WO2022217758A1

WO2022217758A1 - Combined heat and power generation system based on high temperature and low temperature thermal storage media

Info

Publication number: WO2022217758A1
Application number: PCT/CN2021/104126
Authority: WO
Inventors: 钟崴; 孙鹏; 胡亚才; 周懿
Original assignee: 浙江大学
Priority date: 2021-04-16
Filing date: 2021-07-02
Publication date: 2022-10-20
Also published as: CN113153449A; CN113153449B

Abstract

A combined heat and power generation system based on high temperature and low temperature thermal storage media, which comprises a low temperature thermal storage apparatus, a high temperature thermal storage apparatus, a compressor system (3) arranged between the low temperature thermal storage apparatus and the high temperature thermal storage apparatus, a thermal power generation apparatus, and a user of heat (7); the low temperature thermal storage apparatus is formed from a low temperature thermal storage medium storage tank (1) and a low temperature pool (2) being connected by means of a working medium pipe, the high temperature thermal storage apparatus is formed from a high temperature thermal storage medium storage tank (4) and a high temperature pool (5) being connected by means of a working medium pipe, and the compressor system (3) is used for compressing low temperature saturated steam output from the low temperature pool (2) and inputting said steam into the high temperature pool (5); and the compressor system (3) and the thermal power generation apparatus are both in communication with a power grid (8), and acquire from or supply power to the power grid (8). The combined heat and power generation system is a highly efficient energy storage and peak regulation device. In the system, power and heat can simultaneously be stored, and power and heat can also simultaneously be provided, irreversible losses during energy storage and use can be satisfactorily reduced, and energy utilization efficiency and exergy efficiency are greatly improved.

Description

A cogeneration system based on high and low temperature heat storage medium

technical field

The invention relates to an energy storage and energy production system connected to a power grid, in particular to a heat and power cogeneration system based on a high and low temperature heat storage medium.

Background technique

As the international community attaches great importance to energy, climate and environment, the Chinese government has promised to reduce carbon dioxide emissions per unit of GDP by 60% to 65% compared with 2005 levels by 2030. In this context, renewable energy sources such as wind power and photovoltaics will develop on a larger scale in the future. However, renewable energy power generation such as wind power and photovoltaics is volatile, and the large-scale development of new energy power generation will lead to more serious abandonment of wind and light, resulting in energy waste and difficulty in peak regulation of the power grid. Power storage technology is required. To store the supersaturated power generation of new energy, realize the peak shaving and valley filling of the power grid, and reduce the energy waste caused by the abandonment of wind and light. As a large consumer of electricity and heat with a large number of coal-fired steam supply generator sets, the industrial park needs to assume the responsibility of increasing the proportion of new energy supply and reducing carbon emissions. Large-scale power storage in industrial parks when new energy power generation is oversaturated, and using stored new energy power to supply energy when energy load is high is an effective way to reduce carbon emissions. However, the commonly used power storage methods, such as pumped storage projects, are strictly limited by geographical conditions and the site resources are relatively remote. The charging and discharging power of the battery is limited, the charging time is long, and the maintenance cost is high. High temperature molten salt electricity storage has a great impact on the power generation process.

loss and waste of low temperature heat sources. In order to meet the needs of electricity and heat consumption and reducing carbon emissions in industrial parks at the same time, it is of great significance to develop a high-efficiency energy storage power generation system for industrial parks to replace traditional coal-fired power generation and heating units.

In addition, the large-scale development of renewable energy sources such as wind power and photovoltaics will lead to the shutdown of a large number of traditional thermal power units in the future, resulting in a waste of equipment investment. If a method can be provided to utilize these devices and transform power plants into storage power plants in the future energy system dominated by new energy, it will greatly reduce waste and promote the large-scale development of new energy power generation.

SUMMARY OF THE INVENTION

In order to make the industrial park consume more photovoltaic, wind power and other new energy power generation in the form of electricity storage, solve the problem of abandoning light and wind, and achieve the goal of carbon reduction. The invention provides a heat and power cogeneration system based on high and low temperature heat storage medium. The system overcomes the disadvantages of traditional energy storage methods,

High efficiency and flexible layout, it can be distributed in places where electric power and heat energy are needed, and provide electric power and steam for industrial parks flexibly.

