Intermediate liquid supplementing type organic Rankine cycle system

Abstract

The invention relates to the technical field of energy conversion and utilization, and discloses an intermediate liquid supplementing type organic Rankine cycle system which comprises a working medium storage tank, a working medium in the working medium storage tank is conveyed into an evaporator, the working medium forms steam in the evaporator through an external heat source and is conveyed into a turbine, the output end of the turbine is communicated with a condenser, and the output end of the turbine is communicated with the condenser. The condenser is communicated with the working medium storage tank; the liquid supplementing system comprises a conveying unit and a control unit, the working medium storage tank is communicated with the evaporator through the conveying unit, and the conveying unit and the evaporator are respectively connected with the control unit. According to the invention, the dryness can be flexibly adjusted in the evaporation process of the working medium, the phenomenon that the working medium in the evaporator is dried up is effectively inhibited, and the heat transfer performance and variable working condition operation performance of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conversion and utilization, and in particular to an intermediate liquid-replenishing organic Rankine cycle system. Background Art

[0002] The organic Rankine cycle (ORC) uses low-boiling-point organic matter as the working fluid. It primarily consists of an evaporator, expander, condenser, and working fluid pump. As a thermal power generation system that recovers waste heat, the organic working fluid's low boiling point, low freezing point, high condensing pressure, high density, and low specific volume make it a highly promising technology for improving energy efficiency and reducing carbon emissions, with widespread application.

[0003] As a key component of the organic Rankine cycle system, the evaporator absorbs heat from the heat source, vaporizing the pressurized working fluid until it is superheated and then feeding it into the expander to perform work. The heat exchange efficiency of the evaporator has a significant impact on the thermal economic performance of the entire system. During the evaporation process of the organic working fluid, the dryness continuously increases. If the working fluid dryness is too high, a "dry-out" phenomenon will occur, resulting in a deterioration in the heat transfer between the working fluid and the heat source, a decrease in the convective heat transfer coefficient on the working fluid side, and thus affecting the thermal economic performance of the entire system. The use of intermediate rehydration technology can effectively prevent the occurrence of "dry-out". That is, the dryness of the organic working fluid is adjusted by rehydration in the evaporator, alleviating the deterioration of the heat transfer process and improving the thermal economic performance of the system.

[0004] Therefore, there is an urgent need for an intermediate liquid-replenishing organic Rankine cycle system to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide an intermediate liquid-replenishing organic Rankine cycle system to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above-mentioned object, the present invention provides the following solution: The present invention provides an intermediate liquid-replenishing organic Rankine cycle system, comprising:

[0007] a working fluid storage tank, wherein the working fluid in the working fluid storage tank is transported to an evaporator, wherein the working fluid is converted into steam by an external heat source in the evaporator and transported to a turbine, wherein an output end of the turbine is connected to a condenser, and the condenser is connected to the working fluid storage tank;

[0008] The fluid replenishment system includes a delivery unit and a control unit. The working fluid storage tank is connected to the evaporator through the delivery unit. The delivery unit and the evaporator are respectively connected to the control unit.

[0009] According to an intermediate liquid-replenishing organic Rankine cycle system provided by the present invention, the delivery unit includes a delivery pipeline, both ends of which are respectively connected to the working fluid storage tank and the evaporator, and a liquid-replenishing pump is installed on the delivery pipeline.

[0010] According to an intermediate rehydration type organic Rankine cycle system provided by the present invention, a check valve is installed on the delivery pipeline, and the check valve is located between the rehydration pump and the working fluid storage tank.

[0011] According to an intermediate liquid-replenishing organic Rankine cycle system provided by the present invention, the control unit includes a controller, and the liquid-replenishing pump and the evaporator are electrically connected to the controller respectively.

[0012] According to the intermediate liquid-replenishing organic Rankine cycle system provided by the present invention, the working fluid storage tank is connected to the evaporator via a working fluid pump.

[0013] According to an intermediate liquid-replenishing organic Rankine cycle system provided by the present invention, the working medium is converted into steam in the evaporator by an external heat source.

[0014] According to the intermediate liquid-replenishing organic Rankine cycle system provided by the present invention, the working fluid in the condenser releases heat through an external cooling medium.

