Variable operating condition steam generation system and its control method

Abstract

The present invention discloses a variable-condition steam generation system and its control method. The variable-condition steam generation system includes: a first outlet of a first flash tank is connected to an intake port of a steam compressor through a first pipeline, and the first outlet of the first flash tank is also connected to an exhaust port of the steam compressor through a second pipeline; a second outlet of the first flash tank is connected to a buffer water tank through a third pipeline, and the second outlet of the first flash tank is connected to an inlet of a first centrifugal pump through a fourth pipeline; an outlet of the first centrifugal pump is connected to an inlet of a second flash tank, a third outlet of the second flash tank is connected to the intake port of the steam compressor, and a fourth outlet of the second flash tank is connected to an inlet of the buffer water tank; an outlet of the buffer water tank is connected to an inlet of a second centrifugal pump, an outlet of the second centrifugal pump is connected to the inlet of the second flash tank through a fifth pipeline, and the outlet of the second centrifugal pump is also connected to an inlet of a heat absorption pipe through a sixth pipeline.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pumps, and particularly to a variable-condition steam generation system and a control method thereof. Background Art

[0002] Many industrial fields have increasingly higher requirements for energy efficiency. Traditional steam boilers often have low efficiency under partial load, resulting in energy waste. A variable-flow steam generation system can adjust the steam output according to actual demand, reduce energy loss, and conform to the trend of energy conservation and emission reduction.

[0003] With the improvement of industrial automation level, higher requirements are imposed on the control accuracy and response speed of the steam system. A variable-flow steam generation system can achieve precise temperature and flow control to meet the needs of an automated production line. The steam generation system can be widely applied to multiple industries such as chemical industry, pharmaceutical industry, food industry, textile industry, and paper industry. The demands for steam in these industries are different, and the variable-flow steam generation system can meet the personalized needs of different industries.

[0004] Traditional steam boilers are often designed according to the maximum load, but in actual operation, the demand at the gas-using end often changes. A variable-flow steam generation system can adjust the steam output according to actual demand, avoid the situation of steam surplus or shortage, improve production efficiency, increase energy utilization rate, and reduce production costs.

[0005] The design of a large-flow flash tank supporting a large steam generator is difficult, the tank body size is large, the cost is high, the power of the configured circulating water pump is large, and the installation process on site is difficult. It generally cannot be arranged inside a general workshop. During use, when the required steam flow is low, the power consumption of the configured circulating water pump is large and the operating cost is high. If multiple small flash tanks are used for gas supply linkage control, the equipment manufacturing difficulty is low, the construction difficulty is low, the operating cost is low, and the cost is low.

[0006] A variable-condition steam generation system can achieve precise temperature and flow control, ensure the stable quality of steam, meet the process requirements with higher requirements for steam quality, can reduce manual intervention, and lower the operation and maintenance costs. At the same time, because the system operates more stably, it can also reduce equipment failures and lower the maintenance costs.

[0007] Therefore, there is an urgent need for a variable-condition steam generation technology to replace the defects of traditional steam boilers and make up for the defects that traditional heat pump units on the current market cannot achieve steam flow and temperature regulation. Summary of the Invention

[0008] In view of the above technical problems, the present invention provides a variable-condition steam generation system and a control method thereof, which can adjust the steam output according to actual demand, avoid the situation of steam surplus or shortage, and improve production efficiency.

[0009] In a first aspect of the present invention, a variable-condition steam generation system is provided, comprising: a condenser, a high-temperature heat pump compressor, an evaporator, a first flash tank, a second flash tank, a buffer water tank, a first centrifugal pump, a second centrifugal pump, and a steam compressor; the condenser includes a heat-releasing pipe and a heat-absorbing pipe, wherein,

[0010] The outlet of the heat-absorbing pipe is communicated with the inlet of the first flash tank. The first outlet of the first flash tank is communicated with the suction port of the steam compressor through a first pipeline, and the first outlet of the first flash tank is also communicated with the exhaust port of the steam compressor through a second pipeline. The second outlet of the first flash tank is communicated with the buffer water tank through a third pipeline, and the second outlet of the first flash tank is communicated with the inlet of the first centrifugal pump through a fourth pipeline;

[0011] The outlet of the first centrifugal pump is communicated with the inlet of the second flash tank. The third outlet of the second flash tank is communicated with the suction port of the steam compressor, and the fourth outlet of the second flash tank is communicated with the inlet of the buffer water tank;

[0012] The outlet of the buffer water tank is communicated with the inlet of the second centrifugal pump. The outlet of the second centrifugal pump is communicated with the inlet of the second flash tank through a fifth pipeline, and the outlet of the second centrifugal pump is also communicated with the inlet of the heat-absorbing pipe through a sixth pipeline.

