CN204084540U - Fused salt regenerative electrochemical heating central heating system - Google Patents

Abstract

The utility model relates to a molten salt heat storage type electric heating central heating system, which belongs to the technical field of heat storage. Including molten salt electric heaters, high-temperature hot salt tanks, low-temperature cold salt tanks, molten salt pumps, brine heat exchangers, and heat users. During the low price and low electricity period at night, the molten salt in the cold salt tank is pumped out through the molten salt pump and sent to the molten salt electric heater to heat the molten salt to a high temperature before entering the hot salt tank. During the peak period of electricity consumption during the day, the molten salt pump is used The high-temperature molten salt accumulated in the hot salt tank is extracted and transported to the molten salt-water heat exchanger to heat the water for municipal heating to generate hot water for heating the residents. For the coal-fired boiler central heating system commonly used at present, it is only necessary to transform the boiler room of the central heating system into a molten salt regenerative electric heating system, and the municipal heating pipe network and heating terminal equipment do not need to be transformed. . The system can cut peaks and fill valleys, reduce coal consumption, and protect the environment.

Description

Molten salt regenerative electric heating central heating system

technical field

The utility model relates to an electric heating heat storage system, in particular to a system which adopts molten salt as a heat storage working medium and utilizes low-valley electricity for centralized heating, and belongs to the technical field of heat storage.

Background technique

Under the current situation of smog covering China, many provinces and cities in China have launched coal-to-electricity projects in order to obtain fresh air. At the same time, Beijing launched a coal-to-gas conversion project, changing various large coal-fired boilers to burn natural gas for heating. As a result, Beijing's natural gas is seriously insufficient. In addition, the development of society and the improvement of people's living standards have brought about drastic changes in my country's power consumption structure. The peak power is seriously insufficient, the peak-to-valley difference continues to increase, and the low-efficiency operation of generator sets during the valley period. In order to solve this contradiction, in the power The industry has put forward the measures of "cutting peaks and filling valleys", implementing peak and valley electricity prices, and encouraging electricity consumption during valley periods. The electric heating molten salt system is used to realize central heating, which can convert excess electricity into heat energy and store it in high-temperature molten salt during the low electricity consumption period, and then release the stored heat for heating during the peak period of electricity consumption, which not only solves the problem of The air pollution caused by urban coal-fired boilers is an effective technical way to alleviate the peak-valley difference of the power grid.

Utility model content

In view of the deficiencies in the prior art, the utility model provides a molten salt regenerative electric heating central heating system for energy saving and environmental protection by using low-valley electric heating of high-temperature molten salt for heating during peak periods of electricity consumption.

A molten salt regenerative electric heating central heating system, characterized in that it mainly includes a molten salt electric heater 1 for heating molten salt and storing heat, a hot salt tank 2 for storing high-temperature molten salt, and a storage tank for low-temperature molten salt Cold salt tank 3, low temperature molten salt pump 4, high temperature molten salt pump 5, brine heat exchanger 6 for heat exchange between molten salt and water, heat user 7.

The molten salt electric heater 1 adopts a serpentine circular tube 9 as a heating element, and the serpentine circular tube 9 has a shell outside, and the shell is provided with a molten salt outlet and a molten salt inlet, and the molten salt outlet is equipped with a molten salt heater outlet The temperature sensor 10, the molten salt inlet is equipped with a molten salt heater inlet temperature sensor 11, which is used to monitor the temperature of the heated molten salt, and the serpentine circular tube 9 of the molten salt electric heater 1 is connected to a power supply, and is used to control the temperature of the electric heater. Start and stop.

The molten salt outlet of the molten salt electric heater 1 is connected to the inlet of the hot salt tank 2 through a pipeline, and the outlet of the hot salt tank 2 is connected to the tube-side inlet of the brine heat exchanger 6 through the high-temperature molten salt pump 5, and the brine heat exchanger The tube side outlet of 6 is connected with the inlet of cold salt tank 3, and the outlet of cold salt tank 3 is connected with the inlet of molten salt electric heater 1 via low temperature molten salt pump 4, electric heater 1, hot salt tank 2, cold salt tank 3. The closed pipeline formed by the low-temperature molten salt pump 4, the high-temperature molten salt pump 5, and the brine heat exchanger 6 is a molten salt circuit.

The shell side of the brine heat exchanger 6 is connected to the heat user through the water supply pipeline 30 and the return water pipeline 31 to form a water circuit. A water circuit system pressure sensor 24 and a water circuit system pressure sensor 24 are installed on the water supply pipeline at the outlet of the brine heat exchanger 6 shell side. The system temperature sensor 25, the flow sensor 26 of the water circuit system, the circulating water pump 27 and the constant pressure replenishment and water treatment system 28 are installed on the return water pipeline 31.

