Heat engine Definition and 157 Threads

Homework Statement Calculate the Power, Efficiency, air to fuel ratio. torque-3.809Nm speed-3137.207 l/min T1 Temperature Exhaust=412.598degC T2 Temperature Ambient=19.141degC T3 Temperature Fuel=18.994degC dv/dt Volumetric Flow Air=109.954 l/min p fuel Fuel Pressure= 21.475 mbar...

The law says that the maximum thermal efficiency of a heat engine can be 88%. If I have and internal combustion engine using 9.8 cc/min instead of 25 to 30 cc/min and the other accepted figure is a 2L 4 cylinder engine for idle is it uses approx 5 HP of fuel just just to idle. So I am doing...

Homework Statement An inventor claims to have invented an engine which operates between constant-temperature reservoirs at 400K and 300K. Data on the engine, per cycle of operation: Qh = 200J Qc -175J W = 40J Th = 400K Tc = 300K Of the first and second laws of thermodynamics, which (if...

A carnot engine has an efficiency of 59% and performs 2.5x104 J of work in each cycle. a) how much heat does the engine extract from its heat source in each cycle? b) suppose the engine exhausts heat at room temp (20oC) what is the temperature of the heat source? I know that the...

We have a carnot engine with Th = 800 degrees Celsius, and Tc = 50 degrees Celsius. This produces a work which is drives a carnot heat pump which has heat reservoirs at Th' = 50 degrees celsius and Tc' = 0 degress Celsius. What is the ratio of heat absorbed by the Heat Engine to the heat...

Two bodies have the same Internal Energy. (U = N C T) Both N and C are the same for each of these bodies. The initial Temperatures of these bodies are T1i and T2i Using these bodies to produce work from a Carnot Heat Engine, they are brought to a final temperature Tf. What is this final...

Homework Statement A heat engine operates in a reversible cycle with the following steps: (i) An ideal gas characterized by γ = 1.4 expands adiabatically, so that it cools from an initial temperature of 330°C to 30°C. (ii) It is compressed isothermally until it reaches its initial volume...

Hello. I have a question about a theoretical heat engine I recently encountered in my coursework: The setup is two chambers, one with more moles of a gas than the other, separated by a heat-conducting barrier. The right chamber has a small piston attached to it and is at a lower temperature...

Homework Statement The hot reservoir of a heat engine is steam at 100 Celsius while the cold reservoir is ice at 0Celsius In 1.4 hours of operation, 12 kg of steam condenses and 60 kg of ice melts. What is the power output of the heat engine? Homework Equations Efficiency =...

Hi. Im trying to measure the efficiency of a heat engine. I therefore need to work out what the input energy is to the heat engine. I have two problems. Firstly, how should I measure the heat going into the stirling rather than the heat coming out of the heater. Is it ok to measure the...

Homework Statement The hot reservoir of a heat engine is steam at 100^ C while the cold reservoir is ice at 0 C. In 1.3 hr of operation, 11 kg of steam condenses and 52 kg of ice melts. Homework Equations I think power output is W=Qin-Qout The Attempt at a Solution I believe the...

I have a qualitative understanding of a heat engine; that being that when heat moves through a heat engine from a source to a sink, an amount of energy that passes through the heat engine will be absorbed, until no heat gradient exists between the source and the sink The attachment is a...

Homework Statement A heat engine operating between temperatures of 500 K and 300 K is used to lift a 10-kilogram mass vertically at a constant speed of 4 meters per second. (a) Determine the power that the engine must supply to lift the mass. (b) Determine the maximum possible efficiency...

Homework Statement A heat pump takes heat from a hot resevoir and dissipates heat to a cold one. Both resevoirs are equal mass and specific heat capacity. Show that as the heat engine does maximal work the final temp of the resevoirs = Tf = SQRT(TcTh) Homework Equations Qin = Wout +...

Homework Statement 21. A heat engine operates in a cycle between temperatures 700 K and 400 K. The heat input to the engine during each cycle is 2800 J. What is the maximum possible work done by the engine in each cycle? (A) 1200 J (B) 1600 J (C) 2100 J (D) 2800 J (E) 4400 J I...

[b]1.A heat engine is rejecting 200btu/h and 30% efficient, how much power does it use in watts? [b]2. QH=w+QC and power=energy/time (1kwh=3412btu) and a power diagram: QC= wasted heat, w=work QH l 30%l---->W l QC [b]3. 200btu/h(1kwh/3412btu)(1000w/1kw)=58.6watts...

