阅读说明：本技术 一种双透平气悬浮orc发电系统及控制方法 (Double-turbine gas suspension ORC power generation system and control method ) 是由 李健 杨晨辉 于 2020-06-23 设计创作，主要内容包括：本发明涉及一种双透平气悬浮ORC发电系统及控制方法,膨胀发电机组包括左侧透平、气悬浮轴承发电机以及右侧透平；左侧透平的入气口与右侧透平的入气口连通；左侧透平的出气口与右侧透平的出气口连通。蒸发器为组合式满液蒸发器；蒸发器的预热段出口与膨胀发电机组的发电机之间通过供液冷却管路与其相连；蒸发器的蒸发段出口与膨胀发电机组之间设有进气管路与其旁路。本发明中采用的膨胀机为对称的双透平气悬浮膨胀机,ORC系统实现无油运行结构简单,发电效率高；膨胀机配有旁通管路和控制阀门,可以有效保护膨胀机,进气量更大,相比同发电量的螺杆、透平ORC发电机组,尺寸小,系统效率高。(The invention relates to a double-turbine gas suspension ORC power generation system and a control method, wherein an expansion power generator set comprises a left turbine, a gas suspension bearing generator and a right turbine; the gas inlet of the left turbine is communicated with the gas inlet of the right turbine; the air outlet of the left turbine is communicated with the air outlet of the right turbine. The evaporator is a combined full liquid evaporator; the outlet of the preheating section of the evaporator is connected with a generator of the expansion generator set through a liquid supply cooling pipeline; an air inlet pipeline and a bypass thereof are arranged between the outlet of the evaporation section of the evaporator and the expansion generator set. The expansion machine adopted in the invention is a symmetrical double-turbine gas suspension expansion machine, and the ORC system realizes oil-free operation and has simple structure and high power generation efficiency; the expander is provided with the bypass pipeline and the control valve, so that the expander can be effectively protected, the air input is larger, and compared with a screw and a turbine ORC generator set with the same generating capacity, the expander is small in size and high in system efficiency.)

1. A double-turbine gas suspension ORC power generation system comprises an evaporator (1), an expansion generator set, a condenser (7), a working medium pump (8) and the evaporator (1) which are connected in a circulating mode; the method is characterized in that: the expansion generator set comprises a left turbine (4), a gas suspension bearing generator (6) and a right turbine (5); the air inlet of the left side turbine (4) is communicated with the air inlet of the right side turbine (5); the air outlet of the left side turbine (4) is communicated with the air outlet of the right side turbine (5);

the evaporator (1) is a combined flooded evaporator (1), an internal partition plate with liquid equalizing holes is arranged in an inner cavity of the combined flooded evaporator (1) to divide the evaporator (1) into an upper part and a lower part which are communicated, the upper part is a flooded evaporation section (18), and the lower part is a working medium preheating section (19);

an outlet of the preheating section of the evaporator is connected with a generator of the expansion generator set through a liquid supply cooling pipeline; the liquid supply cooling pipeline comprises an evaporator preheating section outlet, a pressure stabilizing pump electromagnetic valve (12), a pressure stabilizing pump (11) and a coolant inlet of the air suspension bearing generator (6) which are connected in sequence; the liquid supply cooling pipeline also comprises a bypass liquid supply cooling pipeline which is connected with a pressure stabilizing pump electromagnetic valve (12) and a pipeline where the pressure stabilizing pump is arranged in parallel; the bypass liquid supply cooling pipeline comprises a bypass pressure stabilizing pump electromagnetic valve (13); the pressure stabilizing pump electromagnetic valve (12) and the bypass pressure stabilizing pump electromagnetic valve (13) are in an interlocking state;

an air inlet pipeline is arranged between an outlet of an evaporation section of the evaporator (1) and the expansion generator set; the air inlet pipeline comprises an evaporation section outlet of the evaporator (1), an air inlet valve (2), a left turbine air inlet and a right turbine air inlet which are connected in sequence; the air inlet pipeline also comprises a bypass pipeline of the air inlet pipeline; and the bypass path of the air inlet pipeline comprises an evaporation section outlet of the evaporator (1), a bypass valve (3) and air outlets of two turbines which are sequentially connected.

2. A dual turbine gas suspended ORC power generation system according to claim 1, wherein: the expansion generator set is an integrated generator set; wherein the air suspension bearing generator is a variable-speed permanent magnet generator; the rotor in the variable-speed permanent magnet generator rotates along with the rotating shaft; two ends of the rotating shaft are respectively provided with impellers to form two turbines; the air inlet pipe of one turbine is connected with the air inlet pipe of the other turbine, and a left turbine and a right turbine are correspondingly formed.

