Energy-saving preheating system and energy-saving preheating method of ship ammonia fuel supply system

Abstract

The invention belongs to the technical field of ship and ocean engineering construction, and discloses an energy-saving preheating system and an energy-saving preheating method of a ship ammonia fuel supply system. The problem that steam generated by boiler fuel oil assists in operation of an ammonia fuel supply system is effectively solved. Comprising a main engine cylinder sleeve water cooling system, a water glycol heating system and a water glycol closed circulating system, the water glycol heating system comprises a water glycol heater and a water glycol hot water booster pump; the water glycol heater adopts a plate heat exchanger type; an outlet of the degassing barrel is connected with an inlet of the water glycol hot water booster pump, an outlet of the water glycol hot water booster pump is connected with a hot water inlet of the water glycol heater, and a hot water outlet of the water glycol heater and an outlet of the fresh water generator are both connected into an inlet of the main machine cylinder sleeve water cooler. And a water glycol inlet and a water glycol outlet of the water glycol heater are connected to the water glycol closed circulating system. By means of waste heat utilization of the main engine cylinder sleeve, oil consumption of ship operation is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ship and ocean engineering construction, and particularly relates to an energy-saving preheating system and method for a ship ammonia fuel supply system. BACKGROUND

[0002] To achieve the carbon emission standard of the ship transportation industry, green ammonia is a zero-carbon fuel, which can be transported in liquid bulk, does not need ultra-low temperature storage, and is convenient to obtain in industrial production, and can be used as a ship fuel. The ship is filled with liquid ammonia, and the liquid ammonia fuel is stored in a semi-cold and semi-pressure manner. The liquid ammonia is transported to the ship propulsion main engine for combustion after being preheated and warmed up by the ammonia fuel supply system.

[0003] At present, the ammonia fuel supply system is equipped with an ammonia preheating module, which usually uses steam to heat water glycol, and uses the heated water glycol to preheat the ammonia fuel.

[0004] The steam of the ship is obtained by heating boiler water to obtain steam by using high-temperature flue gas generated by burning fuel oil by the main / auxiliary engine exhaust heat or the boiler burner on the boiler exhaust gas side. The conventional design adopts a steam heating type, consumes a large amount of steam to achieve ammonia fuel supply preheating. Because the heat value of green ammonia is lower than that of fuel oil, the exhaust gas temperature and mass flow of ammonia fuel engine are lower than those of fuel oil engine under the same environmental conditions, especially under ISO environmental conditions, the exhaust gas temperature of the main engine ammonia fuel mode CSR and below is low, and the waste heat cannot generate steam for ammonia preheating module steam heating.

[0005] In order to cooperate with the operation of the main engine ammonia mode, the boiler burner needs to be actively started to generate steam by consuming fuel oil to assist the operation of the ammonia fuel supply system. Under ISO environmental conditions or in winter, the exhaust gas temperature of the main engine is lower than the temperature of 6bar saturated steam, which is 165℃. The main engine flue gas flows through the boiler exhaust gas side, which will reversely take away part of the boiler fuel oil side heat, increasing the boiler fuel oil consumption. SUMMARY

[0006] An object of the present application is to provide an energy-saving preheating system for a ship ammonia fuel supply system, which effectively solves the problem of the existing ammonia fuel supply system assisted by the boiler fuel oil to generate steam.

[0007] To solve the above technical problems, the technical solution adopted by the present application is: an energy-saving preheating system for a ship ammonia fuel supply system, comprising a main engine cylinder jacket water cooling system, a water glycol heating system and a water glycol closed circulation system.

[0008] The main engine cylinder jacket water cooling system comprises a main engine, a main engine cylinder jacket water preheating pump, a main engine cylinder jacket water preheater, a degassing bucket, a main engine cylinder jacket cooling fresh water pump, a main engine cylinder jacket water cooler, a water generator and a high-temperature fresh water expansion tank.

[0009] The water glycol heating system comprises a water glycol heater and a water glycol hot water booster pump, and the water glycol heater adopts a plate heat exchanger type.