Given : QH=W+QC and Power= E/t or W/t A heat engine is attached to a 200W lamp. If we power the lamp for 1 hour and extract 700 btu from the heat source, how much heat is rejected? Attempt: 200w(3.412btu/1w) = 682.4 btu now, 700 btu-682.4 btu =17.6 btu rejected??

Homework Statement 18. (II) At a steam power plant, steam engines work in pairs, the heat output of the first one being the approximate ehat input of the second. Th eoperating temeprautres of the first are 680 degrees C and 430 degrees C, and of the second 415 degrees C and 280 degrees C...

Homework Statement The hot reservoir of a heat engine is steam at 100 while the cold reservoir is ice at 0. In 1.3 of operation, 12 of steam condenses and 59 of ice melts. What is the power output of the heat engine? Homework Equations W=Q_h - Q_c n=W/Q_h=1 - (T_c/T_h) Q=ML...

1. The pressure is constant at 1Mpa how come it goes up after touching saturation vapor line.?Shouldn't it remain constant throughout? Please look at the Tv diagram below: http://www.ent.ohiou.edu/~thermo/Intro/Chapt.1_6/ideal_gas/tv_ideal.gif 2. Why quasi-static equilibrium is necessary...

Hi! I am wondering if anyone here knows of a generic heat engine simulator. I.e. something that can simulate the behavior of reciprocating engines, Stirling engines, and so forth. The outputs I'm interested in include things like power and efficiency. The input variables that I would play...

Homework Statement A heat engine uses a diatomic gas that follows the pV cycle shown in Figure. Part 2→3 is adiabat, part 3→1 is isotherm, V=1040 cm3, P=100 kPa, T1=212 K. Determine the pressure at point 2. Determine the volume at point 2. Determine the temperature at point...

Homework Statement "A gas storage system contains oxygen at a pressure of 5 atmospheres at 300 K. (Here, you may assume that oxygen behaves as an ideal gas.) The volume of the cylinder is initially 150 L. (State 1.) In a fire the gas is initially heated by 200 K, with a safety system keeping...

Homework Statement A heat engine operates between a reservoir at 25 degrees Celsius and one at 375 degrees Celsius. What is the maximum efficiency possible for this engine? Homework Equations e = \frac{Qc}{Qh} The Attempt at a Solution I'm afraid that the equation above...

Homework Statement An object maintained at constant volume has heat capacity Cv, which is independent of T. The object is initially at a temperature Th, and a heat reservior at a lower temperature Tc is available. Show that the maximum work that can be extracted when a heat engine operating...

Homework Statement The question is: An ideal heat engine takes in heat Q(in) at a temp T(h). It exhausts heat Q(out). So: (a) how much work is done by engine (b) what is efficiency of engine (c) what is exhaust temp of engine and (d) calculate the answers to above for heat input of 460J at a...

Homework Statement A heat engine using 5.00 g of helium gas is initially at STP. The gas goes through the following closed cycle: - Isothermal compression until the volume is halved. - Isobaric expansion until the volume is restored to its initial value. - Isochoric cooling until the pressure...

Homework Statement A hypothetical engine, with an ideal gas as the working substance, operates on the cycle shown in Figure 1. Show that the efficiency of this engine is e = 1 - \frac{1}{\gamma}\left(\frac{1 - \frac{p_3}{p_1}}{1 - \frac{v_3}{v_1}}\right) Where \gamma =...

Homework Statement Calculate the maximum possible efficiency of a heat engine that uses surface lake water at 19°C as a source of heat and rejects waste heat to the water 0.100 km below the surface where the temperature is 4.1°C. Homework Equations eta = 1 - Tc / Th The Attempt at...

Gun is a kind of heat engine? if so ,the efficiency of a gun is limited by carnot heat engine?

A brass piston of diameter 25 cm at 20 degrees C must be able to function at 150 degrees C. In order to do so it must fit inside a steel cylidrical chamber. What must the minimum initial diameter of the cylinder be so that the piston never rubs against it. alpha=2x10^-5 for brass...

Homework Statement A reversible composite heat engine operates between three reservoirs at temperatures of 400K, 300K and 200K. One engine operates between the 400K and 300K reservoirs and a second engine operates between the 300K and 200K reservoirs and is synchronised with the first. In...

Homework Statement A reversible heat engine operates between two reservoirs having temperatures T1 and T2 (T2 > T1). The temperature T1 of the cold reservoir remains constant, whereas the warmer reservoir consists of n moles of a gas at constant volume with specific heat capacity Cv. After the...

