Continuous low-temperature water supply system of steam generator

Abstract

The utility model relates to a continuous low-temperature water supply system of a steam generator. The device comprises a normal-pressure water tank, an energy saver, a condenser, an evaporator body, a circulating pump and a water feeding pump, the normal-pressure water tank is connected with the condenser, the circulating pump is arranged on a pipeline for connecting the normal-pressure water tank and the condenser, the condenser is connected with the energy saver, the energy saver is connected with the normal-pressure water tank, and the water feeding pump is arranged on the pipeline for connecting the normal-pressure water tank and the condenser. The energy saver and the condenser are both arranged on the evaporator body, the normal-pressure water tank is connected with the evaporator body, a water feeding pump is arranged on a pipeline connecting the normal-pressure water tank and the evaporator body, a liquid level meter is arranged on the evaporator body and connected with a liquid level transmitter, the liquid level transmitter is connected with a liquid level controller, and the liquid level controller is connected with the normal-pressure water tank. And the liquid level controller is respectively connected with the circulating pump and the water feeding pump.

Description

Technical Field

[0001] The utility model relates to a continuous low-temperature water supply system for a steam generator. Background Art

[0002] Steam generators mainly use natural gas as their power source. In the field of small-scale steam demand, they have firmly occupied a core position in the market due to their advantages such as flexible layout, no need for monitoring and inspection, and low cost of use, demonstrating their indispensable importance.

[0003] Since the water volume of the pressure-bearing body of the steam generator is limited (water volume ≤ 30L), the tail heating surface including the economizer and condenser is often designed to operate at normal pressure and circulate with the water tank through a circulating pump. Usually, the water tank is at normal pressure, with no partition inside, and the same as the atmosphere. The water in the water tank passes through the circulating pump, first enters the condenser, then enters the economizer, and returns to the water tank after heating, and then is sent to the condenser by the circulating pump, and repeats over and over again, forming a normal pressure water circulation loop. The heated water is sent to the steam generator body by the feed water pump at the appropriate position of the water tank for further heating into steam. The circulating pump is a conventional water pump, which does not change frequency and always maintains a certain circulation flow. When the actual evaporation of the steam generator is less than the circulation flow, the water temperature in the water tank will slowly rise, that is, the water temperature entering the condenser will slowly rise, and the corresponding exhaust gas temperature at the outlet of the condenser will rise, the thermal efficiency of the steam generator will decrease, and energy consumption and emissions will increase. Utility Model Content

[0004] The purpose of the utility model is to overcome the above-mentioned deficiencies in the prior art and to provide a continuous low-temperature water supply system for a steam generator which has a reasonable structural design and is conducive to improving the thermal efficiency of the steam generator, saving energy and reducing emissions.

[0005] The technical solution adopted by the utility model to solve the above-mentioned problem is: the continuous low-temperature water supply system of the steam generator has the following structural characteristics: it includes a normal pressure water tank, an economizer, a condenser, an evaporator body, a circulation pump and a water supply pump, the normal pressure water tank is connected to the condenser, and a circulation pump is arranged on the pipeline connecting the normal pressure water tank and the condenser, the condenser is connected to the economizer, the economizer is connected to the normal pressure water tank, the economizer and the condenser are both arranged on the evaporator body, the normal pressure water tank is connected to the evaporator body, and a water supply pump is arranged on the pipeline connecting the normal pressure water tank and the evaporator body, the evaporator body is provided with a liquid level gauge, and the liquid level gauge is respectively connected to the circulation pump and the water supply pump.

[0006] Furthermore, the liquid level meter is connected to a liquid level transmitter, the liquid level transmitter is connected to a liquid level controller, and the liquid level controller is respectively connected to a circulation pump and a water supply pump.

[0007] Furthermore, an insulating partition is provided in the normal pressure water tank, and the insulating partition divides the normal pressure water tank into a hot water area and a cold water area, and the hot water area and the cold water area are connected through a hot and cold water channel.

[0008] Furthermore, the side wall of the hot water zone is provided with a hot water outlet and a hot water inlet, and the side wall of the cold water zone is provided with a cold water outlet and a water replenishment port.