[0010] The outlet of the main engine cylinder jacket water preheating pump is connected with the inlet of the main engine cylinder jacket water preheater, the outlet of the main engine cylinder jacket water preheater is connected with the inlet of the main engine, the outlet of the main engine is connected with the inlet of the degassing bucket, the outlet of the degassing bucket is connected with the inlet of the main engine cylinder jacket water preheating pump, the inlet of the water generator and the inlet of the water glycol hot water booster pump through a three-way temperature control valve, the outlet of the water glycol hot water booster pump is connected with the hot water inlet of the water glycol heater, the hot water outlet of the water glycol heater and the outlet of the water generator are connected with the inlet of the main engine cylinder jacket water cooler, the outlet of the main engine cylinder jacket water cooler is connected with the inlet of the main engine cylinder jacket cooling fresh water pump, and the outlet of the main engine cylinder jacket cooling fresh water pump is connected with the inlet of the main engine.

[0011] The outlet of the high-temperature fresh water expansion tank is connected with the inlet of the main engine cylinder jacket water preheating pump and the inlet of the main engine cylinder jacket cooling fresh water pump through a pipeline.

[0012] The water glycol inlet and the water glycol outlet of the water glycol heater are connected with the water glycol closed circulation system.

[0013] When the cylinder jacket water cools the main engine cylinder jacket, the high-temperature cylinder jacket water at the outlet of the main engine is transported to the water glycol heater through the water glycol hot water booster pump, and heat is transferred to the water glycol through the interwall heat exchange; the water glycol after heat exchange and temperature rise preheats and warms the ammonia fuel to meet the use requirement of the main engine, and the cylinder jacket water after heat exchange and temperature drop flows back to the inlet of the main engine cylinder jacket cooling fresh water pump through the main engine cylinder jacket water cooler.

[0014] Further, the water glycol heater is arranged in parallel with the water generator.

[0015] Further, the arrangement position of the water glycol heater is higher than the arrangement positions of the main engine and the water generator.

[0016] Another object of the present application is to provide an energy-saving preheating method of a ship ammonia fuel supply system, which is applied to the energy-saving preheating system described in the above embodiments and comprises the following steps: S1, starting the main engine cylinder jacket water preheating pump, and the cylinder jacket water is transported to the main engine after being heated by the main engine cylinder jacket water preheater, and the main engine is warmed up before starting.

[0017] S2, the cylinder jacket water flows out of the main engine and flows back to the inlet of the main engine cylinder jacket water preheating pump through the degassing bucket and the three-way temperature control valve, and the cylinder jacket water circulates in the closed pipeline, so that the main engine is preheated.

[0018] S3, after the main engine is warmed up, the main engine cylinder jacket water preheating pump and the main engine cylinder jacket water preheater stop working, the cylinder jacket water is transported to the main engine through the main engine cylinder jacket cooling fresh water pump, after the main engine cylinder is cooled, the cylinder jacket water is heated to high temperature.

[0019] S4, the high-temperature cylinder jacket water at the outlet of the main engine is divided into the water generator and the water glycol heating system after flowing through the degassing bucket.

[0020] S5, in the water glycol heating system, the high-temperature cylinder jacket water is transferred to the water glycol heater through the water glycol hot water booster pump, the heat of the high-temperature cylinder jacket water is conducted to the water glycol through the heat exchange between the walls, and the water glycol heated by the heat exchange is preheated to a temperature required by the main engine through the water glycol closed circulation system.

[0021] S6, the cylinder jacket water cooled by the water glycol heating system is combined with the cylinder jacket water divided into the water generator in step S4, and then is returned to the inlet of the main engine cylinder jacket water cooling fresh water pump after being cooled by the main engine cylinder jacket water cooler; the cylinder jacket water circulates in the closed cooling system.

[0022] Compared with the prior art, the beneficial technical effects of the present application are: (1) the waste heat of the main engine cylinder jacket water is utilized twice in the present application, the cooling load of the main engine cylinder jacket water cooling system is reduced, the heat exchange area and the number of plates of the main engine cylinder jacket water cooler can be reduced, the purchase cost is reduced, the operation load of the ship central cooling system is further reduced, the cooling water demand is reduced, the power load of the cooling water pump is reduced, the steam consumption of the ship is reduced, the steam users are reduced, the steam pipeline arrangement is reduced, the steam leakage risk is reduced, the safety factor of the engine room is improved, and the health of the engine room crew is ensured.

