阅读说明：本技术 液位自动调节的orc发电装置及其调节方法 (ORC power generation device with automatic liquid level adjustment function and adjusting method thereof ) 是由 姚恩亮 于 2020-06-22 设计创作，主要内容包括：本发明公开了一种液位自动调节的ORC发电装置,包括通过主管道顺次连接的蒸发器、膨胀机、冷凝器和工质泵；所述蒸发器与外部的热源相连接,所述蒸发器上安装有蒸发器液位计；在所述蒸发器与工质泵之间设置有主路调节阀；在所述膨胀机的输出端与工质泵的输出端之间设置有旁路管道,在所述旁路管道上设置有旁路调节阀；在所述膨胀机上连接有动力单元。本发明所述的液位自动调节的ORC发电装置,在正常起机、运行、停机过程中,当热源参数波动范围较小时,液位偏离信号都会及时反馈给工质泵出口的主路调节阀和旁路调节阀,通过主路调节阀和旁路调节阀自动动作,使液位值回归设定值,保障ORC发电装置内部循环稳定。(The invention discloses an ORC power generation device with an automatic liquid level adjusting function, which comprises an evaporator, an expander, a condenser and a working medium pump, wherein the evaporator, the expander, the condenser and the working medium pump are sequentially connected through a main pipeline; the evaporator is connected with an external heat source, and an evaporator liquid level meter is mounted on the evaporator; a main path regulating valve is arranged between the evaporator and the working medium pump; a bypass pipeline is arranged between the output end of the expansion machine and the output end of the working medium pump, and a bypass regulating valve is arranged on the bypass pipeline; and the expander is connected with a power unit. According to the ORC power generation device with the automatic liquid level adjustment, disclosed by the invention, in the normal starting, running and stopping processes, when the fluctuation range of the heat source parameter is small, liquid level deviation signals are timely fed back to the main path adjusting valve and the bypass adjusting valve at the outlet of the working medium pump, and the liquid level value returns to a set value through the automatic actions of the main path adjusting valve and the bypass adjusting valve, so that the internal circulation stability of the ORC power generation device is ensured.)

1. The utility model provides a liquid level automatically regulated's ORC power generation facility which characterized in that: comprises an evaporator (2), an expander (4), a condenser (7) and a working medium pump (8) which are connected in sequence through a main pipeline;

the evaporator (2) is connected with an external heat source, and an evaporator liquid level meter (3) is installed on the evaporator (2);

a main path regulating valve (9) is arranged between the evaporator (2) and the working medium pump (8);

a bypass pipeline is arranged between the output end of the expansion machine (4) and the output end of the working medium pump (8), and a bypass regulating valve (6) is arranged on the bypass pipeline;

the expander (4) is connected with a power unit (5).

2. The automatic liquid level regulated ORC power plant of claim 1, wherein: the expander (4) is a turbine expander.

3. The automatic liquid level regulated ORC power plant of claim 1, wherein: the working medium pump (8) is a power frequency working medium pump.

4. The automatic liquid level regulated ORC power plant of claim 1, wherein: the working medium pump (8) is a variable-frequency working medium pump.

5. The automatic liquid level regulated ORC power plant of claim 1, wherein: the expander (4) is connected with the power unit (5) through a coupler.

6. A liquid level automatic regulating method of an ORC power generation device is characterized by comprising the following steps:

1) normal startup process of the ORC power generation device:

the method comprises the steps that firstly, a bypass regulating valve (6) at the outlet of a working medium pump (8) is fully opened, the working medium pump (8) is started, then a heat source inlet regulating valve (1) of an evaporator (2) is gradually opened, in order to maintain a set value at a liquid level value of an evaporator liquid level meter (3), the opening degree of a main path regulating valve (9) at the outlet of the working medium pump is automatically increased, and after the main path regulating valve (9) is fully opened, the opening degree of the bypass regulating valve (6) is automatically reduced;

2) normal operation process of the ORC power generation device:

when the heat source parameter of the evaporator (2) fluctuates, in order to maintain the set value at the liquid level value of the evaporator liquid level meter (3), the opening degree of the main path adjusting valve (9) at the outlet of the working medium pump is unchanged, and the bypass adjusting valve (6) is controlled by the liquid level value signal to automatically increase or decrease the opening degree;

3) normal shutdown process of the ORC power generation device:

the evaporator (2) is gradually closed by the heat source inlet regulating valve (1), the opening degree of the working medium pump outlet bypass regulating valve (6) is automatically increased for maintaining the set value at the liquid level value of the evaporator liquid level meter (3), and the opening degree of the main path regulating valve (9) is automatically reduced after the bypass regulating valve (6) is fully opened. And stopping the pump and the machine of the ORC power generation device until the regulating valve (9) is closed.

Technical Field

The invention belongs to the technical field of organic Rankine cycle power generation, and particularly relates to an ORC power generation device capable of automatically adjusting liquid level and an adjusting method.

