阅读说明：本技术 一种冷凝解耦与梯级蒸发耦合冷热电联产系统 (Combined cooling, heating and power system with condensation decoupling and cascade evaporation coupling ) 是由 李太禄 孔祥飞 刘青华 孟楠 贾亚楠 秦浩森 于 2020-04-28 设计创作，主要内容包括：本发明公开了一种冷凝解耦与梯级蒸发耦合冷热电联产系统,包括第一蒸发器、第一膨胀机、第二膨胀机、冷凝器、第一流量计、第一工质泵、第二蒸发器、第二流量计、第二工质泵、第三流量计、测功机、换热器、第四流量计、第五流量计、节流阀、第三蒸发器、压缩机、第六流量计、第七流量计、空压机、空气冷却器、第三膨胀机。本系统将ORC发电系统、蒸气压缩制冷系统、冷凝与环境解耦冷却系统和供热系统四个子系统相结合。ORC发电系统、蒸气压缩制冷系统、冷凝与环境解耦冷却系统通过共用冷凝器耦合在一起,且蒸气压缩制冷系统与ORC发电系统可以共用同一种有机工质,实现了冷凝解耦、梯级蒸发与非共沸混合工质变温相变三者相耦合。(The invention discloses a condensation decoupling and cascade evaporation coupling combined cooling, heating and power generation system which comprises a first evaporator, a first expander, a second expander, a condenser, a first flow meter, a first working medium pump, a second evaporator, a second flow meter, a second working medium pump, a third flow meter, a dynamometer, a heat exchanger, a fourth flow meter, a fifth flow meter, a throttle valve, a third evaporator, a compressor, a sixth flow meter, a seventh flow meter, an air compressor, an air cooler and a third expander. The system combines an ORC power generation system, a vapor compression refrigeration system, a condensation and environment decoupling cooling system and a heat supply system. The ORC power generation system, the vapor compression refrigeration system and the condensation and environment decoupling cooling system are coupled together through a shared condenser, and the vapor compression refrigeration system and the ORC power generation system can share the same organic working medium, so that the coupling of condensation decoupling, step evaporation and non-azeotropic mixed working medium temperature-changing phase change is realized.)

1. A combined cooling, heating and power system with condensation decoupling and cascade evaporation coupling is characterized by comprising a first evaporator, a first expander, a second expander, a condenser, a first flow meter, a first working medium pump, a second evaporator, a second flow meter, a second working medium pump, a third flow meter, a dynamometer, a heat exchanger, a fourth flow meter, a fifth flow meter, a throttle valve, a third evaporator, a compressor, a sixth flow meter, a seventh flow meter, an air compressor, an air cooler and a third expander;

the heat source inlet of the first evaporator is communicated with an external heat source, the heat source outlet is communicated with the heat source inlet of the second evaporator through a third flowmeter, and the working medium outlet is communicated with the inlet of the first expander; the outlet of the first expander is communicated with the inlet of the second expander; the outlet of the second expander is communicated with the working medium inlet of the condenser; an air inlet of the condenser is communicated with an outlet of the third expansion machine, and an air outlet of the condenser is used for supplying air; a working medium outlet of the condenser is respectively communicated with an inlet of the first working medium pump through a first flow meter and is communicated with an inlet of the throttle valve through a fifth flow meter;

the outlet of the first working medium pump is communicated with the working medium inlet of the second evaporator; a first working medium outlet of the second evaporator is communicated with an inlet of the second expander; a second working medium outlet of the second evaporator is communicated with an inlet of a second working medium pump through a second flowmeter, and an outlet of the second working medium pump is communicated with a working medium inlet of the first evaporator; a heat source outlet of the second evaporator is communicated with a heat source inlet of the heat exchanger, and the heat source outlet of the heat exchanger discharges the heat source after heat exchange to the outside; a heat supply inlet of the heat exchanger is communicated with an external water source through a fourth flowmeter, and a heat supply outlet is used for supplying heat;

the outlet of the throttle valve is communicated with the working medium inlet of the third evaporator; a chilled water inlet of the third evaporator is communicated with chilled water return water through a sixth flowmeter, and a chilled water outlet is used for providing cold energy; the working medium outlet of the third evaporator is communicated with the inlet of the compressor, and the outlet of the compressor is communicated with the working medium inlet of the condenser;

an inlet of the air compressor is communicated with outdoor air through a seventh flowmeter, and an outlet of the air compressor is communicated with an inlet of the air cooler; the outlet of the air cooler is communicated with the inlet of the third expansion machine, and the air compressor is coaxially connected with the third expansion machine.

