Patent Publication Number: US-2022213814-A1

Title: Single-working-medium vapor combined cycle

Description:
FIELD 
     The present invention belongs to the flied of energy and power technology. 
     BACKGROUND 
     Cold demand, heat demand and power demand are common in human life and production. It is an important way to obtain and provide power by the conversion of thermal energy into mechanical energy. In general, the temperature of heat source reduces and varies with the release of heat. When fossil fuels are used as the primary energy, the heat source has the dual characteristics of both high temperature and variable temperature. Therefore, only one single thermodynamic cycle cannot achieve an ideal efficiency for refrigeration, heating or power generation. 
     Take the vapor power device with external combustion for example, its heat source has the dual characteristics of high temperature and variable temperature. For those vapor power devices based on the Rankine cycle, the material&#39;s temperature resistance and pressure resistance abilities and safety concerns limit the parameters of the cycle&#39;s working medium. Therefore, there is a big temperature difference between the working medium and the heat source, which leads to big irreversible loss and low efficiency. 
     Humans need new basic theory of thermal science to use fuel or other high temperature thermal energy simply, actively, efficiently for achieving refrigeration, heating or power. In the basic theory system of thermal science, thermodynamic cycles are the theoretical basis of thermal energy utilization devices, and the core of energy utilization systems. The establishment, development and application of thermodynamic cycles will play an important role in the rapid development of energy utilization and will promote actively for social progress and productivity development. 
     Based on the principles of simple, active and efficient utilization of temperature difference, aiming at the power generation application of high temperature heat sources or variable temperature heat sources, and striving to provide theoretical support for the simplification and high efficiency of thermo-power systems, the present invention proposes a single-working-medium vapor combined cycle. 
     THE CONTENTS OF THE PRESENT INVENTION 
     The single working-medium vapor combined cycle and the vapor power device for combined cycle are mainly provided in the present invention, and the specific content of the present invention is as follows: 
     1. A single-working-medium vapor combined cycle method consisting of thirteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (8) of the H kg of working medium, performing a pressurization process to set a state (8) to (5) of the M 2  kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 1 +M 2 ) kg of working medium, performing a depressurization process to set a state (6) to (7) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (7) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (8) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (8) to (9) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (9) to (1) of the (M 1 +H) kg of working medium. 
     2. A single-working-medium vapor combined cycle method consisting of fourteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a depressurization process to set a state (5) to (7) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (9) of the H kg of working medium, performing a pressurization process to set a state (9) to (6) of the M 2  kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the M 2  kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (9) to (c) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (c) to (1) of the (M 1 +H) kg of working medium. 
     3. A single-working-medium vapor combined cycle method consisting of fourteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (7) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (9) of the H kg of working medium, performing a pressurization process to set a state (9) to (5) of the M 2  kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the M 2  kg of working medium, performing a depressurization process to set a state (6) to (7) of the M 2  kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (9) to (c) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (c) to (1) of the (M 1 +H) kg of working medium. 
     4. A single-working-medium vapor combined cycle method consisting of fifteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a depressurization process to set a state (5) to (9) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (6) of the M 2  kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the M 2  kg of working medium, performing a depressurization process to set a state (7) to (8) of the M 2  kg of working medium, performing a heat-releasing process to set a state (8) to (9) of the M 2  kg of working medium, performing a heat-releasing process to set a state (9) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     5. A single-working-medium vapor combined cycle method consisting of fifteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a depressurization process to set a state (5) to (6) of the M 1  kg of working medium, performing a heat-releasing process to set a state (6) to (9) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (7) of the M 2  kg of working medium, performing a heat-absorption process to set a state (7) to (8) of the M 2  kg of working medium, performing a depressurization process to set a state (8) to (9) of the M 2  kg of working medium, performing a heat-releasing process to set a state (9) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     6. A single-working-medium vapor combined cycle method consisting of sixteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (5) of the M 2  kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 1 +M 2 ) kg of working medium, performing a depressurization process to set a state (6) to (9) of the X kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the (M 1 +M 2 −X) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 −X) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 −X) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 −X) kg of working medium and H kg of working medium, performing a mixing heat-releasing process to set a state (9) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     7. A single-working-medium vapor combined cycle method consisting of sixteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (8) of the H kg of working medium, performing a pressurization process to set a state (8) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (5) of the (M 2 -M) kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 1 +M 2 ) kg of working medium, performing a depressurization process to set a state (6) to (7) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (7) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (8) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (8) to (9) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (9) to (1) of the (M 1 +H) kg of working medium. 
