Performance Analysis And Comprehensive Evaluation Of Marine Double Stage Coupled Heat Pump System

In2009the global climate conference in Copenhagen, China had announced to the worldthat prior to2020the carbon emission intensity will be reduced by40%to45%than2005.The per capita resource of China is relatively poor,the responsibility of energy-savingand emission reduction is very huge. In our country, ship has been the "major" of energyconsumption and pollutant emission for a long time,and the marine air conditioning energyconsumption accounts for a larger proportion of the total energy consumption of the ship.Howto achieve low energy consumption and high energy efficiency of the marine air conditioninghas become an important research direction.Application of heat pump technology is a effective way to achieve energy saving andemission reduction.This paper takes a bulk carrier as research object,in the light of its annualair conditioning loads,puts forward the marine double-stage coupled seawater source heatpump system which can be applied to the cold sea area. The mathematical models ofcompressor and expansion valve and the distribution parameters models of evaporator andcondenser are established respectively,then according to the quality and energyconservation,the mathematical model of the double-stage coupled heat pump system isconstructed throug using the order module method,and the simulation program is compiled.This paper analyses the steady state heating characteristics of the first-order,second-order andthe double-stage coupled heat pump system, determines the reasonable matching of thefirst-order cycle and the second-order cycle equipment design capacity.Finally, theapplication of the double-stage coupled heat pump system is evaluated comprehensively fromthe economic, energy and environment and other aspects by using Analytic HierarchyProcess.The result shows that the application of double-stage coupled heat pump system in shipimproves the heating characteristics of single-stage seawater source heat pump at the lowseawater temperature effectively, and solves the problem that the heating capacity of thetraditional single-stage heat pump can not meet the operation requirements at the lowtemperature. The main factors which affect the system performance include seawatertemperature,end loop water temperature and intermediate loop water temperature. Thedouble-stage coupled heat pump system can work in the single or two-stage operation mode, and has a good ability to adapt to the load, the unit’s energy efficiency ratio is improvedeffectively,it reduces the pollutants which are produced by the energy consumption of coldand heat source,and have less impact on the environment. The performance analysis andcomprehensive evaluation of double-stage coupled heat pump provide the theory reference forexpanding the single-stage heat pump working temperature range and promoting heat pumpapplied in marine air-conditioning system,and have a guiding significance for the marine airconditioning energy-saving emission reduction.