Hot molten salt pump 5 and cold molten salt pump 4 are installed on the top of hot salt tank 2 and cold salt tank 3 to provide power for molten salt respectively. Two molten salt pumps are installed on the top of each tank, one for use and one for standby; A hot brine tank temperature sensor 12 for monitoring temperature is installed on the tank 2, a hot brine tank liquid level monitoring port 14 for monitoring liquid level is installed on the upper part, and a hot brine tank discharge port 16 for emptying molten salt is installed at the lower part; A cold salt tank temperature sensor 13 for monitoring temperature is installed on the cold salt tank 3, a cold salt tank liquid level monitoring port 15 for monitoring liquid level is installed on the upper part, and a cold salt tank discharge port for emptying molten salt is installed at the lower part 17.

A hot salt pipeline pressure sensor 18, a hot salt pipeline temperature sensor 19, a hot salt pipeline flow sensor 20 are installed on the pipeline between the molten salt electric heater 1 and the hot salt tank 2. A cold salt pipeline pressure sensor 21 , a cold salt pipeline temperature sensor 22 , and a cold salt pipeline flow sensor 23 are installed on the pipeline between the salt tanks 3 .

Molten salt circuit system (large dotted line box), including all piping systems used to carry molten salt, as well as pressure sensors 18, 21, temperature sensors 19, 22, and flow sensors 20, 23 installed on the piping system;

The brine heat exchanger 6 adopts a shell-and-tube structure, the molten salt is in the pipeline system, and the water is in the shell-side system, and the heat exchange between the two adopts the form of forced convection heat exchange.

The water circuit system (small dotted line box), including water supply pipes, return pipes, and temperature sensors 25, pressure sensors 24, flow sensors 26, circulating water pumps 27, heat users 7, constant pressure water replenishment and water treatment systems installed on the piping system 28.

The molten salt regenerative electric heating centralized heating system of the utility model also includes a controller 8, which is respectively connected with the sensors and the power supply 8 of the molten salt loop system and the water loop system.

The heat user 7 is the user end of the heating, and the reserved municipal pipeline hot water system can be used for heating, and the user's terminal device does not need to be changed.

A molten salt regenerative electric heating central heating system that uses mixed molten salt as the heat storage medium and utilizes off-peak electricity for heat storage. During the low price and low electricity period at night, the molten salt in the cold salt tank is pumped out through the molten salt pump and sent to the molten salt electric heater to heat the molten salt to a high temperature (about 500°C) before entering the hot salt tank, and electricity is used during the day During the peak period, the molten salt pump is used to extract the high-temperature molten salt accumulated in the hot salt tank and transport it to the molten salt-water heat exchanger to heat the water for municipal heating to generate hot water for heating the residents. For the coal-fired boiler central heating system commonly used at present, it is only necessary to transform the boiler room of the central heating system into a molten salt regenerative electric heating system, and the municipal heating pipe network and heating terminal equipment do not need to be transformed. .

The beneficial effects of the utility model are: the utility model adopts the combination of central heating and electric heating heat storage, and uses mixed molten salt with excellent thermal performance as the heat storage medium. Molten salt has a wide liquid temperature range, large heat capacity, and low vapor pressure. The molten salt circuit system is safe and reliable, has excellent heat storage performance, is non-toxic and harmless, and is cheap and easy to obtain. The molten salt is heated at night to store energy for heating during the day, making full use of off-peak electricity, alleviating the peak-valley difference in the power grid, and saving energy. By using off-peak electricity instead of coal burning, the consumption of coal is reduced, and air pollution is greatly reduced.

Description of drawings

Fig. 1 is a composition structure diagram of the utility model;

In the figure: 1. Molten salt electric heater, 2. High-temperature hot salt tank, 3. Low-temperature cold salt tank, 4. Low-temperature molten salt pump, 5. High-temperature molten salt pump, molten salt circuit system (large dotted line frame), 6. Brine heat exchanger, 7. Heat user, water circuit system (small dotted line box), 8. Controller, 9. Serpentine heating round tube, 10. Outlet temperature sensor of molten salt heater, 11. Inlet temperature of molten salt heater Sensors, 12. Hot salt tank temperature sensor, 13 Cold salt tank temperature sensor, 14. Hot salt tank liquid level monitoring port, 15. Cold salt tank liquid level monitoring port, 16. Hot salt tank salt discharge port, 17. Cold salt tank Tank drain outlet, 18, hot salt pipeline pressure sensor, 19, hot salt pipeline temperature sensor, 20, hot salt pipeline flow sensor, 21, cold salt pipeline pressure sensor, 22, cold salt pipeline temperature sensor, 23. Cold salt pipeline flow sensor, 24. Water circuit system pressure sensor, 25. Water circuit system temperature sensor, 26. Water circuit system flow sensor, 27. Circulating water pump, 28. Constant pressure water supply and water treatment system, 29. Power supply, 30 water supply pipelines, 31, return water pipelines.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the embodiments.

