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Lc_shi
08-06-2005, 01:11 AM
I've read a patent about a heat pump system which can provide 40~100 Centigrade degree water. But I can't see how it's realized by the patent description. Is there heat pump able to boil water? thx in advance.


rgds
lichuan

Temprite
08-06-2005, 10:43 AM
Hello ic shi

I do a bit of work on Quantum heat pump hot water services. They are becoming quite popular in Australia.

I think you would be struggling to get one to boil water though.

Lc_shi
09-06-2005, 01:43 AM
how about the hot water temp? Is it possible more than 100C degree?

chemi-cool
09-06-2005, 08:27 AM
I've read a patent about a heat pump system which can provide 40~100 Centigrade degree water.

Please bring all the info so we can relate.

Chemi :)

Lc_shi
10-06-2005, 01:25 AM
Hi Chemi,
You're right.It's a Chinese patent. Pls refer to attachment.
the critical idea is the condenser in series and supply different temp water from 40 to 100 C degree. Pls comment.


rgds
lichuan :)

Sirac
10-06-2005, 02:05 AM
Hello ic shi

I do a bit of work on Quantum heat pump hot water services. They are becoming quite popular in Australia.

I think you would be struggling to get one to boil water though.
]

I happened to see this forum while surfing. We are manufacturing heat pump water heaters in China. Being Exported to half a dozen countries now. Maximum outlet water temperature 60 degrees.

Temprite
10-06-2005, 12:21 PM
Quantum hot water service also 60 degrees c.

http://www.
enviro-friendly.com/quantum-heat-pump-water-heater.shtml

Site wont let me write it as a direct link for some reason.Keeps making it shorter.

Peter_1
10-06-2005, 07:50 PM
]

I happened to see this forum while surfing. We are manufacturing heat pump water heaters in China. Being Exported to half a dozen countries now. Maximum outlet water temperature 60 degrees.
What's the name of the companies website? Or a distributors website.

Peter_1
10-06-2005, 07:55 PM
Seen pure thermodynamically, it can only be done with very high pressures and high superheat.
But if it's running then efficient and if the compressor isn't suffering...., that's another story.

We installed several systems in the past without increasing high pressure or increasing superheat and can deliver in the summer water of +/- 75C. In winter it decreases to +/- 45C.

Temprite
10-06-2005, 11:38 PM
Peter

The Quantums have a de superheating set up on them.

Did you have to use a similar thing on the systems you built?

Peter_1
11-06-2005, 10:15 AM
What we did was in fact really simple: we took a standard vertical electrical boiler. We removed the electrical resistance out of the center and inserted instead a 1/2" coil (+/- 15 m) which we had wound around an iron tube in a lathe machine.

We inserted this coil in line with the aircooled condenser.
So at start up, when the water is cold, it is used as a water condensor and the water heats up.
As soon the water is heated up to a temperature where there can't be sufficient condensed anymore, the fans of the aircooled condensor are turned on (via a HP switch)
But the discharge gasses passes still through the water coil and are desuperheated. The water then heats up to a temperature +/- 3 K lower then the discharge temperatures.

chemi-cool
11-06-2005, 11:22 AM
Hi Peter.

Good and simple, I liked it ;)

Chemi :)

Temprite
11-06-2005, 01:46 PM
What we did was in fact really simple: we took a standard vertical electrical boiler. We removed the electrical resistance out of the center and inserted instead a 1/2" coil (+/- 15 m) which we had wound around an iron tube in a lathe machine.

We inserted this coil in line with the aircooled condenser.
So at start up, when the water is cold, it is used as a water condensor and the water heats up.
As soon the water is heated up to a temperature where there can't be sufficient condensed anymore, the fans of the aircooled condensor are turned on (via a HP switch)

Nice.

No need for suction de superheating

Was the evaporator used for anything?

Peter_1
11-06-2005, 02:48 PM
1 st installation (butchery): 2 boilers of 200 l. - 2 compressors, 1,5 Hp freezer room and 1,5 hp Cooling room.
Each compressor has his own boiler. The discharge line of each compressor goes in the boiler.
Installed: +/- 15 years ago

2nd: a small pack, 3 compressor; 1 HP, 2 HP and 4 HP, cooling of 5 cold rooms. No oil egalisation nor oil separator. Main discharge split in two different boilers of 2 x 200 L.
Installed +/- 15 years ago.