[0009] Furthermore, the economizer is connected to the hot water inlet through a hot water inlet pipe, the cold water outlet is connected to the condenser through a cold water outlet pipe, the circulating pump is arranged on the cold water outlet pipe, the hot water outlet is connected to the evaporator body through a hot water outlet pipe, and the water supply pump is arranged on the hot water outlet pipe.

[0010] Furthermore, the height of the hot water outlet is higher than the height of the hot water inlet, and the area between the hot water inlet and the lower end of the insulation partition in the hot water area serves as a buffer zone.

[0011] Furthermore, a first transverse partition and a second transverse partition are provided in the buffer zone, and a first channel and a second channel are formed in the hot water zone, the first transverse partition and the second transverse partition are staggered, and the first channel and the second channel are staggered.

[0012] Furthermore, the bottom of the normal pressure water tank is provided with supporting feet.

[0013] Compared with the prior art, the utility model has the following advantages:

[0014] 1. An insulating partition is installed in the atmospheric pressure water tank to separate the cold water from the hot water. The replenishing water enters the cold water area, and the water entering the condenser is introduced from the cold water area to ensure that the water inlet temperature of the condenser is always at the lowest, thereby reducing the exhaust temperature and improving the thermal efficiency.

[0015] 2. A buffer zone is set in the hot water area of ​​the normal pressure water tank. When the circulation flow is greater than the water supply flow, the volume of the buffer zone should be greater than the difference between the circulation flow and the water supply flow, so that hot water will not enter the cold water zone and the water temperature in the cold water zone will not rise.

[0016] 3. Both the circulation pump and the water supply pump adopt frequency conversion, which reduces power consumption

[0017] 4. Under normal working conditions, the flow of the circulation pump matches that of the water supply pump, and the flow of the circulation pump is slightly smaller than that of the water supply pump. Cold water enters the hot water area from the cold water area through the cold and hot water channels, and hot water does not enter the cold water area from the hot water area, ensuring that the water temperature in the cold water area does not rise.

[0018] 5. The cold and hot water areas of the atmospheric pressure water tank are separated by an insulating partition. When the outlet water temperature of the economizer is greater than 90°C, it can also remove part of the oxygen in the feed water, which has the function of deoxygenation and prolongs the service life of the evaporator body. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a continuous low-temperature water supply system for a steam generator according to an embodiment of the utility model.

[0020] Figure 2 It is a schematic diagram of the main structure of the atmospheric pressure water tank of an embodiment of the utility model.

[0021] Figure 3 It is a schematic diagram of the top view of the normal pressure water tank of the embodiment of the utility model.

[0022] In the figure: normal pressure water tank 1, insulation partition 11, hot water area 12, cold water area 13, hot water outlet 14, hot water inlet 15, hot and cold water channels 16, cold water outlet 17, water replenishment port 18, first transverse partition 19a, second transverse partition 19b, support leg 110, first channel 11a, second channel 11b, economizer 2, condenser 3, evaporator body 4, liquid level gauge 41, circulation pump 5, water supply pump 6, hot water inlet pipe 7a, cold water outlet pipe 7b, hot water outlet pipe 7c, liquid level transmitter LT, liquid level controller LC. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are provided to explain the present invention, but the present invention is not limited to the following examples.

[0024] Example

[0025] See also Figures 1 to 3 As shown, it should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, if there are references to terms such as "upper", "lower", "left", "right", "middle" and "one" in this specification, they are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship, without substantially changing the technical content, should also be regarded as the scope of the implementation of the utility model.

[0026] The continuous low-temperature water supply system for the steam generator in this embodiment includes a normal pressure water tank 1, an economizer 2, a condenser 3, an evaporator body 4, a circulating pump 5 and a feed water pump 6. The normal pressure water tank 1 is connected to the condenser 3, and a circulating pump 5 is arranged on the pipeline connecting the normal pressure water tank 1 and the condenser 3. The condenser 3 is connected to the economizer 2, and the economizer 2 is connected to the normal pressure water tank 1. The economizer 2 and the condenser 3 are both arranged on the evaporator body 4. The normal pressure water tank 1 is connected to the evaporator body 4, and a feed water pump 6 is arranged on the pipeline connecting the normal pressure water tank 1 and the evaporator body 4. A liquid level meter 41 is arranged on the evaporator body 4, and the liquid level meter 41 is connected to the liquid level transmitter LT, and the liquid level transmitter LT is connected to the liquid level controller LC, and the liquid level controller LC is respectively connected to the circulating pump 5 and the feed water pump 6.

