Marine Wine Fridges

[Globe76]

Hi Forum Users,

I am a engineer on a 140ft motor yacht, I am responsible for all mechanical and electricals onboard.

At the moment we are having problems with our wine fridges. We have three fridges that are not cooling down to set tempretures depending if they are for white wine, red wine and champanges etc. These have been preset on control panel. The technician has come in and recharged our refrigirant which is R-12. The fridge make is Frigomar and Italian Company. As yacht was built in Italian Yard.

I will use one fridge as an example, the fridge temp is set to 4 degrees celcius and only cools down to 19 degrees celcius.

The Compressor and Condensors are located in a floorspace in the yacht and located about 3 meters from the actuall fridges. I think the expansion valve and Evaporater are located within the wine fridge housing.

The space where the compressor and condensors are situated are extremely warm as the compressors are working full time to try and keep the fridges to preset temperatures and are still failing to do so. Tried installing a extract air fan to try cool things down.

We called a refrigeration technician in and he charged the refrigerant up with r-12.

I will post some pictures for u and see if any of you pro's can help in troubleshooting this for me.

Pics 2 follow

[Globe76]

This first picture is of the compressor and condensor which is situated about three meters from actuall fridges.
This is where the tempretures are very high as there are three compressors and condensors and fans working in here.

[Globe76]

the next picture is the actuall wine fridges so u can see their size etc

[Globe76]

This picture shows the space at the bottom of the fridge where I think that the piping from comp/condensor arrives to expansion valve and evapourator??

[Globe76]

This is inside the actual space.....Both pictures one from each angle.

[Globe76]

this is the control panel of unit

[Globe76]

If u look at the pics of what i think is the evapourator there is ducting where the cool air is being introduced into the wine fridge, why is it there as hot air rises and cold air introduced will sink.

Any ideas or comments on my problem will be greatly appreciated

Cheers

[US Iceman]

Hi Globe76,

Welcome to the RE forum.

The first thing that I see is a problem related to the air cooled condensers with what appears to be an enclosed space.

As the compressors pull the heat from the wine coolers, this heat plus some additional heat (added by the compressors) is rejected by the condensers. The fans pull air through the condenser coils. This air is warmed by the total amount of heat that the condensers are trying to reject.

If the air in the space where the units are located is not dissipated, the heat continues to increase the air temperature.

As the air temperature entering the condensers continues to increase the compressors loose their cooling capacity.

This whole process continues until the refrigeration systems reach some sort of an equilibrium and continue to run constantly with no apparent decrease in the wine cooler temperature.

An exhaust fan for this space may be insufficient. You also need some means of providing ambient air into the space where the condensers are located.

In effect, the condenser area needs to be well ventilated so that no increase in air temperature occurs in this area.

I seriously doubt all units needed to be recharged or have refrigerant added to them.

If there are some hatch covers you can temporarily remove to allow this space to be well ventilated you should see a noticeable decrease in the wine cooler temperatures.

Hope this helps.

[Globe76]

thanks for that reply, appreciate that, I thought that it could have something to do with that, 2 morrow i will open the hatch and try get some off the hot air to escape out the locker, this is the bow thruster locker in the forepeak of the yacht, it is usually sitting in the water but we are also in dry dock at the moment, so usually there is the cooling effect on the space.

Any other comments will be greatly appreciated.

Regards

[Globe76]

just another thought, there are sea water valves in this space which are not in use is there anyway that I could run sea water for condensors or would I have to replace the condensors??

ANy thoughts....

[US Iceman]

this is the bow thruster locker in the forepeak of the yacht, it is usually sitting in the water but we are also in dry dock at the moment, so usually there is the cooling effect on the space.

The cooling effect could have been taken into account as part of the design. But if this is the case, would this still be sufficient if the ship was in the Mediterranean Sea? I don't have any idea about this aspect.

Perhaps one of the other RE members can shed some light on this.

Just saw your other post. Sea water condensers are very common on marine applications. Do you know what the sea water valves are for? Perhaps they were intended for future use as a supply to sea water condensers. Are there other heat exchangers in this area of the ship?