In order to achieve the above purpose, a heat and power cogeneration system based on a high and low temperature heat storage medium of the present invention includes a low temperature heat storage device and a high temperature heat storage device, and a compressor system is arranged between the low temperature heat storage device and the high temperature heat storage device. , the system also includes a thermal power generation device and a thermal user; the low-temperature thermal storage device is formed by connecting a low-temperature thermal storage medium storage tank and a low-temperature pool through a working fluid pipeline, and the high-temperature thermal storage device consists of a high-temperature thermal storage medium storage tank and a low-temperature thermal storage medium. The high-temperature pool is formed by connecting the working fluid pipeline, and the compressor system is used to compress the low-temperature saturated steam output from the low-temperature pool and input it into the high-temperature pool; the compressor system and the thermal power generation device are all connected with the power grid, and take electricity from the power grid or Power transmission; the low temperature pool is connected with the low temperature heat source through the pipeline, and the low temperature heat source supplements the working medium and heat to the low temperature pool;

Low temperature pool and compressor system, compressor system and high temperature pool, high temperature pool and thermal power generation device, high temperature pool and heat user, thermal power generation device and low temperature pool, low temperature pool and low temperature heat source are sequentially provided with valves v1, v2, v3 , v4, v5, v6, different working processes are realized by controlling the switch of each valve.

There are low temperature heat storage medium in the storage tank of low temperature heat storage medium, such as magnesium chloride hexahydrate, paraffin, fatty acid, etc. There is a saturated working medium with vapor and liquid coexisting in the low temperature pool. The working medium is usually water, and it can also be other working medium such as lithium bromide solution. The low temperature pool and the low temperature heat storage medium storage tank are communicated through the working fluid pipeline, and a heat exchanger is arranged in the low temperature heat storage medium storage tank. The medium storage tank completes the exothermic or endothermic process with the low-temperature heat storage medium through the heat exchanger and returns to the low-temperature pool.

The compressor system is connected to the low temperature pool through the working fluid pipeline. The compressor system draws electricity from the power grid, consumes electricity to extract the working fluid steam from the low temperature pool, compresses it into high temperature and high pressure high parameter steam, and transports the high parameter steam through the medium pipeline to the High temperature pool.

The high temperature pool and the high temperature heat storage medium storage tank are communicated through the working fluid pipeline. There are high temperature heat storage medium in the high temperature heat storage medium storage tank, such as LiNO3, polymer resin materials, etc. There is a saturated working medium with vapor and liquid coexisting in the high temperature pool. The high temperature pool and the high temperature heat storage medium storage tank are communicated through the working medium pipeline, and a heat exchanger is arranged in the high temperature heat storage medium storage tank. The tank is returned to the high temperature pool after the heat release or heat absorption process with the high temperature heat storage medium is completed through the heat exchanger.

The high temperature pool is connected to the thermal power generation device (usually a steam turbine) and the heat user through the working fluid pipeline, and the high-parameter steam of the high temperature pool enters the steam turbine to do work or deliver it to the heat user.

The steam turbine and the low temperature pool are connected by the working fluid pipeline. The exhaust steam of the steam turbine enters the low temperature pool and releases heat to the low temperature heat storage medium storage tank, and then condenses into a liquid working medium again. The heat released by the condensation of the spent steam is stored in the low temperature heat storage medium storage tank.

A low-temperature heat source is arranged outside the low-temperature pool and is connected to the low-temperature pool through a working fluid pipeline, and the working fluid and heat are supplemented from the low-temperature heat source to the low-temperature pool. The low temperature heat source can be geothermal heat, industrial waste gas, etc.

In the solution of the present invention, low temperature and high temperature are relative terms, and are not limited to specific temperatures. Both the low temperature heat storage medium and the high temperature heat storage medium are phase change materials, the melting point of the high temperature heat storage medium is higher than that of the low temperature heat storage medium, and the melting point of the material is selected according to the actual application;

