A heating system and control method

Abstract

The present application relates to the technical field of heat supply, in particular to a heat supply system and a control method. The heat supply system comprises a gas combined heat and power module, which generates heat; a heat receiving terminal, which receives heat; and a phase change heat storage device, which comprises a phase change element and is connected to the gas combined heat and power module and the heat receiving terminal in a pipeline manner. When the temperature of the phase change element is lower than the phase change point temperature, the phase change element absorbs and stores heat. When the temperature of the phase change element is higher than the phase change point temperature, the phase change element releases heat to the heat receiving terminal. The present application solves the problem that the long-term and concentrated use of "electricity instead of coal" in the winter heating process increases the power supply burden and increases the risk of power limitation and power outage, thereby providing a heat supply system and a control method.

Description

Technical Field

[0001] This invention relates to the field of heating technology, specifically to a heating system and control method. Background Technology

[0002] Rural areas in northern China have a high demand for energy. During the winter heating season, many rural areas in the north still rely on scattered coal burning for self-heating, with annual coal consumption equivalent to about 200 million tons of standard coal. Carbon emissions from heating account for about 45% of the total carbon emissions in rural areas of northern China.

[0003] During the winter heating season, "electricity replacing coal" is characterized by high power output, strong rigidity, and concentrated time periods. Its large-scale development brings an additional burden to the power grid on ensuring supply during peak periods. Long-term and concentrated use by users increases the burden on power supply and raises the risk of power rationing and outages. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing technology of "electricity replacing coal" in winter heating, which increases the power supply burden and the risk of power rationing and power outages due to long-term and concentrated use by users, thereby providing a heating system and control method.

[0005] To address the above problems, the present invention provides a heating system, comprising:

[0006] A gas-fired cogeneration module, wherein the gas-fired cogeneration module generates heat;

[0007] A heating terminal, wherein the heating terminal is used to receive heat;

[0008] A phase change thermal storage device includes a phase change element. The phase change thermal storage device is connected to a gas-fired cogeneration module and a heating terminal pipeline. When the temperature of the phase change element is lower than the phase change point temperature, the phase change element absorbs heat for storage. When the temperature of the phase change element is higher than the phase change point temperature, it emits heat and transfers it to the heating terminal.

[0009] Optionally, a heat pump module is also provided between the gas-fired cogeneration module and the phase change heat storage device.

[0010] Optionally, the heat pump module includes a high-temperature stage compressor, a condenser, a high-temperature throttling device, an auxiliary heat exchanger, and a condenser-evaporator. The high-temperature stage compressor, condenser, high-temperature throttling device, auxiliary heat exchanger, and condenser-evaporator are sequentially connected by pipelines to form a closed-loop circulation. The condenser is connected to the phase change element by pipeline.

[0011] Optionally, the heat pump module further includes a low-temperature stage compressor, an evaporator, and a low-temperature throttling device, wherein the low-temperature stage compressor, condenser-evaporator, low-temperature throttling device, and evaporator are sequentially connected by pipelines to form a closed-loop circulation.

[0012] Optionally, the gas-fired cogeneration module includes a natural gas combustion chamber, a flue gas heat exchanger, a gas turbine, and a generator, which are connected in sequence.

[0013] Optionally, the gas-fired cogeneration module further includes a circulating pump, and the flue gas heat exchanger, auxiliary heat exchanger, and circulating pump are connected in sequence via pipelines to form a closed-loop circulation.

[0014] Optionally, the condenser is connected to the heating terminal pipeline, and a water pump and a pressure tank are connected to the pipeline between the phase change heat storage device and the heating terminal.

[0015] Optionally, it also includes a control component, which is communicatively connected to the heat pump module, the phase change thermal storage device, the gas-fired cogeneration module, and the heat-receiving terminal.

