Steam production system and control method thereof

Abstract

The invention provides a steam production system and a control method thereof. The steam production system comprises an electric heat pump unit, a high-temperature heat storage tank and a flash evaporation unit. The electric heat pump unit is provided with an evaporator inlet, an evaporator outlet, a condenser outlet and a condenser inlet. The evaporator inlet and the evaporator outlet of the electric heat pump unit are used for being connected with a heat source water supply pipeline and a heat source water return pipeline respectively. A first interface and a second interface of the high-temperature heat storage tank are respectively connected with a condenser outlet and a condenser inlet of the electric heat pump unit; a water inlet and a water outlet of the flash evaporation unit are connected with the third connector and the fourth connector of the high-temperature heat storage tank respectively, and a steam outlet of the flash evaporation unit is used for being connected with a steam conveying pipeline. The economical efficiency of the steam production system can be improved, and the adjusting capacity of peak load shifting can be improved.

Description

Technical Field

[0001] The present application relates to the field of industrial heat technology, and in particular to a steam production system and a control method thereof. Background Art

[0002] Industrial heat mainly includes heating, distillation, drying, sterilization and other processes, accounting for more than 60% of the energy consumption structure of most industrial industries. At present, industrial heat mainly comes from decentralized coal-fired / gas-fired boilers and centralized steam transportation of cogeneration. Among them, decentralized boiler heating generally adopts the mode of high-pressure production and terminal throttling, which seriously wastes high-quality energy. As for centralized steam transportation of cogeneration, because thermal power plants are often far away from heat users, during long-distance transportation, due to pipeline heat dissipation and resistance along the way, the temperature, pressure and other parameters of steam will change greatly, which limits the development and application of long-distance steam transportation systems. Therefore, water vapor conversion technology that supplies high-quality steam by recycling low-temperature waste heat in the factory or by long-distance heating of hot water and reusing flash evaporation or flash evaporation after compression at the user has also been proposed. Although the problems of grade mismatch and transportation difficulties have been solved, the technology has not been applied and promoted in the field of industrial heating due to high power consumption and high cost.

[0003] In recent years, the installed capacity of renewable energy has gradually increased. The intermittent, volatile and random characteristics of renewable energy generation will lead to the redundancy of wind power and photovoltaic power, resulting in serious "wind abandonment" and "light abandonment" phenomena, which will also have a great impact on the regulation of the power grid system. Therefore, it is very important to improve the utilization efficiency of heat source water, increase the amount of steam preparation, absorb electricity during low electricity price periods, and reduce electricity consumption during high electricity price periods. Summary of the invention

[0004] The purpose of the present application is to provide a steam production system and a control method thereof, which can improve the economy of the steam production system and enhance the regulation capability of peak shaving and valley filling.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] Technical solution 1: A steam production system, comprising:

[0007] The electric heat pump unit has an evaporator inlet, an evaporator outlet, a condenser outlet and a condenser inlet, wherein the evaporator inlet and the evaporator outlet of the electric heat pump unit are respectively used to connect with a heat source water supply pipeline and a heat source water return pipeline;

[0008] A high-temperature heat storage tank, wherein the first interface and the second interface of the high-temperature heat storage tank are respectively connected to the condenser outlet and the condenser inlet of the electric heat pump unit;

[0009] A flash unit, wherein the water inlet and the water outlet of the flash unit are respectively connected to the third interface and the fourth interface of the high-temperature heat storage tank, and the steam outlet of the flash unit is used to be connected to the steam delivery pipeline.

[0010] Technical Solution 2: The steam production system as described in Technical Solution 1 further includes a low-temperature heat storage tank, and the electric heat pump unit is used to connect to the heat source water supply pipeline and the heat source water return pipeline through the low-temperature heat storage tank, wherein:

[0011] The first interface and the second interface of the low-temperature heat storage tank are respectively used to connect to the heat source water supply pipeline and the heat source return pipeline, and the third interface and the fourth interface of the low-temperature heat storage tank are respectively connected to the evaporator inlet and the evaporator outlet of the electric heat pump unit.

[0012] Technical Solution 3: In the steam production system as described in Technical Solution 2, the first interface and the third interface of the low-temperature heat storage tank are connected through a first bypass pipeline, and the second interface and the fourth interface of the low-temperature heat storage tank are connected through a second bypass pipeline; the first interface and the third interface of the high-temperature heat storage tank are connected through a third bypass pipeline, and the second interface and the fourth interface of the high-temperature heat storage tank are connected through a fourth bypass pipeline.

[0013] Technical Solution 4: In the steam production system described in Technical Solution 2, the electric heat pump unit includes a multi-stage electric heat pump, and the multi-stage electric heat pumps are connected in series in sequence, wherein:

[0014] The third interface and the fourth interface of the low-temperature heat storage tank are respectively connected to the evaporator inlet of the first-stage electric heat pump and the evaporator outlet of the last-stage electric heat pump, and the evaporator inlet and evaporator outlet of the two adjacent stages of the electric heat pump are connected;

[0015] The first interface and the second interface of the high-temperature heat storage tank are respectively connected to the condenser outlet of the first-stage electric heat pump and the condenser inlet of the last-stage electric heat pump, and the condenser inlet and condenser outlet of the two adjacent stages of the electric heat pump are connected.

