Ageing of thermal insulation materials. Determination of the long-term change in thermal resistance of closed-cell plastics (accelerated laboratory test methods)

2021 ◽  
Vol 11 (19) ◽  
pp. 9354
Author(s):  
Hyun-Jung Choi ◽  
Hosang Ahn ◽  
Gyeong-Seok Choi ◽  
Jae-Sik Kang ◽  
Jung-Ho Huh

Two experiments were executed to examine the slice accelerated test method, suggested in ISO 11561 “Ageing of thermal insulation materials—Determination of the long-term change in thermal resistance of closed-cell plastics (accelerated laboratory test methods)” and to observe the changes in the thermal performance of insulation material over time by the real-time ageing process. The accelerated test method was conducted for 120 consecutive days using 10 mm thick-sliced specimens, which were sampled from a 50 mm thick plate body. The real-time ageing process was performed for 5000 consecutive days under constant temperature and relative humidity conditions as of 20 ± 5 °C and 50 ± 5% without any slicing. Degradation of thermal performance was shown to be stabilized at around 38 to 41% down from the initial values, which were correspondent with the approximately 10 days after the initial time. The real-time ageing process revealed similar degradation levels at around 130 days after the starting point. Converting the results using the scaling method specified in ISO 11561, the change was found in the range of 37 to 41% for the thermal resistance after 25 years and of 30 to 38% for the 25-year-average thermal resistance, respectively. Within the 10% error range, both the accelerated method and real-time ageing resulted in a similar level of degradation. Consequently, it was our observation that the slice accelerated test was quite enough to predict the practical degradation of insulation materials with at least 90% of accuracy under the specified time duration, temperature and thickness satisfactions.


Author(s):  
Frank Grealish ◽  
Iggy Roddy

There are currently a wide variety of insulation systems available for deep water subsea applications. These systems are applied in a number of different configurations including externally bonded systems, pre-manufactured insulation modules that are strapped on to subsea structures and pipe-in-pipe (PIP) insulation systems. The most common insulation materials include polymers such as polyurethane, epoxies and polypropylene and for deep water applications these are used in two main forms; syntactic foam and composite syntactic foam. The limits associated with current insulation systems include lack of experience on the performance of these systems in long-term deepwater service and relatively low temperature limits when exposed to hot/wet conditions. At present, tests for assessing their thermal and physical properties are manufacturer-dependent and, for a purchaser of such systems, need to be interpreted across a range of existing and new materials and manufacturer specifications. The immediate and long-term effects of temperature, hydrostatic pressure and environmental exposure are not yet fully understood. Currently there is a lack of agreed-upon standards for insulation materials. There is a requirement in the industry for the development of consistent standards for the specification, design, materials, manufacturing and testing of insulation materials and systems. To address this requirement a Joint Industry Project (JIP) commenced in April 2000 to develop a new industry wide standard for insulation and buoyancy materials, designated the InSpec JIP. Twenty companies are participating in the JIP, including nine oil companies, eight manufacturers of insulation/buoyancy products and three contractors. This paper presents a review of the current state-of-the-art for thermal insulation systems for deep water applications. The capabilities of alternative systems are reviewed and evaluated. The key issues associated with each system type and critical parameters for the most common insulation materials are presented and discussed. The development of industry standards within the InSpec JIP to address the critical issues for qualification is highlighted within this paper.


2020 ◽  
Vol 8 (4) ◽  
pp. 445-455
Author(s):  
A.M. Lesin ◽  

This article poses a problem associated with the difficulties of studying and identifying the motivational potential of the value sphere, as well as the discrepancy between the content of the same values in different people or in the same, but at different times. The article describes the results of a theoretical search associated with different approaches to understanding and studying values in different sciences and scientific schools. Also, the main variants of classifications of values and the ways of their formation in the direction of the personality in the process of ontogenesis are determined. The difficulties associated with the study of values with the help of tests, taking into account the social desirability and expectation of answers or the lack of self-reflection ability of the respondents, are described. The modern non-test methods and approaches to the study of the value sphere are analyzed, which make it possible to identify personally significant values and the level of their motivational potential. A method is proposed for determining the personal significance of values , as opposed to their reflec tive representation, using the magnitude of the conflict between the significance and the implementation of values. The long-term experience of using this method among various respondents is described. Variants of the destructive level of personal significance of some values are demonstrated. The possibilities and examples of the study of values in relation to the psychological structure of initiative are shown. The possibilities of content analysis in determining the content are illustrated, examples of different semantic content of the same values are given. It is concluded that, in addition to classical test methods, it is necessary to apply such methods as well, which will help to distinguish between value ideas and personal values proper, as well as to determine their content.


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