Background

The Organic Rankine Cycle (ORC) power generation technology is more and more widely applied to industrial waste heat utilization industries such as solar energy and geothermal energy, and the single machine capacity is different from dozens of kilowatts to several megawatts. At present, in the field of industrial waste heat utilization, a power generation technology is a reasonable utilization scheme, and due to the characteristics of high condensation pressure, large display/latent heat ratio, adoption of dry working media and the like, compared with the traditional water vapor Rankine cycle, the power generation technology has the characteristics of simple system and high heat utilization rate in the field of low-temperature power generation.

The industrial waste heat is inevitably influenced by the operating condition of upstream equipment due to the working characteristics of the industrial waste heat, so the industrial waste heat is in a continuous fluctuation state, the operation control of an Organic Rankine Cycle (ORC) generator set is required to be simple as much as possible, the waste heat parameter change can be automatically adapted, manual active intervention control is not required, the automatic control method of the Organic Rankine Cycle (ORC) generator set commonly used at present is carried out by a liquid level regulation and rotating speed regulation mode (see CN201710611225.4), but the automatic regulation mode needs to constantly regulate the rotating speed of a working medium pump, and the service life of the working medium pump is greatly shortened.

Disclosure of Invention

The present invention aims to provide an ORC power generation device with automatic liquid level adjustment and an adjusting method thereof, so as to solve the problems in the background art.

In order to achieve the purpose, the invention provides the following technical scheme:

an ORC power generation device with automatic liquid level adjustment comprises an evaporator, an expander, a condenser and a working medium pump which are sequentially connected through a main pipeline;

the evaporator is connected with an external heat source, and an evaporator liquid level meter is mounted on the evaporator;

a main path regulating valve is arranged between the evaporator and the working medium pump;

a bypass pipeline is arranged between the output end of the expansion machine and the output end of the working medium pump, and a bypass regulating valve is arranged on the bypass pipeline;

and the expander is connected with a power unit.

In this embodiment, a turbine expander is preferably used as the expander.

Preferably, the working medium pump is a power frequency working medium pump.

Preferably, the working medium pump is a variable frequency working medium pump.

Preferably, the expander is coupled to the power unit by a coupling.

The embodiment of the invention also provides an automatic liquid level adjusting method of the ORC power generation device, which comprises the following steps:

1) normal startup process of the ORC power generation device:

firstly, a bypass regulating valve at the outlet of a working medium pump is fully opened, the working medium pump is started, then a heat source inlet regulating valve of an evaporator is gradually opened, the opening degree of a main path regulating valve at the outlet of the working medium pump is automatically increased in order to maintain a set value at a liquid level value of an evaporator liquid level meter, and the opening degree of the bypass regulating valve is automatically reduced after the main path regulating valve is fully opened;

2) normal operation process of the ORC power generation device:

when the heat source parameter of the evaporator fluctuates, in order to maintain the set value at the liquid level value of the liquid level meter of the evaporator, the opening of the main regulating valve at the outlet of the working medium pump is unchanged, and the bypass regulating valve (6) is controlled by a liquid level value signal to automatically increase or decrease the opening;

3) normal shutdown process of the ORC power generation device:

the heat source inlet regulating valve of the evaporator is gradually closed, the opening degree of the bypass regulating valve at the outlet of the working medium pump is automatically increased in order to maintain a set value at the liquid level value of the liquid level meter of the evaporator, and the opening degree of the main path regulating valve is automatically reduced after the bypass regulating valve is fully opened. And stopping the pump and the machine of the ORC power generation device until the regulating valve is closed.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the ORC power generation device with the automatic liquid level adjustment, in the normal starting, running and stopping processes of the ORC power generation device, when the fluctuation range of the heat source parameter is small (for example, when the fluctuation range of the heat source parameter is less than or equal to minus or plus 20 percent, a liquid level deviation signal is timely fed back to a main path adjusting valve and a bypass adjusting valve at the outlet of a working medium pump, the main path adjusting valve and the bypass adjusting valve automatically act to enable a liquid level value to return to a set value, and the internal circulation of the ORC power generation device is guaranteed to be stable; when the fluctuation of the heat source parameters is large (for example, when the fluctuation range of the heat source parameters is more than or equal to +/-20%), the heat source inlet regulating valve on the pipeline connecting the evaporator and the external heat source participates in the automatic regulation.

(2) According to the automatic liquid level adjusting method for the ORC power generation device, the bypass pipeline is arranged on the main pipeline, and the main pipeline adjusting valve on the main pipeline and the bypass adjusting valve on the bypass pipeline are used for cooperative adjustment, so that the internal circulation stability of the ORC power generation device can be realized without frequency conversion adjustment (namely rotating speed adjustment) of the working medium pump, and the service life of the working medium pump is greatly prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of an ORC power plant with automatic level regulation according to an embodiment of the present invention;

reference numerals:

1. the system comprises a heat source inlet adjusting valve, 2, an evaporator, 3, an evaporator liquid level meter, 4, an expander, 5, a generator, 6, a bypass adjusting valve, 7, a condenser, 8, a working medium pump, 9 and a main path adjusting valve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention.