[0015] According to the intermediate liquid-filling organic Rankine cycle system provided by the present invention, the turbine is connected to a generator.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects:

[0017] The present invention provides an intermediate-liquid replenishment organic Rankine cycle system. When in use, a low-boiling-point organic substance serves as the circulating working fluid. High-temperature, high-pressure steam forms in the evaporator, which then enters the turbine to perform work. The working fluid at the turbine outlet enters the condenser, where it is converted back into a low-temperature liquid for recycling. When a control unit detects changes in the dryness of the working fluid in the evaporator, it controls a delivery unit to replenish the working fluid in the evaporator. This application allows for flexible adjustment of the working fluid's dryness during evaporation, effectively preventing the "drying out" of the working fluid in the evaporator and improving the system's heat transfer performance and variable operating performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work.

[0019] Figure 1It is a schematic diagram of the overall structure of the present invention;

[0020] Among them, 1. working fluid pump; 2. evaporator; 3. turbine; 4. generator; 5. condenser; 6. working fluid storage tank; 7. external heat source; 8. external cooling medium; 9. controller; 10. check valve; 11. fluid replenishment pump. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Reference Figure 1 The present invention provides an intermediate liquid-replenishing organic Rankine cycle system, comprising:

[0024] A working fluid storage tank 6 is provided. The working fluid in the working fluid storage tank 6 is transported to the evaporator 2. The working fluid is converted into steam in the evaporator 2 by an external heat source 7 and is transported to the turbine 3. The output end of the turbine 3 is connected to the condenser 5, and the condenser 5 is connected to the working fluid storage tank 6.

[0025] The fluid replenishing system includes a delivery unit and a control unit. The working fluid storage tank 6 is connected to the evaporator 2 through the delivery unit. The delivery unit and the evaporator 2 are respectively connected to the control unit.

[0026] In one embodiment of the present invention, low-boiling-point organic matter is used as a circulating working fluid during use, high-temperature and high-pressure steam is formed in the evaporator 2, and enters the turbine 3 to perform work. The working fluid at the outlet of the turbine 3 enters the condenser 5, and becomes a low-temperature liquid again for recycling. When the control unit monitors the change in the dryness of the working fluid in the evaporator 2, the working fluid is replenished into the evaporator 2 through the control-set delivery unit.

[0027] As an optional embodiment, the delivery unit includes a delivery pipeline, both ends of which are connected to the working fluid storage tank 6 and the evaporator 2 respectively, and a liquid replenishing pump 11 is installed on the delivery pipeline.

[0028] In one embodiment of the present invention, the liquid replenishing pump 11 serves as a liquid replenishing device, which can actively replenish the liquid working medium into the evaporator 2 when the dryness of the low-temperature liquid working medium in the evaporator 2 is 0.

[0029] As an optional embodiment, a check valve 10 is installed on the delivery pipeline, located between the rehydration pump 11 and the working fluid storage tank 6. When the system shuts down or the rehydration pump 11 stops operating, the high-pressure working fluid remaining in the evaporator 2 may generate reverse pressure due to temperature changes. The check valve 10 automatically closes, protecting the rehydration pump 11 from high-pressure shocks and extending the life of the equipment.

[0030] In one embodiment of the present invention, the check valve 10 can prevent the high-pressure steam or working fluid in the evaporator 2 from flowing back to the replenishment pump 11 and the working fluid storage tank 6, thereby avoiding pressure shock or working fluid contamination caused by backflow in the replenishment system.

[0031] As an optional embodiment, the control unit includes a controller 9 , and the rehydration pump 11 and the evaporator 2 are electrically connected to the controller 9 respectively.

[0032] In one embodiment of the present invention, the controller 9 monitors the change in the dryness of the working medium in the evaporator 2 in real time and determines whether liquid replenishment is needed accordingly. The controller 9 is connected to the liquid replenishment pump 11 to control the opening and closing of the liquid replenishment system.

[0033] As an optional implementation, the working fluid storage tank 6 is connected to the evaporator 2 through the working fluid pump 1 .