[0016] A control method for a heating system, wherein during the heating process, when the power grid is in a low-temperature period and the temperature of the phase change element is lower than the phase change point temperature, the phase change element stores heat by absorbing heat; when the power grid is in a high-temperature period and the temperature of the phase change element is higher than the phase change point temperature, the phase change element releases heat and transfers it to the heating terminal.

[0017] Optionally, the following steps are included:

[0018] 1) Start the heat pump module. The condenser in the heat pump module provides heat to the phase change element for heat storage.

[0019] 2) During the heat storage process, when the power grid is in a low-load period, the controller determines whether the heat pump module can meet the controlled heat output based on monitoring indicators. If the heat pump module can meet the target heat output, the gas cogeneration module is shut down, and the frequency of the low-temperature stage compressor is reduced to achieve the output heat output of the heating system. If the heat pump module cannot meet the target heat output, the gas cogeneration module is started, and the waste heat is provided through the auxiliary heat exchanger of the natural gas-fired heat pump module. The frequency of the low-temperature stage compressor is adjusted to control the output heat output of the system. At the same time, current is generated and fed into the power grid.

[0020] 3) When the temperature of the heat storage material of the phase change element is higher than the phase change point temperature, the power grid is in peak period, the heat storage process ends, the heat pump module and the gas cogeneration module stop working, the phase change element releases heat to provide heat to the heat receiving terminal;

[0021] 4) Repeat steps 1)-3) to alternate between heat storage and heat release to provide heating to the heating terminals. When the heating system reaches its operating time, the heating system will stop operating.

[0022] The technical solution of this invention has the following advantages:

[0023] 1. The heating system provided by this invention includes: a gas-fired cogeneration module to generate heat; a heating terminal to receive heat; and a phase change heat storage device, including a phase change element connected to the gas-fired cogeneration module and the heating terminal piping respectively. When the temperature of the phase change element is lower than the phase change point temperature, the phase change element absorbs and stores heat; when the temperature of the phase change element is higher than the phase change point temperature, it releases heat and transfers it to the heating terminal. Through the heat storage and transfer of the phase change element, heat storage and transfer are achieved, thereby adjusting the heat release and storage mode of the heating system and reducing the heating pressure on the gas-fired cogeneration module. Simultaneously, through the intermediate role of the phase change element, heating can be provided during peak grid periods and heat storage can be achieved during off-peak periods, avoiding long-term, concentrated power consumption by the heating terminal during peak periods, effectively reducing the power supply burden, ensuring the stability of the system's heating supply, and reducing the risk of power rationing and outages.

[0024] 2. The heating system provided by the present invention further includes a heat pump module between the gas-fired cogeneration module and the phase change heat storage device. The heat pump module is used to adjust the gas-fired cogeneration module to ensure the stability of the heating system.

[0025] 3. The heating system provided by the present invention includes a pump module comprising a high-temperature stage compressor, a condenser, a high-temperature throttling device, an auxiliary heat exchanger, and a condenser-evaporator. The high-temperature stage compressor, condenser, high-temperature throttling device, auxiliary heat exchanger, and condenser-evaporator are sequentially connected by pipelines to form a closed-loop circulation. The condenser is connected to the phase change element by pipelines. The high-temperature stage closed-loop circulation is achieved through the sequential connection of the high-temperature stage compressor, condenser, high-temperature throttling device, auxiliary heat exchanger, and condenser-evaporator to provide heat to the auxiliary heat exchanger. At the same time, the condenser in the high-temperature stage circulation provides heat to the phase change element.

[0026] 4. The heating system provided by this invention includes a heat pump module further comprising a low-temperature stage compressor, an evaporator, and a low-temperature throttling device. The low-temperature stage compressor, condenser-evaporator, low-temperature throttling device, and evaporator are sequentially connected by pipelines to form a closed-loop cycle. Through the sequential pipeline connection of the low-temperature stage compressor, evaporator, and low-temperature throttling device, a low-temperature stage closed-loop cycle is formed. That is, if the heat pump module can meet the target heating capacity, the gas-fired cogeneration module is shut down, and the system output heating capacity is achieved by reducing the frequency of the low-temperature stage compressor in the heat pump module.

