.

6. The waste heat recovery power generation system for a dual-fuel powered dredging vessel according to claim 1, characterized in that: The waste water and waste gas heat source inlet and outlet of the main engine high temperature water preheater are connected to the cylinder jacket cooling water pipeline of the ship's main diesel engine for power generation.

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