[0013] In an optional embodiment, the inlet of the heat-releasing pipe is communicated with the exhaust port of the high-temperature heat pump compressor, and the outlet of the heat-releasing pipe is communicated with the inlet of the evaporator through a solenoid valve.

[0014] In an optional embodiment, a first stop valve and a second stop valve are provided on the first pipeline, a third stop valve is provided on the second pipeline, a fifth stop valve is provided on the third pipeline, a fourth stop valve is provided on the fourth pipeline, and a sixth stop valve is provided on the fifth pipeline.

[0015] In an optional embodiment, the inlet of the second stop valve is also communicated with the third outlet of the second flash tank, the fourth stop valve is communicated with the inlet of the first centrifugal pump, and the sixth stop valve is communicated with the inlet of the second flash tank.

[0016] In an optional embodiment, a flow meter is provided at the exhaust port of the steam compressor, and the flow meter is connected to the high-temperature heat pump compressor, the first centrifugal pump, the second centrifugal pump, the first stop valve, the second stop valve, the third stop valve, and the steam compressor through signal lines.

[0017] In an optional embodiment, a check valve is further provided between the exhaust port of the steam compressor and the flow meter.

[0018] In an alternative embodiment, the variable-condition steam generation system further includes a first pressure gauge and a first thermometer, and the first pressure gauge and / or the first thermometer are disposed on a pipeline for connecting the outlet of the heat absorption pipe to the inlet of the first flash tank.

[0019] In an alternative embodiment, the variable-condition steam generation system further includes a second pressure gauge and a second thermometer, and the second pressure gauge and / or the second thermometer are disposed on the fifth pipeline.

[0020] In an alternative embodiment, the high-temperature heat pump compressor is respectively connected to the condenser and the evaporator, the first flash tank is communicated with the second flash tank, and the first flash tank and the second flash tank are respectively connected to the buffer water tank.

[0021] In a second aspect of the present invention, there is provided a control method for a variable-condition steam generation system, including:

[0022] When the steam demand flow rate is X1 and the temperature requirement is lower than the threshold, start the second centrifugal pump and the high-temperature heat pump compressor, and control the outlet of the heat absorption pipe to be communicated with the first flash tank, the buffer water tank, the second centrifugal pump, and the inlet of the heat absorption pipe; control the outlet of the heat absorption pipe to be communicated with the first flash tank and supply steam through the second pipeline;

[0023] When the steam demand flow rate is X2 and the temperature requirement is lower than the threshold, start the first centrifugal pump, the second centrifugal pump, and the high-temperature heat pump compressor. The second outlet of the first flash tank is connected to the inlet of the second flash tank through the first centrifugal pump, and the second outlet of the second flash tank is communicated with the buffer water tank, the second centrifugal pump, and the inlet of the heat absorption pipe; control the outlet of the heat absorption pipe to be communicated with the first outlet of the first flash tank and the first outlet of the second flash tank and supply steam through the second pipeline;

[0024] When the steam demand flow rate is X3 and the temperature requirement is lower than the threshold, start the high-temperature heat pump compressor, control the outlet of the heat absorption pipe to be communicated with the first outlet of the first flash tank and supply steam through the second pipeline; control the second centrifugal pump to be communicated with the second flash tank through the sixth pipeline and control the second outlet of the first flash tank to be communicated with the buffer water tank, so that the second outlet of the first flash tank, the buffer water tank, the second centrifugal pump, and the inlet of the second flash tank form a passage and are connected to the second pipeline. Start the second centrifugal pump to connect the buffer water tank to the inlet of the heat absorption pipe;

[0025] Wherein X1 < X2 < X3.