2. The combined cooling, heating and power system as claimed in claim 1, wherein the third evaporator is located above the throttle valve.

3. The combined cooling, heating and power system according to claim 1, wherein the first expander, the second expander and the dynamometer are coaxially connected.

Technical Field

The invention belongs to the field of heat energy engineering, and particularly relates to a combined cooling, heating and power system with condensation decoupling and cascade evaporation coupling.

Background

Organic Rankine Cycle (ORC) is a way of using Organic working media as thermodynamic Cycle, and uses geothermal energy, solar energy or other low-grade heat sources to heat the Organic working media to generate steam, so as to drive a turbo generator set to generate electricity. The inlet temperature of the heat source fluid of the organic rankine cycle is usually above 80 ℃, the evaporator is the part generating the maximum irreversible loss in the ORC, and especially under the condition of high enthalpy drop of the inlet and the outlet of the heat source fluid, the irreversible loss of the evaporator is further increased. Therefore, the multi-stage evaporators are reasonably arranged, so that the heat source fluid is connected with the evaporators at all stages, the liquid working medium is heated into saturated or superheated steam with different pressures in the evaporators at all stages, and good temperature matching between the heat source and the working medium is realized.

The lithium bromide absorption refrigeration cycle does not need a compressor to provide power for the cycle, accordingly, the input of system electric energy is reduced, and the exhausted waste heat is used as an auxiliary heat source of the low-pressure evaporator of the ORC, so that the evaporation load of the ORC is increased, and the net generating power is increased.

The combined cooling heating and power system can save energy and protect environment, has extremely high economic and social benefits, and is a necessary choice for sustainable development in the energy field. However, most of the existing combined cooling heating and power systems combine a gas turbine with a steam rankine cycle and absorption refrigeration to perform combined cooling, heating and power, and although high-grade energy can be obtained by combustion of fuel, the exhaust heat temperature of the system is still high, and the system cannot be used as the best thing. At the same time, the combustion of fossil fuels also causes a certain degree of pollution to the environment.

The organic Rankine cycle power generation can well avoid the problem of the traditional combined cooling heating and power system. The medium-low temperature heat source is common and easy to obtain in life, has low taste but huge reserves, and can be used as the heat source of a co-production system. Meanwhile, the organic working medium is utilized, the requirement of the organic Rankine cycle on the lowest temperature of a heat source is greatly reduced, the organic Rankine cycle can be well matched with a medium-low temperature heat source by selecting the appropriate working medium, and the cooling capacity, the heat capacity and the electric quantity can be efficiently provided by combining absorption refrigeration, so that the best use is realized, and the energy saving and the environmental protection are realized.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to solve the technical problem of providing a combined cooling, heating and power system with condensation decoupling and cascade evaporation coupling.

The invention provides a condensation decoupling and cascade evaporation coupling combined cooling, heating and power system, which is characterized by comprising a first evaporator, a first expander, a second expander, a condenser, a first flow meter, a first working medium pump, a second evaporator, a second flow meter, a second working medium pump, a third flow meter, a dynamometer, a heat exchanger, a fourth flow meter, a fifth flow meter, a throttle valve, a third evaporator, a compressor, a sixth flow meter, a seventh flow meter, an air compressor, an air cooler and a third expander, wherein the first evaporator is connected with the first working medium pump;

the heat source inlet of the first evaporator is communicated with an external heat source, the heat source outlet is communicated with the heat source inlet of the second evaporator through a third flowmeter, and the working medium outlet is communicated with the inlet of the first expander; the outlet of the first expander is communicated with the inlet of the second expander; the outlet of the second expander is communicated with the working medium inlet of the condenser; an air inlet of the condenser is communicated with an outlet of the third expansion machine, and an air outlet of the condenser is used for supplying air; a working medium outlet of the condenser is respectively communicated with an inlet of the first working medium pump through a first flow meter and is communicated with an inlet of the throttle valve through a fifth flow meter;

