Fluid conditioning arrangements

Abstract

A fluid conditioning arrangement comprises a primary heat exchanger configured to cool and / or heat the fluid; a secondary heat exchanger configured to cool and / or heat the fluid; and a controller for operating said secondary heat exchanger when said primary heat exchanger fails to cool and / or heat the fluid at a predetermined acceptablelevel; wherein said primary heat exchanger is a phase change material (PCM) based heat exchanger.

Description

FIELD OF THE INVENTION[0001]The invention relates to fluid conditioning arrangements, phase change material (PCM) modules and / or components operated in conjunction with these. The invention is of particular applicability to the use of PCM for the ambient temperature control, for example within domestic and commercial buildings.BACKGROUND[0002]Phase change materials use the latent heat property of material to store thermal energy and can be used in methods of controlling temperature. Phase change materials are either organic such as paraffin or non-paraffin compounds, inorganic (salt hydrates and metallics) or eutectic (organic-organic, organic-inorganic, inorganic-inorganic). Typically, PCMs have a latent heat capacity at least ten times larger than their specific heat capacity.[0003]The following prior art documents are acknowledged: DE102007013779, U.S. Pat. No. 5,647,225, U.S. Pat. No. 7,124,594, U.S. Pat. No. 7,162,878, U.S. Pat. No. 5,255,526, U.S. Pat. No. 7,363,772, U.S. Pat....

AI Technical Summary

Benefits of technology

[0006]This configuration improves the overall performance of the system as it allows the PCM heat exchanger to do most of the work of cooling and / or heating for minimal energy usage, but provides a backup system to improve performance and reliability when needed. For example, a PCM may be selected which freezes / melts around room temperature (20-26 C). In many climates such as Northern Europe the night time temperatures fall below 20 C, even in summer. Therefore the PCM can be used to store cool energy from the night to provide space cooling during the day. Because these cycles rely on natural fluctuations and the weather, on occasion the night time temperatures may not be low enough to freeze or recharge the PCM. In this situation, a back up or booster system can be used to provide additional cooling during the night, because the temperature is already lower at night the back up or booster system has to do less work than if it was run during the day and has the advantage of using cheaper night time electricity. In this situation the backup booster may only need to cool the night time air by the difference between the target temperature and the actual night time temperature, for example if the temperature needed to freeze the PCM is 18 C, and the night time temperature is 20 C the booster only needs to provide an additional 2 degrees of cooling.

[0027]Further aspects improve one or more of the following: the effectiveness of the PCM, the turbulence of the flow, the compactness of the system relative to its effectiveness, its overall packaging weight and its manufacturing requirements.

Problems solved by technology

Because these cycles rely on natural fluctuations and the weather, on occasion the night time temperatures may not be low enough to freeze or recharge the PCM.

Because the latent heat store is finite there may be occasions where the system is required to provide more energy than stored.

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