[0026] In an alternative embodiment, when the vapor demand flow rate is X1 and the temperature requirement is higher than the threshold value, the second centrifugal pump, the high-temperature heat pump compressor, and the steam compressor are started. The first outlet of the first flash tank is controlled to communicate with the suction port of the steam compressor, and steam is provided through the first pipeline. Also, the outlet of the heat absorption pipe is controlled to communicate with the first flash tank, the buffer water tank, the second centrifugal pump, and the inlet of the heat absorption pipe;

[0027] When the vapor demand flow rate is X2 and the temperature requirement is higher than the threshold value, the first centrifugal pump, the second centrifugal pump, the high-temperature heat pump compressor, and the steam compressor are started. The outlet of the heat absorption pipe is controlled to communicate with the first outlet of the first flash tank and the first outlet of the second flash tank, and steam is provided through the first pipeline. The second outlet of the first flash tank is connected to the inlet of the second flash tank through the first centrifugal pump. The second outlet of the second flash tank is controlled to communicate with the buffer water tank, the second centrifugal pump, and the inlet of the heat absorption pipe;

[0028] When the vapor demand flow rate is X3 and the temperature requirement is higher than the threshold value, the high-temperature heat pump compressor is started. The outlet of the heat absorption pipe is controlled to communicate with the first outlet of the first flash tank, and steam is provided through the first pipeline. The second centrifugal pump is controlled to communicate with the second flash tank through the sixth pipeline, and the second outlet of the first flash tank is controlled to communicate with the buffer water tank, so that the second outlet of the first flash tank, the buffer water tank, the second centrifugal pump, and the inlet of the second flash tank form a path and are connected to the first pipeline. The second centrifugal pump is started to connect the buffer water tank with the inlet of the heat absorption pipe and the inlet of the second flash tank, and at the same time, the buffer water tank is connected to the inlet of the heat absorption pipe.

[0029] In the present invention, the first flash tank and the second flash tank are connected in a series-parallel manner, which can enable multiple pipelines to provide steam for the gas-using end. Moreover, the multiple pipelines are connected to the buffer water tank, which can utilize the water in the buffer water tank to store heat and adjust the steam output by selecting different series-parallel methods according to different working conditions using the stored heat, avoiding the situation of steam surplus or shortage and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of a variable-condition steam generation system in an embodiment of the present invention.

[0031] 1. Evaporator; 2. Condenser; 3. High-temperature heat pump compressor; 4. Solenoid valve; 5. First flash tank; 6. Second flash tank; 7. Steam compressor; 8. Buffer water tank; 9. First centrifugal pump; 10. Second centrifugal pump; 11. First thermometer; 12. First pressure gauge; 13. Second thermometer; 14. Second pressure gauge; 15. First stop valve; 16. Second stop valve; 17. Third stop valve; 18. Check valve; 19. Flowmeter; 20. Third thermometer; 21. Third pressure gauge; 22. Fourth stop valve; 23. Fifth stop valve; 24. Sixth stop valve; a1. Inlet of the heat release pipe; a2. Outlet of the heat release pipe; a3. Outlet of the heat absorption pipe; a4. Inlet of the heat absorption pipe; c1. Inlet of the first flash tank; c2. First outlet; c3. Second outlet; d1. Inlet of the second flash tank; d2. Third outlet; d3. Fourth outlet; e1. Inlet of the buffer water tank; e2. Outlet of the buffer water tank; f1. Suction port of the steam compressor; f2. Discharge port of the steam compressor. Detailed implementation mode

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0033] It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0034] Please refer to Figure 1, the present invention provides a variable operating condition steam generation system, including a condenser 2, a high-temperature heat pump compressor 3, an evaporator 1, a first flash tank 5, a second flash tank 6, a buffer water tank 8, a first centrifugal pump 9, a second centrifugal pump 10, and a steam compressor 7. The high-temperature heat pump compressor 3 is respectively connected to the condenser 2 and the evaporator 1 to form a heating cycle. The first flash tank 5 is communicated with the second flash tank 6, and the first flash tank 5 and the second flash tank 6 are respectively connected to the buffer water tank 8.

[0035] The operating power of the high-temperature heat pump compressor 3 is proportional to the steam demand and the temperature demand. The greater the steam demand and the higher the temperature demand, the greater the power of the high-temperature heat pump compressor 3. When there is a steam usage demand, the high-temperature heat pump compressor 3 starts, raises the temperature and pressure of the refrigerant, releases heat in the condenser 2, and after the condensed refrigerant is depressurized by the solenoid valve 4, it enters the evaporator 1 to absorb heat from the environment and then enters the high-temperature heat pump compressor 3 to form a closed cycle.