[0023] (2) the present application can solve the contradiction between the insufficient boiler evaporation capacity caused by the low temperature and flow of the main engine flue gas and the large amount of steam consumed by the ammonia preheating in the ammonia main engine project. Through the utilization of the waste heat of the main engine cylinder, the fuel consumption of the ship is reduced, and the energy efficiency is improved and resources are saved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a connection structure diagram of the energy-saving preheating system (the water glycol closed circulation system is not shown) of the present application.

[0025] Mark explanation: main engine-1; main engine cylinder jacket water preheating pump-2; main engine cylinder jacket water preheater-3; degassing bucket-4; main engine cylinder jacket cooling fresh water pump-5; main engine cylinder jacket water cooler-6; water generator-7; high-temperature fresh water expansion tank-8; water glycol heater-9; water glycol hot water booster pump-10; three-way temperature control valve-11. DETAILED DESCRIPTION

[0026] Example 1: An energy-saving preheating system for a ship's ammonia fuel supply system, comprising a main engine cylinder liner water cooling system, a water glycol heating system, and a water glycol closed-loop circulation system.

[0027] like Figure 1 As shown, the main engine cylinder liner water cooling system includes the main engine 1, the main engine cylinder liner water preheating pump 2, the main engine cylinder liner water preheater 3, the degassing tank 4, the main engine cylinder liner cooling fresh water pump 5, the main engine cylinder liner water cooler 6, the water maker 7, and the high-temperature fresh water expansion tank 8. The water glycol heating system includes a water glycol heater 9 and a water glycol hot water booster pump 10. The water glycol heater 9 adopts a plate heat exchanger type.

[0028] The outlet of the main engine cylinder liner water preheating pump 2 is connected to the inlet of the main engine cylinder liner water preheater 3. The outlet of the main engine cylinder liner water preheater 3 is connected to the inlet of the main engine 1. The outlet of the main engine 1 is connected to the inlet of the degassing tank 4. The outlet of the degassing tank 4 is connected to the inlet of the main engine cylinder liner water preheating pump 2, the inlet of the water maker 7, and the inlet of the water glycol hot water booster pump 10 via a three-way thermostatic valve 11. The outlet of the water glycol hot water booster pump 10 is connected to the hot water inlet of the water glycol heater 9. The hot water outlet of the water glycol heater 9 and the outlet of the water maker 7 are both connected to the inlet of the main engine cylinder liner water cooler 6. The outlet of the main engine cylinder liner water cooler 6 is connected to the inlet of the main engine cylinder liner cooling fresh water pump 5. The outlet of the main engine cylinder liner cooling fresh water pump 5 is connected to the inlet of the main engine 1. The outlet of the high-temperature fresh water expansion tank 8 is connected to the inlet of the main engine cylinder liner water preheating pump 2 and the inlet of the main engine cylinder liner cooling fresh water pump 5 via a pipeline. The water glycol inlet and outlet of the water glycol heater 9 are both connected to a closed-loop water glycol circulation system. In addition, the outlet pipe of the main engine 1 is also connected to the inlet of the main engine cylinder liner water cooler 6 via a three-way thermostatic valve 11.

[0029] In this embodiment, the water glycol heater 9 and the water generator 7 are arranged side by side, and the water glycol heater 9 is arranged at a high position in the engine room, that is, the arrangement position of the water glycol heater 9 is higher than the arrangement position of the main engine 1 and the water generator 7.

[0030] After the cylinder liner water cools the main engine cylinder liner, the high-temperature cylinder liner water from the outlet of main engine 1 is transported to the water glycol heater 9 via the water glycol hot water booster pump 10. Heat is transferred to the water glycol through a heat exchanger. The heated water glycol then preheats the ammonia fuel to the required temperature for main engine 1 via a closed-loop water glycol circulation system. The cooled cylinder liner water is then returned to the inlet of the main engine cylinder liner cooling fresh water pump 5 via the main engine cylinder liner water cooler 6. The cylinder liner water circulates repeatedly in the closed-loop cooling system, thus achieving the purpose of preheating the ammonia fuel.

