Power
Refers to the amount of work done by an object in unit time, that is, power is a physical quantity that describes the speed of doing work. The amount of work is certain, the shorter the time, the greater the power value. The unit is watt w, and the power units include kW, Ps, hp, bhp, whpmw, etc. Here, kilowatt kW is the international standard unit, 1kW=1000W, and if 1000 joules of work is done in 1 second, the power is 1kw.
SI unit of power: Watt (W)
Common units: 1 kW=1×103W, 1 MW=1×103kW=1×106W, 1 horsepower=735W
Horsepower: The greater the power, the higher the speed, and the higher the top speed. Maximum power is often used to describe dynamic performance. Maximum power is generally expressed in horsepower(PS) or kilowatts (kW). 1 horsepower is equal to 0.735 kilowatts. 1W=1J/s.
Voltage
Voltage, also known as potential difference or potential difference, is a measure of the difference in potential energy of a unit charge moving in an electric field. The unit of voltage is volt (V). In a diesel generator set, voltage is an important output parameter. Generally speaking, the output voltage of a diesel generator set is related to its rated voltage, which refers to the maximum voltage that the generator can produceunder safe conditions. The voltage used for diesel generator sets in domestic industry is 400V/230V. 6300V, 10500V, foreign diesel use voltage 220V/127V, 480V, 440V, etc.
Frequency
The frequency of a diesel generator refers to the frequency of the alternating current it outputs, in Hertz (Hz). In most countries and regions, the standard power frequency is 50Hz or 60Hz.
Power factor 1
Power factor is a parameter used to measure the efficiency of electrical equipment. It represents the ratio of the power consumed by the electrical appliance during use to the power provided. Equipment with power factor 1 generally refers to resistive equipment.
Power factor 0.8; 0.6: Power factor is a parameter used to measure the efficiency of electrical equipment. It represents the ratio of the power consumed by the electrical appliance during use to the power provided. A power factor of 0.8 means that the electrical appliance is in use during use. The active power consumed accounts for 80% of the total power, and the remaining 20% exists in the form of reactive power; correspondingly, if the power factor is 0.6, then the active power consumed accounts for 60% of the total power, and the remaining 20% exists in the form of reactive power. 40% exists in the form of reactive power.、
Standby Power
Standby power refers to the maximum power that the unit is allowed to output for 1 hour every 12 hours of operation, which is the full load state. Standby power is 1.1 times the rated power、、
Continuous power
Refers to the power that a device or system can continuously output during long-term operation.
The working principle of the engine
The working principle of the engine is to convert internal energy into mechanical energy. It is a machine that can convert other forms of energy into mechanical energy. Engines include internal combustion engines, external combustion engines, steam engines, jet engines, electric motors and other types. There are two types of internal combustion engines: reciprocating piston engines and rotary piston engines. The body is the skeleton of the engine. All the main parts and accessories of the engine are installed inside the body. The body must have sufficient strength. When a mixture of fuel and air is injected into the cylinder and ignited, the volume of the mixture expands as it burns, and the energy generated drives the piston. The up-and-down motion of the piston is converted into rotational motion by the crankshaft, which makes the engine run.
Engine power
The rated power of the engine generally refers to the use of standard fuel, lubricating oil, and coolant in the standard environment: altitude 1000m, ambient temperature 25°C, relative humidity 60%, 1500r/min for 12 hours Continuous operating power (excluding the net power consumed by the engine such as fans). Long-term low-load operation will affect the reliability and life of the engine, and even damage the engine. According to the relevant tests of Cummins Engine Company, long-term load operation below 30% of the rated power will directly lead to engine damage. The generator set manufacturer should take necessary measures to limit the occurrence of this situation.
Bore diameter
Bore diameter is the diameter of the cylinder in the diesel generator set. It is one of the important factors affecting engine power, fuel consumption, reliability, etc. The size of the bore directly affects the power and speed of the engine, as well as the volume and weight of the engine.