[0034] In one embodiment of the present invention, the working fluid pump 1 serves as the main circulation power source and is responsible for pressurizing the liquid working fluid in the working fluid storage tank 6 and delivering it to the evaporator 2, ensuring that the working fluid fully absorbs heat and vaporizes in the evaporator to form high-pressure steam to drive the turbine 3 to perform work.

[0035] The selection of the working fluid pump 1 needs to match the system design flow and head. The working fluid pump 1 and the fluid replenishment pump 11 form a dual pump collaboration: the main pump maintains the basic circulation flow, and the fluid replenishment pump 11 responds to the fluid replenishment demand.

[0036] As an optional implementation, the working medium is converted into steam in the evaporator 2 by an external heat source 7 .

[0037] In one embodiment of the present invention, low-boiling-point organic matter is used as the circulating working fluid. In the evaporator 2, the working fluid absorbs heat provided by the external heat source 7 to form high-temperature and high-pressure steam, which enters the turbine 3 to perform work.

[0038] As an optional implementation, the working medium in the condenser 5 releases heat through the external cooling medium 8 .

[0039] In one embodiment of the present invention, an external cooling medium 8 (such as air, water, or refrigerant) absorbs the latent heat of the working fluid vapor in the condenser 5, condensing it into a liquid state and completing the closed cycle. Cooling efficiency directly affects the system's circulating pressure and turbine output.

[0040] As an optional embodiment, the turbine 3 is connected to a generator 4 .

[0041] In one embodiment of the present invention, turbine 3 converts the thermal energy of high-pressure steam into mechanical energy, driving generator 4 for power generation. This achieves direct conversion of thermal energy into electrical energy and serves as the core energy output unit of the ORC system. The type of turbine 3 must be optimized based on the properties of the working fluid and the system scale. The efficiency and load matching capability of generator 4 affect the overall power generation of the system. The use of a permanent magnet synchronous generator improves efficiency and, through a frequency converter, enables flexible connection to the power grid, adapting to distributed energy applications.

[0042] In one embodiment of the present invention, the rehydration branch can be set to multiple groups, and the controller 9 performs real-time detection of the dryness in the evaporator 2 to determine whether rehydration is needed, the rehydration position and the rehydration amount. In special cases, multiple rehydration can be performed at different positions along the evaporator 2.

[0043] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0044] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. An intermediate liquid-replenishing organic Rankine cycle system, characterized in that: include: a working fluid storage tank (6), wherein the working fluid in the working fluid storage tank (6) is transported to the evaporator (2) to form steam and then transported to the turbine (3); an output end of the turbine (3) is connected to a condenser (5), and the condenser (5) is connected to the working fluid storage tank (6); The fluid replenishment system comprises a delivery unit and a control unit, wherein the working fluid storage tank (6) is connected to the evaporator (2) via the delivery unit, and the delivery unit and the evaporator (2) are respectively connected to the control unit.

2. The intermediate liquid-replenishing organic Rankine cycle system according to claim 1, characterized in that: The delivery unit comprises a delivery pipeline, the two ends of which are respectively connected to the working medium storage tank (6) and the evaporator (2), and a fluid replenishment pump (11) is installed on the delivery pipeline.

3. The intermediate liquid-replenishing organic Rankine cycle system according to claim 2, characterized in that: A check valve (10) is installed on the delivery pipeline, and the check valve (10) is located between the fluid infusion pump (11) and the working fluid storage tank (6).

4. The intermediate liquid-replenishing organic Rankine cycle system according to claim 2, characterized in that: The control unit includes a controller (9), and the rehydration pump (11) and the evaporator (2) are electrically connected to the controller (9) respectively.

5. The intermediate liquid-replenishing organic Rankine cycle system according to claim 1, characterized in that: The working fluid storage tank (6) is connected to the evaporator (2) via a working fluid pump (1).

6. The intermediate liquid-replenishing organic Rankine cycle system according to claim 1, characterized in that: The working medium forms steam in the evaporator (2) through an external heat source (7).

7. The intermediate liquid-replenishing organic Rankine cycle system according to claim 1, characterized in that: The working medium in the condenser (5) releases heat through an external cooling medium (8).

8. The intermediate liquid-replenishing organic Rankine cycle system according to claim 1, characterized in that: The turbine (3) is connected to a generator (4).

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