[0027] 5. The heating system provided by the present invention includes a gas-fired cogeneration module comprising a natural gas combustion chamber, a flue gas heat exchanger, a gas turbine, and a generator. The natural gas combustion chamber, the flue gas heat exchanger, the gas turbine, and the generator are connected in sequence, and the gas turbine is driven to rotate by burning natural gas to generate electricity.

[0028] 6. The heating system provided by the present invention further includes a gas-fired cogeneration module, a circulating pump, a flue gas heat exchanger, an auxiliary heat exchanger, and the circulating pump connected in sequence by pipelines to form a closed loop circulation, wherein the flue gas heat exchanger provides heat to the auxiliary heat exchanger.

[0029] 7. The heating system provided by this invention includes a condenser connected to a heating terminal pipeline, and a water pump and a pressure tank connected to the pipeline between the phase change heat storage device and the heating terminal. The condenser is connected to the heating terminal pipeline to provide heat to the heating terminal. The water pump drives water flow to achieve heat exchange, and the pressure tank monitors the pipeline pressure.

[0030] 8. The heating system provided by the present invention also includes a control component, which is communicatively connected to the heat pump module, the phase change heat storage device, and the gas cogeneration module to realize automatic monitoring and control. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of a heating system provided in an embodiment of the present invention.

[0033] Explanation of reference numerals in the attached diagram: 1. Gas-fired cogeneration module; 101. Natural gas combustion chamber; 102. Flue gas heat exchanger; 103. Gas turbine; 104. Generator; 105. Circulating pump; 2. Heat pump module; 201. Low-temperature throttling device; 202. Evaporator; 203. Low-temperature stage compressor; 204. Condenser-evaporator; 205. Auxiliary heat exchanger; 206. High-temperature throttling device; 207. High-temperature stage compressor; 208. Condenser; 3. Phase change heat storage device; 301. Phase change element; 302. Pressure tank; 303. Water pump; 4. Heating terminal; 401. Radiator. Detailed Implementation

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] like Figure 1 One specific implementation of the provided heating system includes: a gas-fired cogeneration module 1, a heat pump module 2, a phase change thermal storage device 3, and a heat receiving terminal 4.

[0039] like Figure 1 As shown, the gas-fired cogeneration module 1 includes a natural gas combustion chamber 101, a flue gas heat exchanger 102, a gas turbine 103, a circulating pump 105, and a generator 104, wherein the natural gas combustion chamber 101, the flue gas heat exchanger 102, the gas turbine 103, and the generator 104 are connected in sequence.

[0040] like Figure 1 As shown, the heat pump module 2 includes a high-temperature compressor 207, a condenser 208, a high-temperature throttling device 206, an auxiliary heat exchanger 205, and a condenser-evaporator 204. The high-temperature compressor 207, condenser 208, high-temperature throttling device 206, auxiliary heat exchanger 205, and condenser-evaporator 204 are sequentially connected by piping to form a closed-loop circulation. The condenser 208 is connected by piping to the phase change element 301 of the phase change heat storage device 3. Figure 1 As shown, the heat pump module 2 also includes a low-temperature stage compressor 203, an evaporator 202, and a low-temperature throttling device 201. The low-temperature stage compressor 203, the condenser-evaporator 204, the low-temperature throttling device 201, and the evaporator 202 are sequentially connected by pipelines to form a closed-loop cycle. For connection with the gas-fired cogeneration module 1, as shown... Figure 1As shown, the flue gas heat exchanger 102, auxiliary heat exchanger 205, and circulating pump 105 are connected in sequence via pipelines to form a closed-loop circulation. Figure 1 As shown, the condenser 208 is connected to the heating terminal 4 via a pipeline.

[0041] like Figure 1 As shown, the phase change heat storage device 3 includes a phase change element 301, a water pump 303, and a pressure tank 302. The water pump 303 and the pressure tank 302 are connected to the pipeline between the phase change heat storage device 3 and the heating terminal 4.

