calculation of expansion vessel

[HARRY 7]

Good evening guys!How can i calculate the expansion vessel in a water circuit?No drawings available.

[NoNickName]

Warm water heating?

[HARRY 7]

Hi NoNickname! heat pump water chiller.

[NoNickName]

open vase or closed vase?

[HARRY 7]

closed vessel.

[NoNickName]

open vessel



closed vessel with no diaphragm



closed vessel with diaphragm:



Vv = expansion vessel volume (L)
Vw = volume of water in the plant (L)
v1 = specific volume of water at the lowest temperature t1 (m3 / kg)
v2 = specific volume of water at the highest temperature t2 (m3 / kg)
α = expansion coefficient of metals
- for steel α = 1,2 . 10-5 (1/K)
- for copper α = 1,65 10-5 (1/K)


http://www.tempcoblog.it/1596/il-vaso-di-espansione/

t1 is generally the temperature to which the system is charged (10-15°C)

[HARRY 7]

How can i find the volume of water in the plant?

[NoNickName]

How can i find the volume of water in the plant?

Charge it and measure the amount of water that goes into it. Or if already filled, empty the plant and measure the volume of water removed, by pouring it into a known volume.
I suppose you know how to calculate the volume of a solid.

[HARRY 7]

It is a big plant nonickname.Any other way??

[NoNickName]

You could inject a small amount of a tracing radioisotope into the main loop, and install an ultrasonic flowmeter on the main header. By measuring the time the radioisotope crosses the geiger sensor, multiplying by the average water flow measured by the flowmeter, you would be able to find the volume with reasonable accuracy.

[HARRY 7]

A little difficult to do this.Is there any way to find it from the water pump?

[NoNickName]

not that I know.

[HARRY 7]

thanks for the replies nonickname.
if anybody else can help?

[Brian_UK]

Rough calculation of water quantity is normally by relating it to the system duty.

Have a look here, data mostly refers to heating but by using 30°C as maximum system temperature you can ache8ive an answer.

www.mikrofill.com/images/PDF/n-and-de-range.pdf

[nike123]

thanks for the replies nonickname.
if anybody else can help?

Measure pipe lengths and diameters. Collect volume data of equipment (chiller, fan-coils, puffer, etc). Calculate volume in each element and sum it. That is your volume for calculation of vessel.
This is good site for calculation of vessels:
http://87.128.225.163/index.php

Software:
http://www.reflex.de/fileadmin/user_...reflex4_de.exe

[NoNickName]

Brian, his system is existing already, and is a warm water plant.

[HARRY 7]

Thanks all of you for replys guys.Brian i used 40C.It is a heat pump.