# Engineering Thermodynamics

Good Essays
1012 Words
Grammar
Plagiarism
Writing
Score
Engineering Thermodynamics
czyET 3200 – Engineering Thermodynamics
Homework Assignment #6
Due June 15, 2013 @ 5:00 PM

Problem 4.8 - A Home Heat Pump for Space Heating
We wish to do a preliminary thermodynamic evaluation of a 1kW input power home heat pump system for space heating using refrigerant R134a. Consider the following system flow diagram

Thus the heat pump system absorbs heat from the evaporator placed outside in order to pump heat into the air flowing through the insulated duct over the condenser section. The fan provides an air flow of 8 m3/minute, which is enough to cool the refrigerant in the condenser to 30°C, In this analysis we will neglect the power provided to the fan. We also assume that the duct is adiabatic, and that all the heat rejected by the condenser is absorbed by the air flowing in the duct.
Plot the four processes on the P-h diagram provided below and use the R134a refrigerant property tables in order to determine the following: * Determine the mass flow rate of the refrigerant R134a [0.0185kg/s] * Determine the mass flow rate of the air flowing in the insulated duct [0.161kg/s]. * Determine the heat rejected by the condenser [-3.7kW]. Assuming that all this heat is absorbed by the air, determine the exit temperature of the air at station (6) [37.9°C]. Is this value reasonable? Why? (Note: This problem involves heat being transferred from the refrigerant in the condenser to the air flowing through the condenser, and is solved as shown below)

* Determine the heat absorbed by the evaporator [2.7kW]. * Determine the Coefficient of Performance of the heat pump (COPHP) (defined as the heat rejected by the condenser divided by the work done on the compressor) [3.7].

Problem 4.11 - A Home Geothermal Heat-Pump
We wish to do a preliminary thermodynamic analysis of the following home geothermal heat pump system designed for wintertime hot water and space heating. Notice that with suitable valving this system can be used both in winter

## You May Also Find These Documents Helpful

• Satisfactory Essays

It was noted from the above solution that the true value of COP obtained from the experiment was 4.875. The ideal value of COP as obtained directly from the P-h chart would correspond to 4.81. Also, the work of the compressor is high with superheating i.e. ( ) and is greater than the ideal…

• 472 Words
• 2 Pages
Satisfactory Essays
• Powerful Essays

The laboratory session for refrigeration system was performed in order to investigate the main concepts of the vapour-compression refrigeration cycle. Simple refrigeration system studied in the laboratory is a prototype for a variety of engineering applications utilized in industrial, domestic and scientific purposes. The detailed goals include the study of how the refrigeration process is affected by the water flow rate through the condenser and evaporator. The optimal flow rate is determined for condenser and evaporator. Finally, the efficiency of the refrigeration system is analyzed.…

• 2619 Words
• 11 Pages
Powerful Essays
• Good Essays

Air conditioners and heat pump systems are used by most people in the world today. They are used to cool in the summer time and to heat in the winter time. These machines are bought and used when most people do not even understand the principle on which they work. The machines are expected do what they are designed to do, and when they cease to do this, they can be costly to repair. Air conditioners and heat pumps are similar in appearance and operation, but while using the same components they can perform completely different tasks. Knowing the difference between the two and the principle in which they perform their tasks will enable each person to make an informed decision when the time comes to repair or replace a piece of equipment.…

• 1483 Words
• 6 Pages
Good Essays
• Powerful Essays

Fig. 8 Experimental and theoretical power of heat exchanger for assumed temperatures behind heat exchanger Tout at 3300 rpm.…

• 2468 Words
• 10 Pages
Powerful Essays
• Good Essays

AC Load: The duty of the air conditioning system is to compensate for other thermal loads so that the cabin temperature remains within the acceptable comfort range. In cold weather conditions, positive AC load (heating) is required for the cabin. Inversely, in warm conditions, negative AC load (cooling) is needed for maintaining the comfort conditions. The actual load created by the AC system depends on the system parameters and working conditions. In this work, it is assumed that an AC (or heat pump) cycle is providing the thermal load calculated by…

• 1672 Words
• 7 Pages
Good Essays
• Powerful Essays

The main purposes of this experiment are to allow students to get familiarized with air conditioning system and also to obtain experimental data so that the state point can be plotted on a psychrometric chart. The apparatus used in this experiment are SOLTEQ air-conditioning module (Model:HE166-02) which is designed to work with the Base Condensing Unit. The major part of the evaluation procedure is carried out with the aid of psychrometric chart. Thus, the heating power, cooling power and steam enthalpy can be calculated through the experiment.…

• 2043 Words
• 12 Pages
Powerful Essays
• Satisfactory Essays

Geothermal (ground-source or water-source) heat pumps achieve higher efficiencies by transferring heat between your house and the ground or a…

• 895 Words
• 4 Pages
Satisfactory Essays
• Good Essays

What is the difference between sensible and latent heat? Identify the components of a marine propulsion boiler in which each type of heat is added to water to generate steam.…

• 392 Words
• 2 Pages
Good Essays
• Good Essays

For the ﬁxed inlet/outlet pressure ratio of turbine stage, the high rpm reduces the heat transfer coeﬃcient on the rotor due to the low…

• 8608 Words
• 35 Pages
Good Essays
• Powerful Essays

It is well known that an IC engine has an efficiency of about 35-40%, which means that only one-third of the energy in the fuel is converted into useful work and about 60-65% is wasted to environment. In which about 28-30% is lost by cooling water and lubrication losses, around 30-32% is lost in the form of exhaust gases and remainder by radiation, etc. In a Vapour Absorption Refrigeration System, a physicochemical process replaces the mechanical process of the Vapour Compression Refrigeration System by using energy in the form of heat rather than mechanical work. The heat required for running the Vapour Absorption Refrigeration System can be obtained from that which is wasted into the atmosphere from an IC engine.…

• 7927 Words
• 32 Pages
Powerful Essays
• Good Essays

* “Advertised” figures for coefficient of performance (COP) of 3-4 implying an efficiency of 300% - 400%, i.e. 1kW electricity in and 4kW heat out.…

• 1164 Words
• 5 Pages
Good Essays
• Good Essays

3) To be able to explain at a level understandable by a high school senior or nontechnical person how various heat engines work (e.g. a refrigerator, an IC engine,…

• 936 Words
• 7 Pages
Good Essays
• Powerful Essays

The system that is used by Loughborough University contains two boilers and two chillers, which are set to work in certain conditions. The conditions are if the CHP heat and power rejection is insufficient to drive the system and the demand of heat and power are at its maximum point.…

• 1006 Words
• 5 Pages
Powerful Essays
• Better Essays

Even though many studies have been conducted with the aim of investigating and evaluating GSHP, still more studies are needed to understand the performance of GHX when GSHP is used for both cooling and heating applications. Some of the researchers [8, 10-11, 13-14, 17] are carried out optimization of horizontal and vertical ground-coupled heat pump system to reduce the cost of the system. Gang and Wang [25] applied static and dynamic models of ANN to predict the exit temperature of GHX. They concluded that compared to static model; the dynamic model was able to predict…

• 881 Words
• 4 Pages
Better Essays
• Powerful Essays

Copyright 2003, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Reprinted by permission from the International Journal of HVAC&R Research, Vol. 9, No. 3, July 2003. This article may not be copied nor distributed in either paper or digital form without ASHRAE 's permission.…

• 2101 Words
• 9 Pages
Powerful Essays