Example 1

As shown in Figure 1, a regenerative electric heating central heating system using molten salt as a heat storage working medium includes a power supply for providing electric energy, a molten salt heating system, a molten salt heat storage system, a molten salt heat exchange system and The specific structure of urban heating system is as follows:

The molten salt electric heater 1 uses a serpentine circular tube 9 as a heating element, which is less limited by thermal stress and has a faster start-up speed, which is suitable for frequent power supply start-stop and variable load operation requirements. The heat storage working medium is mixed molten salt. The mixed molten salt has many advantages such as large heat capacity, good thermal stability, low viscosity, low vapor pressure, wide liquid temperature range, and low cost. Converted into high-temperature heat energy and stored in high-temperature molten salt. The molten salt heat storage system adopts a double-tank arrangement structure, which includes a cold salt tank 3 for storing low-temperature molten salt and a hot salt tank 2 for storing high-temperature molten salt, both of which are cylindrical in structure. Stainless steel, dome cover, external insulation, vertical placement. The cold salt tank 3 is used to store the low-temperature molten salt released by the heat exchange system at the initial stage of system startup or during operation, and the hot salt tank 2 is used to store the high-temperature molten salt heated by the molten salt heater; in the cold salt tank 3 Two low-temperature molten salt pumps 4 and two high-temperature molten salt pumps 5 are respectively installed on the top of the hot salt tank 2, all adopting the form of one for use and one for standby, so as to prevent accidents of the entire system caused by failure of the molten salt pump. The molten salt pumps are all long-axis submerged pumps, which are installed vertically on the top. The cold brine tank 3 and the hot brine tank 2 are equipped with temperature sensors 12 and 13 for monitoring the temperature of the two. Both are provided with liquid level monitoring ports 14, 15, and the safe liquid level of the molten salt can be fed back through the liquid level sensor. Salt discharge outlets 16 and 17 for molten salt are designed at the bottom of the salt tank to empty the molten salt during accidents or routine maintenance.

The molten salt circuit system (large dotted line frame) includes hot salt pipeline, cold salt pipeline, pressure sensors 18, 21, temperature sensors 19, 22, and flow sensors 20, 23 on the pipelines. These sensors transmit signals to the controller 8, and the controller 8 synthesizes these signals to continuously adjust the frequency of the high-temperature molten salt pump 5 and the low-temperature molten salt pump 4 to meet different operating conditions. The water circuit system (small dotted line box) includes water supply pipes, water return pipes and pressure sensors 24 on the pipelines, temperature sensors 25, flow sensors 26, circulating water pumps 27, heat users 7 and constant pressure replenishment and water treatment systems 28 .

In addition, the molten salt heat exchange equipment adopts the arrangement of the molten salt on the shell side and the high-pressure water/steam on the pipe side, thereby greatly reducing the shell wall and saving costs. It is also conducive to emptying the molten salt during system accidents or routine maintenance .

Working principle and realization process of the present utility model are as follows:

Taking the peak-valley electricity price in Beijing as an example, from 22:00 at night to 8:00 the next morning, the molten salt electric heater is activated, and the low-temperature molten salt (about 200 ℃) to a high temperature (about 500 ℃), adjust the flow rate of the molten salt inlet and outlet of the high-temperature hot salt tank through the flow sensor, so that a part of the high-temperature molten salt is stored in the hot salt tank for heating during the peak period of electricity consumption, Part of it enters the brine heat exchanger for heating at night. The high-temperature molten salt entering the brine heat exchanger and the municipal water exchange heat through forced convection, heating the municipal water from about 70°C at the inlet to 95°C, and the low-temperature molten salt after heat exchange returns to the cold salt tank to complete a cycle exchange hot. The heated municipal water enters the water separator and is distributed to each hot user. After the municipal water completes a cycle, it is collected in the water collector for the next heat exchange with the high-temperature molten salt. From 8:00 to 22:00 in the daytime, the electric heater stops running, and the molten salt pump of the hot salt tank continuously transports high-temperature molten salt to the brine heat exchanger for heat exchange between molten salt and municipal water, realizing Heating during peak electricity consumption. The molten salt that has released heat and cooled down returns to the low-temperature molten salt tank.