     8. A single-working-medium vapor combined cycle method consisting of seventeen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (5) to (7) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (9) of the H kg of working medium, performing a pressurization process to set a state (9) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (6) of the (M 2 -M) kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the (M 2 -M) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (9) to (c) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (c) to (1) of the (M 1 +H) kg of working medium. 
     9. A single-working-medium vapor combined cycle method consisting of seventeen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption and vaporization process to set a state (4) to (7) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (9) of the H kg of working medium, performing a pressurization process to set a state (9) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (5) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 2 −M) kg of working medium, performing a depressurization process to set a state (6) to (7) of the (M 2 −M) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (9) to (c) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (c) to (1) of the (M 1 +H) kg of working medium. 
     10. A single-working-medium vapor combined cycle method consisting of eighteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (5) to (9) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (6) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the (M 2 −M) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 2 −M) kg of working medium, performing a heat-releasing process to set a state (8) to (9) of the (M 2 −M) kg of working medium, performing a heat-releasing process to set a state (9) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     11. A single-working-medium vapor combined cycle method consisting of eighteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (5) to (6) of the (M 1 +M) kg of working medium, performing a heat-releasing process to set a state (6) to (9) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (7) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (7) to (8) of the (M 2 −M) kg of working medium, performing a depressurization process to set a state (8) to (9) of the (M 2 −M) kg of working medium, performing a heat-releasing process to set a state (9) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     12. A single-working-medium vapor combined cycle method consisting of nineteen processes which are conducted with M 1  kg of working medium, M 2  kg of working medium and H kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (5) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 1 +M 2 ) kg of working medium, performing a depressurization process to set a state (6) to (9) of the X kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the (M 1 +M 2 −X) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 −X) kg of working medium, performing a heat-releasing process to set a state (8) to (c) of the (M 1 +M 2 −X) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 −X) kg of working medium and H kg of working medium, performing a mixing heat-releasing process to set a state (9) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a type 1 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 2  is a type 2 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 3  is a type 3 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 4  is a type 4 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 5  is a type 5 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 6  is a type 6 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 7  is a type 7 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 8  is a type 8 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 9  is a type 9 example general flow chart of a single-working-medium combined cycle provided in the present invention. 
         FIG. 10  is a type 10 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 11  is a type 11 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
         FIG. 12  is a type 12 example general flow chart of a single-working-medium vapor combined cycle provided in the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The first thing to note is that, when describing the cycle&#39;s structures and processes, the processes will not be repeatedly described if not necessary, and the obvious processes will not be described. The detailed description of the present invention is as follows: 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 1  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts thirteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (8) of the H kg of working medium, performing a pressurization process to set a state (8) to (5) of the M 2  kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 1 +M 2 ) kg of working medium, performing a depressurization process to set a state (6) to (7) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (7) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (8) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (8) to (9) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (9) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-8 is released by the heat-releasing process f-8 of (M 1 +M 2 ) kg of working medium, or by an external heat source. The process 2-3 of M 1  kg of working medium, the process 4-5 of M 1  kg of working medium and the process 5-6 of (M 1 +M 2 ) kg of working medium, the absorbed heat is usually provided by an external heat source, or by the heat-releasing process 7-f of (M 1 +M 2 ) kg of working medium (regeneration) and an external heat source. 
     {circle around (2)} Heat-releasing processes: The heat released (M 1 +M 2 ) kg of working medium in process 7-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to 8 points. The heat-releasing process f-8 is completed. The heat released by (M 1 +H) kg of working medium in process 9-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process 8-5 of M 2  kg of working medium is usually achieved by a compressor. The depressurization (and expansion) process 3-4 of M 1  kg of working medium, the depressurization (and expansion) process 6-7 of (M 1 +M 2 ) kg of working medium and the depressurization (and expansion) process 8-9 of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 2  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts fourteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a depressurization process to set a state (5) to (7) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (9) of the H kg of working medium, performing a pressurization process to set a state (9) to (6) of the M 2  kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the M 2  kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (9) to (c) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (c) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-9 is released by the heat-releasing process f-9 of (M 1 +M 2 ) kg of working medium, or by an external heat source. The process 2-3 of M 1  kg of working medium, the process 4-5 of M 1  kg of working medium and the process 6-7 of M 2  kg of working medium, the absorbed heat is usually provided by an external heat source, or by the heat-releasing process 8-f of (M 1 +M 2 ) kg of working medium (regeneration) and an external heat source. 