[0027] The normal pressure water tank 1 can be a rectangular parallelepiped or a cylinder or other shapes. The upper part of the normal pressure water tank 1 is connected to the atmosphere and is not closed. A support leg 110 is provided at the bottom of the normal pressure water tank 1. An insulating partition 11 is provided in the normal pressure water tank 1, and the insulating partition 11 divides the normal pressure water tank 1 into a hot water area 12 and a cold water area 13. The lower end of the insulating partition 11 and the bottom of the normal pressure water tank 1 form a hot and cold water channel 16, and the hot water area 12 and the cold water area 13 are connected through the hot and cold water channel 16.

[0028] A hot water outlet 14 and a hot water inlet 15 are provided on the side wall of the hot water area 12, a cold water outlet 17 and a water replenishment port 18 are provided on the side wall of the cold water area 13, the economizer 2 is connected to the hot water inlet 15 via a hot water inlet pipe 7a, the cold water outlet 17 is connected to the condenser 3 via a cold water outlet pipe 7b, the circulation pump 5 is arranged on the cold water outlet pipe 7b, the hot water outlet 14 is connected to the evaporator body 4 via a hot water outlet pipe 7c, and the water supply pump 6 is arranged on the hot water outlet pipe 7c.

[0029] A cold water outlet 17 is provided at the lower part of the cold water zone 13 for supplying water to the condenser 3 and the economizer 2; a water replenishment port 18 is provided at the upper part of the cold water zone 13, and whether to replenish water is controlled by a float valve or an electrode, so that the liquid level of the normal pressure water tank 1 is maintained between the lowest water level VLL and the highest water level VLH of the water tank, so that the normal pressure water tank 1 maintains a certain water level; a hot water outlet 14 is provided at the hot water zone 12 for supplying water to the evaporator body 4, and the distance h1 between the hot water outlet 14 and the lowest water level of the water tank should ensure that there is no air when the water outlet pipe discharges water, and it is recommended that h1 ≥ 100mm; a hot water inlet 15 is provided at the hot water zone 12 for receiving hot water from the economizer 2, and the hot water inlet 15 is arranged below the hot water outlet 14.

[0030] The cold water in the cold water area 13 first enters the condenser 3 through the circulation pump 5, then enters the economizer 2, becomes hot water after absorbing heat, and enters the hot water area 12 through the hot water inlet 15. The hot water in the hot water area 12 is sent to the evaporator body 4 from the hot water outlet 14 by the water supply pump 6.

[0031] The circulation pump 5 is a variable frequency pump, and the operating temperature should be no less than 30°C. The head of the circulation pump should be greater than the sum of the resistances of the condenser 3, the economizer 2 and the corresponding pipelines.

[0032] The water supply pump 6 is a variable frequency pump, the operating temperature of which should be no less than 100°C. It is used to supply water to the evaporator body 4, and the lift should be higher than the maximum working pressure of the evaporator body 4.

[0033] The height of the hot water outlet 14 is higher than that of the hot water inlet 15. The area between the hot water inlet 15 and the lower end of the insulating baffle 11 in the hot water zone 12 serves as a buffer zone. A first transverse baffle 19a and a second transverse baffle 19b are provided in the buffer zone, and a first channel 11a and a second channel 11b are formed in the hot water zone 12. The first transverse baffle 19a and the second transverse baffle 19b are staggered, and the first channel 11a and the second channel 11b are staggered.

[0034] In the normal pressure water tank 1, there should be a sufficient distance h3 between the hot water inlet 15 and the lower end of the insulating partition 11. The volume formed by the hot water area 12 within this distance serves as a buffer volume. When the flow rate of the water supply pump 6 is less than the flow rate of the circulating pump 5, the buffer volume should be greater than the flow difference between the water supply pump 6 and the circulating pump 5.

