船舶发动机余热回收热力循环的理论优化及试验研究
发布时间：2019-07-03 14:01
【摘要】：在各行各业节能减排的背景下,作为国际贸易主要的运输工具,船舶消耗着巨大能源的同时也受到了国际排放法规的严苛限制,其节能减排的工作具有非常重要的现实意义。从船舶的能流平衡分析来看,大型二冲程柴油机的热效率高达48-51%,但仍有一半左右的能量以废气、缸套水和增压空气等废热方式释放到环境中,余热能量巨大。由于船舶发动机具有运行工况稳定以及可以直接使用海水作为冷源等优点,促使船舶发动机余热回收利用成为船舶节能减排领域中一个极具潜力的技术手段。基于此,本文针对船舶余热能量达和船舶存在电、冷等多能量需求的特点,以提高余热回收热力系统的总能效率为目标,对船舶发动机余热回收热力系统展开了理论探索和试验研究。本文以瓦锡兰12RTA96C低速船舶柴油机为研究对象,根据发动机在不同工况下的运行参数,对发动机的能流特性进行了理论分析。按照发动机燃油成分和进气参数,通过燃烧反应方程式推导方法分析了排气成分的含量,采用混合气体的混合法则对发动机排气的热物性参数进行了计算分析,在此基础上对各余热源在不同发动机工况下的“能流”和“?流”特性进行了理论分析,为余热回收系统性能研究提供了理论依据。结果表明,随着发动机负荷的增加,各热源的能量和?量均增加,在所有余热源中,发动机排气能量最大,在110%CMCR工况下达到最大值42808kW。同时,当发动机负荷增加时,增压空气的能量和?量比例增加,缸套水和排气的能量和?量比例却减小了。在探明船舶发动机余热特性的基础上,建立了朗肯循环余热回收系统数学模型,开展了系统的热力学性能分析,为试验系统的设计提供依据。根据系统的性能、稳定性、安全性、经济性与环保性等因素筛选了11种工质,展开了蒸发压力、冷凝温度和发动机工况对系统性能的影响分析。结果表明,对于大部分选取的工质,余热回收系统的输出电量随着蒸发压力的增大先增大后减小且存在最大值,随着冷凝温度的减小而增大,在发动机大负荷下余热回收潜力巨大。Cyclohexane作为工质时系统的净输出电量最大,发动机的热效率达52.08%,比原机提高6.5%;而使用水作为工质时系统的热效率和?效率最高。以YC6L330-30柴油机作为船舶发动机模拟机器,建立了导热油中间换热的有机朗肯循环余热回收系统试验平台,进行了采用膨胀阀和透平式膨胀装置时的系统性能研究。当发动机在转速1700rpm、功率225kW工况下运转时,膨胀阀进口工质?最大达到19.3kW,占发动机功率的8.58%;当动机在转速为1900rpm、功率为228kW时,透平膨胀装置所产生的最大发电量仅为253W,占发动机功率的0.11%。在此基础上,分析了系统所存在的问题,提出了下一步改进的方向。为提高余热回收热力系统的总能效率,在简单朗肯循环的基础上,分析了缸套水预热系统、水蒸气中间再热系统、水蒸气双段双压系统、双级朗肯循环系统和朗肯-吸收式冷电联产系统等5种不同循环结构的余热回收热力系统,构建其数学模型并进行了热力学性能对比分析。结果表明,在相同的蒸发压力下,除了缸套水预热系统外,其余的余热回收系统的净输出电量均比简单朗肯循环高,朗肯-吸收式冷电联产系统总能转化效率最高,其最高等效输出电量达6068kW,此时其电量和制冷量分别为2927kW和12765kW,符合船舶上多能量需求的特点,是适合船舶发动机余热回收的技术手段。本论文对选定的朗肯-吸收式冷电联产系统进行了进一步的优化。按照船舶上的能量需求,采用朗肯-带再生器的吸收式冷电联产系统对电量和冷量输出比例进行了重新调整,在降低冷量输出的基础上增加电量输出。系统的输出电量增加到5121kW,而制冷量降低为489.3kW。不仅数量上满足供需平衡,而且能质上也得到了很好的匹配。
[Abstract]:Under the background of energy-saving and emission reduction in all walks of life, as the main transportation means of international trade, the ship consumes huge energy and is severely restricted by the international emission regulations, and the energy-saving and emission-reducing work of the ship is of great practical significance. From the analysis of the energy flow of the ship, the thermal efficiency of the large-scale two-stroke diesel engine is as high as 48-51%, but the energy still has about half of the energy is released into the environment by waste heat such as waste gas, cylinder liner water and pressurized air, and the waste heat energy is huge. Because the ship engine has the advantages of stable operating condition and direct use of seawater as a cold source, the waste heat recovery of the ship engine can be used as a great potential technical means in the field of energy-saving and emission reduction of the ship. On the basis of this, in order to improve the energy efficiency of the waste heat recovery and heat system, the theoretical exploration and experimental study of the heat system of the waste heat recovery of the ship engine are carried out in the light of the characteristics of the energy requirements of the ship's residual heat energy and the electric and cold energy of the ship. Based on the operating parameters of the engine under different operating conditions, the energy flow characteristics of the engine are analyzed theoretically. according to the fuel composition and the intake parameter of the engine, the content of the exhaust gas component is analyzed through the combustion reaction equation derivation method, and the thermal physical property parameters of the engine exhaust gas are calculated and analyzed by the mixing rule of the mixed gas, On this basis, the "energy flow" and "? flow" characteristics of the residual heat sources under different engine operating conditions are analyzed, and the theoretical basis for the performance research of the waste heat recovery system is provided. The results show that with the increase of the engine load, the energy and the energy of each heat source. The amount of exhaust gas is increased. In all the remaining heat sources, the engine exhaust energy is the largest, and the maximum value is 4280kW at 110% CMRCR. At the same time, when the engine load is increased, the energy of the charge air and? The volume ratio is increased, and the energy and the energy of the cylinder liner and the exhaust gas are increased. The amount ratio is reduced. On the basis of finding the waste heat characteristic of the ship engine, a mathematical model of the Rankine cycle waste heat recovery system is established, and the thermodynamic performance analysis of the system is carried out, and the basis for the design of the test system is provided. According to the performance, stability, safety, economy and environmental protection of the system,11 working fluids were selected, and the effects of evaporation pressure, condensation temperature and engine operating conditions on the system performance were analyzed. The results show that, for most of the selected working medium, the output electric quantity of the waste heat recovery system is reduced with the increase of the evaporation pressure and