     {circle around (2)} Heat-releasing processes: The heat released (M 1 +M 2 ) kg of working medium in process 8-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to 9 points. The heat-releasing process f-9 is completed. The heat released by (M 1 +H) kg of working medium in process c-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process 9-6 of M 2  kg of working medium is usually achieved by a compressor. The depressurization (and expansion) process 3-4 of M 1  kg of working medium, the depressurization (and expansion) process 5-7 of M 1  kg of working medium, the depressurization (and expansion) process 7-8 of (M 1 +M 2 ) kg of working medium and the depressurization (and expansion) process 9-c of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 3  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts fourteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (7) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (9) of the H kg of working medium, performing a pressurization process to set a state (9) to (5) of the M 2  kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the M 2  kg of working medium, performing a depressurization process to set a state (6) to (7) of the M 2  kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (9) to (c) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (c) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-9 is released by the heat-releasing process f-9 of (M 1 +M 2 ) kg of working medium, or by an external heat source. The process 2-3 of M 1  kg of working medium, the process 4-7 of M 1  kg of working medium and the process 5-6 of M 2  kg of working medium, the absorbed heat is usually provided by an external heat source, or by the heat-releasing process 8-f of (M 1 +M 2 ) kg of working medium (regeneration) and an external heat source. 
     {circle around (2)} Heat-releasing processes: The heat released (M 1 +M 2 ) kg of working medium in process 8-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to 9 points. The heat-releasing process f-9 is completed. The heat released by (M 1 +H) kg of working medium in process c-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process 9-5 of M 2  kg of working medium is usually achieved by a compressor. The depressurization (and expansion) process 3-4 of M 1  kg of working medium, the depressurization (and expansion) process 6-7 of M 2  kg of working medium, the depressurization (and expansion) process 7-8 of (M 1 +M 2 ) kg of working medium and the depressurization (and expansion) process 9-c of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 4  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts fifteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a depressurization process to set a state (5) to (9) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (6) of the M 2  kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the M 2  kg of working medium, performing a depressurization process to set a state (7) to (8) of the M 2  kg of working medium, performing a heat-releasing process to set a state (8) to (9) of the M 2  kg of working medium, performing a heat-releasing process to set a state (9) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-c is released by the heat-releasing process f-c of (M 1 +M 2 ) kg of working medium, or by an external heat source. The process 2-3 of M 1  kg of working medium, the process 4-5 of M 1  kg of working medium and the process 6-7 of M 2  kg of working medium, the absorbed heat is usually provided by an external heat source, or by the heat-releasing process 9-f of (M 1 +M 2 ) kg of working medium (regeneration) and an external heat source. 
     {circle around (2)} Heat-releasing processes: The heat released M 2  kg of working medium in process 8-9 and (M 1 +M 2 ) kg of working medium in process 9-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to c points. The heat-releasing process f-c is completed. The heat released by (M 1 +H) kg of working medium in process d-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process c-6 of M 2  kg of working medium is usually achieved by a compressor. The depressurization (and expansion) process 3-4 of M 1  kg of working medium, the depressurization (and expansion) process 5-9 of M 2  kg of working medium, the depressurization (and expansion) process 7-8 of M 2  kg of working medium and the depressurization (and expansion) process c-d of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 5  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts fifteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a depressurization process to set a state (5) to (6) of the M 1  kg of working medium, performing a heat-releasing process to set a state (6) to (9) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (7) of the M 2  kg of working medium, performing a heat-absorption process to set a state (7) to (8) of the M 2  kg of working medium, performing a depressurization process to set a state (8) to (9) of the M 2  kg of working medium, performing a heat-releasing process to set a state (9) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-c is released by the heat-releasing process f-c of (M 1 +M 2 ) kg of working medium, or by an external heat source. The process 2-3 of M 1  kg of working medium, the process 4-5 of M 1  kg of working medium and the process 5-6 of M 2  kg of working medium, the absorbed heat is usually provided by an external heat source, or by the heat-releasing process 6-9 of M 1  kg of working medium (regeneration) and the heat-releasing process 9-f of (M 1 +M 2 ) kg of working medium (regeneration). 
