Dr. SaMeH S. Ahmed

Civil and Environmental Engineering Department

Heat pump


Heat pump


     

heat pump is a device that transfers thermal energy from a source to a sink that is at a higher temperature than the source. Thus, heat pumps move thermal energy in a direction which is opposite to the direction of spontaneous heat flow. The heat pump uses some form of low entropy energy to accomplish the desired transfer of thermal energy from source to sink.

Compressor-driven air conditioners and freezers are examples of heat pumps. However, the term "heat pump" is more general and applies to devices which are used to heat a conditioned-space (i.e., a confined space such as a building), that must be warmer than a cold environment. A heat pump can provide either heating or cooling of a given conditioned-space, depending upon whether the surrounding environment is cooler or warmer than the conditioned-space. When a heat pump is used for heating, it uses the same basic refrigeration-type cycle employed by an air conditioner or a refrigerator, but releasing heat into the conditioned-space rather than into the surrounding environment. In this use, heat pumps generally draw heat from the cooler external air or from the ground.[1]

Heat pumps are used to provide heating because less high-grade (i.e., low-entropy) energy is required for their operation, than appears in the released heat. In general, most of the energy for heating in such systems comes from the external environment, and only a fraction comes from the high-grade energy source. For example, in an electrically powered heat pump, the heat power released to the conditioned environment can be typically two or three times larger than the electrical power consumed, making the system efficiency 200 or 300%, as opposed to the 100% efficiency of a conventional electrical heater, in which all heat is produced from input electrical energy.

Some heat pumps are able to accomplish either conditioned-space cooling or warming, depending on operational setting. Reversible-cycle heat pumps are devices designed to work in either thermal direction, in order to provide heating or cooling of the same conditioned environment. These devices operate by changing which coil is the condenser and which coil is the evaporator, rather than physically turn the device around. Such a function is achieved by a "reversing valve." In heating and air conditioning (HVAC) applications, the term heat pump usually refers to easily reversible vapor-compression refrigeration devices that are optimized for high efficiency in both directions of thermal energy transfer.


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Monday:      12-1

Wednesday: 10-11

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Time Table 2018-19S


Civil Eng. Students


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Love your department and be proud of your field of study

As we approaching the second midterm exams..  Get ready and remember our offices are open to answer you . do not hesitate to .contact me if you have difficulties

For CE 370 students : Your second midterm exam will be on Wednesday 27 March 2019. In the surveying lab

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Please visit the  announcement box for the relevant course and make sure that you can download and upload easily, otherwise

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There will be an orientation session in the midell of this term to help you select your track in Civil and Environmental Engineering

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Special Issue

Electrical Power Resources: Coal versus Renewable Energy



Published Online on January 2016


Mining Engineering


Mining engineering is an engineering discipline that involves practice, theory, science, technology, and the application of extracting and processing minerals from a naturally occurring environment. Mining engineering also includes processing minerals for additional value.

Environmental Engineering


Environmental engineers are the technical professionals who identify and design solutions for    environmental problems. Environmental engineers provide safe drinking water, treat and properly dispose of wastes, maintain air quality, control water pollution, and remediate sites contaminated due to spills or improper disposal of hazardous substances. They monitor the quality of the air, water, and land. And, they develop new and improved means to protect the environment.

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College of Eng. MU

http://mu.edu.sa/ar


Univeristies

Universities I've worked in


Assuit University (Home University), Egypt


Imperial College, London, UK


Faculty of Engineering, Al-Mergeb University, Libya


King Saud University, KSA

,Majmaah University


Majmaah University has a very nice web page that provide  all information regarding deanships, colleges, activities,  campuses and many others. Search your request in
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https://www.researchgate.net/profile/Sameh_Ahemd

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Sports

Ahly vs Zamalek, 30 March 2019

Africa Nation Cup, June 2019


Course 2018/19-2


  1. Surveying 1 CE 370
  2. Surveying II  CE 371
  3. Senior Design II  (round 6) CE 499




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Latest

Member of the Editorial Board: " Journal of Water Resources and Ocean Sciences"  2013 till now

https://www.researchgate.net/profile/Sameh_Ahmed5/?ev=hdr_xprf

Participating in The Third International Conference on Water, Energy and Environment,(ICWEE) 2019 - American University of Sharjah, UAE 26-28 March 2019 with a Paper and Poster

New article


Coming soon



2nd Midterm Exams on 3/4/2019

Student Conference



Participation  in the 6Th Student Conference

With a paper and oral presentation

From the Senior Design Project CE499 -35

See inside, the paper, and presentation

CE 370 Course

Surveying I

2018-2019S




Power point


Sheets


Lecture notes
15

3-4-2019

:Second Midterm Exam



Results


Model Answer
Inside, please follow

Working  marks is available -Click on Surveying I

CE 371 Course

Surveying II

2018-2019-2




Lectures





First midterm exam


Lab


Results

See Inside

Working marks out of 60 is  available- Click on Surveying 2

CE 474 Course

Photogrammetry

2018-2019-1



Available 0-1-2-3-4 Power point

Available

Quizzes 2 and 3 with model Answer

Quizzes
Available Chapter 1,2,3,4,5 Lecture notes

Report 1  Cameras Report

Y

60 marks Exams

See Inside

Student Performance Records


CE 499 Course

Senior Design 2


Second Best paper from Senior Design Projects in 2015

Paper title:

Evaluation of Groundwater Quality Parameters using Multivariate Statistics- a case Study of Majmaah, KSA

Students:

Abdullah A. Alzeer

Husam K. Almubark

Maijd M. Almotairi

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Civil and Environmental Engineering Department
College of Engineering, Majmaah University
Majmaah, P.O. 66, 11952, KSA

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