Energy-saving and environment-friendly power waste heat utilization device for refrigerated ship

Abstract

The utility model relates to ship refrigeration and waste heat recovery technical field, concretely is energy -conserving and environment -friendly cold storage ship power waste heat utilization device, including double -way waste heat recovery unit, waste heat collection buffer tank, lithium bromide absorption refrigerating unit and intelligent refrigeration distribution unit. Double -way waste heat is pretreated after smoke and dust filter and water filter, respectively from the upper and lower end of buffer tank, in -tank is equipped with arc spoiler and promotes mixture, and realizes stable control through liquid level, temperature sensor and spare export, and heat energy drives lithium bromide unit refrigeration, and refrigerant water is stabilized after buffer tank, is distributed to each cabin distributed end from centralized host, and the end is independently adjusted flow and pump speed according to cabin temperature sensor feedback, and overall technical scheme is unified by controller coordination flow regulating valve, frequency conversion pump and exhaust valve, realizes on -demand cooling, high -efficient energy -conserving, and the device can recover more than 60% waste heat of host, significantly reduces fuel consumption and carbon emission, is suitable for green intelligent cold storage ship.

Description

Technical Field

[0001] This utility model relates to the field of ship refrigeration and waste heat recovery technology, specifically an energy-saving and environmentally friendly refrigerated ship power waste heat utilization device. Background Technology

[0002] Marine main engines, such as low-speed diesel engines, generate a large amount of waste heat during operation. The heat energy contained in high-temperature exhaust and cylinder liner cooling water accounts for more than 40% of the total fuel energy. However, existing refrigerated ships generally do not effectively utilize this part of low-grade energy, resulting in serious energy waste.

[0003] Currently, some ships are attempting to use single waste heat recovery methods, such as using only exhaust gas to drive an organic Rankine cycle for power generation or using only cooling water to heat domestic water. However, these methods suffer from problems such as low recovery efficiency, system complexity, and mismatch with cooling demands. While lithium bromide absorption refrigeration technology can utilize medium- and low-temperature heat sources for cooling, it faces two major bottlenecks in marine applications: First, waste heat sources are dispersed and parameters fluctuate greatly. For example, exhaust gas contains dust, and cooling water contains impurities, which can easily lead to heat exchanger blockage, corrosion, or scaling, affecting system stability. Second, there is a lack of a coordinated integration mechanism for multiple waste heat sources, making it difficult to achieve a stable supply of heat energy and load matching, resulting in frequent start-ups and shutdowns of refrigeration units or decreased efficiency.

[0004] Furthermore, existing refrigeration distribution systems mostly adopt a constant flow design, which cannot dynamically adjust the cooling output according to the actual temperature requirements of each cargo hold, resulting in overcooling or undercooling, which wastes energy and affects cargo quality. At the same time, there is a lack of pretreatment of waste heat media, such as flue gas filtration, water purification, buffering and stabilization, and intelligent control methods, resulting in insufficient system reliability and automation level, making it difficult to adapt to the complex operating conditions of ships. Utility Model Content

[0005] (a) Technical problems to be solved In view of the shortcomings of the existing technology, this utility model provides an energy-saving and environmentally friendly waste heat utilization device for refrigerated ships.

[0006] (II) Technical Solution To achieve the above objectives, this utility model provides the following technical solution: The energy-saving and environmentally friendly waste heat recovery device for refrigerated ships includes a dual-path waste heat recovery unit, a waste heat collection buffer tank, a lithium bromide absorption chiller, a refrigeration distribution unit, and connecting pipes and valve assemblies. The dual-path waste heat recovery unit includes an exhaust waste heat exchanger and a cooling water waste heat exchanger. The input end of the waste heat collection buffer tank is connected to the dual-path waste heat recovery unit via connecting pipes, and the output end of the waste heat collection buffer tank is connected to the lithium bromide absorption chiller via connecting pipes. The lithium bromide absorption chiller is connected to the refrigeration distribution unit via connecting pipes.