Homework Statement A heat engine follows the cycle shown in the figure. a) How much net work is done by the engine in one cycle? b) what is the heat flow into the engine per cycle? Diagram: http://farm4.static.flickr.com/3050/2703330973_26acb35c27.jpg?v=0 Homework Equations W =...

Homework Statement An ideal gas engine that works according to the following cycle. Find the efficiency of this engine assuming that the heat capacities of the gas may be taken to be constant. Recall that the efficiency may be defined as: \eta = \frac{Net work done over full cycle}{Heat...

Homework Statement A machine with COP = 5.0 removes 25kJ of heat from a cold reservoar. If the machine is reversible and driven the other way as a heat engine, what is the efficiency? The Attempt at a Solution COP = QL/W --> W = 5kJ e = QH/W Is QH the same as QL som that e = 20%

Homework Statement A nuclear power plant generates 2000 MW of heat energy from nuclear reactions in the reactor's core. This energy is usd to boil water and produce high pressure steam at 300 degrees C. The steam spins a turbine, which produces 700 MW of electric power, then the steam is...

Attached is a graph of a system that has undergone heating/cooling, expansion/compression. The question is: Suppose now that this system is being used as a heat engine, to convert the heat added into mechanical work. Estimate the efficiency of this engine. I'm confused...in this system, there...

Thank you in advance... 1. Homework Statement Suppose a power plant delivers energy at 918MW using steam turbines. The steam goes into the turbines superheated at 626K and deposits its unused heat in river water at 286K. Assume that the turbine operates as an ideal Carnot engine. If the...

Homework Statement A heat engine operates between a high-temperature reservoir at 690 K and a low-temperature reservoir at 320 K. In one cycle, the engine absorbs 6700 J of heat from the high-temperature reservoir and does 2200 J of work. What is the magnitude of the net change in entropy as a...

Okay, I thought that I got these two easy problems but for some reason I'm making them hard. The first problem reads like this. "A heat engine operates between a tank containing 1*10^3 m^3 of water and a river at a constant temperature of 10 degrees Celcius. If the temperature of the tank is...

A reversible heat engine has an efficiency of 34.2%, removing heat from a hot reservoir and rejecting heat to a cold reservoir at 0°C. If the engine now operates in reverse, how long would it take to freeze 1.10 kg of water at 0°C, if it operates on a power of 183 W? I am getting stuck...

1. A heat engine is run with a large block of metal as a reservoir with initial temperature T_i and constant heat capacitance C. The ocean is used as a cold reservoir, with constant temperature T_0. What is the maximum work that could be done by the engine in terms of T_i T_0 and C 2. C =...

Homework Statement An engine works at 26% efficiency. The engine raises a 6-kg crate from rest to a vertical height of 11 m, at which point the crate has a speed of 5 m/s. How much heat input is required for this engine? Homework Equations e=work output / heat input = W/Qin W=Fd...

Homework Statement Calculate the maximum possible efficiency of a heat engine that uses surface lake water at 18.5°C as a source of heat and rejects waste heat to the water 0.100 km below the surface where the temperature is 4.3°C. Homework Equations e=1-Qc/Qh Q=cm(deltaT) The...

Hey i have a heat engine that operates in a Carnot cycle between 354.05K and 711.15K, it absorbs 22415J of energy per cycle from hot resevoir. The duration of each cycle is 0.98s. First question was to find the mechanical power output...i calculated this and got W = Qh - Qc = 22415 - 11159.43...

I'm not sure if I'm interpreting this question correctly A heat engine operated between 40C and 380C. Being a real engine, it efficiency is only 60% of that theoretically possible for a Carnot engine at these temperatures. If it absorbs heat at a rate of 60kW at what rate does it exhaust...

http://img20.imageshack.us/img20/2964/physics16ri.th.png The working substance of a cyclic heat engine is 0.75kg of an ideal gas. The cycle consists of two isobaric processes and two isometric processes as shown in Fig. 12.21 (image above). What would be the efficiency of a Carnot engine...

Calculate the ideal (Carnot) efficiency of a heat engine operating between 23.0 degrees and 515 degrees. How much heat would be rejected by the engine if 1.00 x 10^6 calories were taken from the high temperature resivoir. Would you just use e=1-(T(c)/T(H))? And for the second part i don't...

I really don't have any idea. Can someone shows me any direction of doing it?