Google Search for this blog

Showing posts with label How to ?. Show all posts
Showing posts with label How to ?. Show all posts

What would happen if compressor is removed from the refrigerator?

Simply, refrigerator would STOP! but why? 

To answer this question, one need to know the Second law of thermodynamics (Clausius Statement) which states "It is impossible to construct a heat pump which continuously takes away the heat from low temperature region to high temperature region without taking any external work". 

Here, heat pump is our refrigerator which keep on throwing heat from low temperature environment to room temperature. As per the above statement, external work is must to run the refrigerator. That external work is represented by "Compressor".

Second thing, to have heat transfer from evaporator to condenser, you need to  change the phase of the substance. The change of phase absorb or liberate the heat depending on the phase change. Thus, heat of food can be transferred to condenser by changing the liquid phase refrigerant to vapor phase in evaporator and this heat is rejected at condenser at room temperature. This task is performed by compressor by changing the pressure of the refrigerant.

How to write an abstract for technical report or article or paper?

If you are an engineer and working in industry or academics, you need to submit technical report or research paper to express the findings and working of stuffs.

An Abstract is an important element of any technical report or any research paper/article. It is something which people normally prefer to read before taking a look at the whole article. The abstract must contain the enough information which highlights and give the complete essence of the article. 

Normally abstract should deliver objectives of the research, methods that one has used for research, key results obtained and a clear and concise conclusion. 

The abstract should contain minimum 100 to 200 words. The content of the abstract should be clear and concise. 

It should highlight the main objectives and motivation of the research. Do not write an equation and related stuff in it. 

Avoid putting references in an abstract. One should not use in this 'paper' or 'article' but use 'research' or 'investigation'. 

The abstract must have enough information which develops the interest to read the full paper or article.

How to change dimension text height and arrow size in AutoCAD 2015 ?

If you using AutoCAD and want to change the text height and arrow size for drawing, view this video.

How to select object in AutoCAD 2015 with two options?

The latest version of AutoCAD comes with two options to select the drawing. View this video to know it.


What will be the change in room temperature if door of refrigerator kept open?

What will be the change in room temperature if door of refrigerator kept open? This question is often asked at mechanical engineering job interview and also in engineering examination.

Ans: NO, Rather, temperature of the room will increase over the time, not instantly.


To understand this, let us first understand the working of domestic refrigerator. It contains four different equipment namely compressor, condenser, capillary tube and evaporator and it also has refrigerant or working fluid/medium which continuously circulating through all these four different equipment to enable heat transfer and thus cooling. The refrigerant while passing through different parts, changes phase and this enable cooling in domestic refrigerator.

How to create animation in AutoCAD software?

In Mechanical Engineering curriculum, student need to understand many mechanisms like piston-slider mechanism, slider crank or four bar chain mechanism. These mechanism can be better understood by use of animations. There are many options available to create animation like use of flash software, power point presentation. But animation creation in AutoCAD can be beneficial for mechanical engineer by use of 'mslide' and 'script' command.

Tips/How to write technical/engineering report/document

Follow the following details during making/writing technical report.

Always choose (most of the time) Times New Roman as font type with font size 16,14,12.
Where 16 font size is for chapter/experiment name, 14 is for main heading and 12 for content text of document.

Always use 'Equation editor' or any equation maker software to write each equation of technical writing. Copy and paste that equation in report. Always make sure where to put superscript and subscript in equation. Give equation number as per chapter name. e.g. 5th equation of 4th chapter should be given equation number as (4.5). For Microsoft Word, go to Insert - Object - Microsoft Equation 3.0

How to operate Vacuum Pump and Working of Liquid Nitrogen Plant

Want to know about "How to operate Vacuum Pump and Working of Liquid Nitrogen Plant"?

Please have a look at this links

1. How to operate Vacuum Pump

Vacuum requirements is one of the critical factor that affects the cryogenics temperature. Without Vacuum no cryogenics systems survive. Look at Pulse Tube Cryocooler and related Cryocooler, which always require vacuum to keep resists atmospheric temperature and minimize conduction and convection losses because Vacuum is having no medium and heat transfer requires medium except radiation heat transfer.
Once you have Vacuum pump but it is not sufficient, you need to know how to operate it. Visit URL as under:

How to operate Helium Leak Detection System?

Importance of Helium and why it is necessary to detect the leak of Helium?

Helium is very rare gas found from earth and it is believed that it is going to be depleted in 2030. So, It is our duty as cryogenics engineering people to save helium as possible as we can. We need to look for the leak from the cryogenics system which involve use of helium as working gas.

Leak from the system also cause poor vacuum conditions. So, we need to rectify that leakage and try to save helium. Normally any pressurized Helium gas system is not 100 % leak proof and one's aim is to detect this leak as early as possible and try to  solve this.

How to Operate Helium Leak Detection System?

Here is a standard procedure to use Helium Leak Detection System.

Helium leak detection system consists of turbo molecular pump which helps us to detect the helium gas leaking from system. Connector is the place where sniffer probe is attached with proper cable and is directed to leaking point at the system and this probe detects the leaking helium in milibar per second rate.