[0007] Preferably, the system further includes a filtration assembly, which includes a dust filter and a water filter. The input end of the exhaust waste heat exchanger is provided with an exhaust guide pipe, and the exhaust guide pipe is provided with a plurality of air inlet pipes. The input end of the cooling water waste heat exchanger is provided with a liquid guide pipe, and the liquid guide pipe is provided with a plurality of liquid inlet pipes. The dust filter is screwed onto the air inlet pipe via a threaded structure, and a plurality of dust filters are provided on the air inlet pipe. The water filter is screwed onto the liquid inlet pipe via a threaded structure, and a plurality of water filters are provided on the liquid inlet pipe.

[0008] More preferably, the dust filter uses a ceramic fiber filter element, the water filter uses a stainless steel woven mesh filter element, the top of the air inlet pipe and the liquid inlet pipe are equipped with flow regulating valves, and the bottom of the air inlet pipe and the liquid inlet pipe are equipped with flow sensors.

[0009] Preferably, the exhaust waste heat exchanger is connected to the upper end of the waste heat collection buffer tank via a connecting pipe, the cooling water waste heat exchanger is connected to the bottom end of the waste heat collection buffer tank via a connecting pipe, and the tail end of the waste heat collection buffer tank is provided with a spare outlet, which is equipped with a flow regulating valve.

[0010] Preferably, a liquid level sensor is provided on the side wall of the waste heat collection buffer tank, several arc-shaped baffles are arranged axially on the inner wall of the waste heat collection buffer tank, and an exhaust pipe is provided on the top of the waste heat collection buffer tank, with an exhaust valve on the exhaust pipe.

[0011] More preferably, the refrigeration distribution unit includes a centralized main unit and distributed terminals. The centralized main unit includes a mainboard heat exchanger, a main variable frequency circulating pump, and distributed control pipelines. The distributed terminals include terminal plate heat exchangers, in-cabin variable frequency pumps, and in-cabin temperature sensors. The mainboard heat exchanger is connected to the lithium bromide absorption chiller unit via connecting pipelines. The output end of the mainboard heat exchanger is connected to the main variable frequency circulating pump via connecting pipelines. The output end of the main variable frequency circulating pump is connected to the distributed control pipelines. The distributed control pipelines are provided with several branch pipelines. The branch pipelines are connected to the input ends of the terminal plate heat exchangers. The output ends of the terminal plate heat exchangers are connected to the in-cabin variable frequency pumps. The branch pipelines are provided with flow regulating valves. The mainboard heat exchanger and the in-cabin variable frequency pumps are connected to the lithium bromide absorption chiller unit via return pipelines.

[0012] Preferably, the exhaust pipe, liquid pipe, and waste heat collection buffer tank are all equipped with temperature detectors, and the system also includes a controller. The controller is electrically connected to the temperature detectors, the cabin temperature sensor, the flow regulating valve, the main variable frequency circulation pump, the cabin variable frequency pump, and the exhaust valve.

[0013] Preferably, the front end of the mainboard heat exchanger is provided with a refrigerant water buffer tank, the input end of which is connected to the lithium bromide absorption chiller unit through a connecting pipe, and the input end of which is connected to the mainboard heat exchanger through a connecting pipe.

[0014] (III) Beneficial Effects Compared with the prior art, this utility model provides an energy-saving and environmentally friendly waste heat recovery device for refrigerated ships, which has the following beneficial effects: This technical solution utilizes a dual-path waste heat recovery unit—an exhaust waste heat exchanger and a cooling water waste heat exchanger—to recover low-grade heat energy from the high-temperature flue gas of the main unit and the cylinder liner cooling water, respectively. Pre-treatment by dust filters and water filters effectively prevents heat exchanger blockage and corrosion, extending equipment lifespan. The waste heat collection buffer tank integrates an upper and lower inlet structure and an arc-shaped baffle to achieve uniform mixing and stable output of the heat medium. Safety redundancy control is achieved through a level sensor, temperature detector, and a backup outlet.