3. A control method of a dual-turbine gas-suspended ORC power generation system according to any one of claims 1 or 2, characterized in that: the method comprises the following steps:

the method comprises the following steps: the system starts to operate, the air inlet valve is closed, the bypass valve is opened, the organic working medium steam enters the condenser through the bypass passage, is cooled by an external cold source in the condenser and condensed into liquid working medium, and then the liquid working medium is pumped into the preheating section of the combined type full liquid evaporator through the operation of the working medium pump; the high-pressure working medium is conveyed to the generator cavity and the air suspension bearing through a liquid supply cooling pipeline and is used for cooling the generator and supplying air to the air suspension bearing; detecting the air pressure of the organic working medium of the air inlet valve, and if the air pressure of the organic working medium of the air inlet valve is within the preset normal working air pressure, opening the air inlet valve and closing the bypass valve; organic working media simultaneously enter the left turbine and the right turbine to drive the generator to do work for power generation, exhaust gas after doing work enters the condenser to be condensed into liquid working media, and the liquid working media are pumped into the evaporator through the working media pump to complete the whole cycle;

step two: detecting the air pressure at the outlet of the preheating section of the evaporator, and if the air pressure is higher than the preset air pressure of the cooling pipeline, opening the electromagnetic valve of the pressure stabilizing pump and closing the electromagnetic valve of the bypass pressure stabilizing pump; if the air pressure is lower than the preset air pressure of the liquid supply cooling pipeline, closing the electromagnetic valve of the pressure stabilizing pump, opening the electromagnetic valve of the bypass pressure stabilizing pump, and keeping the pressure obtained by the air suspension bearing of the air suspension bearing generator stable through the pressure stabilizing pump;

step three: when the engine is stopped, the bypass valve is opened from a closed state, and the air inlet valve is closed from an open state; gaseous organic working medium enters a condenser through a bypass valve; and (4) stopping the working medium pump until the external heat source is closed and the evaporator does not exchange heat any more.

Technical Field

The invention relates to the technical field of industrial waste heat recovery and clean energy, in particular to a double-turbine gas suspension ORC power generation system and a control method.

Background

The Organic Rankine Cycle (ORC) is a technology for realizing Rankine cycle power generation by adopting a low-boiling-point organic working medium (such as a refrigerant) and completing the phase change of the organic working medium by utilizing a heat source with a lower temperature. The liquid organic working medium is heated by low-temperature waste heat in an evaporator (sometimes called a waste heat exchanger) to generate high-temperature high-pressure gas, the high-temperature high-pressure gas is expanded by an expander to drive a generator to generate electric energy, the low-temperature low-pressure gaseous working medium after passing through the expander is cooled into liquid in a condenser, and the liquid is pressurized by a refrigerant pump and sent back to the evaporator to complete a cycle. The ORC waste heat power generation technology has the problems of low cycle efficiency, less generated energy, high operation and maintenance cost and long investment return period. The expansion generator is a key device for restricting the performance of an ORC unit, and the expansion generator mainly comprises two types, namely a screw machine and a centripetal turbine expander. The screw machine can run at low speed to directly drive the power frequency generator to generate power, and the centripetal turbine rotates at high speed and drives the power frequency motor to generate power after being decelerated by the gear box.

Disclosure of Invention

1. The technical problem to be solved is as follows:

aiming at the technical problem, the invention provides a double-turbine gas suspension ORC power generation system, wherein an expansion power generation unit adopts a static pressure air bearing, so that the friction loss is lower and the power generation efficiency is high; by adopting a double-turbine structure, the working condition of high expansion ratio is practical, and the system efficiency is higher; the air inlet structure adopts a bypass loop to realize the protection of the expansion machine; the liquid supply cooling pipeline is provided with a pressure stabilizing pump with a bypass, and the on-off is controlled by an electromagnetic valve to ensure the stable pressure supply of the gas suspension bearing.

2. The technical scheme is as follows:

a double-turbine gas suspension ORC power generation system comprises an evaporator, an expansion generator set, a condenser, a working medium pump and an evaporator which are connected in a circulating manner; the method is characterized in that: the expansion generator set comprises a left turbine, a gas suspension bearing generator and a right turbine; the gas inlet of the left turbine is communicated with the gas inlet of the right turbine; and the air outlet of the left side turbine is communicated with the air outlet of the right side turbine.

The evaporator is a combined flooded evaporator, an internal partition plate with liquid equalizing holes is arranged in an inner cavity of the combined flooded evaporator to divide the evaporator into an upper part and a lower part which are communicated, the upper part is a flooded evaporation section, and the lower part is a working medium preheating section.

