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 Wysłany: Śro 13:51, 15 Gru 2010 Temat postu: air jordan shoes cheap Marine refrigeration device |
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Marine refrigeration device to R134a as refrigerant instead of R12
0.79l0.6l5 standard vaporization temperature, the heat of vaporization (kj / kg) 2l9.8165.325 (℃) when the thermal conductivity (w / mk) steam 0.00830.0097 liquid 0.1l80.06825 \atmospheric pressure dynamic viscosity (Ns / m) 1.23 * 10'51 .1 l10'5 vapor liquid 2.52 * 1024 \Solubility (mass percentage) 0.15 Table 2 The results under different operating conditions of refrigerant Rl34aRl2 power consumption per unit mass of refrigerant (kJ / kg) 3528 cooling capacity per unit mass (kJ / kg) l80l39 heat per unit mass of refrigerant ( kJ / kg) 2l5l67 poor conditions most people Ju pressure (Mpa) 1.2251.2 conditions the maximum power consumption of power (kW) 2.182.36 comparison can be seen from the theoretical calculation, using R134a replace R12, if the same displacement compressor, in the standard conditions, the cooling capacity per unit mass increased by 30%. However, the corresponding power consumption increases 25%, the corresponding coefficient of performance increases were 3.8%. Cooling capacity from the view, to achieve the cooling effect of the original R12, but the power consumption increases. Increase in volume of people as refrigeration,[link widoczny dla zalogowanych], the cooling effect to achieve the same processing time and extended downtime, if the original start and stop time to keep unchanged the structure in the compressor to take measures to reduce the compressor displacement, not to keep the original cooling capacity change; such as: by reducing the compressor speed. Conditions by the comparison of the maximum pressure can be seen,[link widoczny dla zalogowanych], replaced,[link widoczny dla zalogowanych], the difference between high and low voltage devices from the 1.2Mpa increased to 1.225Mpa, increased 2.1%, as the main equipment and accessories for refrigeration equipment design strength of its security check will not be affected by a large margin, that is the strength of equipment and accessories to meet the requirements. Comparison of the maximum power can work. 25. \meets the requirement. Maximum pressure condition, the evaporation temperature. 30 ℃, then the corresponding evaporation pressure of R134a 0.075Mpa, below atmospheric pressure, does not meet the needs of ships, for replacement, in order to prevent the evaporation pressure lower than atmospheric pressure,[link widoczny dla zalogowanych], control elements must be adjusted accordingly, an increase in pressure following electrical devices operating pressure to ensure that only regular J_ = for. Fourth, after the replacement refrigerant R134a and freezers measures Shantou because the solubility problem, replace the R12 to R134a, the compression mechanism to ensure the normal lubrication, oil lipids must be replaced, for the current domestic oil production is full of frozen R134a seeking from reference 2. High and low voltage disconnect relay a corresponding increase in pressure, to ensure the normal work of the evaporation pressure of not less than atmospheric pressure. V. Conclusion and RI2 of R134a as a refrigerant used in the calculation of ship refrigeration equipment that: direct replacement for R12 with R134a is feasible. Consistent with the development of domestic and international trends and needs,[link widoczny dla zalogowanych], and easy without the need for equipment, components for large changes, modifications, low cost, to meet the actual requirements. References 1. Gao Xiang ((ship auxiliary machinery \],[pressure and crisis. Appendix: Summary of Zhejiang cold storage survey (as at the end of September 2004) summary tables, Zhejiang cold storage for a lO-7 region in 2004 the number of storage capacity (tonnes) 252 235 600 Note not included in the construction of Ningbo and the preparation of the 6 Thirty Il50l70700 house 78,000 tons without 2 units under construction in Zhoushan 266l65000 18,000 tons of non-5 under construction 35,000 tons of Hangzhou, Wenzhou llOl23000 without preparation thirty f257l300 55,000 tons in the four non-3 Shaoxing 23l8600 14,000 tons under construction in Jiaxing Library Lishui, Jinhua 1,624,500 42,900 2,226,000 Total 868,837,600 Note: 1, there are remote areas to be completed Qu l City Data, statistics are not included, is expected to total less than 2000 tons. 2, 1o0 tons more than a small number of free libraries. .26 .
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