对一个已安装完成的系统，系统所处的环境已确定，产水效率也完全由系统结构

对一个已安装完成的系统，系统所处的环境已确定，产水效率也完全由系统结构和材料确定，此时可把系统当作一个静态系统分析。从纯经济学的观点，该系统建设当年的总投资一般包括4部分：1）太阳能集热系统f1 ；2）所需要的电辅助系统f2 ；3）基建f3 ；4）海水淡化系统主机（包括控制系统）f4。事实上，上面4部分的投资是有关联的，比如，太阳能集热系统的投资f1增加，海水淡化系统主机的投资f2就可能相应减少，因此，f1和f2是相互关联的。再有，f3与f1和f2也可能是相互关联的。比如，如果电辅助系统采用风能发电系统，在冬季与夜间，海水淡化系统用电量不多，但风能发电系统照常发电，此时，风能发电系统除了供海水淡化系统使用外，还可向用户提供多余的电力，从而回收部分投资。也可能太阳能集热系统在冬季集热温度达不到70 ℃，从而不能驱动海水淡化系统，但可改为为用户提供生活热水，也可回收部分投资（冬季温度太低关闭淡化系统）。为了详细分析海水淡化系统的经济性，令系统在建设当年的总投资为F，系统在寿命期内总回报为M，系统寿命为N 年，银行年利率为i ，系统产生的淡水价格为α ，能源价格或水价平均年增加率为e。所以系统在建设当年的总投资费用F为：

結果 (英文) 1:

A system installed completed, the environment in which the system has been determined, the water is completely determined by the productivity and material structure of the system, then the system can be analyzed as a static system. From a purely economic point of view, the total investment of the year system generally includes four parts: 1) a solar collector system f1; 2) f2 required electric auxiliary system; 3) infrastructure F3; 4) desalination system host (including control system) f4.
In fact, the investment part 4 above are associated, for example, the solar collector system increases investment f1, f2 desalination system may host a corresponding reduction of investment, therefore, f1 and f2 are interrelated. Further, f3 and f1 and f2 may be interrelated. For example, if the electric auxiliary system using wind power generating system, in winter and night electricity much desalination systems, but generating wind power generating system as usual, this time, in addition to wind power generating system for desalination system, the user may provide excess power to recover part of the investment. May solar collector system in the winter temperature of the collector is less than 70 ℃, desalination systems and thus can not drive, but may instead provide hot water for the users, but also recovered part of the investment (too low temperature in winter desalination system off).
For a detailed analysis of the economics of desalination system, so the system total investment of the year is F, the total return on the life of the system is M, N years for the life of the system, the bank interest rate of i, the price system to produce fresh water α energy prices or price annual growth rate plus e. So the system in total investment costs for the year F:

結果 (英文) 2:

For an installed system, the environment in which the system is located has been determined and the water efficiency is determined entirely by the system structure and materials, at which point the system can be analyzed as a static system. From a purely economic point of view, the total investment in the year of the construction of the system generally consists of 4 parts: 1) solar heat collection system f1; 2) the required electrical assistance system f2; 3) infrastructure f3; and 4) desalination system host (including control system) f4.
In fact, the investment in the above four parts is related, for example, the investment in solar heat collection system f1 increases, the saltwater system host investment f2 may be correspondingly reduced, so that f1 and f2 are related. Then again, f3 and f1 and f2 may be related. For example, if the electrical auxiliary system uses wind power generation systems, in winter and at night, desalination systems use little electricity, but wind power systems generate electricity as usual, at which time wind power systems can provide excess electricity to users in addition to desalination systems, thereby recovering some of the investment. It is also possible that the solar heat collection system does not reach 70 degrees C in winter heat collection, which cannot drive the desalination system, but can be replaced by providing users with domestic hot water or to recover some of the investment (winter temperatureist is too low to shut down the desalination system).
In order to analyze the economy of the desalination system in detail, the total investment of the system in the year of construction is F, the total return of the system in the life of the system is M, the system life is N years, the annual interest rate of the bank is i, the system produces fresh water price is alpha, the average annual rate of energy or water price is e. So the total investment cost of the system in the year of construction F is:

結果 (英文) 3:

For an installed system, the environment of the system has been determined, and the water production efficiency is completely determined by the system structure and materials. At this time, the system can be analyzed as a static system. From the point of view of pure economics, the total investment in the construction of the system in that year generally includes four parts: 1) solar energy collection system F1; 2) electric auxiliary system F2; 3) infrastructure F3; 4) desalination system host (including control system) F4.
In fact, the investment in the above four parts is related. For example, if the investment in the solar energy collector system increases, the investment in the main engine of the desalination system may decrease accordingly. Therefore, F1 and F2 are related to each other. Furthermore, F3 and F1 and F2 may also be related to each other. For example, if the electric auxiliary system adopts the wind power generation system, in winter and night, the power consumption of the desalination system is not much, but the wind power generation system still generates power as usual. At this time, the wind power generation system can provide users with extra power in addition to the use of the desalination system, so as to recover part of the investment. It is also possible that the solar energy heat collection system can not drive the desalination system in winter when the heat collection temperature is less than 70 ℃, but it can provide domestic hot water for users instead, and it can also recover part of the investment (close the desalination system when the temperature is too low in winter).
In order to analyze the economy of the desalination system in detail, the total investment of the system in the construction year is f, the total return of the system in the life cycle is m, the system life is n years, the bank annual interest rate is I, the fresh water price generated by the system is α, and the average annual increase rate of energy price or water price is e. Therefore, the total investment cost F of the system in the construction year is: