The Effect of Plate Spacing in Plate Heat Exchanger Design as a Condenser in Organic Rankine cycle for Low Temperature Heat Source

Abstract

Plate spacing is one of variable that influences plate heat exchanger (PHE) design as a condenser in Organic Rankine Cycle (ORC) system. The rises of plate spacing have effects to channel cross sectional area, channel velocity, equivalent diameter, and Reynold number at hot and cold fluid sides in PHE. Those parameters affect the total heat transfer area and total pressure drop that influence the PHE condenser performance. This paper investigated the detail effect of the plate spacing increments in the final total heat transfer area and total pressure drop design result. The plate spacing in design calculation method is varied and the other independent variables are assumed to be constant. The design was conducted by calculating condenser capacity at both sides and both zones, estimating overall heat transfer coefficient, and calculating heat transfer area and plate film coefficient. Analysis continued by calculating overall heat transfer coefficient that has small percent of error with the estimated overall heat transfer coefficient, calculating pressure drop, total plate number and total heat transfer area. The result of calculation shows that the rises of plate spacing increase the total heat transfer area and decrease the cold and hot fluid total pressure drop. The rises of plate spacing increase channel cross sectional area and equivalent diameter, and decrease channel velocity and Reynold number at zone 1 (without phase change) and zone 2 (with phase change). Therefore, the increment of heat transfer areas is unpreferable and the decrement of pressure drops is preferable.

Perancangan Plate Heat Exchanger Sebagai High Temperature Short Time Pasteurizer Susu

“…Dimana 𝑄 𝑐𝑜𝑙𝑑 adalah heat flow rate fluida dingin (W), 𝑄 ℎ𝑜𝑡 adalah heat flow rate fluida panas (W), 𝑚 𝑐𝑜𝑙𝑑 adalah laju massa aliran fluida dingin (kg/jam), 𝑚 ℎ𝑜𝑡 adalah laju massa aliran fluida panas (kg/jam), 𝐶𝑝 𝑐𝑜𝑙𝑑 adalah kapasitas panas massa fluida pendingin (J/kg.K), 𝐶𝑝 ℎ𝑜𝑡 adalah kapasitas panas massa fluida panas (J/kg.K), 𝑡 1 adalah suhu aliran fluida dingin masuk (K), 𝑡 2 adalah suhu aliran fluida dingin keluar (K), 𝑇 1 adalah suhu aliran fluida panas masuk (K), 𝑇 2 adalah suhu aliran fluida panas keluar (K) [8].…”

“…Selisih overall heat coefficient perhitungan dan trial dapat digunakan jika < 5% [8]. Jika tidak memenuhi, perlu dilakukan trial ulang nilai 𝑈 hingga mendapatkan nilai yang sesuai.…”

Heat Exchanger Sizing for Organic Rankine Cycle

“…The two-phase design method stems from the methodology outlined by Rohmah et al [38]. The governing equations are the same as for the single phase, with Reynolds number expressions Equations ( 9) and ( 10):…”

Deriving guidelines for the design of plate evaporators in heat pumps using zeotropic mixtures

“…In literature a number of studies can be found on simultaneous optimization of plate heat exchangers used as evaporators and/or condensers and thermodynamic cycle design, mostly focusing on low temperature applications and pure fluids. Some of the works are related to the assessment of the impact of some specific cycle parameters on the PHE design [19,20], whilst other studies performed combined cycle-PHE optimization procedures with the aim of maximizing the cycle efficiency [21], and by including also an economic analysis [22,23]. The pressure drops were mostly considered as pumping cost on the heat source/sink side, and none of the studies assessed the impact of the working fluid pressure drops on the outlet condition of the evaporator.…”