Norsun Q-sol series plate collector Internals

[rumleyfips]

I have decided that I don't need a bypass. The outlet temperature doesn't need to be any specific level because It's a pool not domestic hot water. The pump delivers 1500 gallons (US) per hour at 75 watts. The filter and salt water chlorinator are designed for that flow. The btu's are the same no matter the flow so this is fine.

We will see how compatible the innards of the Norsuns are with the salt.

Thanks:
John

[MikeSolar]

I have decided that I don't need a bypass. The outlet temperature doesn't need to be any specific level because It's a pool not domestic hot water. The pump delivers 1500 gallons (US) per hour at 75 watts. The filter and salt water chlorinator are designed for that flow. The btu's are the same no matter the flow so this is fine.

We will see how compatible the innards of the Norsuns are with the salt.

Thanks:
John

Be careful, if the pool has chlorine, bromine or salt, those panels won't last very long. Also, 25gpm (1500gph) is suitable for a 2" pipe and definitely not smaller than 1.5" without lots of wear. I would think about a HX and second pump. Unfortunately, this adds cost.

[rumleyfips]

Mike:

I have another pump and my neighbour has a piece of 1 1/4 copper pipe I can steal to solder up a heat exchanger. The pump that came with the pool came with 1 1/4" fittings but has restriction in 2 shutoff vaves, a 1" outlet nozzle and the salt/chlorine generator. The 3/4 tube through the exchanger in the panels may be OK. The two panels raise the water temp about 6 to 10 degreesF.

The pool is 5 years old, the panels 30 and I'm 65. Which do you expect to fail first.

Do you have an experience using a 10 gallon water heater to use excess PV production and act as a brake on my 2k turbine. Everthing seems to workk except the SSR. I'm going to try going from a PWM signal from the Midnite Classic 250 to a 12 volt relay trigger on high battery voltage. I'll be at this as soon as I get my wood cut , split and piled.

Thanks:

John

[MikeSolar]

Mike:

I have another pump and my neighbour has a piece of 1 1/4 copper pipe I can steal to solder up a heat exchanger. The pump that came with the pool came with 1 1/4" fittings but has restriction in 2 shutoff vaves, a 1" outlet nozzle and the salt/chlorine generator. The 3/4 tube through the exchanger in the panels may be OK. The two panels raise the water temp about 6 to 10 degreesF.

The pool is 5 years old, the panels 30 and I'm 65. Which do you expect to fail first.

Do you have an experience using a 10 gallon water heater to use excess PV production and act as a brake on my 2k turbine. Everthing seems to workk except the SSR. I'm going to try going from a PWM signal from the Midnite Classic 250 to a 12 volt relay trigger on high battery voltage. I'll be at this as soon as I get my wood cut , split and piled.

Thanks:

John

You have a lot on the go.....

I expect the panels to go first especially as you are cutting and splitting your wood, so I expect you are in shape. Pool HX are usually stainless steel shell and tube beasts. Copper won't last very long which is why I think they will go first, and I have seen them go within a couple of years.

SSR are either 24v or 120/240vac coils or they are digital 0-10Vdc at least the ones I have used. PWM is used but I'm afraid I haven't used them nor have I used an element as a load for the turbine so i can't be of any help there. Sorry.

[rumleyfips]

It would only take a few minutes to remove the inlet and outlet tubing, flush the 3/4 tube with a garden hose and hook everything up again. Any opinion on how often would extend the panel life? Once a week is not much work.

I suppose that a season of only three months a year also has to be factored in.

Hot sunny day today in Nova Scotia. The pool has gone from 57F to 74F in 4 days. When In took the dogs out at 7:30 it was pouring rain.

John

[rumleyfips]

I googled about and found some interesting things about copper. Copper pipe is fairly pure and more prone to corrosion than alloys. Luckily it's only .001 inch per year in sea water. Seawater is 30.000 ppm and pool water is 3,000 ppm. Also a pool is only used 3 months a year. I think the panels could last a long time.

John

[inetdog]

[QUOTE=rumleyfips;79397]Copper pipe is fairly pure and more prone to corrosion than alloys. Luckily it's only .001 inch per year in sea water. /QUOTE]

But keep in mind that the corrosion rate goes up fast with increasing temperature. Even though you may keep the panel temp down by circulating a high volume of water, when the system is shut off the stagnation temperatures in the collectors can get very high.

[Naptown]

Those panels are about the end of life
Run with them till they go and when you replace them do it correctly

[rumleyfips]

Inetdop:

I turn the pump on at 10AM and off at 6PM. There's little stagnation before or after the heating day. During the day they run at about 76 in 83-86 F out.

Naptown:

At $150 a panel , the experiment is already a sucess. The water went in at 57F last Thursday and my wife swam at 88F today. I'll run em till they explode and happily drink a Guiness in their memory.

I think solar is more fun if I regard it as a hobby.
John

[russ]

I googled about and found some interesting things about copper. Copper pipe is fairly pure and more prone to corrosion than alloys. Luckily it's only .001 inch per year in sea water. Seawater is 30.000 ppm and pool water is 3,000 ppm.
John

It is never used by an equipment designer for that purpose - at least not more than once. Even for machinery cooling water circuits we tend to use admiralty brass.

The 0.001 must be at very cold temps.

[inetdog]

The 0.001 must be at very cold temps.

Arctic Ocean maybe?

Some additional tidbits of research:

1. When electrically isolated copper sheets are exposed to periodic immersion in seawater, the corrosion rate is ~.07mm/year, or roughly .003 inches per year for the first year. That rate increases with time however.
2. This rate is not realistic for swimming pool situations for several reasons:
a. Velocity:

Many metals are significantly affected by the flow velocity of seawater. For example, in the case of copper, there is a
critical velocity, above which the corrosion becomes excessive.
However, when the velocity of seawater is less or equal to 1 m/s, copper behaves well, without any significant corrosion rate. Seawater velocity can cause corrosion of special forms, such as corrosion-cavitation; a phenomenon resulting from the joint action of corrosion and cavitation

What is the linear flow rate through the piping? The localized flow rate will be much greater than the average in pipe sections that result in turbulent flow.
b. Temperature: The rate above was for 60 degrees F.
c. The problem that corrosion is not uniform over the whole pipe surface, making it easy to develop pinholes without any significant loss of average thickness.
d. The aerated water in a swimming pool is more corrosive than water with the same chemical content but with less dissolved oxygen.