     {circle around (2)} Heat-releasing processes: The heat released M 1  kg of working medium in process 6-9 and (M 1 +M 2 ) kg of working medium in process 9-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to c points. The heat-releasing process f-c is completed. The heat released by (M 1 +H) kg of working medium in process d-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process c-7 of M 2  kg of working medium is usually achieved by a compressor. The depressurization (and expansion) process 3-4 of M 1  kg of working medium, the depressurization (and expansion) process 5-6 of M 1  kg of working medium, the depressurization (and expansion) process 8-9 of M 2  kg of working medium and the depressurization (and expansion) process c-d of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 6  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts sixteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M 1  kg of working medium, performing a depressurization process to set a state (3) to (4) of the M 1  kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the M 1  kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (5) of the M 2  kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 1 +M 2 ) kg of working medium, performing a depressurization process to set a state (6) to (9) of the X kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the (M 1 +M 2 −X) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 −X) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 −X) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 −X) kg of working medium and H kg of working medium, performing a mixing heat-releasing process to set a state (9) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-c is released by the heat-releasing process f-c of (M 1 +M 2 ) kg of working medium and process f-9 of (M 1 +M 2 −X) kg of working medium, or by an external heat source. The process 2-3 of M 1  kg of working medium, the process 4-5 of M 1  kg of working medium and the process 5-6 of (M 1 +M 2 ) kg of working medium and the process 6-7 of (M 1 +M 2 −X) kg of working medium, the absorbed heat is usually provided by an external heat source, or by the heat-releasing process 8-f of (M 1 +M 2 −X) kg of working medium (regeneration) and an external heat source. 
     {circle around (2)} Heat-releasing processes: The heat released (M 1 +M 2 −X) kg of working medium in process 8-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 −X) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 −X) kg of working medium is reduced to 9 points. The heat-releasing process f-9 is completed. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to c points. The heat-releasing process 9-c is completed. The heat released by (M 1 +H) kg of working medium in process d-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process c-5 of M 2  kg of working medium is usually achieved by a compressor. The depressurization (and expansion) process 3-4 of M 1  kg of working medium, the depressurization (and expansion) process 6-9 of X kg of working medium, the depressurization (and expansion) process 7-8 of (M 1 +M 2 −X) kg of working medium and the depressurization (and expansion) process c-d of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 7  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts sixteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (8) of the H kg of working medium, performing a pressurization process to set a state (8) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (5) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 1 +M 2 ) kg of working medium, performing a depressurization process to set a state (6) to (7) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (7) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (8) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (8) to (9) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (9) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-8 is released by the heat-releasing process f-8 of (M 1 +M 2 ) kg of working medium, or by an external heat source. The heat to be absorbed by M 1  kg of working medium in process 2-b is released by M kg of superheated vapor during the mixing process or an external heat source can be provided at the same time. The process b-3 of (M 1 +M) kg of working medium, the process 4-5 of (M 1 +M) kg of working medium and the process 5-6 of (M 1 +M 2 ) kg of working medium, the absorbed heat is usually provided by an external heat source, or by an external heat source and the heat-releasing process 7-f of (M 1 +M 2 ) kg of working medium (regeneration). 