The work of the cogeneration system based on high and low temperature heat storage medium according to the present invention can include two processes. The first is the process of power consumption and heat storage. When energy storage is required, open the valves v1 and v2, start the compressor system, and use electricity to drive the compressor system to work. The compressor system extracts working fluid vapor from the low temperature pool to reduce the pressure of the low temperature pool , resulting in a decrease in the saturation temperature of the working medium in the low-temperature pool. The saturated liquid working medium with parameters in the low-temperature pool is T0 (temperature), P0 (pressure), and H0 (enthalpy), which absorbs the heat stored in the low-temperature heat storage medium storage tank and the low-temperature heat source. Under the action of evaporation, the produced working fluid steam with parameters of T1, P1 and H1, the steam is compressed to the high temperature pool by the electric-driven compressor system, and converted into high temperature and high pressure working fluid steam with parameters of T2, P2 and H2, in the high temperature pool Because the temperature of the high-parameter working fluid steam is higher than the phase transition temperature of the phase-change heat-storage medium in the high-temperature heat-storage medium storage tank, the energy is absorbed by the high-temperature heat-storage medium in the high-temperature heat-storage medium storage tank, and stored in the high-temperature heat-storage medium. In the medium storage tank, the high-parameter steam is condensed into a liquid saturated working medium, which is stored in a high-temperature pool. After the power consumption and heat storage process, the valves v1 and v2 are closed; the second is the power generation and heating process. Open the valves v3, v4, v5, the pressure drop in the high temperature pool causes the saturation temperature of the working medium in the high temperature pool to decrease, and the working medium absorbs the heat stored in the high temperature heat storage medium storage tank and evaporates into a high temperature and high pressure saturated working medium with parameters T3, P3 and H3 Steam, the working medium steam drives the steam turbine to generate electricity or supplies high-parameter steam to the outside world. The exhaust steam with parameters T4, P4 and H4 generated by the steam turbine is discharged into the low temperature pool, and the pressure of the low temperature pool rises. When the temperature of the spent steam is higher than the low temperature heat storage medium storage tank When the heat storage temperature of the internal heat storage medium is reached, the spent steam releases heat to the heat storage medium through the heat exchanger in the low temperature heat storage medium storage tank, and the energy is stored in the low temperature heat storage medium storage tank, and the spent steam becomes saturated again. The liquid working medium is stored in the low temperature pool, and the valves v3, v4 and v5 are closed after the power generation and heating process is completed. Due to reasons such as the inability to recover the working fluid during external heating and insufficient energy recovery of the exhausted steam in the low temperature pool, the working fluid and energy in the low temperature pool and the low temperature heat storage medium storage tank will decrease during operation. In order to maintain the low temperature pool and the low temperature heat storage medium storage The balance of material and energy in the tank needs to supplement the working medium and heat from the low-temperature heat source to the low-temperature pool. The above two processes can be carried out separately or simultaneously according to the actual situation. The energy products exported to the outside world can be either combined heat and power supply or pure heat supply.

When the system operates according to the power consumption and heat storage process and the pure power generation process, the power supply efficiency is calculated by the following formula under the condition that the quality of the power generation working medium is m1 ton and the total efficiency of the generator and transmission system is η3:

Among them, W1 (unit: kW·h) is the power generation, and W2 (unit: kW·h) is the power consumption of the compressor system unit.

W1 is calculated as follows:

W1=(H3-H4)*m1*η3/3.6

W2 is calculated as follows:

W2=(H2-H1)*m1/3.6

The system operates according to the process of power consumption and heat storage and pure heat supply. Under the condition that the quality of the heating medium is m2 tons, the heat pump coefficient is calculated by the following formula:

Among them, Q is the heat supply, and W2 is the power consumption of the compressor system unit.

Q is calculated as follows:

Q=(H3-H0)*m2/3.6

W2 is calculated as follows:

W2=(H2-H1)*m2/3.6

The beneficial effects of the present invention are as follows: First, the cogeneration system based on high and low temperature heat storage medium is a high

Efficient energy storage system, there is no large temperature difference heat transfer during the working fluid cycle, and the irreversible loss is small. Second, when the system operates purely for heating, it uses low-cost electric energy to generate a heat pump effect, giving full play to the high-quality performance of electricity. Third, the flexible conversion between external power supply and heating can flexibly adapt to the actual needs of the industrial park, realize greater consumption of new energy power generation for the industrial park, and reduce carbon emissions. Fourth, the system has a long service life and mature key technologies. The thermal devices and technologies used have mature application experience. Fifth, the scale of the equipment of this system should be large and small, and it can be applied in different occasions. Sixth, the key constituent equipment of the present invention has a large overlap with the traditional thermal power plant, and the original site and equipment of the thermal power plant can be used to transform the thermal power plant into a storage power plant according to this system, which is a new energy-led thermal power plant in the future. The energy system offers a way out.

