Questions tagged [temperature]
The temperature tag has no usage guidance.
59
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How do I determine the temperature inside a transformer vault?
I am trying to determine the temperature of an underground concrete vault buried 10m underground. The vault has the following dimensions: 2640mm x 5995mm x 2640mm with a wall thickness of 250mm. The ...
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0answers
18 views
How to calculate the temperature rise in a PCB with 24 DIMMs?
I've designed a motherboard sized PCB (.8sqft) with 24 DDR2 DIMM modules running on it.
I'm having trouble figuring out how to calculate the temperature rise. My calcs come out to 128F temp rise over ...
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2answers
52 views
Cooling Down Fridge Encased in wooden box
I'm currently working on a project which involves a small fridge encased in a wooden box. It's designed for hotels and the boxes vary slightly, but one common trait is that the box has an open vent ...
2
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1answer
33 views
How to calculate adiabatic air temperature loss caused by increase of humidity?
I'm searching for an approach on how to calculate the adiabatic temperature loss of air when increasing its humidity by a humidifier.
Assumed we have the following setup:
Air measuring position 1 (...
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7 views
What to use as a turbocharger simulator?
I am planning to conduct trials regarding the efficiency of liquid to air intercooling systems for turbocharged automobiles and would like to set up a test bench in a spare room I have available. What ...
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2answers
103 views
Save money with using a refrigerator correctly - blowing cold air to the back of it?
We are heating up our houses in winter to ex.: 21C to then have an insulated box inside the house, which we cold down to 5 and -15C, and we call it a refrigerator.. :)
The situation:
we would buy a ...
5
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1answer
64 views
Easily compute a good approximation of heat conductivity of cooled semi-vacuum (water vapor + air)
I am preparing a classroom demonstration about heat, including a demo of how a satellite loses heat only radiatively, since it's flying through a vacuum. I'd like to make the vacuum-production ...
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1answer
48 views
Epoxy that can withstand up to 800C and is optically transparent?
I'm looking to use an epoxy in a high-temp environment like 800C, and one that is optically transparent at 450nm (not below 90% transmission). But i'm having trouble finding one. It can be made of any ...
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36 views
Tempreture distribution in a furnace
I am simulating a furnace as follows:
Is it possible to capture temperature distribution in this furnace without designing intake fan? Which kind of boundary conditions can replace with intake fan?
...
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2answers
52 views
Is there an optical technology able to measure the temperature of dry air?
Optical IR sensors are able to measure the surface temperature of solids. But is there a range of the EM spectrum that can accomplish the same for measuring the temperature of nitrox (dry nitrogen, ...
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2answers
75 views
What happens when pumps are blocked off?
What will be the result if the pipe losses is greater than head produced by the pump?
What will be the result if outlet is closed?
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1answer
69 views
Can a chain of nested thermal heat pumps be used to to gain thermal energy out of the environment?
Assume the following setup:
...
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1answer
19 views
Heats affect on material permeation?
I know that heat affects material permeation (increasing it); but I have not been able to find much in the way of data other than biologically, on how it effects materials such as plastics.
Does ...
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3answers
54 views
Ventilation setup high sleeper night cooling
I have a high sleeper in my room (width 3,70m, length 4,50m, height 3,30m) consisting of one large plane (yellow) and one window (darker grey). The plance leaves about 80cm space to sleep. The door (...
4
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2answers
90 views
What does “+- %/K” mean?
On a datasheet, sensitivity temperature drift (TCs) is specified in %/K.
I read this as "the percent change per kelvin".
Is this is simple as this sounds, or is there a reason for using kelvin over ...
2
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6answers
113 views
How would you seal a hole in an HDPE container that's in -20C environment
I have a temperature sensor in a -20C freezer. The probe is going into a bottle filled with propylene glycol solution. I want to seal the hole where the probe is inserted into the bottle.
What's a ...
2
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1answer
31 views
Is a Home's Temperature Affected by Solar Gain Through Windows on Cloudy Days?
Do homes increase in temperature due to solar gain with curtains open if it's overcast?
