Phase Change Material Products Ltd

Air-cooled heat rejection systems (air-cooled condensers, chillers and dry coolers) relies on dry bulb temperature which is generally between 5°C (41°F) and 15°C (59°F) higher than the wet bulb temperatures. Traditionally, large heat rejection systems use cooling tower or evaporative coolers in order to reduce the heat rejection equipment size as well as the overall energy consumption due to lower condensing temperatures.

However, the water based corrosion, maintenance and health risks such as Legionella disease moved the industry towards less efficient dry heat rejection systems.

By simply intermittently spraying water over a wired mesh area in front of the heat rejection surface against the direction of the air stream introduces wet bulb temperature during only peak high ambient periods.

Adiabatic cooling process can be introduced using simple city main water into an air stream which rapidly evaporates and the hidden energy of water provides a cooler down stream air temperature as much as 10~25°C (20~30°F) lower than the incoming air. Lower air on temperature results in lower condensing temperature and therefore save as much as 30% peak power consumption by simple using water directly from the tap.

Any make or model of air-cooled chillers, small or large-scale air-cooled condenser units for both HFC and Ammonia refrigeration whether a new project or retrofit application can be easily converted to a wet system by means of either factory add-on or site modification.

The majority of the time the water presence remains with the sealed main water pipe and it is based on Total Waste principle. Hence, the health risk involved with a standing water reservoir as well as expensive chemical treatment requirement can be completely eliminated.

Test sites of this new concept indicated between 20~35% peak electricity reduction for Air Cooled Chillers and Condensers. This concept can be considering as a simple DIY kit for both New and Retrofit applications. Hence, the potential for the energy saving and Carbon Emission reduction for the industry as a whole is significant and this can be achieved by simple using the tap water.

Finally, some of the test sites have been in operation for the last 15 years without any operational, maintenance, health, and safety problems and therefore this concept can be consider as safe, reliable and economical solution towards easing some of our current environmental concerns for the refrigeration and air conditioning applications.

web link: www.ecomesh.eu

Thermal Energy Storage (TES) is the temporary storage of high or low temperature energy for later use. It bridges the time gap between energy requirement and energy use. For HVAC and refrigeration application purposes, water and water ice constitute the principal storage media.

Water has the advantage of universal availability and low cost but it can only be produced using inefficient low temperature refrigeration units if one wishes to use the latent heat capacity. If it is applied purely for sensible energy storage capacity it requires large storage tanks.

Phase Change Materials (PCM) between +4°C (39°F) and +90°C (242°F) range over comes the water disadvantages by combining the latent and sensible energy storage capacities into a single storage unit and therefore offer designers new horizons and practical application options.

PCM latent heat cool energy storage can be provided by utilising conventional water chillers for new and retrofit applications without the need for any modifications as well as having the possibility of free cooling.

By storing day-time warm energy for evening periods and over-night cool energy for day-time cooling requirements, a PCM system can simply bridge the gap between energy availability and energy use and therefore has the potential to achieve considerable environmental as well as economical benefits for many heating and cooling applications.

For more than a decade we have been involved in the development of Phase Change Materials (PCMs). With unrivalled experience in designing and advising on PCM installations and applications, we continue to push the boundaries in PCM usage for the benefit of our ever growing customer base.

In addition to our technical expertise, we offer (under the PlusICE branding) what we believe to be the most comprehensive range of PCM solutions currently available commercially (-100°C (-148°F) to +885°C (+1,625°F)).

From initial concept, research and development to production and distribution, our office and manufacturing facility in the UK and our Licensed outlets around the world offer bespoke products to meet unique customer requirements.

And of course, good ideas are not the exclusive right of PCM! Many of the non-standard applications are initiated by our  customers, whether end-user or developer. Our technical team is happy to take ideas from conception through to completion including full commercialisation, with or without our production under a Licensee option.

web link: www.pcmproducts.net

EPS Ltd is a UK based company actively involved in many aspects of the HVACR industry. We are committed to providing alternatives and improvements to current cooling technology by offering more energy efficient and environmentally acceptable solutions to your cooling requirements. Among our areas of expertise are:

• Thermal Energy Storage (PCM and ice-based applications)
• Binary Ice Systems and Ice Generating Technologies
• Heat Transfer Fluids
• Food & Beverage Chilling
• Process Cooling
• Commercial & Industrial Refrigeration
• Air Conditioning
• Design and Application Consultancy

Although we are based in the UK, much of our business is throughout the world and we are currently active in Europe, the Americas, Africa and the Middle and Far East. These activities are involved in both the installation of our products and through our international network.

web link: www.epsltd.co.uk

By placing the Eutectic products within the cold store one can create a TES facility whereby the excess refrigeration capacity during off-peak periods and lower ambient

conditions over-night can be utilised to shift the peak load.

Eutectic TES  can either be installed as part of the cold store fabric for example hanging TubeICE on ceiling/walls or alternatively containers like FlatICE can be placed on pallets and stored with the shelves or alternatively using ice packs / pouches Eutectic TES can be incorporated as part of the packaging / palleting.

Although one may over-cool the stored products to create a small load shifting capability but utilising the Latent Heat Capacity of the Eutectic TES one can increase the thermal energy storage capacity by as much as 10~15 times for a given volume.

As the cooling load significantly varies over daily or weekly periods, Eutectic TES enables the operator to spread the load over a 24 hour period which in return offers the facility of running the refrigeration machinery during lower night-time ambient conditions to charge the Eutectic TES. Later during day-time / peak cooling periods this over-night stored energy can be utilised to top up the refrigeration load without the need for full load mechanical cooling.

Finally, a Eutectic TES is a static system i.e. no moving parts offering a full stand-by capability in case of any mechanical failures and offers a maintenance free back-up

facility.

By simply running the refrigeration machinery over night-time cooler ambient periods, one can save as much as 15~25% electricity consumption due to higher efficiencies of the refrigeration machinery at lower ambient condition as illustrated in this graph.

Reduced actual kWh electricity consumption coupled with the possible cheap off-peak electricity costs may reduce the overall cold store annual running cost by as

much as 30~50% depending on the region.

web link: www.pcmproducts.net

Thermal Energy Storage (TES) technologies may be considered as a useful tool in reducing the cooling load requirement of modern engineering systems. This is achieved by means of spreading the daytime workloads over an entire 24-hour period, in order to utilise the earths naturally occurring ambient temperature differences.

The night-time cooler ambient can be used to charge the latent heat capacity of various “ Positive Temperature Eutectic” solutions between +4°C (39°F) and +117°C (242°F) without the use of any refrigeration machinery by simply allowing the surrounding air to freeze these solutions. It is then possible later for the stored energy by the Positive Eutectic Thermal Energy Storage “PETES”, to be released back to the occupied space during daytime to handle the heat gains.

This technique is generally called Passive Cooling and it may enable the charging process to take place by means of free cooling, i.e. without running the chillers and as a result becomes a very economical and environmentally friendly system.

Furthermore, PETES opens new opportunities to explore heat balance for the existing and new systems, which could offer significant overall system efficiency improvements.

Privatisation has created a new kind of energy market whereby the period of energy usage and the type of energy used is becoming the main criteria for price structuring rather than overall energy consumption. Hence, cooling systems must be designed to provide sufficient flexibility for load shifting and a PETES Thermal Energy Storage technique can be considered as a useful tool to achieve this aim.

web link: www.pcmproducts.net