[0015] Thermal energy drives a lithium bromide absorption chiller to produce chilled water. After being pressurized by a chilled water buffer tank, the chilled water is distributed from the centralized main engine to the distributed terminals in each cargo hold. The system employs multi-stage variable frequency control: the controller dynamically adjusts the speed of the main / cabin variable frequency pumps, the opening of the flow regulating valves in each branch pipeline, and the status of the exhaust valves based on temperature sensors, flow sensors, and temperature data from each node, achieving on-demand cooling and precise temperature control. Actual measurements show that this device can recover more than 60% of the main engine's waste heat, meeting more than 80% of the refrigeration needs of refrigerated ships, saving 15%–20% of fuel consumption annually, and reducing carbon emissions by approximately 300 tons per ship. The entire unit has a compact structure and a high degree of automation, requiring no additional energy input, significantly improving the ship's energy efficiency and environmental protection level, and is suitable for green shipping scenarios such as ocean-going refrigerated transport. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall equipment architecture of this utility model; Figure 2 This is a schematic diagram of the dual-path waste heat recovery unit architecture of this utility model; Figure 3 This is a schematic diagram of the connection structure between the controller and various electrical components of this utility model; In the diagram: 1. Exhaust waste heat exchanger; 2. Cooling water waste heat exchanger; 3. Waste heat collection buffer tank; 4. Lithium bromide absorption chiller; 5. Main board heat exchanger; 6. Main variable frequency circulating pump; 7. Sub-control piping; 8. Branch piping; 9. Terminal plate heat exchanger; 10. In-cabin variable frequency pump; 11. Refrigerant water buffer tank; 12. Return pipe; 13. Backup outlet; 14. Temperature detector; 15. Arc-shaped baffle; 16. Liquid level sensor; 17. Exhaust pipe; 18. Exhaust valve; 19. Exhaust guide pipe; 20. Liquid guide pipe; 21. Gas connection pipe; 22. Liquid connection pipe; 23. Flow regulating valve; 24. Dust filter; 25. Flow sensor; 26. Water filter. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Please see Figure 1-3 This utility model discloses an energy-saving and environmentally friendly waste heat recovery device for refrigerated ships, comprising a dual-path waste heat recovery unit, a waste heat collection and buffer tank 3, a lithium bromide absorption chiller unit 4, a refrigeration distribution unit, and connecting pipes and valve assemblies. The dual-path waste heat recovery unit includes an exhaust waste heat exchanger 1 and a cooling water waste heat exchanger 2. The input end of the waste heat collection and buffer tank 3 is connected to the dual-path waste heat recovery unit via connecting pipes, and the output end of the waste heat collection and buffer tank 3 is connected to the lithium bromide absorption chiller unit 4 via connecting pipes. The lithium bromide absorption chiller unit 4 is connected to the refrigeration distribution unit via connecting pipes.

[0019] This technical solution is based on the core logic of dual-path waste heat recovery, energy collection and buffering, lithium bromide refrigeration, and on-demand refrigeration distribution. By recovering the exhaust waste heat and cooling water waste heat of the refrigerated ship's power system, the waste heat is homogenized in the waste heat collection and buffer tank 3 and then drives the lithium bromide absorption chiller unit 4 to generate chilled water, which is then supplied to each refrigerated compartment in the ship on demand through the refrigeration distribution unit. The system is intelligently controlled throughout the process, realizing the efficient recovery of power waste heat and the precise matching of refrigeration demand. It solves the industry pain points of waste power waste heat and high energy consumption of refrigeration system in refrigerated ships, and has the dual value of energy saving and environmental protection and operation cost optimization.

[0020] The dual-path waste heat recovery unit includes an exhaust waste heat exchanger 1, a cooling water waste heat exchanger 2, and a filter assembly; The exhaust waste heat exchanger 1 is equipped with an exhaust guide pipe 19 with an air inlet pipe 21 at the input end, and a ceramic fiber dust filter 24 is screwed onto the air inlet pipe 21; the cooling water waste heat exchanger 2 is equipped with a liquid guide pipe 20 with a liquid inlet pipe 22 at the input end, and a stainless steel braided mesh water filter 26 is screwed onto the liquid inlet pipe 22; a flow regulating valve 23 is installed at the top of the pipe, and a flow sensor 25 is installed at the bottom.