[0016] Technical Solution 5: The steam production system as described in Technical Solution 1 further includes a compressor unit, and the flash unit is used to connect to the steam delivery pipeline through the compressor unit, wherein:

[0017] The steam outlet of the flash unit is connected to the steam inlet of the compressor unit, and the steam outlet of the compressor unit is used to be connected to the steam delivery pipeline.

[0018] Technical Solution 6: The steam production system as described in Technical Solution 5, wherein the flash unit comprises a multi-stage flash evaporator, and the multi-stage flash evaporators are sequentially connected in series, wherein the third interface and the fourth interface of the high-temperature heat storage tank are respectively connected to the water inlet of the first-stage flash evaporator and the water outlet of the last-stage flash evaporator, and the water outlet and water inlet of the two adjacent flash evaporators are connected;

[0019] The compressor unit comprises a multi-stage compressor, which is connected in series in sequence, wherein the steam outlet of each stage of the flash evaporator is respectively connected to the steam inlet of the corresponding first stage of the compressor, and the steam outlet and steam inlet of two adjacent stages of the compressor are connected.

[0020] Technical Solution 7: In the steam production system as described in Technical Solution 6, the water outlet of each stage of the flash evaporator is connected to the steam outlet of the corresponding first stage of the compressor.

[0021] Technical Solution 8: The steam production system as described in any one of Technical Solutions 1 to 7 further includes a normal temperature water supply pipeline and a water supply heat exchanger, wherein:

[0022] The first interface and the second interface of the make-up water heat exchanger are respectively used to connect to the heat source water supply pipeline and the heat source return water pipeline, the third interface of the make-up water heat exchanger is connected to the normal temperature make-up water pipeline, and the fourth interface of the make-up water heat exchanger is connected to the flash return water pipeline of the water outlet of the flash unit.

[0023] Technical Solution 9: The steam production system as described in any one of Technical Solutions 1 to 7 further includes a condensate recovery pipeline, wherein the condensate recovery pipeline is connected to the flash inlet pipeline of the water inlet of the flash unit.

[0024] Technical Solution 10: In the steam production system as described in any one of Technical Solutions 3 to 7, a first valve is provided in at least one connecting pipeline between the third interface of the low-temperature heat storage tank and the evaporator inlet of the electric heat pump unit and between the fourth interface of the low-temperature heat storage tank and the evaporator outlet of the electric heat pump unit;

[0025] A second valve is provided in at least one connecting pipeline between the first interface of the high-temperature heat storage tank and the condenser outlet of the electric heat pump unit and between the second interface of the high-temperature heat storage tank and the condenser inlet of the electric heat pump unit.

[0026] Technical Solution 11: The steam production system as described in Technical Solution 10, wherein the steam production system has at least one operating mode among a first operating mode, a second operating mode and a third operating mode, wherein:

[0027] In the first operation mode, the first valve and the second valve are closed, the electric heat pump unit stops running, and the low-temperature heat storage tank and the high-temperature heat storage tank are disconnected from the electric heat pump unit;

[0028] In the second operation mode, the first valve and the second valve are opened, and the electric heat pump unit operates normally, wherein the low-temperature heat storage tank releases heat and the high-temperature heat storage tank stores heat;

[0029] In the third operation mode, the first valve and the second valve are closed, and the electric heat pump unit partially operates, wherein the low-temperature heat storage tank does not release heat, and the high-temperature heat storage tank does not store heat.

[0030] Technical Solution 12: For the steam production system as described in Technical Solution 11, during the peak electricity price period, the steam production system is in the first operating mode; during the valley electricity price period, the steam production system is in the second operating mode; during the flat electricity price period, the steam production system is in the third operating mode.

[0031] Technical Solution 13: In the steam production system as described in any one of Technical Solutions 2, 4 to 7, the first interface and the third interface of the high-temperature heat storage tank are merged into one interface, and the second interface and the fourth interface of the high-temperature heat storage tank are merged into another interface; the first interface and the third interface of the low-temperature heat storage tank are merged into one interface, and the second interface and the fourth interface of the low-temperature heat storage tank are merged into another interface.

[0032] Technical Solution 14: A control method for a steam production system, the steam production system comprising an electric heat pump unit, a high-temperature heat storage tank and a flash unit, the control method comprising:

[0033] During the peak electricity price period, the steam production system is controlled to be in a first operation mode, wherein, in the first operation mode, the electric heat pump unit is controlled to stop operating, the high-temperature heat storage tank is disconnected from the electric heat pump unit, and the high-temperature water stored in the high-temperature heat storage tank is flashed into steam through the flash unit and enters the steam delivery pipeline;

[0034] During the valley electricity price period, the steam production system is controlled to be in the second operation mode, wherein in the second operation mode, the electric heat pump unit is controlled to operate normally, a part of the hot water heated by the electric heat pump unit enters the flash unit, is flashed into steam by the flash unit and enters the steam transmission pipeline, and another part of the hot water is stored in the high-temperature heat storage tank.