the outlet of the first working medium pump is communicated with the working medium inlet of the second evaporator; a first working medium outlet of the second evaporator is communicated with an inlet of the second expander; a second working medium outlet of the second evaporator is communicated with an inlet of a second working medium pump through a second flowmeter, and an outlet of the second working medium pump is communicated with a working medium inlet of the first evaporator; a heat source outlet of the second evaporator is communicated with a heat source inlet of the heat exchanger, and the heat source outlet of the heat exchanger discharges the heat source after heat exchange to the outside; a heat supply inlet of the heat exchanger is communicated with an external water source through a fourth flowmeter, and a heat supply outlet is used for supplying heat;

the outlet of the throttle valve is communicated with the working medium inlet of the third evaporator; a chilled water inlet of the third evaporator is communicated with chilled water return water through a sixth flowmeter, and a chilled water outlet is used for providing cold energy; the working medium outlet of the third evaporator is communicated with the inlet of the compressor, and the outlet of the compressor is communicated with the working medium inlet of the condenser;

an inlet of the air compressor is communicated with outdoor air through a seventh flowmeter, and an outlet of the air compressor is communicated with an inlet of the air cooler; the outlet of the air cooler is communicated with the inlet of the third expansion machine, and the air compressor is coaxially connected with the third expansion machine.

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

(1) in terms of system design, the system combines four subsystems, namely an ORC power generation system, a vapor compression refrigeration system, a condensation and environment decoupling cooling system and a heating system. The ORC power generation system, the vapor compression refrigeration system and the condensation and environment decoupling cooling system are coupled together through the shared condenser, and the vapor compression refrigeration system and the ORC power generation system can share the same organic working medium, so that the coupling of condensation decoupling, step evaporation and non-azeotropic mixed working medium temperature-changing phase change is realized, and the whole system is compact in structure and easy to adjust and control.

(2) The organic Rankine cycle system has the advantages that condensation decoupling and variable-working-medium-flow gradient evaporation are applied to the organic Rankine cycle aiming at the characteristic that the condensation temperature of the organic Rankine cycle is relatively high, condensation and environment decoupling and variable-working-medium-flow gradient evaporation cooperation are achieved, thermoelectric conversion performance of the organic Rankine cycle is improved, the purposes of refrigerating and heating are achieved while power is generated, combined cooling, heating and power is achieved, and the problem that the power generation performance of a single organic Rankine cycle is poor is solved.

(3) In the aspect of dynamic regulation and control of the system, a dynamic regulation and control method for coupling non-azeotropic mixed working medium component regulation and variable working medium flow gradient evaporation control is realized, and the cooperation of active working medium flow regulation and passive mixed working medium component regulation is realized to obtain a dynamic operation method of the system matched with the load requirement of a user side.

(4) The medium and low grade energy sources such as geothermal energy and solar energy are used as the heat source of the system, so that the energy is saved and the environment is protected.

(5) The system connects the heat source after exchanging heat with the first evaporator with the second evaporator, and the heat source after exchanging heat with the second evaporator is connected with the heat exchanger, so that the system can be used for heating in winter or supplying hot water all year round according to the requirements of building users. Based on the temperature-changing characteristic of the heat source fluid, the heat source is utilized in different temperature sections by considering different heat source grades and available temperature differences of the heat source, and the gradient utilization of energy is realized.

(6) Aiming at the problem that the performance of the medium-low temperature heat energy driven organic Rankine cycle is relatively poor, the cooling medium used in the condenser of the system is not cooling water, but compressed air with low temperature after expansion is used for replacing the cooling water as a cold source of the organic Rankine cycle, so that the whole system is more economical, efficient, environment-friendly and safe.

Drawings

Fig. 1 is a schematic view of the connection of the integral parts of the present invention.

In the figure: 1-a first evaporator; 2-a first expander; 3-a second expander; 4-a condenser; 5-a first flow meter; 6-a first working medium pump; 7-a second evaporator; 8-a second flow meter; 9-a second working medium pump; 10-a third flow meter; 11-a dynamometer; 12-a heat exchanger; 13-a fourth flow meter; 14-a fifth flow meter; 15-a throttle valve; 16-a third evaporator; 17-a compressor; 18-a sixth flow meter; 19-a seventh flow meter; 20-an air compressor; 21-an air cooler; 22-third expander.

