内燃式水动力系统工作性能的试验研究

内燃式水动力系统将传统内燃机与柱塞式水泵技术集成为一体，直接利用活塞往复直线运动输出水动力。试验表明，系统全工况输出压力比传统内燃机驱动柱塞泵系统提高15．21％～76．61％；输出流量降低0．69％～2．13％；输出功率提高13．63％～74．75％。系统在80％油门开度下实现了输出压力1．15MPa，输出流量4．8m^3／h的额定输出指标，对应系统转速约为1900r／min。内燃式水动力系统的工作原理正确、运行正常，实现了预期设计功能。     

三缸内燃式水动力系统动力特性试验研究

研究了试验条件下三缸内燃式水动力系统在不同油门和转速组合下的动力性指标。通过多组重复性试验确定试验数据,建立了相应的万有特性曲线并与传统内燃机驱动柱塞泵系统进行了分析比较。结果表明,当曲轴转速为1500r／min时,系统容积效率降低,导致系统输出流量和有效功率先降低后升高,全工况条件下受油门开度影响不大。系统输出压力随转速变化缓慢,随着油门开度增加系统输出压力明显升高。全工况条件下系统输出压力相对改善18．78％-84．36％,系统输出流量全工况基本保持不变,系统有效热效率相对改善18．78％-84．36％。因此,相比传统内燃机驱动柱塞泵系统,三缸内燃式水动力系统有效动率在全工况条件下提升显著。     

CPICP阀式配流系统工作特性的实验研究

提出了约束活塞型内燃式水泵的概念和它的工作原理,对其阀式配流系统进行了动力分析。为了证实仿真模型可以作为约束活塞型内燃式水泵性能分析和其它系统性能比较的依据,对其阀式配流系统的工作特性进行了实验研究,并对此阀式配流系统工作特性的实验结果和仿真结果进行了对比分析,分析结果发现误差在6%以内。实验表明,在油门开度相同的情况下,随着转速的增加,出水阀的压力变化平稳,而出水阀的流量明显增加;在转速相同的情况下,随着油门开度的加大,出水阀的压力明显增加,而出水阀的流量变化不大。实验结果与仿真结果非常接近,可以说明有关的理论分析计算是正确的,仿真模型可以作为约束活塞型内燃式水泵性能分析和其它系统性能比较的依据。     

一种主动调谐式内燃机吸振器的设计

在内燃机振动控制中,为了在各工况下达到比较理想的减振效果,本以内燃机振动速度为控制目标,以单片机为主控微机,采用闭环主动减振控制方法来实现内燃机的振动控制。针对传统减振器的缺陷,设计了一种主动调谐式吸振器。该结构可改善内燃机整机振动特性,提高内燃机工作效率。为整车的运行稳定性提供了可靠保障。     

一种新的分布式水泵供热布置方案分析

供热管网的用户端应用分布式水泵代替阀门来调节水力工况有助于节约水泵能耗。在比较单热源枝状管网采用传统阀门调节和分布式水泵调节供热方案的水力工况和节能性能的基础上,提出一种新的分布式水泵供热布置方案。通过理论及案例分析了多热源环状管网应用这一新方案下的变工况水力调节性能、水温稳定性能及节能性能。结果表明,新的分布式水泵布置方案有利于降低供热系统的功耗、减缓用户水温波动,并具有供热质与量的调节相对独立、调节控制策略简便的特点。     

四冲程内燃机作功过程分析仪设计

四冲程内燃机作功过程分析仪是一种能使人们准确，迅速，直观地了解和掌四冲程多缸内燃各缸在任意 指定时刻工作状态，并且由工作状态确定气门闭状态的一种新仪器，就此论述了该分析仪的设计原理和工作原理以及设计的合理性，工作的可靠性和工艺的可行性。     

内燃机水泵试验台测控系统的研制

利用计算机测控技术开发内燃机水泵试验台测控系统，实现测试过程的全自动化．同时介绍了该系统软硬件的集成，软件功能的实现和一种基于智能PID控制在系统中的应用．     

三缸机械液压约束活塞发动机性能仿真

阐述了三缸机械液压约束活塞发动机(HCPE)工作原理,建立了系统工作过程的微分方程.对系统在转速为1000r/min～2400r/min、油门开度为30%～100%下的工况进行了仿真研究.与KM385B发动机驱动柱塞泵系统相比,输出流量全工况基本一致,输出压力大幅度提高(20.67%～87.67%),燃油消耗率相对改善(20.67%～87.67%),有效热效率相对改善(20.67%～87.67%).     

