Effects of operating parameters on the performance of a CO2 air conditioning system for vehicles

Kim, Sung Chul; Won, Jong Phil; Kim, Min Soo

doi:10.1016/j.applthermaleng.2008.12.017

Cited by 81 publications

(14 citation statements)

References 12 publications

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“…According to Gellerstedt (2002), 4,000 control inputs per hour have to be carried out by the operator, due to the lack of automatic functions of the boom and harvester head. Despite the ergonomic design of the cabs, the operators of mobile machinery are exposed mainly to noise (Hansson 1990;Axelsson 1998;Marsili et al 1998;Nieuwenhuis, Lyons 2002;Messingerová et al 2005;Sümer 2006;Beuk et al 2007;Gerasimov, Sokolov 2009;Aybek et al 2010;Bilski 2013), whole-body vibrations (Boileau, Rakheja 1990;Burdorf, Swuste 1993;Magnusson et al 1993;Hansson 1995;Huston et al 1999;Hinz et al 2002;Paddan, Griffin 2002;Hostens, Ramon 2003;Chen et al 2003;Sherwin et al 2004a,b;Deprez et al 2005;Kolich et al 2005;Tiemessen et al 2007;Li et al 2008;Gerasimov, Sokolov 2009), microclimatic conditions -mostly temperature, and airflow velocity inside the cab (Gao, Niu 2004;Kaynakli, Kilic 2005;Huang et al 2006;Mezrhab, Bouzidi 2006;Cengiz, Babalik 2007;Farzaneh, Tootoonchi 2008;Kim et al 2009;Zhang et al 2009a,b;Alahmer et al 2011), and severe mental and sensory load (Axelsson, Pontén 1990;Poschen 1993;…”

mentioning

confidence: 99%

Objective and subjective assessment of selected factors of the work environment of forest harvesters and forwarders

Martin¹,

Messingerová²,

Ferenčík³

et al. 2016

J. For. Sci.

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This article was aimed at assessment of selected factors of the work environment, which influenced the operators of harvesters and forwarders. The selection of the work environment factors was based on a thorough literature survey. From the survey exposure to whole-body vibrations, noise (equivalent and peak), microclimatic conditions and mental load were selected for detailed observations. The measurements were conducted according to international standards and assessed according to European or national legislation. Subjective assessment of the effects of the work environment was conducted through a structured interview. The exposure to whole-body vibrations was 0.5 m·s -2 . The equivalent noise exposure was 78 dB, peak noise exposure was 130 dB. The average temperature inside the machine cabs was 17.9°C and average airflow velocity was 0.06 m·s -2 . Mental load was high according to the Meister questionnaire, three operators considered the load inadequate, two considered it adequate. Subjective assessment showed that operators considered other factors to be light or no load.Keywords: noise exposure; whole-body vibrations; microclimate; mental load Work environment is a set of all conditions in which workers carry out their work. It consists of all workers and factors present at the workplace, or of those who have to do with the work and influence the health or comfort of workers. The worker is exposed to many harmful factors which interact and their joint effect can be synergistic or complementary (Schwartz et al. 2013).Operators of multi-operational machinery carry out their tasks in ergonomically designed cabs capable of partial attenuation of noise and vibrations caused by the machine movement, driving gear, and working parts of the machine. Cabs are also equipped with air conditioning and glare reducing windows. Some factors (e.g. electromagnetic, ionising radiation, various chemical factors, or energy expenditure) do not apply to the jobs of multioperational machinery operators. Their assessment would only consume time with no significant effect on the overall outcome of the assessment. The nature of work in mechanized logging partially shifted from physical to mental after employment of multi-operational machinery. The need for muscular activity decreased and the need to stay concentrated and alert through long periods grew in importance. Harvester operators have to be able to process a lot of information, react quickly, and retain their concentration in monotonous, repetitive operations (Axelsson, Pontén 1990;Poschen 1993;Gellerstedt 1997;Gellestedt et al. 1999;Tsioras 2012). Operating the machines is quite demanding. According to Gellerstedt (2002), 4,000 control inputs per hour have to be carried out by the operator, due to the lack of automatic functions of the boom and harvester head. Despite the ergonomic design of the cabs, the operators of mobile machinery are exposed mainly to noise (Hans-