[0035] Technical Solution 15: In the steam production system according to Technical Solution 14, the control method further comprises:

[0036] During the period of flat electricity price, the steam production system is controlled to be in a third operation mode, wherein in the third operation mode, the electric heat pump unit is controlled to partially operate, the electric heat pump unit is disconnected from the high-temperature heat storage tank, the hot water heated by the electric heat pump unit directly enters the flash unit, and is flashed into steam by the flash unit and enters the steam delivery pipeline, and the high-temperature heat storage tank does not store heat.

[0037] Technical Solution 16: The steam production system according to Technical Solution 15, wherein the steam production system further comprises a low-temperature heat storage tank, and the control method further comprises:

[0038] In the first operation mode, the low-temperature heat storage tank is disconnected from the electric heat pump unit, and the low-temperature heat storage tank is only connected to the heat source water supply pipeline and the heat source water return pipeline, wherein the hot water in the heat source water supply pipeline is supplemented into the low-temperature heat storage tank, replaces the original low-temperature water in the low-temperature heat storage tank, and then enters the heat source water return pipeline;

[0039] In the second operation mode, the low-temperature heat storage tank is connected to the electric heat pump unit, and the hot water in the heat source water supply pipeline and the hot water in the low-temperature heat storage tank enter the electric heat pump unit together, wherein the low-temperature heat storage tank releases heat;

[0040] In the third operation mode, the low-temperature heat storage tank is disconnected from the electric heat pump unit, and only hot water in the heat source water supply pipeline enters the electric heat pump unit, wherein the low-temperature heat storage tank does not release heat.

[0041] Technical Solution 17: According to the control method of any one of Technical Solutions 14 to 16, the steam production system further includes a compressor unit, wherein the control method further includes:

[0042] The steam flashed by the flash unit is further compressed by the compressor unit and then enters the steam delivery pipeline.

[0043] The steam production system and control method thereof provided by one or more technical solutions of the present application adopt a steam production method that consumes excess renewable energy electricity and transmits water to produce steam, thereby overcoming the problem of poor economic efficiency of traditional steam production methods.

[0044] The steam production system and control method thereof provided by one or more technical solutions of the present application utilize a high-temperature heat storage tank, a low-temperature heat storage tank, and an electric heat pump unit to transfer electricity from periods of low electricity prices to periods of high electricity prices, thereby facilitating the absorption of renewable energy and the regulation of the power grid.

[0045] The steam production system and control method provided by one or more technical solutions of the present application improve the economy of the steam production system by adjusting the operation strategies in different time periods, changing the equipment operation mode in different electricity price periods, using more electricity in low electricity price periods, and reducing electricity in high electricity price periods. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic structural diagram of the steam production system of the first embodiment of the present application.

[0047] Figure 2 This is a schematic structural diagram of a steam production system according to a second embodiment of the present application.

[0048] Figure 3 This is a schematic structural diagram of a steam production system according to the third embodiment of the present application.

[0049] Figure 4 This is a schematic structural diagram of a steam production system according to a fourth embodiment of the present application.

[0050] Figure 5 This is a schematic structural diagram of a steam production system according to the fifth embodiment of the present application.

[0051] Figure 6 This is a schematic structural diagram of a steam production system according to the sixth embodiment of the present application.

[0052] Figure 7 This is a schematic structural diagram of a steam production system according to the seventh embodiment of the present application.

[0053] Figure 8 This is a schematic structural diagram of a steam production system according to the eighth embodiment of the present application.

[0054] Fig. 9 This is a schematic structural diagram of a steam production system according to the ninth embodiment of the present application.

[0055] Fig.10 This is a schematic diagram of the state of the steam production system of the present application in the first operating mode.

[0056] Fig.11 This is a schematic diagram of the state of the steam production system of the present application in the second operating mode.

[0057] Fig.12 This is a schematic diagram of the status of the steam production system of the present application in the third operating mode. DETAILED DESCRIPTION

[0058] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0059] This application proposes a steam production system and a control method thereof, which optimizes the system process of using hot water to produce industrial steam, and proposes corresponding operation modes in different power consumption periods. The hot water transmission technology is mature and reliable, and the water transmission and steam production technology is environmentally friendly and has significantly improved thermal efficiency. In addition, while retaining the advantages of water transmission and steam production, this application reduces the heating cost of the system, improves the absorption capacity of renewable energy, and reduces the "wind and solar abandonment" phenomenon caused by the volatility and intermittent characteristics of renewable energy, thereby broadening the application prospects of water transmission and steam production technology.

[0060] The steam production system and control method thereof of various embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0061] First embodiment

[0062] Figure 1 The structural schematic diagram of the steam production system of the first embodiment of the present application is disclosed. Figure 1 As shown, the steam production system includes a low-temperature heat storage tank 1, an electric heat pump unit 2, a high-temperature heat storage tank 3, a flash unit 4 and a compressor unit 5.