[0036] The condenser 2 delivers heat to the first flash tank 5. Specifically, the condenser 2 includes a heat release pipe and a heat absorption pipe. The inlet a1 of the heat release pipe is communicated with the exhaust port of the high-temperature heat pump compressor 3, and the outlet a2 of the heat release pipe is communicated with the inlet of the evaporator 1 through the solenoid valve 4. The outlet a3 of the heat absorption pipe is communicated with the inlet c1 of the first flash tank, and the inlet a4 of the heat absorption pipe is communicated with the buffer water tank 8 through the second centrifugal pump 10.

[0037] The first flash tank 5 includes two steam output pipes. One is the first pipeline: the first outlet c2 at the upper part of the first flash tank 5 is communicated with the suction port f1 of the steam compressor through the first pipeline. A first stop valve 15 and a second stop valve 16 are provided on the first pipeline, and the inlet of the second stop valve 16 is also communicated with the third outlet d2 of the second flash tank 6. The other is the second pipeline: the first outlet c2 of the first flash tank 5 is communicated with the exhaust port f2 of the steam compressor through the second pipeline; a third stop valve 17 is provided on the second pipeline. The first pipeline and the second pipeline can be determined by the positions of the first stop valve 15, the second stop valve 16, and the third stop valve 17. Specifically, refer to Figure 1 .

[0038] The second outlet c3 below the first flash tank 5 is connected to the buffer water tank 8 through a third pipeline, and a fifth stop valve 23 is provided on the third pipeline. By controlling the fifth stop valve 23, the first flash tank 5 can be connected to the inlet e1 of the buffer water tank. The second outlet c3 of the first flash tank 5 is connected to the inlet of the first centrifugal pump 9 through a fourth pipeline, and a fourth stop valve 22 is provided on the fourth pipeline. The fourth stop valve 22 is connected to the inlet of the first centrifugal pump 9. The outlet of the first centrifugal pump 9 is connected to the inlet d1 of the second flash tank.

[0039] The third outlet d2 above the second flash tank 6 is connected to the suction port f1 of the steam compressor through a second stop valve 16, and the fourth outlet d3 below the second flash tank 6 is directly connected to the inlet e1 of the buffer water tank. Since the design of a large-flow flash tank is difficult, the tank body size is large, the cost is high, the power of the configured circulating water pump is large, and the installation process on site is difficult, it is generally impossible to arrange inside the workshop. For example, when the steam flow rate requirement is low during use, the power consumption of the configured circulating water pump is large and the operating cost is high. The present invention uses two small flash tanks for air supply linkage control, with low operating costs and low construction costs.

[0040] The outlet e2 of the buffer water tank is connected to the inlet of the second centrifugal pump 10. The outlet of the second centrifugal pump 10 is connected to the inlet d1 of the second flash tank through a fifth pipeline, and a sixth stop valve 24 is provided on the fifth pipeline. The sixth stop valve 24 is connected to the inlet d1 of the second flash tank. The outlet of the second centrifugal pump 10 is also connected to the inlet a4 of the heat absorption pipe through a sixth pipeline. Through the above connection method, the water storage temperature in the buffer water tank 8 can be used to adjust the temperature, making the system operation more stable.

[0041] Please continue to refer to Figure 1 The exhaust port f2 of the steam compressor is provided with a flow meter 19. The flow meter 19 is connected to the high-temperature heat pump compressor 3, the first centrifugal pump 9, the second centrifugal pump 10, the first stop valve 15, the second stop valve 16, the third stop valve 17, and the steam compressor 7 through signal lines, facilitating unified control and adjustment of the system. A check valve 18 is also provided between the exhaust port f2 of the steam compressor and the flow meter 19 to prevent gas from flowing back at the gas-using end.

[0042] Further, the variable-condition steam generation system further includes a first pressure gauge 12 and a first thermometer 11. The first pressure gauge 12 and / or the first thermometer 11 are disposed on a pipeline for connecting the outlet of the heat absorption pipe and the inlet c1 of the first flash tank. In some embodiments, the variable-condition steam generation system further includes a second pressure gauge 14 and a second thermometer 13, and the second pressure gauge 14 and / or the second thermometer 13 are disposed on the fifth pipeline. The thermometer and the pressure gauge can monitor the temperature and pressure of the gas supply system in real time, so as to better control the temperature and gas flow rate.

[0043] The variable-condition steam generation system provided by the present invention will be further described below in combination with the control method of the variable-condition steam generation system. Taking the design flow rate of a single flash tank of 2 t / h, the heat release condensation temperature of the high-temperature heat pump of 120 °C, and the flash temperature difference of 5 °C as an example. Wherein X1 < X2 < X3.