The whole system is realized through the intelligent control of the microcomputer controller 8. The microcomputer controller intelligently adjusts the start-stop and heating power of the molten salt electric heater through the feedback signals of the temperature sensor and the flow sensor, and adjusts the frequency of the molten salt pump in the cold and hot salt tanks to control the flow of the molten salt to meet the heat requirements. Different needs of users.

Claims (6)

1. A molten salt regenerative electric heating central heating system, characterized in that: it mainly includes a molten salt electric heater (1) for heating and storing molten salt, and a hot salt tank (2) for storing high-temperature molten salt , cold salt tank (3) for storing low-temperature molten salt, low-temperature molten salt pump (4), high-temperature molten salt pump (5), brine heat exchanger (6) for heat exchange between molten salt and water, heat user ( 7); The molten salt electric heater (1) adopts a serpentine circular tube (9) as a heating element. There is a shell outside the serpentine circular tube (9). The shell is provided with a molten salt outlet and a molten salt inlet. The molten salt outlet is installed A temperature sensor (10) at the outlet of the molten salt heater is provided, and an inlet temperature sensor (11) of the molten salt heater is installed at the inlet of the molten salt to monitor the temperature of the heated molten salt. The serpentine circular tube of the molten salt electric heater (1) (9) Connected to the power supply, used to control the start and stop of the electric heater; The molten salt outlet of the molten salt electric heater (1) is connected to the inlet of the hot salt tank (2) through a pipeline, and the outlet of the hot salt tank (2) is connected to the brine heat exchanger (6) via a high-temperature molten salt pump (5) The tube side inlet of the brine heat exchanger (6) is connected to the inlet of the cold salt tank (3), and the outlet of the cold salt tank (3) is connected to the molten salt electric heater via the low temperature molten salt pump (4) The inlet of (1) is connected, electric heater (1), hot salt tank (2), cold salt tank (3), low temperature molten salt pump (4), high temperature molten salt pump (5), brine heat exchanger (6 ) The closed pipeline formed is a molten salt circuit; The shell side of the brine heat exchanger (6) is connected with the heat user through the water supply pipeline (30) and the return water pipeline (31) to form a water circuit, and there is water on the water supply pipeline at the outlet of the shell side of the brine heat exchanger (6). The loop system pressure sensor (24), the water loop system temperature sensor (25), the water loop system flow sensor (26), the circulating water pump (27) and the constant pressure replenishment and water treatment system ( 28). the 2. According to the molten salt regenerative electric heating central heating system according to claim 1, it is characterized in that: hot molten salt pumps ( 5), cold molten salt pump (4), two molten salt pumps are installed on the top of each tank, one for use and one for standby. the 3. According to the molten salt regenerative electric heating central heating system according to claim 1, it is characterized in that: a hot salt tank temperature sensor (12) for monitoring temperature is installed on the hot salt tank (2), and a hot salt tank temperature sensor (12) for monitoring the temperature is installed on the upper part. The liquid level monitoring port (14) of the hot brine tank is installed at the lower part, and the salt discharge port (16) of the hot brine tank for emptying the molten salt is installed on the lower part; the temperature sensor of the cold brine tank for monitoring the temperature is installed on the cold brine tank (3) (13), the top is equipped with a cold salt tank liquid level monitoring port (15) for monitoring liquid level, and the bottom is equipped with a cold salt tank discharge port (17) for emptying molten salt. the 4. The molten salt regenerative electric heating central heating system according to claim 1, characterized in that: a hot salt pipeline pressure sensor is installed on the pipeline between the molten salt electric heater (1) and the hot salt tank (2) (18), hot salt pipeline temperature sensor (19), hot salt pipeline flow sensor (20), cold salt pipeline is installed on the pipeline between the molten salt electric heater (1) and the cold salt tank (3) Pressure sensor (21), cold salt pipeline temperature sensor (22), cold salt pipeline flow sensor (23). the 5. The molten salt regenerative electric heating central heating system according to claim 1, characterized in that: the brine heat exchanger (6) adopts a shell-and-tube structure, the molten salt is in the pipeline system, and the water is in the shell-side system. The two adopt the form of forced convection heat exchange for heat exchange. the 6. The molten salt regenerative electric heating central heating system according to claim 1, characterized in that it further comprises a controller (8) connected to the sensors and power sources of the molten salt loop system and the water loop system respectively. the