3th: same setup pack 1 - 2 - 4 - 2 x 7,5, and a 5 HP freezer Cooling of 7 coldrooms and 1 freezer on 1 main discharge(included the freezer). Discharge goes in 2 coil in coil HE (*****/water), installed in line1: 1 st is for make up of cleaning water and 2nd is for (pre)heating of the offices.

We even installed it a few times in vending vans with eutectic plates for heating water (+/- 50 l) Explained it in another post.

The biggest we installed was +/- 20.000 l, preheating of cleaning water and the supply for a industrial steamer.

Peter_1
13-07-2005, 09:36 PM
We had to service today one of the heat reclaim systems.
One of the water reservoirs was leaking.
This was also a good opportunity to open the boiler and take some pictures of the coil we made years ago.
You can see it's still in relative good condition. Costs only a fraction of the standard systems.

Any comments welcome.

1. Entrance (discharge) of the 2 upper coils and the entrance of the lower coil
2. Complete coil standing up. You can see the 3 coils, connected to 1 main coil.
3. Entrance of the upper coil.
4. Bottom collector (3 x 3/8 coil) brazed in one 5/8 coil.
5. Water reservoir with the coil in front of it.

Lc_shi
14-07-2005, 01:38 AM
Hi Peter,
It's a very good case. Is it copper tube coil? the white is the fouling or scaling? how about the heat transfer coefficient?

have a good time :)

rgds
lichuan

Peter_1
14-07-2005, 06:33 AM
The white is indeed the scaling on the copper tubes.
For the heat transfer coefficient: you mean the scaling around the copperlines I suppose. To be honest,.. I realy don't know but it's of no importance for me.
Because it's anyway waste heat, we have plenty of heat available and the scaling protects the copper (I think :confused: )
This coil is connected at 2 parallel Copeland compressors of 1 HP.

US Iceman
01-08-2005, 09:21 PM
You may want to review some compressor information from Sabroe. They have a high-pressure version of their reciprocating compressor that has been used for a heat pump with ammonia.

CuGe
14-08-2005, 04:53 AM
You would be pushing it to get 100 C, the pressure will be pretty high - Buy a boiler!!

US Iceman
14-08-2005, 10:10 PM
Mycom did a lot of research in this area about 20 years ago. At that time we could still use R-114 for a high temperature heat pump with screw compressors. This was a good low-pressure refrigerant suited for high temperature applications.

If the application can use recip. compressors, their discharge temperature is greater than screws. The oil injection in the screw compressors decreases the actual discharge temperature you can work with for heat pump duty.

As someone else stated, if the compressor is designed to work in the application and no harm is done, it is worth reviewing.

With ammonia systems we have high temperatures (with recip. compressors) so this may be a possibility.

Primary energy costs are already expensive. If the process produces heat as a by-product, why not use it? Why burn gas or oil to produce heat, if a suitable heat source is available?

The temperatures and heating loads determine the requirements, therefore we should look at all possibilities in the application of refrigeration systems. Some will not work, others might!

US Iceman

Lc_shi
15-08-2005, 01:38 AM
agree with Iceman.
If we can get 100C water by heat pump and the COP is more than 1.0 it will save electricity in electric heating. Now the CO2 system heat pump water heater is phasing in, i wonder it's feasible to supply high temp water.

rgds
Lichuan :)

timthefridge
08-10-2005, 08:29 PM
I have worked on dishwasher heatpumps on R407c running at 24-25.5bar with Copeland scroll compressor water leaving heat exchanger at 75 c

Lc_shi
09-10-2005, 03:49 AM
what type of the compressor? If Pc is 24~25.5bar,the Tc is around 60C, how do you get 75C water leaving?
Is it from de-superheating?

rgds
LC

Peter_1
09-10-2005, 11:18 AM
Lichuan,
Assuming condensing at 25 bar, evaporating at + 5C and 5 K SH, you have discharge temperatures of 93C.

I posted in the past some pictures of cylindrical copper coils we made and inserted in a standard water boiler. As long as water is cold enough we rejected all the heat in the water and the boiler was capable of condensing everything.

Water temperature finally rises and becomes after some time too hot to condense everything. Then the fan of the air cooled condenser in serie with the coil jumps in to help the condensing completely.