Detailed Description

Specific examples of the present invention are given below. The specific examples are only intended to illustrate the invention in further detail and do not limit the scope of protection of the claims of the present application.

The invention provides a condensation decoupling and cascade evaporation coupling combined cooling, heating and power system (a system for short, see figure 1), which is characterized in that the system is divided into four subsystems, namely an ORC power generation system, a vapor compression refrigeration system, a condensation and environment decoupling cooling system and a heating system; the system comprises a first evaporator 1, a first expander 2, a second expander 3, a condenser 4, a first flow meter 5, a first working medium pump 6, a second evaporator 7, a second flow meter 8, a second working medium pump 9, a third flow meter 10, a dynamometer 11, a heat exchanger 12, a fourth flow meter 13, a fifth flow meter 14, a throttle valve 15, a third evaporator 16, a compressor 17, a sixth flow meter 18, a seventh flow meter 19, an air compressor 20, an air cooler 21 and a third expander 22;

the ORC power generation system comprises a first evaporator 1, a first expansion machine 2, a second expansion machine 3, a condenser 4, a first flow meter 5, a first working medium pump 6, a second evaporator 7, a second flow meter 8, a second working medium pump 9, a third flow meter 10 and a dynamometer 11; the vapor compression refrigeration system comprises a condenser 4, a fifth flow meter 14, a throttle valve 15, a third evaporator 16, a compressor 17 and a sixth flow meter 18; the condensation and environment decoupling cooling system comprises a condenser 4, a seventh flow meter 19, an air compressor 20, an air cooler 21 and a third expansion machine 22; the heating system comprises a heat exchanger 12 and a fourth flow meter 13;

a heat source inlet of the first evaporator 1 is communicated with a medium-low temperature heat source, a heat source outlet is communicated with an inlet of the third flow meter 10, and a working medium outlet is communicated with an inlet of the first expander 2; the outlet of the first expander 2 is communicated with the inlet of the second expander 3, and the first expander 2, the second expander 3 and the dynamometer 11 are coaxially connected; the outlet of the second expander 3 is communicated with the working medium inlet of the condenser 4; an air inlet of the condenser 4 is communicated with an outlet of the third expansion machine 22 and receives a cooling air source discharged from the outlet of the third expansion machine 22; the air outlet of the condenser 4 is used for supplying air to an air conditioning system or a refrigeration house; a working medium outlet of the condenser 4 is respectively communicated with an inlet of the first flowmeter 5 and an inlet of the fifth flowmeter 14 through a tee joint;

an outlet of the first flowmeter 5 is communicated with an inlet of a first working medium pump 6, and an outlet of the first working medium pump 6 is communicated with a working medium inlet of a second evaporator 7; a first working medium outlet of the second evaporator 7 is communicated with an inlet of the second expander 3; a second working medium outlet of the second evaporator 7 is communicated with an inlet of a second flow meter 8, an outlet of the second flow meter 8 is communicated with an inlet of a second working medium pump 9, and an outlet of the second working medium pump 9 is communicated with a working medium inlet of the first evaporator 1; the heat source inlet of the second evaporator 7 is communicated with the outlet of the third flow meter 10; a heat source outlet of the second evaporator 7 is communicated with a heat source inlet of the heat exchanger 12, and a heat source outlet of the heat exchanger 12 is used for discharging a heat source subjected to heat exchange to the external environment; a heat supply inlet of the heat exchanger 12 is communicated with an external water source through a fourth flowmeter 13, and a heat supply outlet can be communicated with heat supply equipment (in the embodiment, user heating equipment) for supplying heat or hot water;

the outlet of the fifth flowmeter 14 is communicated with the inlet of a throttle valve 15, and the outlet of the throttle valve 15 is communicated with the working medium inlet of a third evaporator 16; a chilled water inlet of the third evaporator 16 is communicated with chilled water return water of refrigeration equipment through a sixth flowmeter 18, and a chilled water outlet is communicated with the refrigeration equipment (indoor air conditioning equipment in the embodiment) and used for providing cold energy; a working medium outlet of the third evaporator 16 is communicated with an inlet of a compressor 17, and an outlet of the compressor 17 is communicated with a working medium inlet of the condenser 4;

an inlet of the seventh flow meter 19 is communicated with outdoor air through a pipeline, an outlet of the seventh flow meter 19 is communicated with an inlet of an air compressor 20, and an outlet of the air compressor 20 is communicated with an inlet of an air cooler 21; the outlet of the air cooler 21 communicates with the inlet of the third expander 22, and the air compressor 20 and the third expander 22 are coaxially connected.