[0063] The electric heat pump unit 2 is used to connect to the heat source water supply pipeline 71 and the heat source return water pipeline 72 through the low-temperature heat storage tank 1. The low-temperature heat storage tank 1 has a first interface 11, a second interface 12, a third interface 13 and a fourth interface 14. Among them, the first interface 11 and the second interface 12 of the low-temperature heat storage tank 1 are used to connect to the heat source water supply pipeline 71 and the heat source return water pipeline 72 respectively.

[0064] The electric heat pump unit 2 has an evaporator inlet, an evaporator outlet, a condenser outlet and a condenser inlet. The third interface 13 and the fourth interface 14 of the low-temperature heat storage tank 1 are connected to the evaporator inlet and the evaporator outlet of the electric heat pump unit 2 respectively.

[0065] The high temperature heat storage tank 3 has a first interface 31, a second interface 32, a third interface 33 and a fourth interface 34. The first interface 31 and the second interface 32 of the high temperature heat storage tank 3 are connected to the condenser outlet and the condenser inlet of the electric heat pump unit 2 respectively.

[0066] The water inlet and the water outlet of the flash unit 4 are respectively connected to the third interface 33 and the fourth interface 34 of the high-temperature heat storage tank 3, and the flash unit 4 can supply steam to the user after being compressed by the compressor unit 5. Among them, the steam outlet of the flash unit 4 is connected to the steam inlet of the compressor unit 5, and the steam outlet of the compressor unit 5 is used to be connected to the steam delivery pipeline 73, and the steam is supplied to the user through the steam delivery pipeline 73.

[0067] Second embodiment

[0068] Figure 2 The structural schematic diagram of the steam production system of the second embodiment of the present application is disclosed. Figure 2 As shown, Figure 2 The steam production system shown is Figure 1 The steam generation system shown differs in that Figure 2 In the steam production system shown, a first valve 81 is provided in at least one connecting pipeline between the third interface 13 of the low-temperature heat storage tank 1 and the evaporator inlet of the electric heat pump unit 2 and between the fourth interface 14 of the low-temperature heat storage tank 1 and the evaporator outlet of the electric heat pump unit 2.

[0069] A second valve 82 is provided in at least one connecting pipeline between the first interface 31 of the high temperature heat storage tank 3 and the condenser outlet of the electric heat pump unit 2 and between the second interface 32 of the high temperature heat storage tank 3 and the condenser inlet of the electric heat pump unit 2 .

[0070] Of course, it can be understood that the setting form, setting number and setting position of the valves in the steam production system of the present application are not limited to those shown in the drawings of the present application. The steam production system of the present application can also set valves in other connecting pipelines. As long as all valves added play a shut-off role in the system, they will be covered within the protection scope of the present application.

[0071] Third embodiment

[0072] Figure 3 The structural schematic diagram of the steam production system of the third embodiment of the present application is disclosed. Figure 3 As shown, Figure 3 The steam production system shown is Figure 2 The steam generation system shown differs in that Figure 3 In the steam production system shown, the first interface 11 and the third interface 13 of the low-temperature heat storage tank 1 can be connected through a first bypass pipeline, and the second interface 12 and the fourth interface 14 of the low-temperature heat storage tank 1 can be connected through a second bypass pipeline; the first interface 31 and the third interface 33 of the high-temperature heat storage tank 3 can be connected through a third bypass pipeline, and the second interface 32 and the fourth interface 34 of the high-temperature heat storage tank 3 can be connected through a fourth bypass pipeline.

[0073] Fourth embodiment

[0074] Figure 4 The structural schematic diagram of the steam production system of the fourth embodiment of the present application is disclosed. Figure 4 As shown, Figure 4 The steam production system shown is Figure 2 The steam generation system shown differs in that Figure 4 In the steam production system shown, the electric heat pump unit 2 includes a multi-stage electric heat pump 20, and the multi-stage electric heat pump 20 is connected in series. Among them, the third interface 13 and the fourth interface 14 of the low-temperature heat storage tank 1 are respectively connected to the evaporator inlet of the first-stage electric heat pump 20 and the evaporator outlet of the last-stage electric heat pump 20, the evaporator inlet and the evaporator outlet of the adjacent two-stage electric heat pump 20 are connected, and the water outlet on the side of the third interface 13 of the low-temperature heat storage tank 1 passes through the evaporator in the multi-stage electric heat pump 20 in sequence; the first interface 31 and the second interface 32 of the high-temperature heat storage tank 3 are respectively connected to the condenser outlet of the first-stage electric heat pump 20 and the condenser inlet of the last-stage electric heat pump 20, and the water outlet on the side of the second interface 32 of the high-temperature heat storage tank 3 passes through the condenser in the multi-stage electric heat pump 20 in reverse order; the condenser inlet and the condenser outlet of the adjacent two-stage electric heat pump 20 are connected.

[0075] Fifth embodiment

[0076] Figure 5 The structural schematic diagram of the steam production system of the fifth embodiment of the present application is disclosed. Figure 5 As shown, Figure 5 The steam production system shown is Figure 2 The steam generation system shown differs in that Figure 5 In the steam production system shown, the flash unit 4 has multiple stages of flash evaporation and the compressor unit 5 has multiple stages of compression.