The size of the cylinder bore needs to be determined according to the purpose and power of the diesel generator set. Generally speaking, the larger the cylinder diameter, the greater the power, and the fuel consumption will increase accordingly, but the volume and weight will also decrease accordingly; conversely, the smaller the cylinder diameter, the power and fuel consumption will decrease, but the volume and weight will also increase accordingly.
Number of cylinders: The number of cylinders in a diesel generator set can vary according to different models and uses. Common ones are four-cylinder, six-cylinder, twelve-cylinder, sixteen-cylinder, etc.
Stroke
The piston of a diesel engine (including diesel generator set) has four strokes in a working cycle, namely the intake stroke, compression stroke, power stroke and exhaust stroke.
Intake stroke: The piston moves downward from top dead center, the intake valve opens, and the exhaust valve closes. The air enters the cylinder through the air filter and completes the intake stroke.
Compression stroke: The piston moves upward and both the intake and exhaust valves close. The air is compressed, the temperature and pressure increase, and the compression process is completed.
Power stroke: When the piston is about to reach its peak, the fuel injector sprays fuel into the combustion chamber in the form of mist, mixes it with the high-temperature and high-pressure air, and immediately ignites and burns on its own. The high pressure formed pushes the piston downward to do work, pushing the crankshaft to rotate, completing the action. power stroke.
Exhaust stroke: The piston moves from bottom to top, the exhaust valve opens to exhaust, and the exhaust stroke is completed.
Displacement
Displacement refers to the displacement volume of the piston from top dead center to bottom dead center in each working cycle of the internal combustion engine. It is usually expressed in milliliters (or cubic centimeters) and represents the capacity of the engine. Displacement size directly affects the engine's power output and fuel consumption. Larger displacement usually means more cylinder volume and higher maximum output power, while smaller displacement means relatively lower power and better fuel economy.
Displacement is calculated by measuring the bore and stroke of each cylinder of the engine. The bore is the axial diameter of the piston, and the stroke is the distance the piston moves up and down in the cylinder. Total displacement is found by taking the square of the bore size times the stroke times the number of cylinders (usually 4, 6, 8, etc.). For example, for an engine with 4 cylinders, each cylinder has a bore of 75 mm and a stroke of 90 mm, the displacement calculation formula is: (75 mm/2)^2 × 3.14159 × 90 mm × 4 = approximately 1297 ml .
Oil Capacity
How much oil the engine holds. Engine oil is one of the key factors for the normal operation of diesel generator sets. It plays multiple roles such as lubrication, cooling, cleaning and rust prevention.
Fuel Capacity
The volume of fuel in the engine. The standard fuel capacity of Kachai silent engine unit is the fuel tank used by the unit for 8 hours. Can be configured with an external fuel tank.
Starting Voltage
The impulse voltage of electrical equipment when it is just started is the voltage change from the moment the motor or inductive load is powered on to the short period of time when it runs smoothly. The starting voltage is generally 4-7 times the rated voltage. National regulations stipulate that for the safe operation of lines and the normal operation of other electrical equipment, high-power engines must be equipped with starting equipment to reduce the starting voltage.
Speed Regulation Mode
Mechanical speed regulation: The flyweight structure is used to adjust the throttle lever. The flyweight opens or closes according to the speed, affecting the throttle lever. The mechanical speed regulator needs to be started manually, and its sensitivity and accuracy are slightly worse, but it has a simple structure and is easy to maintain. It is mostly used in low-power diesel engines.
Electronic speed regulation: the mainstream speed regulation method for engines above 30KW. Use the control panel to implement closed-loop control of the motor and speed sensor to adjust the speed.
Electronic speed regulation can control the throttle according to the load, with higher accuracy and better dynamic response. It is mostly used in medium and high-power diesel engines.
Compared with mechanical speed regulation, the stability of the engine is better (can reach the speed regulation performance of G2). When the load is suddenly increased, the ESC controller will automatically accelerate.
Electronic injection: Electronic control of the fuel injection system to achieve real-time control of the fuel injection amount and fuel injection timing according to operating conditions.