In other words, Does having curtains closed reduce the temperature of the home on an overcast day?
In other ...
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0answers
11 views
Why does my piezoelectric actuator stick at low temperatures?
I use a piezoelectric actuator on an experimental set up. At low temperatures (Lower than 0 Celsius), the piezo will freeze. Meaning, it will actuate about half way, and then stop moving. Other than ...
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1answer
63 views
Would creep have been a major problem for pykrete designs?
During world war two the British had plans for an aircraft carrier made of pykrete (a mixture of 14% sawdust or wood pulp and 86% ice.) the idea was to have a refrigeration system to stop the ice from ...
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1answer
63 views
Store seeds at 1°C
I have prunus pits that I stratify in a refrigerator during winter.
Normally, the seeds germinate in springtime, which is ideal.
However, often some of the seeds germinate prematurely. When this ...
2
votes
2answers
85 views
Prolong frozen ground conditions (to trick fruit trees into flowering later)
There is a common problem with fruit trees in temperate climates where the trees flower before the last frost. Generally speaking, if the tree has flowered, and the temperature drops below freezing, ...
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1answer
8k views
What's the difference between aircon modes Auto, Sun, Snowflake?
Most air conditioners have three modes: Auto, Sun, Snowflake
What is the difference it terms how it works?
1
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1answer
50 views
Thermistor - Steinhart-Hart Coefficients
In order to identify Steinhart-Hart coefficients for a thermistor, three known temperatures may be used to find three resistances.
What is the best way to choose these temperatures to calibrate ...
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2answers
51 views
Correlating relative humidity outside and inside an enclosure
I am building a device and I tried to Google an answer to this question but I am an electrical person and lack knowledge in this field.
I need to know what the relative humidity inside an enclosure (...
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3answers
1k views
O-Ring vs flat washer for air seal
I'm interested in whether a flat rubber washer or equivalent is good enough to replace an o-ring in a low pressure application (edit: I meant low pressure differential. My bad.). The reason is that ...
2
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1answer
75 views
Is it necessary to consider temperature effect on waling?
Many text book literature on braced excavation mention the necessity to consider additional load due to temperature effect on struts. But nothing is mentioned about waling. Why is this so? Wouldn't ...
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1answer
76 views
How to find properties of supercritical CO2 as a working fluid in a system
I'm working on a process flow currently and am using carbon dioxide as the working fluid because of it's heat properties and because its an inert gas. In the reactor that i am designing i'm looking to ...
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1answer
407 views
Cooling an aluminium plate
My friend and I are currently working on a cloud chamber cooled by the compressor of a deep-freezer. We have built an isolated box that contains the cold pipes of the compressor. The pipes cool down ...
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2answers
107 views
Got to pour outdoor concrete next week, but forecast is cold. What are my options?
I have to pour outdoor concrete next week. The pour is in two main parts - a 100 mm cover / 2nd pour over a 6 x 3 m area of existing concrete from a 1st rough pour, and the bottom ...
2
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1answer
1k views
How to measure a bearing temperature in a pump?
I found that Resistance Temperature Detectors (RTD) are mostly used for bearings, but it's not easy to drill the casing and we need to take a signal out to PLC and LabVIEW.
Is there a sensor that can ...
0
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1answer
382 views
What type of control system is this? open loop?
Suppose I have a liquid in a container, the type of liquid is such that it expands when its temperature rises. The contrainer is marked with scale to measure the height of liquid expanded. There is a ...
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1answer
34 views
How large of an area of the earth's surface would we need to cover in mirrors to negate global warming?
How large of an area of the earth's surface would we need to cover in mirrors to negate current levels of global warming?
Let's assume that the reflective component of the mirror is made of aluminium ...
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2answers
88 views
Creating a constant internal temperature that is negligible to the external environment
Okay, Hi there Engineers! I am a newbie to this site, and to engineering.
So, I wanted to make this post to get all the help I can get. I have been set a task of creating a prototype of the following;...