[0042] like Figure 1 As shown, the radiator 401 of the heated terminal 4 is connected to the phase change element 301 and the condenser 208 pipeline respectively.

[0043] To enable monitoring and control, a control component is also included. This control component is communicatively connected to the heat pump module 2, the phase change thermal storage device 3, the gas-fired cogeneration module 1, and the heat receiving terminal 4. For automatic control, the control component includes a controller, temperature sensor, humidity sensor, power meter, pressure sensor, and flow meter. The controller is communicatively connected to the temperature sensor, humidity sensor, power meter, pressure sensor, and flow meter to detect information such as temperature, humidity, power, pressure, and flow rate during the operation of the heating system. To enable monitoring, temperature sensors are installed in the natural gas combustion chamber 101, flue gas heat exchanger 102, phase change element 301, heating terminal 4, condenser-evaporator 204, and condenser 208, respectively; humidity sensors are installed in the heating terminal 4 and evaporator 202, respectively; power meters are installed in the generator 104, low-temperature compressor 203, and high-temperature compressor 207; pressure sensors are installed in the phase change element 301, circulating pump 105, low-temperature compressor 203, and high-temperature compressor 207; and flow meters are installed in the water pump 303, low-temperature throttling device 201, high-temperature throttling device 206, and circulating pump 105.

[0044] A control method for a heating system, suitable for power supply from the power grid, includes the following steps:

[0045] 1) Start the heat pump module 2. The condenser 208 in the heat pump module 2 provides heat to the phase change element 301 for heat storage.

[0046] 2) During the heat storage process, when the power grid is in a low-load period, the controller judges whether the full-load operation of the heat pump module 2 meets the control heat demand based on the monitoring indicators. If the heat pump module 2 can meet the target heat demand, the gas cogeneration module 1 is shut down, and the frequency of the low-temperature compressor 203 is reduced to achieve the output heat demand of the heating system. If the heat pump module 2 cannot meet the target heat demand, the gas cogeneration module 1 is started, and the waste heat is provided by the auxiliary heat exchanger 205 of the natural gas-fired heat pump module 2. The frequency of the low-temperature compressor 203 is adjusted to control the output heat demand of the system. At the same time, the generated current is connected to the power grid.

[0047] 3) When the temperature of the heat storage material of the phase change element 301 is higher than the phase change point temperature, the power grid is in peak period, the heat storage process ends, the heat pump module 2 and the gas cogeneration module 1 stop working, the phase change element 301 releases heat to provide heat to the heating terminal 4.

[0048] 4) Repeat steps 1)-3) to alternate between heat storage and heat release to provide heating for the heating terminal 4. When the heating system reaches its operating time, the heating system will stop operating.

[0049] The heating system provided by the present invention has the following advantages: (1) The heating system of the present invention includes a heat pump module 2, a phase change heat storage device 3 and a gas cogeneration module 1. By coupling air energy, gas energy and heat storage, and using multi-energy complementary technology, multi-source efficiency-enhancing heat pump technology and phase change heat storage technology, under the premise of meeting the basic heating needs of the heating terminal 4 (e.g., rural areas), it solves the problems of high operating cost of heating system, poor heating stability in low temperature environment and high requirements for distribution network capacity, improves the utilization rate of renewable energy in the heating area, reduces the operating cost of the system, improves the stability of system operation, and reduces the power supply pressure of the distribution network in the relevant area; (2) The control method of the present invention adjusts the heat release and heat storage mode of the system by judging the temperature of the phase change material, thereby reducing the power supply pressure of the distribution network in the heating terminal 4 (e.g., rural areas); (3) The control method of the present invention adjusts the opening of the gas cogeneration module 1 of the system by judging the heat output of the heat pump system, and ensures the stability of the heating system by supplementing waste heat.