But on that moment, the coil begins to act as a desuperheater and the water becomes hotter then the condensing temperature (+/- 75C while condensing at +/- 15 to 16 bar!!) It also helps a lot during summer when outside temperatures rises.

ianandkitty
14-10-2005, 09:04 PM
I work for a G.S.H.P installation company in the UK
we use Water furnace units from U.S.A using R410
and 2 water heat exchangers they can get water upto 65 oC with a COP of 2-6 depending on entering water temp

Lc_shi
19-10-2005, 01:25 AM
Hi Peter,
I appreciate your idea to heat water to near discharge temp. My understanding is water heated by condensing reject heat and desuperheat portion and use fan to cool condenser till the water temp is close to condensing temp. It makes sense and seem better for the system efficiency. Realy good idea!

regards
LC-:)

Cofreth
19-10-2005, 06:11 AM
Is this consider a heat re-cliam system?

Peter_1
19-10-2005, 10:19 AM
Yes, it's a heat-reclaim system
http://www.refrigeration-engineer.com/forums/showthread.php?t=2690&highlight=boiler

siddhv
02-02-2006, 02:10 PM
hi i am mechnical engineering student and want to present a seminar on upcoming research topics as it is a technical presentation can you give me the details on the heat pump research you have got

abbasi
03-02-2006, 11:17 AM
forget boilin man i have read the whole description what is mind bobbling (as a DESIGN ENGINEER) is really how is DX coil designed i.e

what is evaporating temperature selected?
what is kind of fins are used?
4 way valve is used?
what is superheat of expansion valve n its capacity?
why TXV when outside air is chilled and you talk of relative temperature why not eliminate txv so that due to high temp difference heat transfer takes place?
why arent condenser tubes immersed in the tank?
how much is 134A charged and is it conventional 134a?
:confused:

star882
03-02-2006, 04:54 PM
http://toad.net/~jsmeenen/recovery.html
Pretty interesting idea. The discharge line temperature on many A/Cs can get quite close to boiling water under some conditions.

US Iceman
03-02-2006, 05:22 PM
An important item to remember is how are you recovering the heat?

The majority of the heat energy is in the condensation of the discharge vapor. The phase change contains almost all of the energy.

If you run the water counter-flow to the discharge gas, the condensation of the vapor provides energy to warm the water. As the water continues through the heat recovery exchanger, the discharge temperature begins to also heat the water.

You have two things occurring. Phase change which happens at a constant temperature. This helps to heat the water.

As the water begins to warm up, the temperature of the water is increased by the sensible heat of the discharge vapor. This is the second part.

To achieve whatever temperature you want, you have to design for both of the above, heat and temperature.

The condensing temperature is simply the requirement for the refrigeration system.

When water heating is not required, but the refrigeration system has to operate you need to be able to reject the heat to an external source other than water.

star882
04-02-2006, 02:52 AM
What about just connect a watercooled condenser before the regular condenser and slow/stop the condenser fan and enable the circulator pump when heat is required?

Andy
04-02-2006, 07:57 PM
Hi:)
any heat pump can be made to boil water if you raise the discharge temperature high enough:D , under charge it, run it with a low evaporation and a high condensing temperature.
Brutal but it will boil water.

Best not try this one at home :eek:

55 or 60 deg C water is normal for heat pumps:) water to water or air to water.

Now you have me thinking what refrigerant would be best to boil water in a heat pump, something that has a low condensing pressure and very high discharge temperatures, this would be the secret that is being patented.

Kind Regards. Andy:)

Andy
04-02-2006, 08:01 PM
http://toad.net/~jsmeenen/recovery.html
Pretty interesting idea. The discharge line temperature on many A/Cs can get quite close to boiling water under some conditions.

Might have tried that myself:D

www.thermosavesystem.com

Look for the thermosave logo

Sorry about the advertizing:)

Kind Regards. Andy:)

phil68
04-02-2006, 08:24 PM
I know that when a cylinder head gasket goes internally on a compressor the heat generated by the high velocity to-ing & fro-ing of the gas through the break is enough to burn the paint off on the outside. Bearing that in mind maybe some sort of 2-stage compressor could be employed:confused:

nick uk
15-09-2010, 09:04 PM
how about a 2 desuperheaters in tandem feeding 2 hot water cylinders in tandem but with the water flow reversed in relation to refrigerant flow same principle as heat recovery ventilation