Description of drawings

FIG. 1 is a schematic diagram of the composition of a heat and power cogeneration system based on a high and low temperature heat storage medium according to the present invention.

FIG. 2 is a pressure-entropy diagram of a working medium during operation of a cogeneration system based on a high and low temperature heat storage medium of the present invention. The horizontal straight lines L1 and L2 in the figure are the phase transition temperature line of the low temperature phase change heat storage material and the phase change temperature line of the high temperature phase change heat storage material, respectively.

Detailed ways

Example 1:

In the power consumption and heat storage-pure power generation mode, the working medium is water, the mass m=1000t, the phase transition temperature of the low temperature thermal storage material is 110℃, and the phase transition temperature of the high temperature thermal storage material is 210℃. When running with power consumption and heat storage, as shown in Figure 1. Open the valves v1 and v2, and open the compressor system 3. The pressure of the low temperature pool 2 decreases, which reduces the saturation temperature of the working medium in the low temperature pool 2. The working fluid in the low temperature pool 2 absorbs the heat of the phase change material in the low temperature heat storage medium storage tank 1 and evaporates. is saturated steam, that is, from point 12 to point 2 in the pressure-entropy diagram in Figure 2. The saturated steam in the low temperature pool 2 is compressed by the compressor system 3 to become high-temperature and high-pressure high-parameter steam, that is, from point 2 to point 3 in the pressure-entropy diagram in Figure 2. The high-parameter steam enters the high-temperature pool 5, and then its heat is absorbed by the phase change material in the high-temperature heat storage medium storage tank 4. After the steam releases heat, it condenses into saturated water in the high-temperature pool 5, that is, in the pressure-entropy diagram in Fig. 2, from 3 o'clock to 41 o'clock. In this process, electricity is drawn from the grid 8 through the compressor system 3, and the electricity in the grid 8 is stored in the heat storage tank 4 to complete the electricity storage process.

When exothermic power supply, open the valve v3, v5 to start the steam turbine 6, the pressure of the high temperature pool 5 decreases, the saturation temperature of the internal working fluid drops, the working fluid absorbs the heat in the high temperature heat storage medium storage tank 4 and evaporates into saturated steam, that is, in the Figure 2. Pressure-entropy diagram from point 42 to point 5. The saturated steam enters the steam turbine 6 to generate power, and becomes wet steam at the outlet of the steam turbine 6, that is, from point 5 to point 6 in the pressure-entropy diagram in Fig. 2 . The exhaust steam from the steam turbine 6 enters the low temperature pool, releases heat to the phase change material in the low temperature heat storage medium storage tank 1 and then condenses into a low temperature saturated liquid. During this process, the heat released by the wet steam is absorbed by the low temperature heat storage material and stored in the low temperature phase change material. , that is, from point 6 to point 11 in the pressure-entropy diagram in Figure 2. complete a cycle.

During the cycle, the heat recovered from the exhausted steam in the expansion exothermic power supply in the low temperature pool 2 and the heat released by the heating working medium during the compression heat storage operation may be unbalanced. If the heat recovered from the exhausted steam in the expansion exothermic power supply in the low temperature pool is less than the heat released by heating the working medium during the compression heat storage operation, it is necessary to open the valve v6 to supplement the heat in the low temperature pool from the low temperature heat source 9, so that the cycle can be maintained go down.