the maximum value is present, and the waste heat recovery potential is great under the large load of the engine as the condensation temperature is reduced. When Cyclohexane is used as a working medium, the net output power of the system is the largest, the thermal efficiency of the engine is 52.08%, which is 6.5% higher than that of the original machine, and the thermal efficiency of the system and the heat efficiency of the system when using water as the working medium. And the efficiency is the highest. Based on the YC6L330-30 diesel engine as a ship engine simulation machine, an organic Rankine cycle waste heat recovery system test platform for heat transfer oil is established, and the performance of the system is studied by using expansion valve and turbine expansion device. When the engine is operating at a speed of 1700 rpm and a power of 225 kW, the expansion valve inlet working medium? The maximum power generated by the turbine expansion device is only 253 W, accounting for 0.11% of the engine power when the motor is at the speed of 1900 rpm and the power is 228 kW. On this basis, the problems existing in the system are analyzed, and the direction of the next improvement is put forward. In order to improve the total energy efficiency of the heat recovery system of the waste heat, on the basis of the simple Rankine cycle, the water preheating system of the cylinder liner, the water vapor intermediate reheating system and the water vapor double-section double-pressure system are analyzed, The thermodynamic system of the waste heat of five different cycle structures, such as the two-stage Rankine cycle system and the Rankine-absorption type cold-electricity generation system, is constructed, and the mathematical model is constructed and the thermodynamic performance comparison analysis is carried out. The results show that, in the same evaporation pressure, in addition to the cylinder jacket water preheating system, the net output power of the remaining waste heat recovery system is higher than that of the simple Rankine cycle, and the Rankine-absorption type cold and electricity generation system has the highest conversion efficiency, and the maximum equivalent output power is 6068kW. At this time, the electric quantity and the cooling capacity of the ship are 2927 kW and 12765kW, respectively, which are in accordance with the characteristics of the multi-energy demand of the ship, and are the technical means suitable for the recovery of the waste heat of the ship engine. This paper further optimizes the selected Rankine-absorption cold-electricity co-production system. According to the energy demand of the ship, the output proportion of the electric quantity and the cold quantity is re-adjusted by using the absorption-type cold-electricity generation system of the Rankine-belt regenerator, and the electric quantity output is increased on the basis of reducing the output of the cold quantity. The output power of the system is increased to 5121 kW, and the cooling capacity is reduced to 489.3 kW. Not only can the balance of the supply and demand be met, but also a good match is obtained.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U664.1;TK115
，
本文编号：2509447
[Abstract]:Under the background of energy-saving and emission reduction in all walks of life, as the main transportation means of international trade, the ship consumes huge energy and is severely restricted by the international emission regulations, and the energy-saving and emission-reducing work of the ship is of great practical significance. From the analysis of the energy flow of the ship, the thermal efficiency of the large-scale two-stroke diesel engine is as high as 48-51%, but the energy still has about half of the energy is released into the environment by waste heat such as waste gas, cylinder liner water and pressurized air, and the waste heat energy is huge. Because the ship engine has the advantages of stable operating condition and direct use of seawater as a cold source, the waste heat recovery of the ship engine can be used as a great potential technical means in the field of energy-saving and emission reduction of the ship. On the basis of this, in order to improve the energy efficiency of the waste heat recovery and heat system, the theoretical exploration and experimental study of the heat system of the waste heat recovery of the ship engine are carried out in the light of the characteristics of the energy requirements of the ship's residual heat energy and the electric and cold energy of the ship. Based on the operating parameters of the engine under different operating conditions, the energy flow characteristics of the engine are analyzed theoretically. according to the fuel composition and the intake parameter of the engine, the content of the exhaust gas component is analyzed through the combustion reaction equation derivation method, and