     {circle around (2)} Heat-releasing processes: The heat released (M 1 +M 2 ) kg of working medium in process 7-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to 8 points. The heat-releasing process f-8 is completed. The heat released by (M 1 +H) kg of working medium in process 9-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process 8-a of M 2  kg of working medium and the pressurization process a-5 of (M 2 −M) kg of working medium are usually achieved by compressors. The depressurization (and expansion) process 3-4 of (M 1 +M) kg of working medium, the depressurization (and expansion) process 6-7 of (M 1 +M 2 ) kg of working medium and the depressurization (and expansion) process 8-9 of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 8  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts seventeen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (5) to (7) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (9) of the H kg of working medium, performing a pressurization process to set a state (9) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (6) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the (M 2 −M) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (9) to (c) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (c) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-9 is released by the heat-releasing process f-9 of (M 1 +M 2 ) kg of working medium, or by an external heat source. The heat to be absorbed by M 1  kg of working medium in process 2-b is released by M kg of superheated vapor during the mixing process or an external heat source can be provided at the same time. The process b-3 of (M 1 +M) kg of working medium, the process 4-5 of (M 1 +M) kg of working medium and the process 6-7 of (M 2 −M) kg of working medium, the absorbed heat is usually provided by an external heat source, or by an external heat source and the heat-releasing process 8-f of (M 1 +M 2 ) kg of working medium (regeneration). 
     {circle around (2)} Heat-releasing processes: The heat released (M 1 +M 2 ) kg of working medium in process 8-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to 9 points. The heat-releasing process f-9 is completed. The heat released by (M 1 +H) kg of working medium in process c-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process 9-a of M 2  kg of working medium and the pressurization process a-6 of (M 2 −M) kg of working medium are usually achieved by compressors. The depressurization (and expansion) process 3-4 of (M 1 +M) kg of working medium, the depressurization (and expansion) process 5-7 of (M 1 +M) kg of working medium, the depressurization (and expansion) process 7-8 of (M 1 +M 2 ) kg of working medium and the depressurization (and expansion) process 9-c of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 9  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts seventeen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption and vaporization process to set a state (4) to (7) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (9) of the H kg of working medium, performing a pressurization process to set a state (9) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (5) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 2 −M) kg of working medium, performing a depressurization process to set a state (6) to (7) of the (M 2 −M) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 ) kg of working medium, performing a heat-releasing process to set a state (8) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (9) to (c) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (c) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-9 is released by the heat-releasing process f-9 of (M 1 +M 2 ) kg of working medium, or by an external heat source. The heat to be absorbed by M 1  kg of working medium in process 2-b is released by M kg of superheated vapor during the mixing process or an external heat source can be provided at the same time. The process b-3 of (M 1 +M) kg of working medium, the process 4-7 of (M 1 +M) kg of working medium and the process 5-6 of (M 2 −M) kg of working medium, the absorbed heat is usually provided by an external heat source, or by an external heat source and the heat-releasing process 8-f of (M 1 +M 2 ) kg of working medium (regeneration). 
     {circle around (2)} Heat-releasing processes: The heat released (M 1 +M 2 ) kg of working medium in process 8-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to 9 points. The heat-releasing process f-9 is completed. The heat released by (M 1 +H) kg of working medium in process c-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process 9-a of M 2  kg of working medium and the pressurization process a-5 of (M 2 −M) kg of working medium are usually achieved by compressors. The depressurization (and expansion) process 3-4 of (M 1 +M) kg of working medium, the depressurization (and expansion) process 6-7 of (M 2 −M) kg of working medium, the depressurization (and expansion) process 7-8 of (M 1 +M 2 ) kg of working medium and the depressurization (and expansion) process 9-c of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 10  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts eighteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (5) to (9) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (6) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the (M 2 −M) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 2 −M) kg of working medium, performing a heat-releasing process to set a state (8) to (9) of the (M 2 −M) kg of working medium, performing a heat-releasing process to set a state (9) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-c is released by the heat-releasing process f-c of (M 1 +M 2 ) kg of working medium, or by an external heat source. The heat to be absorbed by M 1  kg of working medium in process 2-b is released by M kg of superheated vapor during the mixing process or an external heat source can be provided at the same time. The process b-3 of (M 1 +M) kg of working medium, the process 4-5 of (M 1 +M) kg of working medium and the process 6-7 of (M 2 −M) kg of working medium, the absorbed heat is usually provided by an external heat source, or by an external heat source, the heat-releasing process 8-9 of (M 2 −M) kg of working medium (regeneration) and the heat-releasing process 9-f of (M 1 +M 2 ) kg of working medium (regeneration). 