[0077] Specifically, the flash unit 4 includes a multi-stage flash evaporator 40, which is connected in series in sequence, and the flash water passes through the multi-stage flash evaporator 40 in sequence. Among them, the third interface 33 and the fourth interface of the high-temperature heat storage tank 3 are respectively connected to the water inlet of the first-stage flash evaporator 40 and the water outlet of the last-stage flash evaporator 40, and the water outlet and water inlet of two adjacent flash evaporators 40 are connected.

[0078] The compressor unit 5 comprises a multi-stage compressor 50, which is connected in series in sequence, wherein the steam outlet of each stage of the flash evaporator 40 is respectively connected to the steam inlet of the corresponding first-stage compressor 50, and the steam outlet and steam inlet of two adjacent stages of the compressor 50 are connected.

[0079] Sixth embodiment

[0080] Figure 6 The structural schematic diagram of the steam production system of the sixth embodiment of the present application is disclosed. Figure 6 As shown, Figure 6 The steam production system shown is Figure 5 The steam generation system shown differs in that Figure 6 In the steam production system shown, the multi-stage compressor 50 is designed with an inter-stage water spraying link, connecting the water outlet of each stage of the flash evaporator 40 with the steam outlet of the corresponding first-stage compressor 50, so that the flash return water of the flash evaporator 40 can be used to reduce the superheat of the compressor 50 outlet, thereby preventing problems such as carbonization of the compressor 50 lubricating oil and reduction of material stress.

[0081] Seventh embodiment

[0082] When the heat storage temperature of the high-temperature heat storage tank 3 is high, the compressor unit 5 can be eliminated from the steam production system. Figure 7 The structural schematic diagram of the steam production system of the seventh embodiment of the present application is disclosed. Figure 7 As shown, Figure 7 The steam production system shown is Figure 2 The steam generation system shown differs in that Figure 7 In the steam production system shown, the compressor unit 5 is not provided, and the steam outlet of the flash unit 4 can be used to be directly connected to the steam delivery pipeline 73, so that the required steam is directly prepared through the flash unit 4 and the steam is supplied to the user through the steam delivery pipeline 73.

[0083] It can be understood that the situation shown in the seventh embodiment can also be applied to other embodiments of the present application.

[0084] Eighth embodiment

[0085] Since steam is continuously produced and consumed, the steam production system of the present application may have a water replenishment link. Figure 8 The structural schematic diagram of the steam production system of the eighth embodiment of the present application is disclosed. Figure 8 As shown, Figure 8 The steam production system shown is Figure 2 The steam production system shown differs in that Figure 8 The steam production system shown may also include a normal temperature make-up water pipeline 74 and a make-up water heat exchanger 6 .

[0086] The make-up water heat exchanger 6 has a first interface 61, a second interface 62, a third interface 63 and a fourth interface 64. The first interface 61 and the second interface 62 of the make-up water heat exchanger 6 are respectively used to connect with the heat source water supply pipeline 71 and the heat source return water pipeline 72, the third interface 63 of the make-up water heat exchanger 6 is connected with the normal temperature make-up water pipeline 74, and the fourth interface 64 of the make-up water heat exchanger 6 is connected with the flash return water pipeline of the water outlet of the flash unit 4.

[0087] The transported heat source water enters the water supply heat exchanger 6 through the heat source water supply pipeline 71, and returns to the heat source return water pipeline 72 after heat exchange; the normal temperature water supply enters the water supply heat exchanger 6 through the normal temperature water supply pipeline 74 to be heated, and the heated water supply enters the flash return water pipeline. The heat of the transported hot water is used to preheat the water supply, which consumes less electricity and improves the overall efficiency compared with the normal temperature water supply.

[0088] Ninth embodiment

[0089] Since the latent heat of vaporization of steam is mainly utilized, the steam production system of the present application has a condensate recovery link. Fig. 9 The structural schematic diagram of the steam production system of the ninth embodiment of the present application is disclosed. Fig. 9 As shown, Fig. 9 The steam production system shown is Figure 2 The steam production system shown differs in that Fig. 9 The illustrated steam production system may also include a condensate recovery line 75 .

[0090] The condensate recovery pipeline 75 is connected to the flash inlet pipeline of the water inlet of the flash unit 4 .

[0091] When the temperature of the condensed water after the user uses the steam is high, the condensed water recovery pipeline 75 can be designed to be connected to the flash evaporation inlet pipeline of the water inlet of the flash evaporation unit 4, so that the heat can be recovered and utilized while replenishing water.

[0092] In the above embodiments, the steam production system of the present application can also be configured without the low-temperature heat storage tank 1 to balance the heat input from the heat source. When more heat is needed, more heat is taken from the heat source, and no heat is taken during the period when heat is not needed. In the case of eliminating the low-temperature heat storage tank 1, the evaporator inlet and the evaporator outlet of the electric heat pump unit 2 can be used to directly connect to the heat source water supply pipeline 71 and the heat source return water pipeline 72, respectively.