[0031] Embodiment 2: An energy-saving preheating method of a ship ammonia fuel supply system, applied to the energy-saving preheating system of embodiment 1, comprising the following steps: S1, starting the main engine cylinder jacket water preheating pump 2, the cylinder jacket water is heated by the main engine cylinder jacket water preheater 3 and then delivered to the main engine 1 to warm up the main engine 1 before starting.

[0032] S2, after the cylinder jacket water flows out of the main engine 1, it is returned to the inlet of the main engine cylinder jacket water preheating pump 2 through the degassing bucket 4 and the three-way temperature control valve 11, and the cylinder jacket water circulates in the closed pipeline to realize the preheating of the main engine 1.

[0033] S3, after the main engine 1 is preheated and started, the main engine cylinder jacket water preheating pump 2 and the main engine cylinder jacket water preheater 3 stop working, the cylinder jacket water is delivered to the main engine 1 through the main engine cylinder cooling fresh water pump 5, and after cooling the main engine cylinder, the cylinder jacket water is heated to a high temperature (about 90℃).

[0034] The outlet cylinder jacket water temperature of the main engine 1 is controlled by the three-way temperature control valve 11, and the outlet cylinder jacket water temperature of the main engine 1 is set to 90℃. Considering that part of the heat will be lost during pipeline transportation, when the high-temperature cylinder jacket water is delivered to the water glycol heater 9, the water temperature can be ensured to be 85℃. The control logic of the three-way temperature control valve 11 is: when the outlet cylinder jacket water temperature of the main engine 1 is higher than 90℃, the water flow to the main engine cylinder cooler 6 is increased through the three-way temperature control valve 11, so as to reduce the water temperature; vice versa.

[0035] S4, the high-temperature cylinder jacket water outlet of the main engine 1 flows through the degassing bucket 4 and is divided into the water generator 7 and the water glycol heating system.

[0036] S5, in the water glycol heating system, the high-temperature cylinder jacket water is transferred to the water glycol heater 9 through the water glycol hot water booster pump 10, and the heat of the high-temperature cylinder jacket water is conducted to the water glycol through the interwall heat exchange, and the water glycol after heat exchange is heated is preheated to the ammonia fuel to meet the use requirements of the main engine.

[0037] S6, after the cylinder jacket water cooled by the water glycol heating system and the cylinder jacket water divided into the water generator 7 in step S4 are collected, they are cooled by the main engine cylinder jacket water cooler 6 and then returned to the inlet of the main engine cylinder cooling fresh water pump 5. The cylinder jacket water circulates in the closed cooling system to realize the cylinder cooling and ammonia fuel supply preheating purposes of the main engine 1 during operation.

[0038] The present application uses the waste heat of the main engine 1 cylinder jacket water to heat the water glycol to replace the steam heating water glycol in the prior art. Through the design of the cylinder jacket water closed circulation system pipeline, part of the high-temperature cylinder jacket water outlet of the main engine 1 is divided into the water glycol heating system, and then through the water glycol closed circulation system to the ammonia preheating module, the ammonia fuel is preheated by the water glycol heated by the waste heat of the cylinder jacket water.

[0039] The application utilizes the waste heat of the main engine cylinder jacket water, reduces the cooling load of the main engine cylinder jacket water cooling system, can reduce the heat exchange area and the number of plates of the main engine cylinder jacket water cooler 6, reduces the purchase cost, further reduces the operation load of the ship central cooling system, reduces the cooling water quantity demand, reduces the cooling water pump power load, simultaneously reduces the steam consumption of the ship operation, reduces the steam user, reduces the steam pipeline arrangement, reduces the steam leakage risk, improves the safety factor of the engine room, and protects the health of the engine room crew.

[0040] The application can solve the contradiction between the insufficient boiler evaporation capacity caused by the low temperature and flow of the main engine flue gas and the large amount of steam consumed by the ammonia supply preheating in the ammonia main engine project. Through the utilization of the main engine cylinder jacket waste heat, the fuel consumption of the ship operation is reduced, and the energy efficiency is improved and the resources are saved.

[0041] Of course, the above description is not a limitation of the application, and the application is not limited to the above examples. Changes, modifications, additions or replacements made by the person skilled in the art within the essential scope of the application shall also belong to the protection scope of the application.