[0050] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A heating system suitable for being powered by the power grid, characterized in that, include: Gas-fired cogeneration module (1), the gas-fired cogeneration module (1) generates heat; Heating terminal (4), the heating terminal (4) is used to receive heat; The phase change heat storage device (3) includes a phase change element (301). The phase change heat storage device (3) is connected to the gas cogeneration module (1) and the heating terminal (4) respectively. When the temperature of the phase change element (301) is lower than the phase change point temperature, the phase change element (301) absorbs heat for storage. When the temperature of the phase change element (301) is higher than the phase change point temperature, it emits heat and transfers it to the heating terminal (4). A heat pump module (2) is also provided between the gas-fired cogeneration module (1) and the phase change heat storage device (3); The heat pump module (2) includes a high-temperature compressor (207), a condenser (208), a high-temperature throttle (206), an auxiliary heat exchanger (205), and a condenser-evaporator (204). The high-temperature compressor (207), condenser (208), high-temperature throttle (206), auxiliary heat exchanger (205), and condenser-evaporator (204) are connected in sequence by pipelines to form a closed-loop circulation. The condenser (208) is connected to the phase change element (301) by pipeline. The heat pump module (2) also includes a low-temperature stage compressor (203), an evaporator (202), and a low-temperature throttling device (201). The low-temperature stage compressor (203), the condenser-evaporator (204), the low-temperature throttling device (201), and the evaporator (202) are connected in sequence by pipelines to form a closed loop. The condenser (208) is connected to the heating terminal (4) by a pipeline, and a water pump (303) and a pressure tank (302) are connected to the pipeline between the phase change heat storage device (3) and the heating terminal (4). The gas-fired cogeneration module (1) includes a flue gas heat exchanger (102) and a circulating pump (105). The flue gas heat exchanger (102), the auxiliary heat exchanger (205), and the circulating pump (105) are connected in sequence to form a closed loop.

2. The heating system according to claim 1, characterized in that, The gas-fired cogeneration module also includes a natural gas combustion chamber (101), a flue gas heat exchanger (102), a gas turbine (103), and a generator (104), which are connected in sequence.

3. The heating system according to claim 2, characterized in that, It also includes a control component, which is connected in communication with the heat pump module (2), the phase change heat storage device (3), the gas cogeneration module (1), and the heat receiving terminal (4).

4. A control method for a heating system, used to control the heating system of claim 1, characterized in that, During the heating process, when the power grid is in a low period and the temperature of the phase change element (301) is lower than the phase change point temperature, the phase change element (301) stores heat by absorbing it; when the power grid is in a high period and the temperature of the phase change element (301) is higher than the phase change point temperature, it emits heat and transfers it to the heating terminal (4).

5. The control method for the heating system according to claim 4, characterized in that, Includes the following steps: 1) Start the heat pump module (2), and the condenser (208) in the heat pump module (2) provides heat to the phase change element (301) for heat storage; 2) During the heat storage process, the power grid is in a low period. The controller judges whether the heat pump module (2) is running at full load to meet the control heat according to the monitoring indicators. If the heat pump module (2) can meet the target heat production, the gas cogeneration module (1) is shut down and the frequency of the low temperature compressor (203) is reduced to achieve the output heat production of the heating system. If the heat pump module (2) cannot meet the target heat production, the gas cogeneration module (1) is started and the waste heat is provided through the auxiliary heat exchanger (205) of the natural gas heat pump module (2). The frequency of the low temperature compressor (203) is adjusted to control the output heat production of the system. At the same time, the current is generated and connected to the power grid. 3) When the temperature of the heat storage material of the phase change element (301) is higher than the phase change point temperature, the power grid is in peak period, the heat storage process ends, the heat pump module (2) and the gas cogeneration module (1) stop working, the phase change element (301) releases heat to provide heat to the heat receiving terminal (4); 4) Repeat steps 1)-3) alternately to store and release heat to provide heating for the heating terminal (4). When the heating system reaches the operating time, the heating system ends operation.

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