Abstract—In this study, we designed a new plate-type heat
exchanger system for the previous shell-and-tube evaporator
with the same heat rate and additional turbine safety measure.
The new evaporator system consists of two plate heat
exchangers; one for preheating and the other for subsequent
evaporation and superheating. The separate design reduces the
liquid level of the evaporator and lowers the risk of liquid inflow
into the turbine. For an additional driving stability, a co-current
flow configuration was used for the preheater so that a
subcooled liquid is introduced to the evaporator instead of a
liquid-vapor mixture. A detailed design of the plate heat
exchangers was carried out using a commercial software. The
new heat exchangers are 75% smaller in volume and 83%
smaller in weight. The designed heat exchangers were
manufactured and installed in the previous ORC system. The
performance was evaluated using an electric heater and a
cooling tower as a heat source and heat sink. For the test, the
working fluid pump was operated at the design point turbine
inlet pressure of 2.13 MPa. Meanwhile, the condensation
conditions were not matched to the design point due to the
weather effect. Under the analysis condition, the new evaporator
system showed an evaporator heat rate of 1662 kW, which is
91% of the design value with a pressure loss of 46 kPa. We
calculated a pressure loss of 62.8 kPa for the design point using
an equation for simple friction loss. The results showed that our
new evaporator system successfully replaced the previous one
without big performance losses.
Index Terms—Organic rankine cycle, preheater, plate heat
exchanger, shell-and-tube heat exchanger.
T. Sung and K. C. Kim are with the School of Mechanical Engineering,
Pusan National University, Busan 46241, Republic of Korea (e-mail:
taehongsung@pusan.ac.kr, kckim@pusan.ac.kr).
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Cite:Taehong Sung and Kyung Chun Kim, "Development of a 200-kW Organic Rankine Cycle Power System for Low-Grade Waste Heat Recovery," Journal of Clean Energy Technologies vol. 6, no. 2, pp. 121-124, 2018.