[0035] A first transverse partition 19a and a second transverse partition 19b are arranged in the buffer zone. The positions of the first transverse partition 19a and the second transverse partition 19b should be lower than the hot water inlet 15. A first channel 11a is formed between the first transverse partition 19a and the insulating partition 11, and a second channel 11b is formed between the second transverse partition 19b and the side wall of the atmospheric pressure water tank 1. One end of the second transverse partition 19b must be welded to the insulating partition 11, so that the first channel 11a and the second channel 11b must be arranged on different sides to extend the distance from hot water to cold water as much as possible without forming a short circuit, thereby ensuring the buffering effect of the buffer zone.

[0036] The adjustment method of the steam generator continuous low temperature feed water system is as follows:

[0037] The circulation pump 5 and the water supply pump 6 use frequency conversion to adjust the flow rate, and the control signal comes from the same measuring point of the evaporator body 4. The change trends of the frequencies of the circulation pump 5 and the water supply pump 6 are consistent.

[0038] The signal sources of both the circulation pump 5 and the water supply pump 6 are the liquid level of the evaporator body 4. The evaporator body 4 is provided with a liquid level gauge 41. The liquid level of the liquid level gauge 41 outputs a 4-20 mmA electrical signal through the liquid level transmitter LT. The operating frequency of the circulation pump 5 and the water supply pump 6 is controlled by the liquid level controller LC. The liquid level gauge 41 is provided with the evaporator maximum water level SLH and the evaporator minimum water level SLL. When the actual water level in the evaporator body 4 reaches the evaporator maximum water level SLH, the circulation pump 5 and the water supply pump 6 are both in the lowest frequency operation; when the actual water level in the evaporator body 4 reaches the evaporator minimum water level SLL, the circulation pump 5 and the water supply pump 6 are both in the highest frequency operation.

[0039] The circulation pump 5 sets a minimum allowable frequency, which corresponds to the minimum flow rate. As long as the actual circulation flow rate is greater than or equal to the minimum circulation flow rate, it can ensure that the water at the outlet of the economizer 2 will not vaporize. When the system is working, the frequency of the circulation pump 5 is not less than the minimum allowable frequency.

[0040] When the frequencies of the circulation pump 5 and the water supply pump 6 change synchronously from high to low, when the frequency of the circulation pump 5 drops to the minimum allowable frequency, the frequency of the circulation pump 5 will no longer decrease and maintain the minimum allowable frequency, while the frequency of the water supply pump 6 can continue to decrease. In this case, the circulation flow rate is greater than the water supply flow rate, and the buffer zone volume should be greater than the difference between the circulation flow rate and the water supply flow rate.

[0041] That is to say, when the frequencies of the circulating pump 5 and the feed water pump 6 decrease synchronously and the frequency of the circulating pump 5 drops to the minimum allowable frequency, the frequency of the circulating pump 5 will no longer decrease and maintain the minimum allowable frequency, while the frequency of the feed water pump 6 can continue to decrease. Under this operating condition, the circulation flow is greater than the feed water flow, and the buffer volume formed between the height of the hot water inlet 15 of the hot water area 12 and the lower end of the insulation partition 11 should be greater than the flow difference to prevent hot water from entering the cold water area 13 from the hot water area 12. The buffer volume calculation method is as follows: Assuming that the maximum operating time of this operating condition is t minutes, the difference between the circulation flow and the feed water flow is △Q m³ / h, considering a certain margin of 10%, the buffer volume should be greater than or equal to 1.1×△Q×t / 60 m³. In the actual operation of the steam generator, this operating condition generally occurs at low load, and t is generally less than 2 minutes, so the required volume of the buffer is relatively small.

[0042] When the circulating pump 5 operates at a frequency greater than the minimum allowable frequency, the frequency changes of the circulating pump 5 and the water supply pump 6, which cause the flow changes, should be basically consistent. The flow of the circulating pump 5 when it is working should always be kept smaller than the flow of the water supply pump 6 at this time. The recommended flow of the circulating pump 5 is 90% to 95% of the flow of the water supply pump 6. The difference between the flow of the circulating pump 5 and the flow of the water supply pump 6 is compensated by the water flow formed by the cold water in the cold water area 13 entering the hot water area 12 through the cold and hot water channel 16, and it has an automatic compensation function. If the flow of the circulating pump 5 is greater than the flow of the water supply pump, the hot water in the hot water area 12 will enter the cold water area 13 through the channel, thereby increasing the water temperature entering the condenser 3, and the energy-saving effect cannot be achieved.