     {circle around (2)} Heat-releasing processes: The heat released (M 2 −M) kg of working medium in process 8-9 and (M 1 +M 2 ) kg of working medium in process 9-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to c points. The heat-releasing process f-c is completed. The heat released by (M 1 +H) kg of working medium in process d-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process c-a of M 2  kg of working medium and the pressurization process a-6 of (M 2 −M) kg of working medium are usually achieved by compressors. The depressurization (and expansion) process 3-4 of (M 1 +M) kg of working medium, the depressurization (and expansion) process 5-9 of (M 1 +M) kg of working medium, the depressurization (and expansion) process 7-8 of (M 2 −M) kg of working medium and the depressurization (and expansion) process c-d of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 11  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts eighteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (5) to (6) of the (M 1 +M) kg of working medium, performing a heat-releasing process to set a state (6) to (9) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (7) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (7) to (8) of the (M 2 −M) kg of working medium, performing a depressurization process to set a state (8) to (9) of the (M 2 −M) kg of working medium, performing a heat-releasing process to set a state (9) to (f) of the (M 1 +M 2 ) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-c is released by the heat-releasing process f-c of (M 1 +M 2 ) kg of working medium, or by an external heat source. The heat to be absorbed by M 1  kg of working medium in process 2-b is released by M kg of superheated vapor during the mixing process or an external heat source can be provided at the same time. The process b-3 of (M 1 +M) kg of working medium, the process 4-5 of (M 1 +M) kg of working medium and the process 7-8 of (M 2 −M) kg of working medium, the absorbed heat is usually provided by an external heat source, or by an external heat source, the heat-releasing process 6-9 of (M 1 +M) kg of working medium (regeneration) and the heat-releasing process 9-f of (M 1 +M 2 ) kg of working medium (regeneration). 
     {circle around (2)} Heat-releasing processes: The heat released (M 1 +M) kg of working medium in process 6-9 and (M 1 +M 2 ) kg of working medium in process 9-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to c points. The heat-releasing process f-c is completed. The heat released by (M 1 +H) kg of working medium in process d-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process c-a of M 2  kg of working medium and the pressurization process a-7 of (M 2 −M) kg of working medium are usually achieved by compressors. The depressurization (and expansion) process 3-4 of (M 1 +M) kg of working medium, the depressurization (and expansion) process 5-6 of (M 1 +M) kg of working medium, the depressurization (and expansion) process 8-9 of (M 2 −M) kg of working medium and the depressurization (and expansion) process c-d of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The T-s diagram of the single-working-medium vapor combined cycle in  FIG. 12  works as follows: 
     (1) From the perspective of the cycle&#39;s processes. 
     The working medium conducts nineteen processes: performing a pressurization process to set a state (1) to (2) of the M 1  kg of working medium, performing a heat-absorption process to set a state (2) to (b) of the M 1  kg of working medium, performing a heat-absorption and vaporization process to set a state (b) to (3) of the (M 1 +M) kg of working medium, performing a depressurization process to set a state (3) to (4) of the (M 1 +M) kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M 1 +M) kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (c) of the H kg of working medium, performing a pressurization process to set a state (c) to (a) of the M 2  kg of working medium, performing a heat-releasing and condensation process to set a state (a) to (b) of the M kg of working medium, performing a pressurization process to set a state (a) to (5) of the (M 2 −M) kg of working medium, performing a heat-absorption process to set a state (5) to (6) of the (M 1 +M 2 ) kg of working medium, performing a depressurization process to set a state (6) to (9) of the X kg of working medium, performing a heat-absorption process to set a state (6) to (7) of the (M 1 +M 2 −X) kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M 1 +M 2 −X) kg of working medium, performing a heat-releasing process to set a state (8) to (c) of the (M 1 +M 2 −X) kg of working medium, performing a mixing heat-releasing process to set a state (f) to (9) of the (M 1 +M 2 −X) kg of working medium and H kg of working medium, performing a mixing heat-releasing process to set a state (9) to (c) of the (M 1 +M 2 ) kg of working medium and H kg of working medium, performing a depressurization process to set a state (c) to (d) of the (M 1 +H) kg of working medium, performing a heat-releasing and condensation process to set a state (d) to (1) of the (M 1 +H) kg of working medium. 