[jamcool]

Globe76,
Was there ever a time when the units worked as you desired? and if so what has changed since that time and now to be causing this problem? and if there was never a time when it worked as required ,some redesigning might be in order as the iceman said focus on your condenser and comp. temperature in the space that the units are in is very important.
An alternative could be that whenever the fridges are stocked the crew can ensure that the contents of the fridges are drunk as soon as possible ,its the drink in me talking now

[NoNickName]

No, absolutely keep the sea water away from condensers. I would also add my 2 cents to Iceman's. From the photos it is not clear whether cooling is done via direct expansion in the cellar, or via an indirect cooling with an air coil. In this latter case I would make sure there's no dust or dirt on the coil fins, as I would also check the fins of the condenser against dust or debris.

[US Iceman]

Hi Globe76,

If the area where the condensers are located is hidden and effectively limited to natural or forced air circulation/ventilation this can reduce some of the options.

One option may be to use the sea water valves connected to a heat exchanger with a fan in this area. The cool sea water cools the additional heat exchanger that has a fan that circulates the cooler air to the air-cooled condensers.

If the sea water system is pressurized with a pump the flow capacity might be enough to provide a decent amount of space cooling in this area.

This would take some engineering, but it might be the most pleasing option.

Just an idea to consider.

[Peter_1]

My first job ever in refrigeration where I learned the 'metier' was on board of fishing vessels and huge container boats in teh harbour of Seabruges and Antwerp.

My boss then had +/- 500 employees in different disciplines and Refrigeration was of one of the disciplines.

So we installed many systems on board of boats, mainly fishing boats.

We always installed seawater condensors, regulated by a HP controlled flow valve (mainly Penn)
The condensor were always located below the water level so that air escaped automatically out of teh system.
Mainly open Bitzers because their oil-sump was much larger then a normal compressor and this is necessary when the fishing nets are overboard for fishing and the boat is inclining very strong to one side.

Driven then mainly by 110 VDC motors.
Static steel (galvanised) in the storage rooms.
Flake ice generators on board, mostly Ziegra or Maya (Germany) and in some occasions (Scotshman)

We once installed everyting in the storage room in stainless steel (tubes and evaporator)

Helped several times the tech onboard via the radio with a techncial refrigeration problem so that they could keep fishing.

On the larger container boats, mainly Stall and Sabroe.

So in your applictaion, install between condensor and compressor a very small plate HE and many of teh problems will be gone.
They even excists soldered with titanium ofr something like that

The vertical storage cooler seems an Iberna from Italy, normally fit with a Necchi.
Looks there were mouses under this one

[Globe76]

thanks for the response from all of you, today the technician was back having a look at the system and he is looking at the control unit where various settings can be preset, still looking at the bow thruster locker. I will supply more info as soon as can. Great thoughts from all of you.

[Dan]

I just zoomed in on the condensers and they look filthy! Can this be, or is it the poor resolution that is my problem?

[US Iceman]

Hi Dan,

I think you are correct. They do look a little fuzzy. I did not notice this before.

This could certainly be a part of the overall issue. However, if the thrust locker is very warm anyway, we still have an overheating issue with too high of an inlet air temperature to the condensers.

[Globe76]

Yes so many questions, I appreciate all the input, i have not had any time to look further into this as we are on dry dock and there is so much happening, things of higher priority keep taking the front seat for the present moment the fridges have been put on the backburner, i see all ur comments and will keep them in mind when I get to them again.

[Globe76]

Okay everyone thanks for all input, have not been able to focus on fridges as been so busy latley.

A few points too add.....

The bow thruster locker where all the comps and condensers are have 4 units in total, three units are not working and one is working correctly. So after a closer visual inspection I have found a few things.

So if one unit is working in the space then why are three not...well the one that is working has a different setup too the ones that are not working. Also strange that three units are not working properly.

The unit that is working has comp and condensor in locker with a inlet pipe from evaporator going into the compressor and then outlet from compressor to the condesor and then outlet from condensor back toward evap. This is a straight forward fridge cycle.

However the three that are not working are setup a little differently?? I cannot describe but can post a dodgy sketch. The part I can see is the condensor and compressor, the rest in skecth is my assumption of the plant.