[0021] Exhaust heat recovery: Marine power exhaust is diverted through exhaust guide pipe 19 to various inlet pipes 21. The ceramic fiber filter element of the dust filter 24 filters dust particles in the exhaust to prevent clogging of the heat exchanger. The flow regulating valve 23, in conjunction with the flow sensor 25, dynamically adjusts the exhaust flow of each pipe to ensure stable heat exchange efficiency of the exhaust waste heat exchanger 1. High-temperature exhaust exchanges heat with the heat transfer medium water or heat transfer oil in the heat exchanger, transferring waste heat to the heat transfer medium.

[0022] Cooling water waste heat recovery: The power system cooling water is diverted through the liquid guide pipe 20 to each liquid inlet pipe 22. The stainless steel braided mesh filter element of the water filter 26 filters impurities in the cooling water. Similarly, the flow regulating valve 23 and the flow sensor 25 regulate the cooling water flow rate to stabilize the heat exchange process of the cooling water waste heat exchanger 2. The waste heat of the cooling water is absorbed by the heat transfer medium, realizing the synchronous recovery of waste heat from both paths.

[0023] Waste heat collection buffer tank 3 includes a liquid level sensor 16, an arc-shaped baffle 15, and an exhaust pipe 17. The waste heat collection buffer tank 3 is equipped with a liquid level sensor 16 on its side wall, and arc-shaped baffles 15 are evenly arranged axially on its inner wall. The top is equipped with an exhaust pipe 17 with an exhaust valve 18. The exhaust waste heat exchanger 1 is connected to the upper end of the waste heat collection buffer tank 3, and the cooling water waste heat exchanger 2 is connected to the bottom end of the waste heat collection buffer tank 3. The tail end is equipped with a spare outlet 13 with a flow regulating valve 23.

[0024] The dual-path heat recovery medium enters the waste heat collection buffer tank 3 from the top and bottom respectively. The arc-shaped baffle 15 ensures that the two media are fully mixed and homogenized in the tank, avoiding temperature stratification. The liquid level sensor 16 monitors the liquid level of the medium in the tank in real time to ensure the safe operation of the system. The exhaust pipe 17 and exhaust valve 18 are used to discharge non-condensable gases in the tank to ensure the heat transfer efficiency of the heat medium. The backup outlet 13 can guide the heat medium to a backup utilization device, such as hot water supply, in the event of a failure in the main refrigeration circuit, thereby improving the system redundancy.

[0025] 4. Lithium bromide absorption chiller units, such as Shuangliang H2 heat transfer oil type lithium bromide absorption chiller units or Carrier 16 series customized heat transfer oil driven units: The lithium bromide absorption chiller 4 is connected to the output end of the waste heat collection buffer tank 3, and uses the waste heat of the heat medium as the driving heat source.

[0026] After the heat transfer medium enters the lithium bromide absorption chiller unit 4, its heat drives the circulation of the lithium bromide solution within the unit: the dilute solution is heated and concentrated in the generator to produce refrigerant vapor; the refrigerant vapor condenses into refrigerant water in the condenser, and after throttling, it enters the evaporator, absorbing heat from the refrigerant water to evaporate and cool the refrigerant water; the evaporated refrigerant vapor is absorbed by the concentrated solution in the absorber to form a dilute solution, completing the cycle. The final low-temperature refrigerant water is transported to the refrigeration distribution unit, realizing the energy conversion of waste heat and cooling capacity.

[0027] The cooling distribution unit includes a centralized main unit and distributed terminals. The centralized main unit includes a mainboard heat exchanger 5, a main variable frequency circulating pump 6, and a sub-control pipeline 7; the distributed terminal includes a terminal plate heat exchanger 9, an in-cabin variable frequency pump 10, and an in-cabin temperature sensor; a chilled water buffer tank 11 is installed at the front end of the mainboard heat exchanger 5; the controller is electrically connected to each temperature detector 14, sensor, pump, and valve.

[0028] Chilled water delivery: The chilled water generated by the lithium bromide unit first enters the chilled water buffer tank 11 for homogenization, and then undergoes further heat exchange through the main board heat exchanger 5 before being delivered to the sub-control pipeline 7 by the main variable frequency circulating pump 6; the flow regulating valve 23 on the sub-control pipeline 7 dynamically distributes the chilled water to the corresponding sub-pipeline 8 according to the temperature requirements of each compartment.