[0044] When the steam demand flow rate is X1 and the temperature requirement is lower than the threshold, start the second centrifugal pump 10 and the high-temperature heat pump compressor 3, and connect the outlet a3 of the heat absorption pipe with the first flash tank 5, the buffer water tank 8, the second centrifugal pump 10, and the inlet of the heat absorption pipe; control the connection between the outlet a3 of the heat absorption pipe and the first flash tank 5, and provide steam through the second pipeline.

[0045] In one embodiment, when the steam demand flow rate is less than 2 t / h and the temperature requirement is lower than 115 °C, open the third stop valve 17 and the fifth stop valve 23, and close the first stop valve 15, the second stop valve 16, the fourth stop valve 22, and the sixth stop valve 24. The heat generated by the operation of the high-temperature heat pump compressor 3 is transferred to the first flash tank 5, and the first outlet c2 of the first flash tank 5 outputs water vapor through the second pipeline and the third stop valve 17. The second outlet c3 of the first flash tank 5 is connected to the buffer water tank 8 through the fifth stop valve 23 and the third pipeline. The buffer water tank 8 can provide heat energy or extract heat energy for the first flash tank 5. The operation of the second centrifugal pump 10 can transport the heat energy of the buffer water tank 8 to the inlet a4 of the heat absorption pipe and enter the condenser 2.

[0046] When the steam demand flow rate is X2 and the temperature requirement is lower than the threshold, start the first centrifugal pump 9, the second centrifugal pump 10, and the high-temperature heat pump compressor 3. The second outlet c3 of the first flash tank 5 is connected to the inlet d1 of the second flash tank through the first centrifugal pump 9, and the second outlet c3 of the second flash tank 6 is connected to the buffer water tank 8, the second centrifugal pump 10, and the inlet a4 of the heat absorption pipe; control the connection between the outlet a3 of the heat absorption pipe and the first outlet c2 of the first flash tank 5 and the first outlet c2 of the second flash tank 6, and provide steam through the second pipeline.

[0047] In one embodiment, when the vapor demand flow rate is 2 t / h to 3 t / h and the temperature requirement is below 115°C, the third shut-off valve 17 is opened, the fourth shut-off valve 22 is opened, the first shut-off valve 15 is opened, the second shut-off valve 16 is closed, the fifth shut-off valve 23 is closed, and the sixth shut-off valve 24 is closed. The heat generated by the operation of the high-temperature heat pump compressor 3 is transferred to the first flash tank 5 and the water vapor is output through the second pipeline and the third shut-off valve 17. At the same time, the second flash tank 6 is connected to the first flash tank 5 through the fourth shut-off valve 22, and the first outlet c2 of the second flash tank 6 flows through the second pipeline and the third shut-off valve 17 through the first shut-off valve 15 to output water vapor. The buffer water tank 8 can provide heat energy or extract heat energy for the second flash tank 6. The operation of the second centrifugal pump 10 can transport the heat energy of the buffer water tank 8 to the inlet a4 of the heat absorption pipe and into the condenser 2.

[0048] When the vapor demand flow rate is X3 and the temperature requirement is below the threshold value, the high-temperature heat pump compressor 3 is started, the outlet a3 of the heat absorption pipe is controlled to be connected to the first outlet c2 of the first flash tank 5, and the vapor is provided through the second pipeline; the second centrifugal pump 10 is controlled to be connected to the second flash tank 6 through the sixth pipeline, and the second outlet c3 of the first flash tank 5 is controlled to be connected to the buffer water tank 8, so that the second outlet c3 of the first flash tank 5 forms a path with the buffer water tank 8, the second centrifugal pump 10, and the inlet d1 of the second flash tank and is connected into the second pipeline. The second centrifugal pump 10 is started to connect the buffer water tank 8 to the inlet a4 of the heat absorption pipe.

[0049] In one embodiment, when the vapor demand flow rate is 3 - 4 t / h and the temperature requirement is below 115°C, the first shut-off valve 15 is opened, the third shut-off valve 17 is opened, the fifth shut-off valve 23 is opened, the sixth shut-off valve 24 is opened, the second shut-off valve 16 is closed, and the fourth shut-off valve 22 is closed. The high-temperature heat pump compressor 3 operates, and the first flash tank 5 provides water vapor. At the same time, the first flash tank 5 is connected to the buffer water tank 8 through the fifth shut-off valve 23. The second centrifugal pump 10 transports the heat energy of the buffer water tank 8 to the second flash tank 6 through the sixth shut-off valve 24. The first outlet c2 of the second flash tank 6 flows through the second pipeline and the third shut-off valve 17 through the first shut-off valve 15 to output water vapor.