变幅泵站水泵运行工况分析

取水站的水位总是在不断变化，从而引起实际扬程的变化，水泵的工况点因而经常变动，偏离最高效率点，有时还会变得极不稳定。对此可以采用调速的方法，改变水泵的工况特性曲线，使水泵在高效率区工作。对于水位变幅较大的泵站，可选取多种泵型，进行串并联等多种工况组合以适应更宽的扬程范围，或通过调速使其适应更多的水位变化。     

液力平衡增压注水泵的使用及平衡改造

液力平衡型增压注水泵在工作过程中对压力的平衡有较严格的要求,平衡系数须在规定的范围內才能保证水泵的正常工作。对于压力匹配不能满足水泵工况要求的情况,可通过改变水泵柱塞直径、改变水泵流量及改造泵头结构等方法,调整压力匹配,保证水泵的正常工作。     

单组元液压自由活塞发动机关键技术

为解决传统内燃式液压自由活塞发动机对压缩比控制要求严格的缺点,采用单组元推进剂代替传统的矿物燃料,利用单组元燃料催化分解后释放出的高温混合气推动活塞组件往复运动,提出了一种对外输出液压能的新型液压自由活塞发动机.采用Fluent软件模拟在脉冲工作方式下,催化床的床载、比表面积、孔隙率、流阻等对单组元燃料分解特性和寿命的影响.通过在动力腔头部安装辅助电磁排气阀的方式来提高活塞的运行频率,提高输出功率.采用隔热陶瓷和合理的排气口设计来减小动力腔壁面热量损失,提高输出功率.利用软密封和硬密封相结合的方式来阻止动力腔的气体进入液压泵,保证了系统工作可靠.     

Design of Synchronous Drive Mechanism of Opposed-Piston Hydraulic-Output Engine

In order to improve the thermal power conversion capacity of the internal combustion engine,combined with existing opposed-piston two-stroke engine(OP2S) and hydraulic free piston engine (HFPE),the integral structure for a new type of opposed-piston hydraulic-output (OPHO) engine has been designed,an operating principle has been introduced,the composition of its synchronous drive mechanism has been carefully analyzed,and a mathematical model has been built.In addition,the kinematics models of both the mechanism and the conventional crank-link mechanism have been established by utilizing MATLAB,and the movement rules of the pivotal moving components have been obtained.According to the simulation results,the piston movement of this new type of opposed-piston hydraulic-output engine reveals a prominent asymmetry compared to the conventional crank-link engine.Under a fixed engine revolving speed,the compression time of the opposedpiston hydraulic-output engine is shortened while the expanding time is lengthened,thus the gas turbulence intensity is strengthened around the top dead center (TDC) position.Meanwhile,the piston obtains a longer isometric process compared to conventional engines,which could be benefitial to enhance the combustion efficiency.     

Study on pneumatic-fuel hybrid system based on waste heat recovery from cooling water of internal combustion engine

The paper proposes a novel pneumatic-fuel hybrid system,which combines a traditional internal combustion engine(ICE)and a pneumatic engine.One important merit of this concept is that the system can recover waste from cooling water of internal combustion engine to optimize the working process of pneumatic engine,and thus to improve the entire efficiency of the hybrid system.Meanwhile,energy-saving effect due to lower cooling fan power can be achieved on ICE by waste heat recovery of pneumatic engine.Based on thermodynamic analysis,an experimental system is designed and established for verification.The experimental results show that the performance of pneumatic engine is improved when the waste heat recovery concept of the hybrid system is applied.Then an application example on a 4-cylinder engine is analyzed and discussed using numerical simulation.The results show that the fan power of the ICE cooling system can be saved up to 50%by applying the hybrid system.Considering the appreciable improvements on the energy efficiency with only limited system modifications when the concept is applied to traditional ICE based power systems,the proposed hybrid concept has the potential to serve as an alternative technology aiming for energy saving and emission reduction.     