Taking the overall system efficiency of the compressor system η1=0.86, the relative internal efficiency of the steam turbine η2=0.86, and the overall efficiency of the generator and transmission η3=0.98, the parameters of the water in the low-temperature pool are T0=105 during compression and heat storage operation. ℃, P0=0.1209MP, H0=440.2111KJ/Kg, the steam parameters at the outlet of the low temperature pool are T1=106℃, P1=0.1209MP, H1=2683.4KJ/Kg. The adiabatic parameters at the outlet of the compressor system are T21=461.262°C, P21=2.1068MP, H21=3381.451KJ/Kg, and the adiabatic work per kilogram of the steam compressor system w21=H21-H1=698.058KJ/Kg, the actual performance of the steam compressor system per kilogram The work w2=w21/η1=811.696KJ/Kg; the actual parameters of the compressor system outlet are T2=512.724, P2=2.106MP, H2=H1+w2=3495.088KJ/Kg. When the expansion and exothermic power supply is running, the steam parameters at the outlet of the high temperature pool are T3=206℃, P3=1.7243MP, and H3=2794.8KJ/Kg. Turbine exhaust steam adiabatic parameters T41=115.000℃, P41=0.169MP, dryness X41=0.862, H41=2392.036KJ/Kg. The isentropic work of the steam turbine is w41=H3-H41=402.7987KJ/Kg, and the actual work of the steam turbine is w4=w41*η2=342.943KJ/Kg. The actual parameters of steam turbine exhaust are T4=115.000℃, P4=0.169MP, H4=H3-w4=2451.959KJ/Kg, dryness X4=0.889.

The power supply efficiency of the system is

Among them, W1 is the power generation, and W2 is the power consumption of the compressor system unit.

W1 is calculated as follows:

W1=(H3-H41)*η2*η3*m/3.6

After calculation, W1=95261.89974kW·h

W2 is calculated as follows:

W2=(H21-H1)/η1*m/3.6

After calculation, W2=225471.012kW·h

It is calculated that the power supply efficiency of the electricity storage and heat storage device based on the cycle of high and low temperature heat storage medium is 42.25% when it operates in the compression heat storage-expansion heat release power generation mode.

Example 2:

Power consumption and heat storage - pure heat supply mode, the working medium is water, the mass is m=1000t, the phase transition temperature of the low temperature thermal storage material is 110°C, and the phase transition temperature of the high temperature thermal storage material is 210°C. When running with power consumption and heat storage, as shown in Figure 1. Open the valves v1 and v2, and open the compressor system 3. The pressure of the low temperature pool 2 decreases, which reduces the saturation temperature of the working medium in the low temperature pool 2. The working fluid in the low temperature pool 2 absorbs the heat of the phase change material in the low temperature heat storage medium storage tank 1 and evaporates. is saturated steam, that is, from point 12 to point 2 in the pressure-entropy diagram in Figure 2. The saturated steam in the low temperature pool 2 is compressed by the compressor system 3 to become high-temperature and high-pressure high-parameter steam, that is, from point 2 to point 3 in the pressure-entropy diagram in Figure 2. The high-parameter steam enters the high-temperature pool 5, and then its heat is absorbed by the phase change material in the high-temperature heat storage medium storage tank 4. After the steam releases heat, it condenses into saturated water in the high-temperature pool 5, that is, in the pressure-entropy diagram in Fig. 2, from 3 o'clock to 41 o'clock. In this process, electricity is drawn from the grid 8 through the compressor system 3, and the electricity in the grid 8 is stored in the heat storage tank 4 to complete the electricity storage process. The pressure-entropy diagram of this process is shown in Figure 2.

When supplying heat to the outside, open the outlet valve v4 of the high-temperature pool, the pressure of the high-temperature pool decreases, the saturation temperature of the internal working fluid decreases, and the working fluid absorbs the heat in the high-temperature heat storage medium storage tank and evaporates into saturated steam, which is the pressure-entropy in Figure 2. From 42 o'clock to 5 o'clock in the picture. The saturated steam is delivered to the heat user 7 through the working fluid pipeline, and is utilized by the heat user. In order to ensure the normal operation of the low-temperature pool, when outputting hot water in this working mode, the low-temperature pool 2 must be supplemented with a working medium with the same parameters to make up for the loss of mass and energy in the output working medium, that is, open the valve v6, and send the flow from the low-temperature heat source 9 to the low-temperature heat source 9. Low temperature pool 2 supplements energy and working medium. Unlike general electric heating, the output steam increases the pressure, that is, the heat pump effect.

Since the steam supplied to the heat user 7 cannot be recovered to the low temperature pool 2, the valve v6 needs to be opened to supplement the working medium and heat from the low temperature heat source 9 to the low temperature pool 2.