     (2) From the perspective of energy conversion. 
     {circle around (1)} Heat absorption processes: The heat to be absorbed by H kg of working medium in process e-c is released by the heat-releasing process f-9 of (M 1 +M 2 −X) kg of working medium and the heat-releasing process 9-c of (M 1 +M 2 ) kg of working medium, or by an external heat source. The heat to be absorbed by M 1  kg of working medium in process 2-b is released by M kg of superheated vapor during the mixing process or an external heat source can be provided at the same time. The process b-3 of (M 1 +M) kg of working medium, the process 4-5 of (M 1 +M) kg of working medium and the process 6-7 of (M 1 +M 2 −X) kg of working medium, the absorbed heat is usually provided by an external heat source, or by an external heat source and the heat-releasing process 8-f of (M 1 +M 2 −X) kg of working medium (regeneration). 
     {circle around (2)} Heat-releasing processes: The heat released (M 1 +M 2 −X) kg of working medium in process 8-f can be sent externally to meet the corresponding heat demand, or used for the heat absorption demand of other processes in the combined cycle partially. (M 1 +M 2 −X) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 −X) kg of working medium is reduced to 9 points. The heat-releasing process f-9 is completed. (M 1 +M 2 ) kg of working medium mixes with H kg of working medium and releases eat to it. The temperature of (M 1 +M 2 ) kg of working medium is reduced to c points. The heat-releasing process 9-c is completed. The heat released by (M 1 +H) kg of working medium in process d-1 is usually released to the low-temperature heat sink, or be supplied to the heat user when cogeneration is applicable. 
     {circle around (3)} Energy conversion processes. The pressurization process 1-2 of M 1  kg of working medium and the pressurization process 1-e of H kg of working medium are usually achieved by pumps. The pressurization process c-a of M 2  kg of working medium and the pressurization process a-5 of (M 2 −M) kg of working medium are usually achieved by compressors. The depressurization (and expansion) process 3-4 of (M 1 +M) kg of working medium, the depressurization (and expansion) process 6-9 of X kg of working medium, the depressurization (and expansion) process 7-8 of (M 1 +M 2 −X) kg of working medium and the depressurization (and expansion) process c-d of (M 1 +H) kg of working medium are usually achieved by expanders. The total expansion work output is greater than the total pressurization work input; therefore, thermal energy is converted into power (the cycle&#39;s net work), and the single-working-medium vapor combined cycle is completed. 
     The technical effects of the present invention invention: The single-working-medium vapor combined cycle proposed by the present invention has the following effects and advantages: 
     (1) A basic theory of thermal energy (temperature difference) utilization has been created. 
     (2) The present invention greatly reduces the amount of heat absorbed in the phase-change region, and correspondingly increases the amount of heat absorbed in the high-temperature region. Therefore, the single-working-medium vapor combined cycle can achieve high efficiency. 
     (3) The present invention possesses simple methods, reasonable processes and good applicability. It is a common technology to realize the effective utilization of temperature differences. 
     (4) The present invention only uses a single working medium, which is easy to produce and store; The present invention can also reduce the operation cost and improve the flexibility of cycle regulation. 
     (5) The processes in the present invention are shared and reduced, which provides a theoretical basis for reducing equipment investment and improves efficiency. 
     (6) In the high temperature region or the variable temperature region, both the cycle&#39;s working medium and the heat source medium conduct vapor. Therefore, the temperature difference loss is reduced and the efficiency is improved. 
     (7) The present invention adopts the low-pressure and high-temperature operation mode in the high-temperature region; therefore, the contradiction among thermal efficiency, the working medium&#39;s parameters and the material&#39;s temperature resistance and pressure resistance abilities, which is common in traditional vapor power devices, can be resolved. 
     (8) Under the precondition of achieving a high thermal efficiency, the vapor power device provided in the present invention can operate at a low pressure. The present invention provides theoretical support for improving the safety of device operation. 
     (9) The present invention possesses a wide range of applicable working media. The present invention can match energy supply with demand well. It is flexible to match the working medium and the working parameters. 
     (10) The present invention expands the range of thermodynamic cycles for temperature difference utilization, and contributes to a higher-efficiency power generation of high-temperature heat sources and variable-temperature heat sources.