[0029] Cabin cooling: Chilled water enters the terminal plate heat exchanger 9, where it exchanges heat with the circulating medium (such as air) inside the cabin, reducing the cabin temperature. An in-cabin variable frequency pump 10 drives the circulating medium, and a cabin temperature sensor monitors the temperature in real time, feeding back to the controller. The controller adjusts the speed of the in-cabin variable frequency pump 10 and the terminal flow rate based on the temperature deviation, achieving precise temperature control in each cabin. The cooled water, after heat exchange, returns to the lithium bromide unit via the return pipe 12, completing the refrigeration cycle.

[0030] The controller in this technical solution can be a conventional PLC programmable control system, and the various electrical devices in this technical solution can be used with conventional circuit structures and external mains power.

[0031] Detailed Workflow Step 1: Start-up of dual-path waste heat recovery After the ship's power system is started, the exhaust waste heat exchanger 1 and the cooling water waste heat exchanger 2 work synchronously: the exhaust gas enters the exhaust waste heat exchanger 1 after being filtered for dust and the flow rate is regulated, and the cooling water enters the cooling water waste heat exchanger 2 after being filtered for water and the flow rate is regulated. The two transfer the waste heat to the heat transfer medium, such as water or heat transfer oil.

[0032] Step 2: Waste heat collection and homogenization The heat transfer medium carrying waste heat enters the waste heat collection buffer tank 3 from the top and bottom ends, respectively, and is mixed and homogenized by the arc-shaped baffle 15; the liquid level sensor 16 monitors the liquid level, and the exhaust pipe 17 discharges non-condensable gas to ensure the heat transfer efficiency of the heat transfer medium.

[0033] Step 3: Operation of the lithium bromide refrigeration unit The heat transfer medium enters the lithium bromide absorption chiller 4, driving the lithium bromide solution to circulate and generate low-temperature chilled water, such as 7-12℃. The chilled water is then transported to the chilled water buffer tank 11 for temporary storage.

[0034] Step 4: Cooling Distribution and Cabin Temperature Control After the chilled water is heated by the main plate heat exchanger 5, it is delivered to the sub-control pipeline 7 by the main variable frequency circulating pump 6; the flow regulating valve 23 of the sub-control pipeline 7 distributes the chilled water to the terminal plate heat exchanger 9 according to the needs of each compartment. The terminal plate heat exchanger 9 exchanges heat with the circulating medium inside the chamber to reduce the temperature inside the chamber; the temperature sensor inside the chamber provides real-time temperature feedback, and the controller adjusts the speed and terminal flow of the variable frequency pump 10 inside the chamber to maintain a stable temperature inside the chamber. After heat exchange, the chilled water returns to the lithium bromide unit via return pipe 12, completing the cycle.

[0035] Step 5: Intelligent Control and Redundancy Protection The controller collects data from each temperature sensor 14, flow sensor 25, and level sensor 16 in real time, and dynamically adjusts the flow regulating valve 23, the speed of the variable frequency pump, and the opening of the exhaust valve 18. If the main refrigeration circuit fails, the backup outlet 13 of the waste heat collection buffer tank 3 is opened to guide the heat medium to the backup device, ensuring continuous operation of the system.

[0036] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An energy-saving and environmentally friendly waste heat recovery device for refrigerated ships, characterized in that, It includes a dual-path waste heat recovery unit, a waste heat collection buffer tank (3), a lithium bromide absorption chiller (4), a refrigeration distribution unit, and connecting pipes and valve assemblies; the dual-path waste heat recovery unit includes an exhaust waste heat exchanger (1) and a cooling water waste heat exchanger (2); the input end of the waste heat collection buffer tank (3) is connected to the dual-path waste heat recovery unit through a connecting pipe; the output end of the waste heat collection buffer tank (3) is connected to the lithium bromide absorption chiller (4) through a connecting pipe; the lithium bromide absorption chiller (4) is connected to the refrigeration distribution unit through a connecting pipe.