The third evaporator 16 is located above the throttle valve 15.

The working principle and the working process of the invention are as follows:

a medium-low temperature heat source enters the first evaporator 1 to exchange heat with the liquid organic working medium in the first evaporator 1, and the liquid organic working medium after heat exchange becomes a gaseous organic working medium; the heat source after heat exchange flows out of the first evaporator 1, flows into the second evaporator 7 through the third flowmeter 10 and exchanges heat with the second evaporator 7; the heat source after heat exchange flows out of the second evaporator 7, the waste heat of the heat source exchanges heat with the heat exchanger 12, and the heat after heat exchange can be used for heating by users;

the gaseous organic working medium flows out of the first evaporator 1 and enters the first expansion machine 2 to drive a turbine in the first expansion machine 2 to rotate; then the gaseous organic working medium flows out of the first expander 2 and enters the second expander 3 to drive a turbine in the second expander 3 to rotate, so that enthalpy drop in the first expander 2 and the second expander 3 is converted into mechanical work, and the dynamometer 11 is driven to operate to generate electric energy;

the gaseous organic working medium discharged from the second expander 3 enters the condenser 4, and exchanges heat with the cooling air source discharged from the outlet of the third expander 22 in the condenser 4; the air source after heat exchange discharges air which can be used for an air conditioning system of a user or the air supply of a refrigeration house from the condenser 4; condensing the gaseous organic working medium after heat exchange into a saturated liquid organic working medium, and dividing the saturated liquid organic working medium into two parts to flow out of the condenser 4;

a part of saturated liquid organic working medium flowing out of the condenser 4 flows into a first working medium pump 6 through a first flow meter 5, is pressurized by the first working medium pump 6, is sent into a second evaporator 7, and exchanges heat with a heat source in the second evaporator 7; after heat exchange, one part of the liquid organic working medium is changed into a saturated gaseous organic working medium, and the other part of the liquid organic working medium is unchanged or is a liquid organic working medium; the saturated gaseous organic working medium flows out of the second evaporator 7 and enters the second expander 3; the liquid organic working medium flows out of the second evaporator 7, flows into a second working medium pump 9 through a second flowmeter 8, is pressurized by the second working medium pump 9, and is sent into the first evaporator 1 to complete the organic Rankine cycle;

the other part of the saturated liquid organic working medium flowing out of the condenser 4 flows into a throttle valve 15 through a fifth flowmeter 14, becomes a gaseous organic working medium after adiabatic throttling, and the gaseous organic working medium flows upwards into a third evaporator 16 to exchange heat with the chilled water entering the third evaporator 16; the chilled water after heat exchange can be used for providing the cold energy of an indoor air conditioner; the gaseous organic working medium after heat exchange is changed into a saturated state or a superheated state, flows out of the third evaporator 16, is sent into the compressor 17, is compressed into high-temperature and high-pressure organic steam, flows out of the compressor 17, enters the condenser 4, and completes the vapor compression refrigeration cycle;

outdoor air enters the air compressor 20 through the seventh flowmeter 19, is compressed into high-temperature and high-pressure air, is discharged from the air compressor 20, enters the air cooler 21, is cooled into normal-temperature and high-pressure air by the air cooler 21, is discharged from the air cooler 21, and enters the third expander 22; the normal-temperature and high-pressure gas is expanded in the third expander 22 and then changed into low-temperature and normal-pressure gas, the low-temperature and normal-pressure gas enters the condenser 4 and serves as a cold source of the ORC power generation system and the vapor compression refrigeration system, and the temperature of the air discharged by the third expander 22 is obviously lower than the ambient temperature, so that the decoupling between the condensation process and the ambient state of the ORC power generation system and the vapor compression refrigeration system is realized.

The organic working medium used by the whole system is a low-boiling point pure working medium or a non-azeotropic mixed working medium.