[0093] In the above embodiment, the low-temperature heat storage tank 1 in the steam production system of the present application can modify the four interfaces into two interfaces, that is, the first interface 11 and the third interface 13 of the low-temperature heat storage tank 1 can be combined into one interface, and the second interface 12 and the fourth interface 14 of the low-temperature heat storage tank 1 can be combined into another interface; similarly, the high-temperature heat storage tank 3 in the steam production system of the present application can also modify the four interfaces into two interfaces, that is, the first interface 31 and the third interface 33 of the high-temperature heat storage tank 3 can be combined into one interface, and the second interface 32 and the fourth interface 34 of the high-temperature heat storage tank 1 can be combined into another interface. These changes do not affect the creative essence of the steam production system of the present application.

[0094] In addition, it can be understood that the above are only some illustrative embodiments of the steam production system of the present application, however, the embodiments of the steam production system of the present application are not limited thereto, and the schemes shown in the various embodiments of the steam production system shown above in the present application can be combined with each other according to actual conditions. Without departing from the creative essence of the present application, any combination or simple and equivalent transformation of the above embodiments will fall within the protection scope of the present application.

[0095] In some embodiments, the steam production system of the present application may have at least one operation mode among a first operation mode, a second operation mode, and a third operation mode.

[0096] The operation mode of the steam production system of the present application will be described in detail below using the scheme illustrated in the second embodiment.

[0097] During peak electricity price periods, the steam production system of the present application may be in a first operation mode, and the steam production system of the present application may use less electricity. Fig.10 The state diagram of the steam production system of the present application in the first operating mode is disclosed. Fig.10 As shown, in the steam production system of the present application, the first valve 81 and the second valve 82 are closed, the electric heat pump unit 2 stops running, and the low-temperature heat storage tank 1 and the high-temperature heat storage tank 3 are disconnected from the electric heat pump unit 2.

[0098] The high-temperature water stored in the high-temperature heat storage tank 3 generates steam through the flash unit 4, then enters the compressor unit 5 to improve its quality, and finally enters the steam delivery pipeline 73, and the flash return water with a lower temperature after flash evaporation flows back to the high-temperature heat storage tank 3. At the same time, at this time, the low-temperature heat storage tank 1 is only connected to the heat source water supply pipeline 71 and the heat source return water pipeline 72, and hot water is added to the low-temperature heat storage tank 1 to replace the original low-temperature water in the low-temperature heat storage tank 1 and enter the heat source return water pipeline 72.

[0099] During the valley electricity price period, the steam production system of the present application may be in the second operation mode, and the steam production system of the present application may consume more electricity. Fig.11 The state diagram of the steam production system of the present application in the second operation mode is disclosed. Fig.11 As shown, the steam production system of the present application is in the second operating mode, the first valve 81 and the second valve 82 are opened, the electric heat pump unit 2 operates normally, and the low-temperature heat storage tank 1 and the high-temperature heat storage tank 3 are both connected to the electric heat pump unit 2, wherein the low-temperature heat storage tank 1 releases heat and the high-temperature heat storage tank 3 stores heat.

[0100] When the bypass of the low-temperature heat storage tank 1 exists, the heat source water supply pipeline 71 is connected in parallel with the pipeline at the third interface 13 of the low-temperature heat storage tank 1 through the bypass to enter the evaporator inlet of the electric heat pump unit 2, and the evaporator outlet of the electric heat pump unit 2 is respectively connected with the pipeline at the fourth interface 14 of the low-temperature heat storage tank 1 and the bypass of the heat source return water pipeline 72; a part of the hot water heated by the condenser in the electric heat pump unit 2 directly enters the flash unit 4 to produce the required steam through the bypass connecting the first interface 31 and the third interface of the high-temperature heat storage tank 3, and the other part is stored in the high-temperature heat storage tank 3 through the pipeline at the first interface 31 of the high-temperature heat storage tank 3 to be used during the high electricity price period, and the flash return water pipeline of the water outlet of the flash unit 4 is connected to the electric heat pump unit 2 through the bypass connecting the second interface 32 and the fourth interface of the high-temperature heat storage tank 3.

[0101] During the period of flat electricity prices, the steam production system of the present application is in the third operation mode. Fig.12 The state diagram of the steam production system of the present application in the third operation mode is disclosed. Fig.12 As shown, in the steam production system of the present application, the first valve 81 and the second valve 82 are closed, and the electric heat pump unit 2 is running, wherein the low-temperature heat storage tank 1 does not release heat, and the high-temperature heat storage tank 3 does not store heat.

[0102] When the bypass of the low-temperature heat storage tank 1 exists, the heat source water supply pipeline 71 directly enters the evaporator inlet of the electric heat pump unit 2 through the bypass, and the evaporator outlet of the electric heat pump unit 2 is connected to the bypass of the heat source return water pipeline 72; the hot water heated by the condenser in the electric heat pump unit 2 directly enters the flash unit 4 to produce the required steam through the bypass connecting the first interface 31 and the third interface 33 of the high-temperature heat storage tank 3, and the flash return water pipeline of the water outlet of the flash unit 4 is connected to the electric heat pump unit 2 through the bypass connecting the second interface 32 and the fourth interface 34 of the high-temperature heat storage tank 3.