[0050] When the vapor demand flow rate is X1 and the temperature requirement is above the threshold value, the second centrifugal pump 10, the high-temperature heat pump compressor 3, and the water vapor compressor 7 are started. The first outlet c2 of the first flash tank 5 is controlled to be connected to the suction port f1 of the water vapor compressor, and the vapor is provided through the first pipeline. The outlet a3 of the heat absorption pipe is controlled to be connected to the first flash tank 5, the buffer water tank 8, the second centrifugal pump 10, and the inlet a4 of the heat absorption pipe.

[0051] In one embodiment, when the vapor demand flow rate is less than 2 t / h and the temperature requirement is higher than 115 °C, the first stop valve 15 is opened, the second stop valve 16 is opened, the fifth stop valve 23 is opened, the third stop valve 17 is closed, the fourth stop valve 22 is closed, and the sixth stop valve 24 is closed. The high-temperature heat pump compressor 3 operates, and the first outlet c2 of the first flash tank 5 conveys water vapor through the first pipeline. The second outlet c3 of the first flash tank 5 is communicated with the buffer water tank 8 through the fifth stop valve 23. The second centrifugal pump 10 operates to connect the buffer water tank 8 and the condenser 2.

[0052] When the vapor demand flow rate is X2 and the temperature requirement is higher than the threshold value, the first centrifugal pump 9, the second centrifugal pump 10, the high-temperature heat pump compressor 3, and the water vapor compressor are started. The outlet of the heat absorption pipe is controlled to be communicated with the first outlet c2 of the first flash tank 5 and the first outlet c2 of the second flash tank 6, and vapor is provided through the first pipeline. The second outlet c3 of the first flash tank 5 is communicated with the inlet of the second flash tank 6 through the first centrifugal pump 9. The second outlet c3 of the second flash tank 6 is controlled to be communicated with the buffer water tank 8, the second centrifugal pump 10, and the inlet a4 of the heat absorption pipe.

[0053] In one embodiment, when the vapor demand flow rate is 2 - 3 t / h and the temperature requirement is higher than 115 °C, the first stop valve 15 is opened, the second stop valve 16 is opened, the fourth stop valve 22 is opened, the third stop valve 17 is closed, the fifth stop valve 23 is closed, and the sixth stop valve 24 is closed. The high-temperature heat pump compressor 3 operates, and the first outlet c2 of the first flash tank 5 conveys water vapor through the first pipeline. The first flash tank 5 is communicated with the second flash tank 6 through the fourth stop valve 22. The first centrifugal pump 9 operates, and the fourth outlet d3 of the second flash tank 6 is connected to the buffer water tank 8. The buffer water tank 8 adjusts the temperature. The second centrifugal pump 10 operates to connect the buffer water tank 8 and the condenser 2.

[0054] When the vapor demand flow rate is X3 and the temperature requirement is higher than the threshold value, the high-temperature heat pump compressor 3 is started. The outlet of the heat absorption pipe is controlled to be communicated with the first outlet c2 of the first flash tank 5 and vapor is provided through the first pipeline. The second centrifugal pump 10 is controlled to be communicated with the second flash tank 6 through the sixth pipeline, and the second outlet c3 of the first flash tank 5 is controlled to be communicated with the buffer water tank 8, so that the second outlet c3 of the first flash tank 5, the buffer water tank 8, the second centrifugal pump 10, and the inlet of the second flash tank 6 form a passage and are connected to the first pipeline. The second centrifugal pump 10 is started to connect the buffer water tank 8 with the inlet a4 of the heat absorption pipe and the inlet d1 of the second flash tank, and at the same time, the buffer water tank 8 is connected to the inlet a4 of the heat absorption pipe.

[0055] In one embodiment, when the vapor demand flow rate is 3 - 4 t / h and the temperature requirement is higher than 115°C, the first stop valve 15 is opened, the second stop valve 16 is opened, the fifth stop valve 23 is opened, the sixth stop valve 24 is opened, the third stop valve 17 is closed, and the fourth stop valve 22 is closed. The high-temperature heat pump compressor 3 operates, and the first flash tank 5 provides water vapor. At the same time, the first flash tank 5 is connected to the buffer water tank 8 through the fifth stop valve 23. The second centrifugal pump 10 transports the heat energy of the buffer water tank 8 to the second flash tank 6 through the sixth stop valve 24. The first outlet c2 of the second flash tank 6 flows through the second pipeline via the first stop valve 15 and the third stop valve 17 to output water vapor. The second centrifugal pump 10 operates to connect the buffer water tank 8 and the condenser 2.