Gasoline-diesel dual fuel intelligent charge compression ignition (ICCI) combustion: Conceptual model and comparison with other advanced combustion modes

The internal combustion engines can remain the advantage over competitor technologies for automotive driven, especially the engine efficiency, exceeded 50% while maintaining ultra-low emissions. In this paper, a novel combustion mode characterized by dual high-pressure common-rail direct injection systems, denoted as intelligent charge compression ignition(ICCI) combustion, is proposed to realize high efficiency and clean combustion in wide engine operating ranges. Specifically, commercial gasoline and diesel, which are considered to be complementary in physical and chemical properties, are directly injected into the cylinder by the two independent injection systems, respectively. Through this unique design, the in-cylinder air-fuel mixtures can be flexibly adjusted by regulating injection timing and duration of different fuels, consequently obtaining suitable combustion phase and heat release rate. The ICCI mode can widely run from indicated mean effective pressure 2 bar to 16 bar with an utterly controllable cylinder pressure rising rate, around 50% indicated thermal efficiency and low NOxemissions. A series of experiments were carried out to compare the combustion and emissions of ICCI with other combustion modes(including conventional diesel combustion, reactivity-controlled compression ignition, partially premixed combustion, and gasoline compression ignition). The results show that at the medium engine loads, ICCI mode can reach much high indicated thermal efficiency, especially up to 52% along with extremely low NOxemissions. Prospectively, ICCI mode can realize real-time adjustments of in-cylinder mixture stratification and instantaneous combustion mode switch in one cycle at any operating conditions, and has an excellent commercial application prospect for energy conservation and environmental improvement.     

存在热漏的内燃机与斯特林联合循环的有限时间的热力学研究

在分布式电站系统的应用研究中,根据总能系统和能量梯级利用的原则,基于有限时间热力学理论,建立了考虑热阻和热漏的内可逆内燃机循环与斯特林循环联合动力装置的热力学模型,导出了以压缩比、温度比等循环参数表示的联合循环功率和效率表达式。同时由数值计算分析了热漏等循环参数对循环性能的影响,以及循环功率与效率间的关系。所得结果对联合循环动力装置性能研究具有很重要的实际指导意义,同时对联合循环有限时间热力学理论做了进一步的扩充。     

内燃机机体噪声特性的数值仿真分析

结合多体动力学仿真技术与有限元法（FEM）和边界元法（BEM）对一台4缸发动机的机体噪声辐射进行了预测.建立了一台4缸4冲程柴油机曲柄连杆系统的多体动力学模型,通过多体动力学仿真的方法,求解出活塞、连杆、曲轴系统在工作过程中对机体的激励.利用有限元法求解出主轴承作用力、活塞侧向力和在燃烧激励作用下的机体振动特性.建立了机体噪声辐射的边界元模型,利用边界元技术对机体的辐射噪声进行了求解.并根据仿真分析的结果对机体的外声场的噪声特性进行了研究.研究表明,机体裙部的刚度是影响内燃机噪声辐射的重要原因.     

汽油-DMF混合燃料的燃烧性能与排放特性试验

为减少对石油的依赖和环境的污染,使丰富的可再生生物质燃料能够在内燃机中使用|在不改变汽油机点火提前角特性和供油系的前提下用单缸四冲程汽油机对汽油-二甲基呋喃(DMF)以及汽油-乙醇混合燃料进行试验研究.研究表明：汽油-DMF混合燃料的指示热效率与燃烧效率稍低于汽油-乙醇,与纯汽油接近,但缸内燃烧压力与燃烧速率比汽油-乙醇高;而且汽油-DMF的油耗率要优于汽油-乙醇,并且DMF掺混质量分数为10%时油耗率在混合燃料中最低;汽油-DMF的常规排放物总体上低于纯汽油.