[0103] The steam production system of the present application changes the steam production path by adjusting the operation strategy of different electricity consumption periods. During the period of high electricity price, the high-temperature water stored in the high-temperature heat storage tank 3 is used to produce the required steam by flash evaporation; during the period of low electricity price, the electric heat pump unit 2 is used to recover the heat of the low-temperature water in the low-temperature heat storage tank 1, and the required steam is produced while storing heat in the high-temperature heat storage tank 3.

[0104] The steam production system of the present application absorbs electricity during periods of low electricity prices and reduces electricity consumption during periods of high electricity prices. While achieving the peak shaving and valley filling function and assisting in the regulation of the power system, it utilizes the peak-valley electricity price difference on the user side, reduces operating costs, improves economy, and broadens the application scenarios of water transmission and steam production.

[0105] The present application also provides a control method for a steam production system. The steam production system includes an electric heat pump unit 2, a high-temperature heat storage tank 3 and a flash unit 4. The control method for a steam production system of the present application may include steps S1 to S2.

[0106] In step S1, combined with reference Fig.10 As shown, during the peak electricity price period, the steam production system can be controlled to be in the first operation mode, wherein, in the first operation mode, the electric heat pump unit 2 is controlled to stop running, the high-temperature heat storage tank 3 is disconnected from the electric heat pump unit 2, and the high-temperature water stored in the high-temperature heat storage tank 3 is flashed into steam through the flash unit 4 and enters the steam delivery pipeline 73;

[0107] In step S2, combined with reference Fig.11 As shown, during the valley electricity price period, the steam production system can be controlled to be in the second operating mode, wherein in the second operating mode, the electric heat pump unit 2 is controlled to operate normally, a portion of the hot water heated by the electric heat pump unit 2 enters the flash unit 4, is flashed into steam by the flash unit 4 and enters the steam delivery pipeline 73, and the other portion of the hot water is stored in the high-temperature heat storage tank 3.

[0108] In some embodiments, the control method of the steam production system of the present application may further include step S3.

[0109] In step S3, combined with reference Fig.12 As shown, during the period of flat electricity price, the steam production system can be controlled to be in the third operation mode, wherein, in the third operation mode, the electric heat pump unit 2 is controlled to partially operate, the electric heat pump unit 2 is disconnected from the high-temperature heat storage tank 3, and the hot water heated by the electric heat pump unit 2 directly enters the flash unit 4, and is flashed into steam by the flash unit 4 and enters the steam delivery pipeline 73, and the high-temperature heat storage tank 3 does not store heat.

[0110] The steam production system may further include a low-temperature heat storage tank 1. Therefore, in some embodiments, step S1 may further include: in the first operating mode, the low-temperature heat storage tank 1 is disconnected from the electric heat pump unit 2, and the hot water in the heat source water supply pipeline 71 is supplemented into the low-temperature heat storage tank 1, and enters the heat source return water pipeline 72 after replacing the original low-temperature water in the low-temperature heat storage tank 1. Step S2 may further include: in the second operating mode, the low-temperature heat storage tank 1 is connected to the electric heat pump unit 2, and the hot water in the heat source water supply pipeline 71 and the hot water in the low-temperature heat storage tank 1 enter the electric heat pump unit 2 together, wherein the low-temperature heat storage tank 1 releases heat. Step S3 may further include: in the third operating mode, the low-temperature heat storage tank 1 is disconnected from the electric heat pump unit 2, and only the hot water in the heat source water supply pipeline 71 enters the electric heat pump unit 2, wherein the low-temperature heat storage tank 1 does not release heat.

[0111] The steam production system may further include a compressor unit 5. Therefore, in some embodiments, the control method of the steam production system of the present application may further include step S4.

[0112] In step S4 , the steam flashed by the flash unit 4 may be further compressed by the compressor unit 5 and enter the steam delivery pipeline 73 .

[0113] The control method of the steam production system of the present application adopts a steam making method that consumes excess renewable energy power and transmits water to make steam, thereby overcoming the problem of poor economic efficiency of traditional steam making methods.

[0114] The control method of the steam production system of the present application utilizes a high-temperature heat storage tank 3, a low-temperature heat storage tank 1 and an electric heat pump unit 2 to transfer electricity from a period of low electricity prices to a period of high electricity prices, thereby facilitating the consumption of renewable energy and the regulation of the power grid.

[0115] The control method of the steam production system of the present application improves the economy of the steam production system by adjusting the operation strategies in different time periods, changing the equipment operation mode in different electricity price periods, using more electricity in low electricity price periods, and reducing electricity in high electricity price periods.

[0116] The steam production system and control method thereof provided in the embodiment of the present application are introduced in detail above. Specific examples are used herein to illustrate the steam production system and control method thereof in the embodiment of the present application. The description of the above embodiments is only used to help understand the core idea of ​​the present application and is not intended to limit the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the spirit and principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications should also fall within the scope of protection of the claims attached to the present application.