[0043] If the flow rate of the circulation pump 5 is greater than the flow rate of the water supply pump 6, then after running for a period of time, when the buffer volume is not enough to accommodate the difference between the circulation flow rate and the water supply flow rate, the hot water in the hot water area 12 will enter the cold water area 13 through the hot and cold water channels 16, the first channel 11a and the second channel 11b, thereby increasing the water temperature entering the condenser 3 and the final exhaust gas temperature, increasing energy consumption and failing to achieve the energy-saving effect. The operating frequency of the circulation pump 5 and the water supply pump 6 is linearly related to the liquid level of the evaporator body 4.

[0044] The above scheme can keep the water temperature at the cold water outlet 17 at the lowest temperature and will not slowly rise, so that the smoke temperature at the smoke outlet of the condenser 3 is always at the lowest temperature, thereby improving the thermal efficiency of the steam generator, saving energy consumption, and reducing carbon emissions and pollutant emissions.

[0045] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the utility model. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the utility model are included in the protection scope of the utility model patent. Technicians in the technical field of the utility model can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should all fall within the protection scope of the utility model.

Claims

1. A steam generator continuous low temperature water supply system, characterized in that: The invention comprises a normal pressure water tank (1), an economizer (2), a condenser (3), an evaporator body (4), a circulation pump (5) and a water supply pump (6), wherein the normal pressure water tank (1) is connected to the condenser (3), and a circulation pump (5) is arranged on a pipeline connecting the normal pressure water tank (1) and the condenser (3), the condenser (3) is connected to the economizer (2), the economizer (2) is connected to the normal pressure water tank (1), the economizer (2) and the condenser (3) are both arranged on the evaporator body (4), the normal pressure water tank (1) is connected to the evaporator body (4), and a water supply pump (6) is arranged on a pipeline connecting the normal pressure water tank (1) and the evaporator body (4), and a liquid level gauge (41) is arranged on the evaporator body (4), and the liquid level gauge (41) is respectively connected to the circulation pump (5) and the water supply pump (6).

2. The continuous low-temperature water supply system for steam generator according to claim 1, characterized in that: The liquid level meter (41) is connected to a liquid level transmitter (LT), the liquid level transmitter (LT) is connected to a liquid level controller (LC), and the liquid level controller (LC) is respectively connected to a circulation pump (5) and a water supply pump (6).

3. The continuous low temperature water supply system for steam generator according to claim 1, characterized in that: The atmospheric pressure water tank (1) is provided with an insulating partition (11), and the insulating partition (11) divides the atmospheric pressure water tank (1) into a hot water area (12) and a cold water area (13), and the hot water area (12) and the cold water area (13) are connected via a hot and cold water channel (16).

4. The continuous low-temperature water supply system for steam generator according to claim 3, characterized in that: The side wall of the hot water area (12) is provided with a hot water outlet (14) and a hot water inlet (15), and the side wall of the cold water area (13) is provided with a cold water outlet (17) and a water replenishment port (18).

5. The continuous low temperature water supply system for steam generator according to claim 4, characterized in that: The economizer (2) is connected to the hot water inlet (15) via a hot water inlet pipe (7a), the cold water outlet (17) is connected to the condenser (3) via a cold water outlet pipe (7b), the circulation pump (5) is arranged on the cold water outlet pipe (7b), the hot water outlet (14) is connected to the evaporator body (4) via a hot water outlet pipe (7c), and the water supply pump (6) is arranged on the hot water outlet pipe (7c).

6. The continuous low temperature water supply system for steam generator according to claim 4, characterized in that: The height of the hot water outlet (14) is higher than the height of the hot water inlet (15), and the area between the hot water inlet (15) and the lower end of the insulating baffle (11) in the hot water area (12) serves as a buffer zone.

7. The continuous low-temperature water supply system for steam generator according to claim 6, characterized in that: A first transverse partition (19a) and a second transverse partition (19b) are provided in the buffer zone, and a first channel (11a) and a second channel (11b) are formed in the hot water zone (12); the first transverse partition (19a) and the second transverse partition (19b) are staggered, and the first channel (11a) and the second channel (11b) are staggered.

8. The continuous low temperature water supply system for steam generator according to claim 1, characterized in that: The bottom of the normal pressure water tank (1) is provided with a support foot (110).

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