[0056] Furthermore, the first thermometer is arranged on the pipeline between the outlet a3 of the heat absorption pipe in the condenser 2 and the inlet c1 of the first flash tank. When the temperature of the first thermometer 11 is higher than the set value, the operation of reducing the operating power of the high-temperature heat pump compressor 3 is of the highest priority. The second thermometer 13 is arranged on the pipeline where the first centrifugal pump 9 is connected to the inlet d1 of the second flash tank. When the temperature of the second thermometer 13 is lower than the set value, the following controls are of the highest priority: the fourth stop valve 22 is closed, the first centrifugal pump 9 is closed, the fifth stop valve 23 is opened, and the sixth stop valve 24 is opened. A third thermometer 20 and a third pressure gauge 21 are arranged after the flowmeter 19 to monitor the temperature and pressure of the output water vapor.

[0057] The buffer water tank provided by the present invention has a heat storage function. When the ambient temperature is high or the electricity cost is at a low valley, the water in the buffer tank can be utilized for storage, which can effectively buffer the influence of the heat output fluctuation of the high-temperature heat pump compressor on the flash temperature and improve the stability of the flash temperature. When there is a usage fluctuation at the gas consumption end, the water in the buffer tank can store the heat in time to prevent the high-temperature heat pump from shutting down suddenly due to the sudden usage fluctuation at the gas consumption end, resulting in the inability of the system to operate continuously. The present invention realizes six gas supply modes through a small-volume flash tank coupled with the high-temperature heat pump compressor in series, meeting the vapor demand of users with different usage amounts and different temperatures.

[0058] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A variable-condition steam generation system, characterized in that, Including: A condenser, a high-temperature heat pump compressor, an evaporator, a first flash tank, a second flash tank, a buffer water tank, a first centrifugal pump, a second centrifugal pump, and a steam compressor; The condenser includes a heat-releasing pipe and a heat-absorbing pipe, wherein, The outlet of the heat-absorbing pipe is communicated with the inlet of the first flash tank. The first outlet of the first flash tank is communicated with the suction port of the steam compressor through a first pipeline, and the first outlet of the first flash tank is also communicated with the exhaust port of the steam compressor through a second pipeline. The second outlet of the first flash tank is communicated with the buffer water tank through a third pipeline, and the second outlet of the first flash tank is communicated with the inlet of the first centrifugal pump through a fourth pipeline; The outlet of the first centrifugal pump is communicated with the inlet of the second flash tank. The third outlet of the second flash tank is communicated with the suction port of the steam compressor, and the fourth outlet of the second flash tank is communicated with the inlet of the buffer water tank; The outlet of the buffer water tank is communicated with the inlet of the second centrifugal pump. The outlet of the second centrifugal pump is communicated with the inlet of the second flash tank through a fifth pipeline, and the outlet of the second centrifugal pump is also communicated with the inlet of the heat-absorbing pipe through a sixth pipeline.

2. The variable operating condition steam generation system according to claim 1, wherein The inlet of the heat-releasing pipe is communicated with the exhaust port of the high-temperature heat pump compressor, and the outlet of the heat-releasing pipe is communicated with the inlet of the evaporator through a solenoid valve.

3. The variable operating condition steam generation system according to claim 1, characterized in that, A first stop valve and a second stop valve are provided on the first pipeline. A third stop valve is provided on the second pipeline. A fifth stop valve is provided on the third pipeline. A fourth stop valve is provided on the fourth pipeline. A sixth stop valve is provided on the fifth pipeline.

4. The variable operating condition steam generation system according to claim 3, characterized in that, The inlet of the second stop valve is also communicated with the third outlet of the second flash tank. The fourth stop valve is communicated with the inlet of the first centrifugal pump. The sixth stop valve is communicated with the inlet of the second flash tank.

5. The variable operating condition steam generation system according to claim 4, characterized in that, A flowmeter is provided at the exhaust port of the steam compressor. The flowmeter is connected to the high-temperature heat pump compressor, the first centrifugal pump, the second centrifugal pump, the first stop valve, the second stop valve, the third stop valve, and the steam compressor through signal lines.