Take the overall efficiency of the compressor system η1=0.86, when the compression heat storage operation, the parameters of the water in the low temperature pool are T0=105℃, P0=0.1209MP, H0=440.2111KJ/Kg, and the steam parameters at the outlet of the low temperature pool are T1=106 ℃, P1=0.1209MP, H1=2683.4KJ/Kg. The adiabatic parameters at the outlet of the compressor system are T21=461.262°C, P21=2.1068MP, H21=3381.451KJ/Kg, and the adiabatic work per kilogram of the steam compressor system w21=H21-H1=698.058KJ/Kg, the actual performance of the steam compressor system per kilogram The work w2=w21/η1=811.696KJ/Kg; the actual parameters of the compressor system outlet are T2=512.724, P2=2.106MP, H2=H1+w2=3495.088KJ/Kg. When the expansion and exothermic power supply is running, the external steam supply parameters at the outlet of the high temperature pool are: T3=206℃, P3=1.7243MP, H3=2794.8KJ/Kg.

The heat pump coefficient is:

The calculated heat pump coefficient is E=2.901

Example 3:

In the power consumption and heat storage-cogeneration mode, the working medium is selected as water, the mass m=1000t, the phase transition temperature of the low temperature thermal storage material is 110℃, and the phase transition temperature of the high temperature thermal storage material is 210℃. When running with power consumption and heat storage, as shown in Figure 1. Open the valves v1 and v2, and open the compressor system 3. The pressure of the low temperature pool 2 decreases, which reduces the saturation temperature of the working medium in the low temperature pool 2. The working fluid in the low temperature pool 2 absorbs the heat of the phase change material in the low temperature heat storage medium storage tank 1 and evaporates. is saturated steam, that is, from point 12 to point 2 in the pressure-entropy diagram in Figure 2. The saturated steam in the low temperature pool 2 is compressed by the compressor system 3 to become high-temperature and high-pressure high-parameter steam, that is, from point 2 to point 3 in the pressure-entropy diagram in Figure 2. The high-parameter steam enters the high-temperature pool 5, and then its heat is absorbed by the phase change material in the high-temperature heat storage medium storage tank 4. After the steam releases heat, it condenses into saturated water in the high-temperature pool 5, that is, in the pressure-entropy diagram in Fig. 2, from 3 o'clock to 41 o'clock. In this process, electricity is drawn from the grid 8 through the compressor system 3, and the electricity in the grid 8 is stored in the heat storage tank 4 to complete the electricity storage process.

In the case of cogeneration, open the valve v5, and set the outlet valves v4 and v3 of the high temperature pool to a reasonable opening degree according to the needs of power supply and heat supply. The heat in the high temperature heat storage medium storage tank 4 evaporates and becomes saturated steam, that is, from point 42 to point 5 in the pressure-entropy diagram in FIG. 2 . The steam flow from the high temperature pool is divided into two parts, which are respectively sent to the steam turbine for power generation and to the heat user for heat supply to realize cogeneration.

The saturated steam passing through the valve v3 enters the steam turbine 6 to generate power, and becomes wet steam at the outlet of the steam turbine 6, that is, from point 5 to point 6 in the pressure-entropy diagram in Figure 2. The exhaust steam from the steam turbine 6 enters the low temperature pool, releases heat to the phase change material in the low temperature heat storage medium storage tank 1 and then condenses into a low temperature saturated liquid. During this process, the heat released by the wet steam is absorbed by the low temperature heat storage material and stored in the low temperature phase change material. , that is, from point 6 to point 11 in the pressure-entropy diagram in Figure 2.

The saturated steam passing through the valve v4 is delivered to the heat user 7 through the working fluid pipeline, and is used by the heat user.

Due to reasons such as the inability to recover the working fluid during external heating and insufficient energy recovery of the exhausted steam in the low-temperature pool 2, the working fluid and energy in the low-temperature pool 2 and the low-temperature heat storage medium storage tank 1 will decrease during operation. The balance of materials and energy in the low-temperature heat storage medium storage tank 1 needs to be supplemented with working medium and heat from the low-temperature heat source 9 to the low-temperature pool 2 .