the thermal physical property parameters of the engine exhaust gas are calculated and analyzed by the mixing rule of the mixed gas, On this basis, the "energy flow" and "? flow" characteristics of the residual heat sources under different engine operating conditions are analyzed, and the theoretical basis for the performance research of the waste heat recovery system is provided. The results show that with the increase of the engine load, the energy and the energy of each heat source. The amount of exhaust gas is increased. In all the remaining heat sources, the engine exhaust energy is the largest, and the maximum value is 4280kW at 110% CMRCR. At the same time, when the engine load is increased, the energy of the charge air and? The volume ratio is increased, and the energy and the energy of the cylinder liner and the exhaust gas are increased. The amount ratio is reduced. On the basis of finding the waste heat characteristic of the ship engine, a mathematical model of the Rankine cycle waste heat recovery system is established, and the thermodynamic performance analysis of the system is carried out, and the basis for the design of the test system is provided. According to the performance, stability, safety, economy and environmental protection of the system,11 working fluids were selected, and the effects of evaporation pressure, condensation temperature and engine operating conditions on the system performance were analyzed. The results show that, for most of the selected working medium, the output electric quantity of the waste heat recovery system is reduced with the increase of the evaporation pressure and the maximum value is present, and the waste heat recovery potential is great under the large load of the engine as the condensation temperature is reduced. When Cyclohexane is used as a working medium, the net output power of the system is the largest, the thermal efficiency of the engine is 52.08%, which is 6.5% higher than that of the original machine, and the thermal efficiency of the system and the heat efficiency of the system when using water as the working medium. And the efficiency is the highest. Based on the YC6L330-30 diesel engine as a ship engine simulation machine, an organic Rankine cycle waste heat recovery system test platform for heat transfer oil is established, and the performance of the system is studied by using expansion valve and turbine expansion device. When the engine is operating at a speed of 1700 rpm and a power of 225 kW, the expansion valve inlet working medium? The maximum power generated by the turbine expansion device is only 253 W, accounting for 0.11% of the engine power when the motor is at the speed of 1900 rpm and the power is 228 kW. On this basis, the problems existing in the system are analyzed, and the direction of the next improvement is put forward. In order to improve the total energy efficiency of the heat recovery system of the waste heat, on the basis of the simple Rankine cycle, the water preheating system of the cylinder liner, the water vapor intermediate reheating system and the water vapor double-section double-pressure system are analyzed, The thermodynamic system of the waste heat of five different cycle structures, such as the two-stage Rankine cycle system and the Rankine-absorption type cold-electricity generation system, is constructed, and the mathematical model is constructed and the thermodynamic performance comparison analysis is carried out. The results show that, in the same evaporation pressure, in addition to the cylinder jacket water preheating system, the net output power of the remaining waste heat recovery system is higher than that of the simple Rankine cycle, and the Rankine-absorption type cold and electricity generation system has the highest conversion efficiency, and the maximum equivalent output power is 6068kW. At this time, the electric quantity and the cooling capacity of the ship are 2927 kW and 12765kW, respectively, which are in accordance with the characteristics of the multi-energy demand of the ship, and are the technical means suitable for the recovery of the waste heat of the ship engine. This paper further optimizes the selected Rankine-absorption cold-electricity co-production system. According to the energy demand of the ship, the output proportion of the electric quantity and the cold quantity is re-adjusted by using the absorption-type cold-electricity generation system of the Rankine-belt regenerator, and the electric quantity output is increased on the basis of reducing the output of the cold quantity. The output power of the system is increased to 5121 kW, and the cooling capacity is reduced to 489.3 kW. Not only can the balance of the supply and demand be met, but also a good match is obtained.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U664.1;TK115
，
本文编号：2509447
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