Referring to fig. 1, an embodiment of the present invention provides an ORC power generation apparatus with automatic liquid level adjustment, specifically including an evaporator 2, an expander 4, a condenser 7, and a working medium pump 8, which are connected in sequence through a main pipe; the evaporator 2 is connected with an external heat source, a heat source inlet adjusting valve 1 is arranged on a pipeline connecting the evaporator 2 with the external heat source (not marked in the figure), and the evaporator 2 is provided with an evaporator liquid level meter 3. The parameters of the heat source in the evaporator 2 correspond to the parameters of the working medium one by one, when the parameters of the heat source change, the heat exchange balance in the evaporator 2 is broken, the two parameters cannot correspond to each other one by one, the change of the liquid level in the evaporator 2 is directly reflected, and at the moment, the evaporator liquid level meter 3 can change continuously. A main path regulating valve 9 is arranged between the evaporator 2 and the working medium pump 6; a bypass line (not shown) is provided between the output of the expansion machine 4 and the output of the working medium pump 8, and a bypass control valve 6 is provided on the bypass line. When the heat source parameters fluctuate, the liquid level deviation signals can be timely fed back to the main path regulating valve 9 and the bypass regulating valve 6 at the outlet of the working medium pump 8, and the liquid level value on the evaporator liquid level meter 3 returns to the set value through the automatic action of the main path regulating valve 9 and the bypass regulating valve 6, so that the internal circulation stability of the ORC power generation device is guaranteed.

In a further optimized embodiment, the expander 4 is a turbine expander, and the expander 4 is connected with the power unit 5 through a coupler. The power unit 5 is preferably a generator. The working medium pump 8 can be a power frequency working medium pump or a variable frequency working medium pump, and in the embodiment, is preferably a power frequency working medium pump.

The embodiment of the invention also provides an ORC power generation device adjusting method capable of automatically adjusting the liquid level, which comprises the following steps:

1) normal startup process of the ORC power generation device:

firstly, fully opening a bypass regulating valve 6 at an outlet of a working medium pump 8 to start the working medium pump 8, then gradually opening a heat source inlet regulating valve 1 of an evaporator 2, and enabling a heat source to enter the evaporator 2; at the moment, the liquid level value of the evaporator liquid level meter 3 is lower than a set value, and in order to keep the liquid level value of the evaporator liquid level meter 3 always at the set value, the system automatically increases the opening degree of a main path regulating valve 9 on an outlet pipeline of a working medium pump 8; when the main path regulating valve 9 is fully opened, at the moment, the liquid level value of the evaporator liquid level meter 3 is higher than a set value, the system automatically reduces the opening degree of the bypass regulating valve 6, and the liquid level value of the evaporator liquid level meter 3 is always kept at the set value. In this embodiment, the evaporator liquid level set value is determined according to the outer diameter of the shell-and-tube evaporator cylinder, the arrangement of the tube bundles in the tubes, the phase state change in the heat transfer process of the shell-side medium of the heat exchanger, and the like, and the evaporator liquid level set value is taken at the critical point of the shell-side medium of the evaporator changing from a saturated liquid phase to a saturated gas phase, so that a sufficiently high liquid level value is ensured, and the sufficient heat transfer space of the shell-side medium in the heat exchanger in the overheating process is not influenced. The opening adjustable ranges are different due to different flow characteristic selections of the main path adjusting valve 9 and the bypass adjusting valve 6. In this embodiment, the main regulating valve 9 and the bypass regulating valve 6 preferably have equal percentage flow characteristics, and the adjustable range of the general opening degree is 20% to 80%.

2) Normal operation process of the ORC power generation device:

when the heat source parameters of the evaporator 2 fluctuate, in order to keep the liquid level value of the evaporator liquid level meter 3 to maintain a set value, the opening degree of the main regulating valve 9 at the outlet of the working medium pump is unchanged, and the bypass regulating valve 6 is controlled by a liquid level value signal to automatically increase or decrease the opening degree. Specifically, in the embodiment, when the liquid level value of the evaporator liquid level meter 3 is lower than the set value, the opening degree of the main path regulating valve 9 is kept unchanged, and the opening degree of the bypass regulating valve 6 is reduced; and when the liquid level value of the evaporator liquid level meter 3 is higher than the set value, keeping the opening degree of the main path regulating valve 9 unchanged, and increasing the opening degree of the bypass regulating valve 6. The automatic adjustment of the system ensures that the level value of the evaporator liquid level meter 3 is always maintained at a set value.

3) Normal shutdown process of the ORC power generation device:

a heat source inlet regulating valve 1 on an inlet pipeline of the evaporator 2 is gradually closed, at the moment, the liquid level value of the evaporator liquid level meter 3 is lower than a set value, and the opening degree of a working medium pump outlet bypass regulating valve 6 is automatically increased in order to maintain the set value at the liquid level value of the evaporator liquid level meter 3; and when the bypass regulating valve 6 is fully opened, automatically reducing the opening degree of the main path regulating valve 9 until the regulating valve 9 is closed, and stopping the pump and the machine of the ORC power generation device.

Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the invention as defined by the appended claims. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.