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1answer
33 views
Lab Equipment for Monitoring Sub Zero Temperatures [closed]
I am doing research on objects frozen with liquid nitrogen then seeing how they thaw.
I need to monitor objects temperatures as they thaw. Ideally getting the variance of the external and internal ...
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0answers
72 views
How can I define third type boundary condition in ANSYS Mechanical APDL?
I'm currently working on the thermal analysis of a pipe, but i do not know how to define a third type boundary condition on the inner surface.
...
4
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1answer
180 views
How to deal with thermal expansion in a city wide heating system?
How to deal with thermal expansion in a city wide heating system?
Background:
As part of the program to combat pollution in and around Beijing, my adopted city of Zhuozhou (population, over half ...
0
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1answer
225 views
Surface in the sun vs. surface in the shade [closed]
What is the difference in temperature between a surface in the sun as supposed to one in the shade and how is it calculated?
For instance:
What will the temperature be if a metal sheet lies in the ...
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3answers
6k views
Why does moving air feel cold?
I'm taking a thermodynamics class and had the following question. I was going to ask my professor directly, but it seems like a stupid question with a simple answer, so I thought I'd try my luck here ...
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1answer
99 views
Is it possible to use air entrainment for air conditioning
I have seen this video pretending to decrease by 5° the temperature inside home using an air-conditioner based on the air entrainment principle (see the video here at 1m6s).
EDIT : The video is now ...
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3answers
134 views
Controlling the temperature with high precision
I need to control the temperature with high precision, and for this task would be good a temperature controller with pt-100 sensor, something like this one PID Temperature Controller ITC-100. As I see ...
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1answer
8k views
How do train tracks handle really cold weather?
First of all, I'm interested in train track only, not the rolling stock.
How are tracks built to cope with really cold weather? An example might be some place in Canada or Siberia. Ice would ...
0
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1answer
442 views
What is a transparent material that insulates well? [closed]
I need to create a transparent box that can stay warm inside while in cold temperatures, below 0 degrees, for as long as possible. Glass and plastic are transparent but afaik they don't insulate that ...
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1answer
226 views
Rapid Cooling System for Commerical Freezer [closed]
I have a bit of an ambitious project on hand and was looking for some advice/ideas.
My team and I are working on a project that involves retrofitting a commercial grade freezer (model MasterBilt ...
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2answers
188 views
Having three heaters on single PCB
I posted this question on electronics SE, but was suggested that I post it here.
I basically having three heaters (serpentine pattern) on a PCB (fiberglass board), as the following image shows:
The ...
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0answers
19 views
Three heaters on single PCB [duplicate]
(This is a follow-up to the previous question I posted.) I'm basically trying to control three different tempeartures on a single PCB. It looks like the following:
The middle pattern heats up to ...
0
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1answer
257 views
At what cold ambient air temperature will power lines fail?
I'm wondering just how cold it would have to be before electric power can no longer flow through overhead power lines. I know power lines generate a certain amount of heat just as a side effect from ...
2
votes
1answer
388 views
Calculating the Fraction of Steam in a Mixture
I have a stream ($10,000$ $m^3/d$) of inert gas and steam. The temperature of the stream is $195$ $^oC$, and the absolute pressure is $1455$ $kPa$.
I am trying to find the amount of steam that can ...
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1answer
1k views
thermal resistance and thermal time constant with ambient temperature
If water at the same temperature is heated with the same heat power source in two different ambient temperatures (one ambient is low and the other ambient is high) then which water sample will reach ...
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2answers
99 views
Analog PID controller - settings wrt $V_{err}$ - setpoint always higher than room temp
I designed from scratch an analog PID controller to mantain a temperature selected in the range of 60 to 80ºC with a room temp say = 20ºC. The "plant" is a simple 4R7 5 W resistor heated by a PWM-...
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2answers
851 views
Saturation Temperature of Binary Mixture
I have a binary mixture of water and methane. The system is at 2000kPa and I am trying to find the saturation temperature of the water in the mixture.
I know Tsat is a function of partial pressure, ...