6. The variable operating condition steam generation system according to claim 5, characterized in that A check valve is further provided between the exhaust port of the steam compressor and the flowmeter.

7. The variable operating condition steam generation system according to claim 1, wherein It further includes a first pressure gauge and a first thermometer. The first pressure gauge and / or the first thermometer is arranged on the pipeline for communicating the outlet of the heat-absorbing pipe with the inlet of the first flash tank.

8. The variable operating condition steam generation system according to claim 7, characterized in that, It further includes a second pressure gauge and a second thermometer. The second pressure gauge and / or the second thermometer is arranged on the fifth pipeline.

9. The variable operating condition steam generation system according to claim 1, wherein, The high-temperature heat pump compressor is respectively connected to the condenser and the evaporator. The first flash tank is communicated with the second flash tank, and the first flash tank and the second flash tank are respectively connected to the buffer water tank.

10. A control method applied to the variable operating condition steam generation system according to any one of claims 1 to 9, characterized in that, Including: When the steam demand flow rate is X1 and the temperature requirement is lower than the threshold value, start the second centrifugal pump and the high-temperature heat pump compressor, and control the outlet of the heat-absorbing pipe to be communicated with the first flash tank, the buffer water tank, the second centrifugal pump, and the inlet of the heat-absorbing pipe; control the outlet of the heat-absorbing pipe to be communicated with the first flash tank and provide steam through the second pipeline; When the steam demand flow rate is X2 and the temperature requirement is lower than the threshold value, start the first centrifugal pump, the second centrifugal pump, and the high-temperature heat pump compressor. The second outlet of the first flash tank is connected to the inlet of the second flash tank through the first centrifugal pump. The second outlet of the second flash tank is connected to the buffer water tank, the second centrifugal pump, and the inlet of the heat absorption pipe. Control the outlet of the heat absorption pipe to be connected to the first outlet of the first flash tank, the first outlet of the second flash tank, and supply steam through the second pipeline. When the steam demand flow rate is X3 and the temperature requirement is lower than the threshold value, start the high-temperature heat pump compressor. Control the outlet of the heat absorption pipe to be connected to the first outlet of the first flash tank and supply steam through the second pipeline. Control the second centrifugal pump to be connected to the second flash tank through the sixth pipeline, and control the second outlet of the first flash tank to be connected to the buffer water tank, so that the second outlet of the first flash tank, the buffer water tank, the second centrifugal pump, and the inlet of the second flash tank form a path and are connected to the second pipeline. Start the second centrifugal pump to connect the buffer water tank to the inlet of the heat absorption pipe. Where X1 < X2 < X3.

11. The control method according to claim 10, wherein It further includes: When the steam demand flow rate is X1 and the temperature requirement is higher than the threshold value, start the second centrifugal pump, the high-temperature heat pump compressor, and the steam compressor. Control the first outlet of the first flash tank to be connected to the suction port of the steam compressor and supply steam through the first pipeline. Control the outlet of the heat absorption pipe to be connected to the first flash tank, the buffer water tank, the second centrifugal pump, and the inlet of the heat absorption pipe. When the steam demand flow rate is X2 and the temperature requirement is higher than the threshold value, start the first centrifugal pump, the second centrifugal pump, the high-temperature heat pump compressor, and the steam compressor. Control the outlet of the heat absorption pipe to be connected to the first outlet of the first flash tank, the first outlet of the second flash tank, and supply steam through the first pipeline. The second outlet of the first flash tank is connected to the inlet of the second flash tank through the first centrifugal pump. Control the second outlet of the second flash tank to be connected to the buffer water tank, the second centrifugal pump, and the inlet of the heat absorption pipe. When the steam demand flow rate is X3 and the temperature requirement is higher than the threshold value, start the high-temperature heat pump compressor. Control the outlet of the heat absorption pipe to be connected to the first outlet of the first flash tank and supply steam through the first pipeline. Control the second centrifugal pump to be connected to the second flash tank through the sixth pipeline, and control the second outlet of the first flash tank to be connected to the buffer water tank, so that the second outlet of the first flash tank, the buffer water tank, the second centrifugal pump, and the inlet of the second flash tank form a path and are connected to the first pipeline. Start the second centrifugal pump to connect the buffer water tank to the inlet of the heat absorption pipe and the inlet of the second flash tank, and at the same time connect the buffer water tank to the inlet of the heat absorption pipe.

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