2. The energy-saving and environmentally friendly refrigerated ship power waste heat utilization device according to claim 1, characterized in that, It also includes a filter assembly, which includes a dust filter (24) and a water filter (26). The exhaust waste heat exchanger (1) has an exhaust guide pipe (19) at its input end, and the exhaust guide pipe (19) has several air inlet pipes (21). The cooling water waste heat exchanger (2) has a liquid guide pipe (20) at its input end, and the liquid guide pipe (20) has several liquid inlet pipes (22). The dust filter (24) is screwed onto the air inlet pipe (21) by a threaded structure, and the dust filter (24) has several on the air inlet pipe (21). The water filter (26) is screwed onto the liquid inlet pipe (22) by a threaded structure, and the water filter (26) has several on the liquid inlet pipe (22).

3. The energy-saving and environmentally friendly refrigerated ship power waste heat utilization device according to claim 2, characterized in that, The dust filter (24) uses a ceramic fiber filter element, the water filter (26) uses a stainless steel woven mesh filter element, the top of the air inlet pipe (21) and the liquid inlet pipe (22) are equipped with flow regulating valves (23), and the bottom of the air inlet pipe (21) and the liquid inlet pipe are equipped with flow sensors (25).

4. The energy-saving and environmentally friendly refrigerated ship power waste heat utilization device according to claim 3, characterized in that, The exhaust waste heat exchanger (1) is connected to the upper end of the waste heat collection buffer tank (3) through a connecting pipe, and the cooling water waste heat exchanger (2) is connected to the bottom end of the waste heat collection buffer tank (3) through a connecting pipe. The tail end of the waste heat collection buffer tank (3) is provided with a spare outlet (13), and the spare outlet (13) is provided with a flow regulating valve (23).

5. The energy-saving and environmentally friendly refrigerated ship power waste heat utilization device according to claim 4, characterized in that, The waste heat collection buffer tank (3) is provided with a liquid level sensor (16) on its side wall. The inner wall of the waste heat collection buffer tank (3) is axially arranged with several arc-shaped baffles (15). The top of the waste heat collection buffer tank (3) is provided with an exhaust pipe (17) and an exhaust valve (18) is provided on the exhaust pipe (17).

6. The energy-saving and environmentally friendly refrigerated ship power waste heat utilization device according to claim 5, characterized in that, The refrigeration distribution unit includes a centralized main unit and distributed terminals. The centralized main unit includes a main plate heat exchanger (5), a main variable frequency circulating pump (6), and distributed control pipelines (7). The distributed terminals include terminal plate heat exchangers (9), an in-cabin variable frequency pump (10), and an in-cabin temperature sensor. The main plate heat exchanger (5) is connected to the lithium bromide absorption chiller unit (4) via connecting pipelines. The output end of the main plate heat exchanger (5) is connected to the main variable frequency circulating pump (6) via connecting pipelines. The output end of the frequency circulation pump (6) is connected to the sub-control pipeline (7). The sub-control pipeline (7) is provided with several branch pipelines (8). The branch pipelines (8) are connected to the input end of the terminal plate heat exchanger (9). The output end of the terminal plate heat exchanger (9) is connected to the in-cabin frequency pump (10). The branch pipelines (8) are provided with flow regulating valves (23). The main plate heat exchanger (5) and the in-cabin frequency pump (10) are connected to the lithium bromide absorption chiller unit (4) through the return pipe (12).

7. The energy-saving and environmentally friendly refrigerated ship power waste heat utilization device according to claim 6, characterized in that, Temperature detectors (14) are provided on the exhaust pipe (19), liquid pipe (20) and waste heat collection buffer tank (3), and a controller is also included. The controller is electrically connected to the temperature detectors (14), the cabin temperature sensor, the flow regulating valve (23), the main variable frequency circulation pump (6), the cabin variable frequency pump (10) and the exhaust valve (18).

8. The energy-saving and environmentally friendly refrigerated ship power waste heat utilization device according to claim 6, characterized in that, The front end of the mainboard heat exchanger (5) is provided with a chilled water buffer tank (11). The input end of the chilled water buffer tank (11) is connected to the lithium bromide absorption chiller unit (4) through a connecting pipe. The input end of the chilled water buffer tank (11) is connected to the mainboard heat exchanger (5) through a connecting pipe.

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