Single pump: has the independent electronic control characteristics of a single pump
High-pressure common rail: Common rail technology refers to a fuel supply method that completely separates the generation of injection pressure and the injection process in a closed-loop system composed of high-pressure oil pumps, pressure sensors, and ECUs. The high-pressure oil pump delivers high-pressure fuel to the public supply. Oil pipe, by accurately controlling the oil pressure in the public oil supply pipe, the pressure of the high-pressure oil pipe has nothing to do with the engine speed, which can greatly reduce the change of the diesel engine oil supply pressure with the engine speed, thus reducing the traditional diesel engine defect.
Natural air aspiration
Natural air aspiration is an air intake method for diesel engines. It does not use any supercharger to force air intake, but uses atmospheric pressure to force air into the engine for combustion. room. Under atmospheric pressure, air is freely sucked into the engine. The advantage of this air intake method is that the engine can produce higher torque and lower fuel consumption when running at low speeds, and it also reduces engine noise and vibration. In contrast, a turbocharged engine requires the turbine to start to intervene in the intake process after the engine reaches a certain speed, thereby increasing the intake pressure and air flow, and increasing the engine's power and torque.
Turbocharging
Diesel generator turbocharging refers to increasing the power of the diesel generator by increasing the intake pressure. There are two main ways to turbocharge a diesel generator, one is mechanical turbocharging and the other is exhaust gas turbocharging.
The mechanical turbocharging system drives the turbocharger to rotate through the crankshaft of the diesel engine, compressing the air and then sending it into the cylinder. The power consumed by this turbocharging method comes from the energy provided by the crankshaft. Therefore, when the turbocharging pressure is high, the driving power consumed will also be large, resulting in a decrease in the mechanical efficiency of the entire machine. Therefore, the mechanical turbocharging system is usually used in low-turbocharging and low-power diesel engines whose turbocharging pressure does not exceed 160~170KPa.
Exhaust gas turbocharging uses the exhaust gas energy discharged by the diesel engine to drive the turbocharger, compressing the air and then sending it to the cylinder. Exhaust gas turbocharging has high efficiency, so it is widely used in diesel generators
Intake and Exhaust
The intake and exhaust system of a diesel engine includes the air intake system and the exhaust system, which is an important part of the diesel engine. Air intake system: consists of air intake pipe and air filter.
Intake pipe: Its main function is to guide fresh air into the cylinder. It is usually installed on the top of the diesel generator.
Air filter: Used to filter air so that the air entering the engine is free of impurities. Exhaust system: Mainly composed of exhaust manifold, exhaust muffler, etc.
Exhaust manifold: guides the exhaust gases out. It is usually designed in a round or U-shape so that the exhausted exhaust gases are properly buffered before reaching the muffler.
Exhaust muffler: Its main function is to reduce exhaust noise. It has a complex internal structure and can effectively absorb and attenuate noise.
The engine body
The engine body is the core component of the diesel generator set, mainly composed of the crankshaft connecting rod mechanism, valve mechanism, lubrication system and cooling system. The detailed introduction of the body parts is as follows:
Crankshaft connecting rod mechanism: Mainly responsible for converting thermal energy into mechanical energy, including cylinder block, crankcase, cylinder head, piston, piston pin, connecting rod, crankshaft and flywheel.
Valve mechanism: Responsible for ensuring regular intake of fresh air and discharge of combustion exhaust gases, mainly timing gears, camshafts, tappets, push rods, rocker arms, valves, valve springs, valve seats, valve guides, and valve lock blocks , intake and exhaust pipes, air filters, mufflers, superchargers, etc.
Lubrication system: It is mainly composed of an oil pump, an oil filter and a lubricating oil passage. It is used to reduce the friction loss of the diesel engine and ensure the normal temperature of each component. Including oil pump, oil filter, pressure regulating valve, pipelines, instruments, oil cooler, etc.
Cooling system: Mainly composed of water pump, radiator, thermostat, fan, water jacket and other components, used to cool the diesel engine.