An outlet of the preheating section of the evaporator is connected with a generator of the expansion generator set through a liquid supply cooling pipeline; the liquid supply cooling pipeline comprises an evaporator preheating section outlet, a pressure stabilizing pump electromagnetic valve, a pressure stabilizing pump and a coolant inlet of the air suspension bearing generator which are connected in sequence; the liquid supply cooling pipeline also comprises a bypass liquid supply cooling pipeline which is connected with the pressure stabilizing pump electromagnetic valve and a pipeline where the pressure stabilizing pump is arranged in parallel; the bypass liquid supply cooling pipeline comprises a bypass pressure stabilizing pump electromagnetic valve; the pressure stabilizing pump electromagnetic valve and the bypass pressure stabilizing pump electromagnetic valve are in an interlocking state.

An air inlet pipeline is arranged between an outlet of an evaporation section of the evaporator and the expansion generator set; the air inlet pipeline comprises an evaporation section outlet, an air inlet valve, a left turbine air inlet and a right turbine air inlet of the evaporator which are connected in sequence; the air inlet pipeline also comprises a bypass pipeline of the air inlet pipeline; and the bypass path of the air inlet pipeline comprises an evaporation section outlet of the evaporator, a bypass valve and air outlets of the two turbines which are connected in sequence.

Further, the expansion generator set is an integrated generator set; wherein the air suspension bearing generator is a variable-speed permanent magnet generator; the rotor in the variable-speed permanent magnet generator rotates along with the rotating shaft; two ends of the rotating shaft are respectively provided with impellers to form two turbines; the air inlet pipe of one turbine is connected with the air inlet pipe of the other turbine, and a left turbine and a right turbine are correspondingly formed.

A control method of a dual-turbine gas suspension ORC power generation system comprises the following steps:

the method comprises the following steps: the system starts to operate, the air inlet valve is closed, the bypass valve is opened, the organic working medium steam enters the condenser through the bypass passage, is cooled by an external cold source in the condenser and condensed into liquid working medium, and then the liquid working medium is pumped into the preheating section of the combined type full liquid evaporator through the operation of the working medium pump; the high-pressure working medium is conveyed to the generator cavity and the air suspension bearing through a liquid supply cooling pipeline and is used for cooling the generator and supplying air to the air suspension bearing; detecting the air pressure of the organic working medium of the air inlet valve, and if the air pressure of the organic working medium of the air inlet valve is within the preset normal working air pressure, opening the air inlet valve and closing the bypass valve; organic working media simultaneously enter the left turbine and the right turbine to drive the generator to do work and generate power, exhaust gas after doing work enters the condenser to be condensed into liquid working media, and the liquid working media are pumped into the evaporator through the working media pump to complete the whole cycle.

Step two: detecting the air pressure at the outlet of the preheating section of the evaporator, and if the air pressure is higher than the preset air pressure of the cooling pipeline, opening the electromagnetic valve of the pressure stabilizing pump and closing the electromagnetic valve of the bypass pressure stabilizing pump; if the air pressure is lower than the preset air pressure of the liquid supply cooling pipeline, the electromagnetic valve of the pressure stabilizing pump is closed, the electromagnetic valve of the bypass pressure stabilizing pump is opened, and the pressure obtained by the air suspension bearing of the air suspension bearing generator is kept stable through the pressure stabilizing pump.

Step three: when the engine is stopped, the bypass valve is opened from a closed state, and the air inlet valve is closed from an open state; gaseous organic working medium enters a condenser through a bypass valve; and (4) stopping the working medium pump until the external heat source is closed and the evaporator does not exchange heat any more.

3. Has the advantages that:

(1) the expansion machine adopted in the invention is a symmetrical double-turbine gas suspension expansion machine, and the ORC system realizes oil-free operation and has simple structure and high power generation efficiency; the air inflow is larger, and compared with a screw and a turbine ORC generator set with the same generating capacity, the size is small, and the system efficiency is high.

(2) The expander bypass pipeline is arranged to realize the protection of the expander in the starting and stopping state; and a combined full-liquid evaporator with a liquid storage function is used for simultaneously supplying liquid to a liquid cooling pipeline to cool the motor and supply pressure to the air suspension bearing. And the combined evaporator with preheating and liquid storage functions can effectively reduce the size of the unit and reduce the equipment cost.

(3) The liquid supply cooling pipeline is provided with a pressure stabilizing pump with a bypass, so that the system can stably run under the working condition of large heat source fluctuation.