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mentioning

confidence: 99%

Objective and subjective assessment of selected factors of the work environment of forest harvesters and forwarders

Martin¹,

Messingerová²,

Ferenčík³

et al. 2016

J. For. Sci.

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show abstract

“…Kauf [8] Single-stage valve-expansion (1) SD 5.8% for p opt Liao, Zhao and Jakobsen [9] Single-stage valve-expansion (2) SD 1% for p opt Sarkar, Bhattacharyya and Gopal [10] Single-stage valve-expansion (3) N/A Sarkar, Bhattacharyya and Gopal [23] Single-stage valve-expansion (4) R 2 ¼ 0.995 for p opt Chen and Gu [11] Single-stage valve-expansion (5) (6) SD ¼ 0.94% for p opt Kim, Won and Kim [17] Single-stage valve-expansion (7) N/A Aprea and Maiorino [18] Single-stage valve-expansion (8) More accurate than Liao, Zhao and Jakobsen [9] for specific experimental p opt ; Zhang, Fan, Wang and Shen [19] Single-stage valve-expansion (9) More accurate than Liao, Zhao and Jakobsen [9] for specific experimental p opt ; Qi, He, Wang and Meng [16] Single-stage valve-expansion (10) MaxD 5% for experimental p opt ; MaxD 6% for real system COP Wang, Tuo, Cao and Xing [20] Single-stage valve-expansion (11) (12) MaxD ¼ 5.5% for experimental p opt , corresponding COP loss 1.3% Agrawal, Bhattacharyya and Sarkar [12] Two-stage valve-expansion (13) [13] Single/two-stage valve-expansion (16) N/A Ge and Tassou [15] Supermarket boost system (17) N/A Ge and Tassou [14] Supermarket boost system (18) AD ¼ 0.45%, MaxD ¼ 1.89% for p opt Sarkar [22] Single-stage ejector-expansion (19) R 2 ¼ 0.999 for p opt Elbel and Hrnjak [27] Single-stage ejector-expansion (20) N/A Xu, Chen, Tang and Zhu [24] Single-stage ejector-expansion (21) N/A Yari [21] Two-stage ejector-expansion (22) R 2 ¼ 0.9998 for p opt Fig. 2.…”

Section: Literature Cycle Description Equations Statisticsmentioning

confidence: 96%

Minimizing COP loss from optimal high pressure correlation for transcritical CO2 cycle

Liu

Cai

et al. 2015

Applied Thermal Engineering

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“…Based on the measured data, the refrigerant-side heat transfer rate was calculated by equation (1) using the refrigerant enthalpy method (ASHRAE Standard 116, 1983). The air-side heat transfer rate was calculated by equation (2) using both the air flow rate and enthalpy difference suggested by (Kim et al, 2009b). The air-side heat transfer rate was validated against the refrigerant-side heat transfer rate.…”

Section: Introductionmentioning

confidence: 99%

Steady state and start-up performance characteristics of air source heat pump for cabin heating in an electric passenger vehicle

Lee

2016

International Journal of Refrigeration

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Effects of operating parameters on the performance of a CO2 air conditioning system for vehicles

Cited by 81 publications

References 12 publications

Objective and subjective assessment of selected factors of the work environment of forest harvesters and forwarders

Objective and subjective assessment of selected factors of the work environment of forest harvesters and forwarders

Minimizing COP loss from optimal high pressure correlation for transcritical CO2 cycle

Steady state and start-up performance characteristics of air source heat pump for cabin heating in an electric passenger vehicle

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