[Globe76]

Might need to zoom in on pics as there is some writing on the one.
This next pic as the one of what I think is some kind of valve and this is electrically linked to elctric black box of compressor.

[Globe76]

OKAY I am going to post link to another forum where the pictures and text are done better.

Reply on this thread but see pics on link...

http://www.yachtforums.com/forums/te...html#post25503

[Dan]

Dodgy? An understatement. Your first picture indicates the suction and liquid lines ok to me. But the leaving line that is not suction and that passes through the valve has me befuddled. Can you type out all your writing that is in the drawing and the photo? I cannot read it all.

Kindly explain what your writing is regarding the following:

. At the valve, you have large writing beginning with a "C" and some smaller writing... "2-way valve?"

. The liquid line from the condenser passes through something.. "sightglass?" Why is it drawn so oddly. I would expect to see a filter-drier and sightglass in series.

You haven't labelled the thing where the liquid line goes to that is shared with the discharge line. It looks like a heat exchanger. If so, I would expect to see the electrical valve expanding the refrigerant into the discharge line. Is the line cold leaving the electrical valve going into the heat exchanger?

What is the wavy fat line you drew coming off of the electric valve? What is the skinny line going to the compressor from the thing I am calling a heat exchanger?

First dumb guess is that you have a device that tries to lower discharge pressure by injecting liquid into the discharge line, or.. cooling the dishcarge line through a heat exchanger and then having an independant suction line going into the compressor after cooling off the discharge gas.

Control might be dictated through a high pressure control and this might explain the wiring going to the terminal box of the compressor - using this as a junction box for the control circuit.

I assume there is a solenoid on the valve?

Last, but not least, in what manner are these units underperforming?

[Dan]

Okay. I see your pictures better. I think we need to know what the suction pressure is now. This is beginning to look like a desuperheating setup.. an aftermarket desuperheating setup that is unnecessarily adding load to the compressors as it attempts to maintain lower discharge pressures. Definitely time for the gauges on the suction and discharge lines.

[Peter_1]

Is this not a defrost valve? Just guessing?

[Dan]

Not a bad guess, Peter. I dismissed the gas defrost because these are for wine, but you never know.

[NoNickName]

It can be anything.
If it was an evaporating coil, that would look like a dehumidification solenoid valve
If it was a heat pump, it could well be peter's idea of a defrosting valve
Being a condensing coil, I would guess it closed when condensing pressure has to be kept high for condensing control, if the valve is on the inlet to the condenser.
If the valve is on the outlet of condenser, that can also be some sort of liquid injection to prevent high discharge temperatures.
The latter is the most probable to me, because the post originator said the area was very warm, and as such the discharge temperature from the compressor could have been over the cut-out.

But we are in high seas, and it can be anything.

[Dan]

It just dawned on me that this could also be a hot gas bypass arrangement. Maybe the valve is an electrically operated downstream pressure regulator. For wine, it might be desirable to maintain a steady temperature compared to an on/off sort of control?

[NoNickName]

It just dawned on me that this could also be a hot gas bypass arrangement. Maybe the valve is an electrically operated downstream pressure regulator. For wine, it might be desirable to maintain a steady temperature compared to an on/off sort of control?

Can be, but with a solenoid valve? I would arrange it with a modulating valve...

[Peter_1]

Globe76, it should be better that you draw a basic schematic of the setup.
This, together with the pictures will say more.
Especially because we can understand it the other way - especially me - the way you try to explain us.

[Dan]

Can be, but with a solenoid valve? I would arrange it with a modulating valve...

Right, but why not a stepper valve or some other electrically powered pressure regulator?

[Globe76]

I am off on hols for a few days but I have another question regarding refrigerants, what if someone along the line topped the systems up with the incorrect refirgerants? WHat would this mean and could this be sorted out if it is a problem, just trying to look at possible things that could have happened.

Found the manufacturere of the compressor being http://www.tecumseh-europe.fr/index.php

also got the model number so asking them info on refrigerants and how the system could work, what type?? I will update you lot when I am back in 10 days

Laters

Globe

[Globe76]

model is cae4470l

[coolflow]

Sea water- copper- aluminun-= total corrosian =mega money dont go there amigo.