Thermo-economic analysis of two novel low grade sensible heat driven desalination processes

New MED based desalination process for low grade waste heat

“…Produced steam in each flash chamber flows into the appropriate primary MED effect according to the relevant pressure. At the exit of the liquid-liquid heat exchanger, the waste heat source outlet temperature, successfully approaches the mixing point temperature between the flashing chamber and the condenser outlet temperatures as close as is practicable [18,23]; this signifies an effective waste heat utilisation.…”

“…Based on this formula, Rahimi et al [23] presented a new methodology to estimate the capital cost of BMED and FBMED. The total freshwater production rate of BMED and FBMED, namely D t,Design , have been considered as the sum of (i) vapour (which is eventually condensed) production of booster or flash chambers acting as auxiliary equipment D au , and (ii) the freshwater production of an equivalent MED with the capacity of (D t,Design − D au ).…”

“…The total pressure drop of the heat source, including those over the first effect, the booster, and the liquid-liquid heat exchanger, is calculated using Eqs. (23) and (27). The normalised pumping power consumptions are compared in Table 4 and Fig.…”

“…responsible for the steam generation and the second part is the capital cost of the additional heat transfer area in the primary MED to condense steam drawn from boosters/flash chambers [23]. The cost related to the auxiliary equipment is a portion (G) of the equivalent MED cost with D au production rate and the cost for the additional heat transfer area in the primary MED is half of the difference between the evaporator cost of an equivalent MED with D t , Design and D t , MED production rates [23]; only half is considered as the evaporation is effected in the boosters/flash chambers, and only condensation happens in the equivalent MED. For FBMED, there is the additional capital cost of one or more liquid-liquid heat exchangers, Ψ Liq-Liq heat exchanger , which has been inadvertently ignored by Rahimi et al [23], but is now explicitly included.…”

“…Using the IDA data, the capital cost of MED and MSF including supply of equipment, engineering, commissioning, erection, instrumentation and control has been derived as a function of daily production up to 10,000 ( m 3 /day) [23,37]:…”