In terms of the great investment and high energy consumption of natural gas liquefaction process system, the
technological economy of the process equipment can be evaluated reasonably through thermoeconomic analysis. The
process flow was simulated with HYSYS based on the actual process and operation data of a natural gas liquefaction plant.
Thereby, the thermoeconomic cost balance and auxiliary equations of each equipment were constructed based on economic
and exergic analysis to analyze the thermoeconomic cost of streams. Besides, the technological economy of equipment
was evaluated with the relative cost difference and the exergo-economic factor based on the fuel-product definition of the
equipment and the thermoeconomic cost of each stream. Meanwhile, the optimization direction of each equipment was
pointed out, and the influence degree of energy cost and non-energy cost on the unit thermoeconomic cost of the product
was analyzed. The results show that the exergoeconomic factors of No. 3 compressor and No. 2 refrigerant pump in the
process system are relatively high, and it is necessary to reduce their investment cost or the operation and maintenance
cost. Additionally, energy cost is the main factor affecting the production cost of liquefied natural gas, and the unit
thermoecomnomic cost of liquefied natural gas increases by 8.7% if the energy cost is increased by 10%. Generally, the
research results could provide guidance and suggestions on the optimization, operation and maintenance of the natural gas
liquefaction process system . (6 Figures, 4 Tables, 21 References)