Energy management contract issue

[Lc_shi]

Hi Sirs
EMC is starting in our country. The energy efficient technology in HVACR is the main role in various buildings for cost saving. For example, Ice storage chiller system and ground source heat pump etc are put into application of big project.
is there anybody has the related experience can give some briefing ?
I believe there is much market potential for cold storage energy saving tech.Maybe there is business chances for you
welcome your input

regards
LC

[US Iceman]

Hi LC,

There are several different types of ice storage systems:
ice on pipe, encapsulated balls of ice, ice slurry's, and ice harvesters.

The latter is similar to an ice machine. You generate ice on a heat transfer surface. When the ice has reached a suitable thickness, the ice is removed from the heat transfer surface and dropped into a large storage tank that has water in it. The water is circulated to the air-cooling coils in the building.

I think the ice harvesters are a little more energy efficient, but they are more expensive. These almost always require a custom engineered refrigeration system.
(my favorite )

Some of the ice on pipe storage systems (and the encapsulated balls of ice & ice slurry's) sometimes use a low temperature chiller using a glycol to produce the ice. The HVAC manufacturers like this because they can use their standard chillers and derate them for the glycol. And a little more simple to install.

The thermal storage systems have some additional merits. If low temperature water (~1C) is pumped directly to the coils, you can use a larger TD and decrease the size of the cooling coils, fans, and duct work. You will need good insulation and vapor barriers on the duct work as the air temperatures are significantly lower.

If chilled water is used as the storage medium you are limited to a similar applications as any other chilled water system. With these systems the water storage tank can be huge.

The storage tanks for the ice storage systems are considerably smaller than the water only tanks.

How is electricity billed in your area? Does the utility have demand charges for kW in addition to energy charges for kWh?

Do they have ON-Peak & OFF-Peak rates?

How expensive is the electricity? If the power rates are low, it may be hard to sell a thermal storage system.

The other side of this that the utilities may be interested in is: inlet air cooling for combustion turbines used for electricity generation. During the daytime when the wet bulb and dry bulb temperatures are high, a combustion turbine will have a lower power output due to the decreased air density.

By precooling the incoming air to the turbines you can increase the output power. Thermal storage systems are also used for this purpose.

PS. A lot of the large thermal storage systems using ice were built to use either R-22 or ammonia. The same principles of thermal storage can also be used for cooling whole districts of office buildings.

[Lc_shi]

Very good information

How is electricity billed in your area? Does the utility have demand charges for kW in addition to energy charges for kWh?

Do they have ON-Peak & OFF-Peak rates

?
Yes. If plant needs more KW capacity,there're extra charges in addition to fees for KWh.
In my place,the OFF-peak is 0.5 of On-peak rates.It's different in other places.

By precooling the incoming air to the turbines you can increase the output power. Thermal storage systems are also used for this purpose.

Learn from u thanks

regards
LC

[NoNickName]

We are producers of GHPs. We may be interested in a partnership.

[Lc_shi]

What company ?
Tell more about your GHP

[NoNickName]

What company ?
Tell more about your GHP

I can't advertise... but my avatar will give you a clue.

[US Iceman]

LC,

One thing you may want to consider is the type of GHP units that can be used.

Most of the units I am familiar with are mass produced for residential or commercial purposes. In a large office building it is conceivable you could have a very large number of these units located throughout the building.

A lot of potential repairs in expensive office space.

It is possible to use a central system type of installation. This would be similar to a central HVAC system where the chillers and boilers are located in the same room or in adjacent rooms. The chilled or hot water is pumped through piping to the fan-coil units located in the building.

A central system can also be used for GHP if designed properly.

The central system also promotes the use of equipment that can be easily repaired versus equipment that is replaced. Large semi-hermetic or open drive compressors versus hermetic compressors.

I believe the life expectancy of the heavier commercial or industrial equipment will be much longer than the residential or light commercial equipment.

Something to consider...

Best Regards,
US Iceman

[Lc_shi]

I believe you're right
But i've heard other voice that for decentralized system for large building. Like water loop heat pump, using ground source HX as heat sink, heat pumps work at each terminal which can adjust by terminal need.

best regards
LC

[US Iceman]

Hi LC,

Like water loop heat pump, using ground source HX as heat sink, heat pumps work at each terminal which can adjust by terminal need

That is true. In this type of application you are only installing the water loop piping for the heat pumps. The heat pumps then heat or cool the respective zones.

This also places all of the noise and service work next to the room occupants.

With the central system you have to pipe the hot and cold water to the fan-coil units. And you will probably need VAV boxes for space temperature control.

The service for the fan-coil units can be in a separate room, rather than the office space or hallways.

A lot of things to consider...

[NoNickName]

Summer cooling with GHP can happen with direct cooling in the underground. Floor cooling can take place with water at 20/15°C, and considering the underground around 8-12°C, it is possible to exchange heat naturally, without refrigeration circuit.