Claims

A heat and power cogeneration system based on a high and low temperature heat storage medium, characterized in that it comprises a low temperature heat storage device and a high temperature heat storage device, and a compressor system is arranged between the low temperature heat storage device and the high temperature heat storage device, and the system also It includes a thermal power generation device and a thermal user; the low-temperature thermal storage device is formed by connecting a low-temperature thermal storage medium storage tank (1) and a low-temperature pool (2) through a working fluid pipeline, and the high-temperature thermal storage device is stored by a high-temperature thermal storage medium. The tank (4) and the high temperature pool (5) are formed by connecting the working fluid pipeline, and the compressor system (3) is used to compress the low temperature saturated steam output from the low temperature pool and input it into the high temperature pool; the compressor system (3), The thermal power generation devices are all connected with the power grid (8), and take or send electricity to the power grid (8); the low-temperature pool (2) is connected with the low-temperature heat source (9) through a pipeline, and the low-temperature heat source supplements the working medium to the low-temperature pool (2) and heat;

The low temperature pool and the compressor system, the compressor system and the high temperature pool, the high temperature pool and the thermal power generation device (6), the high temperature pool and the heat user (7), the thermal power generation device and the low temperature pool, and between the low temperature pool and the low temperature heat source are arranged in sequence. Valves v1, v2, v3, v4, v5, v6 realize different working processes by controlling the switches of each valve.
A cogeneration system based on a high and low temperature heat storage medium according to claim 1, characterized in that: the low temperature heat storage medium storage tank (1) is provided with a heat exchanger and a low temperature heat storage medium, so The high temperature heat storage medium storage tank (4) is provided with a heat exchanger and a high temperature heat storage medium, the low temperature heat storage medium and the high temperature heat storage medium are both phase change materials, and the melting point of the high temperature heat storage medium is higher than that of the low temperature heat storage medium , select the melting point of the material according to the actual application; the low temperature pool (2) and the high temperature pool (5) are both provided with a saturated working medium of vapor and liquid; the working medium in the low temperature pool flows to the low temperature heat storage medium storage tank, and the heat exchange The working medium in the high temperature pool flows to the storage tank of the high temperature heat storage medium, and returns to the high temperature pool after the heat release or heat absorption process with the high temperature heat storage medium is completed through the heat exchanger. .
The heat and power cogeneration system based on a high and low temperature heat storage medium according to claim 1, characterized in that the thermal power generation device (6) is a steam turbine.
A cogeneration system based on high and low temperature heat storage medium according to claim 3, characterized in that the system can store electricity and heat at the same time, and can also supply power and heat at the same time, including the process of power consumption and heat storage and power generation. The heat supply process, the power generation and heat supply process includes a pure power generation mode, a pure heat supply mode, and a combined heat and power mode.
A cogeneration system based on high and low temperature heat storage medium according to claim 3, characterized in that, the valves v1 and v2 are opened, and the compressor system is opened; the compressor system draws electricity from the power grid, and extracts working fluid from the low temperature pool The steam reduces the saturation temperature of the working medium in the low temperature pool. The saturated liquid working medium in the low temperature pool absorbs the heat stored in the low temperature heat storage tank and evaporates under the combined action of the low temperature heat source to generate steam, which is compressed to the high temperature pool by the compressor system and stored in the high temperature heat. The high temperature heat storage medium in the medium storage tank is absorbed and condensed into a liquid saturated working medium, so that the electric energy in the power grid is stored in the high temperature heat storage medium storage tank to realize the process of power consumption and heat storage.
A cogeneration system based on high and low temperature heat storage medium according to claim 3, characterized in that, open the valves v3, v5, start the steam turbine, and open the valve v6; When the temperature drops, the working fluid absorbs the heat in the high-temperature heat storage medium storage tank and evaporates into saturated steam. The saturated steam enters the steam turbine (6) to generate power, and the steam turbine exhaust steam enters the low-temperature pool, and the low-temperature heat storage medium in the low-temperature heat storage medium storage tank is used for the low-temperature heat storage medium. After the heat is released, it condenses into a low-temperature saturated liquid. In this process, the heat released by the steam turbine exhaust is absorbed and stored by the low-temperature heat storage medium, and the pure power generation mode of the power generation and heat supply process is realized.
A cogeneration system based on high and low temperature heat storage medium according to claim 3, characterized in that, open the valve v4 and open the valve v6; the pressure of the high temperature pool decreases, the saturation temperature of the internal working fluid decreases, and the working fluid decreases. The heat absorbed in the high temperature heat storage medium storage tank is evaporated into saturated steam and sent to the heat user (7) to be utilized by the heat user to realize the pure heat supply mode of the power generation and heat supply process.