Claims

1. A steam production system, characterized in that: include: The electric heat pump unit has an evaporator inlet, an evaporator outlet, a condenser outlet and a condenser inlet, wherein the evaporator inlet and the evaporator outlet of the electric heat pump unit are respectively used to connect with a heat source water supply pipeline and a heat source water return pipeline; A high-temperature heat storage tank, wherein the first interface and the second interface of the high-temperature heat storage tank are respectively connected to the condenser outlet and the condenser inlet of the electric heat pump unit; A flash unit, wherein the water inlet and the water outlet of the flash unit are respectively connected to the third interface and the fourth interface of the high-temperature heat storage tank, and the steam outlet of the flash unit is used to be connected to the steam delivery pipeline.

2. The steam production system according to claim 1, characterized in that: It also includes a low-temperature heat storage tank, and the electric heat pump unit is used to connect to the heat source water supply pipeline and the heat source water return pipeline through the low-temperature heat storage tank, wherein: The first interface and the second interface of the low-temperature heat storage tank are respectively used to connect to the heat source water supply pipeline and the heat source return pipeline, and the third interface and the fourth interface of the low-temperature heat storage tank are respectively connected to the evaporator inlet and the evaporator outlet of the electric heat pump unit.

3. The steam production system according to claim 2, characterized in that: The first interface and the third interface of the low-temperature heat storage tank are connected through a first bypass pipeline, and the second interface and the fourth interface of the low-temperature heat storage tank are connected through a second bypass pipeline; the first interface and the third interface of the high-temperature heat storage tank are connected through a third bypass pipeline, and the second interface and the fourth interface of the high-temperature heat storage tank are connected through a fourth bypass pipeline.

4. The steam production system according to claim 2, characterized in that: The electric heat pump unit comprises a multi-stage electric heat pump, and the multi-stage electric heat pumps are connected in series in sequence, wherein: The third interface and the fourth interface of the low-temperature heat storage tank are respectively connected to the evaporator inlet of the first-stage electric heat pump and the evaporator outlet of the last-stage electric heat pump, and the evaporator inlet and evaporator outlet of the two adjacent stages of the electric heat pump are connected; The first interface and the second interface of the high-temperature heat storage tank are respectively connected to the condenser outlet of the first-stage electric heat pump and the condenser inlet of the last-stage electric heat pump, and the condenser inlet and condenser outlet of the two adjacent stages of the electric heat pump are connected.

5. The steam production system according to claim 1, characterized in that: It also includes a compressor unit, and the flash unit is connected to the steam delivery pipeline through the compressor unit, wherein: The steam outlet of the flash unit is connected to the steam inlet of the compressor unit, and the steam outlet of the compressor unit is used to be connected to the steam delivery pipeline.

6. The steam production system according to claim 5, characterized in that: The flash unit comprises a multi-stage flash evaporator, which is connected in series in sequence, wherein the third interface and the fourth interface of the high-temperature heat storage tank are respectively connected to the water inlet of the first-stage flash evaporator and the water outlet of the last-stage flash evaporator, and the water outlet and water inlet of two adjacent flash evaporators are connected; The compressor unit comprises a multi-stage compressor, which is connected in series in sequence, wherein the steam outlet of each stage of the flash evaporator is respectively connected to the steam inlet of the corresponding first stage of the compressor, and the steam outlet and steam inlet of two adjacent stages of the compressor are connected.

7. The steam production system according to claim 6, characterized in that: The water outlet of each stage of the flash evaporator is connected to the steam outlet of the corresponding stage of the compressor.

8. The steam production system according to any one of claims 1 to 7, characterized in that: It also includes a normal temperature water supply pipeline and a water supply heat exchanger, among which, The first interface and the second interface of the make-up water heat exchanger are respectively used to connect to the heat source water supply pipeline and the heat source return water pipeline, the third interface of the make-up water heat exchanger is connected to the normal temperature make-up water pipeline, and the fourth interface of the make-up water heat exchanger is connected to the flash return water pipeline of the water outlet of the flash unit.

9. The steam production system according to any one of claims 1 to 7, characterized in that: It also includes a condensate recovery pipeline, wherein the condensate recovery pipeline is connected to the flash evaporation inlet pipeline of the water inlet of the flash evaporation unit.

10. A control method for a steam production system, the steam production system comprising an electric heat pump unit, a high-temperature heat storage tank and a flash unit, characterized in that: The control method comprises: During the peak electricity price period, the steam production system is controlled to be in a first operation mode, wherein, in the first operation mode, the electric heat pump unit is controlled to stop operating, the high-temperature heat storage tank is disconnected from the electric heat pump unit, and the high-temperature water stored in the high-temperature heat storage tank is flashed into steam through the flash unit and enters the steam delivery pipeline; During the valley electricity price period, the steam production system is controlled to be in the second operation mode, wherein in the second operation mode, the electric heat pump unit is controlled to operate normally, a part of the hot water heated by the electric heat pump unit enters the flash unit, is flashed into steam by the flash unit and enters the steam transmission pipeline, and another part of the hot water is stored in the high-temperature heat storage tank.

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