Drawings

FIG. 1 is a connection diagram of the overall structure of the present invention;

FIG. 2 is a schematic diagram of the modular flooded evaporator of the present invention.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 1 to fig. 2, a double-turbine gas suspension ORC power generation system comprises an evaporator 1, an expansion generator set, a condenser 7, a working medium pump 8 and the evaporator 1 which are connected in a circulating manner; the method is characterized in that: the expansion generator set comprises a left turbine 4, a gas suspension bearing generator 6 and a right turbine 5; the air inlet of the left turbine 4 is communicated with the air inlet of the right turbine 5; the outlet of the left turbine 4 is communicated with the outlet of the right turbine 5.

The evaporator 1 is a combined flooded evaporator 1, an internal partition plate with liquid equalizing holes is arranged in an inner cavity of the combined flooded evaporator 1 to divide the evaporator 1 into an upper part and a lower part which are communicated, the upper part is a flooded evaporation section 18, and the lower part is a working medium preheating section 19.

An outlet of the preheating section of the evaporator is connected with a generator of the expansion generator set through a liquid supply cooling pipeline; the liquid supply cooling pipeline comprises an evaporator preheating section outlet, a pressure stabilizing pump electromagnetic valve 12, a pressure stabilizing pump 11 and a coolant inlet of the air suspension bearing generator 6 which are connected in sequence; the liquid supply cooling pipeline also comprises a bypass liquid supply cooling pipeline which is connected with the pressure stabilizing pump electromagnetic valve 12 and a pipeline where the pressure stabilizing pump is arranged in parallel; the bypass liquid supply cooling pipeline comprises a bypass pressure stabilizing pump electromagnetic valve 13; the pressure stabilizing pump electromagnetic valve 12 and the bypass pressure stabilizing pump electromagnetic valve 13 are in an interlocking state.

An air inlet pipeline is arranged between an outlet of the evaporation section of the evaporator 1 and the expansion generator set; the air inlet pipeline comprises an evaporation section outlet of the evaporator 1, an air inlet valve 2, a left turbine air inlet and a right turbine air inlet which are connected in sequence; the air inlet pipeline also comprises a bypass pipeline of the air inlet pipeline; and the bypass path of the air inlet pipeline comprises an evaporation section outlet of the evaporator 1, a bypass valve 3 and air outlets of two turbines which are connected in sequence.

Further, the expansion generator set is an integrated generator set; wherein the air suspension bearing generator is a variable-speed permanent magnet generator; the rotor in the variable-speed permanent magnet generator rotates along with the rotating shaft; two ends of the rotating shaft are respectively provided with impellers to form two turbines; the air inlet pipe of one turbine is connected with the air inlet pipe of the other turbine, and a left turbine and a right turbine are correspondingly formed.

A control method of a dual-turbine gas suspension ORC power generation system comprises the following steps:

the method comprises the following steps: the system starts to operate, the air inlet valve is closed, the bypass valve is opened, the organic working medium steam enters the condenser through the bypass passage, is cooled by an external cold source in the condenser and condensed into liquid working medium, and then the liquid working medium is pumped into the preheating section of the combined type full liquid evaporator through the operation of the working medium pump; the high-pressure working medium is conveyed to the generator cavity and the air suspension bearing through a liquid supply cooling pipeline and is used for cooling the generator and supplying air to the air suspension bearing; detecting the air pressure of the organic working medium of the air inlet valve, and if the air pressure of the organic working medium of the air inlet valve is within the preset normal working air pressure, opening the air inlet valve and closing the bypass valve; organic working media simultaneously enter the left turbine and the right turbine to drive the generator to do work and generate power, exhaust gas after doing work enters the condenser to be condensed into liquid working media, and the liquid working media are pumped into the evaporator through the working media pump to complete the whole cycle.

Step two: detecting the air pressure at the outlet of the preheating section of the evaporator, and if the air pressure is higher than the preset air pressure of the cooling pipeline, opening the electromagnetic valve of the pressure stabilizing pump and closing the electromagnetic valve of the bypass pressure stabilizing pump; if the air pressure is lower than the preset air pressure of the liquid supply cooling pipeline, the electromagnetic valve of the pressure stabilizing pump is closed, the electromagnetic valve of the bypass pressure stabilizing pump is opened, and the pressure obtained by the air suspension bearing of the air suspension bearing generator is kept stable through the pressure stabilizing pump.

Step three: when the engine is stopped, the bypass valve is opened from a closed state, and the air inlet valve is closed from an open state; gaseous organic working medium enters a condenser through a bypass valve; and (4) stopping the working medium pump until the external heat source is closed and the evaporator does not exchange heat any more.