Claims

1. An energy-saving preheating system for a ship's ammonia fuel supply system, characterized in that, This includes the main engine cylinder liner water cooling system, the water glycol heating system, and the water glycol closed-loop circulation system; The main engine cylinder liner water cooling system includes the main engine, main engine cylinder liner water preheating pump, main engine cylinder liner water preheater, degassing tank, main engine cylinder liner cooling fresh water pump, main engine cylinder liner water cooler, water maker and high temperature fresh water expansion tank. The water glycol heating system includes a water glycol heater and a water glycol hot water booster pump. The water glycol heater adopts a plate heat exchanger type. The outlet of the main engine cylinder liner water preheating pump is connected to the inlet of the main engine cylinder liner water preheater. The outlet of the main engine cylinder liner water preheater is connected to the inlet of the main engine. The outlet of the main engine is connected to the inlet of the degassing tank. The outlet of the degassing tank is connected to the inlet of the main engine cylinder liner water preheating pump, the inlet of the water maker, and the inlet of the water glycol hot water booster pump via a three-way thermostatic valve. The outlet of the water glycol hot water booster pump is connected to the hot water inlet of the water glycol heater. The hot water outlet of the water glycol heater and the outlet of the water maker are both connected to the inlet of the main engine cylinder liner water cooler. The outlet of the main engine cylinder liner water cooler is connected to the inlet of the main engine cylinder liner cooling fresh water pump. The outlet of the main engine cylinder liner cooling fresh water pump is connected to the inlet of the main engine. The outlet of the high-temperature freshwater expansion tank is connected to the inlet of the main engine cylinder liner water preheating pump and the inlet of the main engine cylinder liner cooling freshwater pump via a pipeline. The water glycol inlet and water glycol outlet of the water glycol heater are both connected to a closed-loop water glycol circulation system. After the cylinder liner water cools the main engine cylinder liner, the high-temperature cylinder liner water from the main engine outlet is transported to the water glycol heater through the water glycol hot water booster pump. The heat is transferred to the water glycol through the indirect heat exchange. The water glycol, after being heated by the heat exchange, preheats the ammonia fuel to meet the main engine's operating requirements through the water glycol closed-loop circulation system. The cylinder liner water, after being cooled by the heat exchange, flows back to the inlet of the main engine cylinder liner cooling fresh water pump through the main engine cylinder liner water cooler.

2. The energy-saving preheating system for a ship ammonia fuel supply system according to claim 1, characterized in that, The water glycol heater is arranged in parallel with the water maker.

3. The energy-saving preheating system for a ship ammonia fuel supply system according to claim 2, characterized in that, The water glycol heater is positioned higher than the main unit and the water maker.

4. An energy-saving preheating method for a ship's ammonia fuel supply system, characterized in that, The energy-saving preheating system applied to any one of claims 1-3 includes the following steps: S1. Start the main engine cylinder liner water preheating pump. The cylinder liner water is heated by the main engine cylinder liner water preheater and then delivered to the main engine to warm up the cylinder before starting the main engine. S2. After the cylinder liner water flows out of the main unit, it flows back to the inlet of the main unit cylinder liner water preheating pump through the degassing tank and the three-way temperature control valve. The cylinder liner water circulates in the closed pipeline to achieve main unit preheating. S3. After the main engine is preheated, the main engine cylinder liner water preheating pump and the main engine cylinder liner water preheater stop working. The cylinder liner water is delivered to the main engine through the main engine cylinder liner cooling fresh water pump. After cooling the main engine cylinder, the cylinder liner water is heated to a high temperature. S4. The high-temperature cylinder liner water from the main engine outlet flows through the degassing tank and is then diverted to the water maker and the water glycol heating system. S5. In the water glycol heating system, the high-temperature cylinder liner water is transported to the water glycol heater by the water glycol hot water booster pump. The heat of the high-temperature cylinder liner water is transferred to the water glycol through the heat exchange between the walls. The water glycol, after heat exchange and temperature rise, preheats the ammonia fuel to meet the requirements of the main unit through the water glycol closed circulation system. S6. The cylinder liner water cooled by the water glycol heating system and the cylinder liner water diverted to the water generator in step S4 are combined and then cooled by the main engine cylinder liner water cooler before flowing back to the inlet of the main engine cylinder liner cooling fresh water pump; the cylinder liner water circulates in the closed cooling system.

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