Magnetic suspension heat pump system for sewage waste heat recovery and purification

Abstract

The invention discloses a magnetic suspension heat pump system for sewage waste heat recovery and purification, which comprises a magnetic suspension heat pump, a temperature acquisition module, a sewage purification module and a temperature prediction algorithm module, and is characterized in that the magnetic suspension heat pump comprises a condenser, an evaporator and a compressor rotating speed control module; the temperature prediction algorithm module performs exponential weighted average on the temperature of the anaerobic tank obtained by the temperature sensing module and the environment temperature obtained by the environment temperature sensing module at the same moment along a time axis, and obtains the temperature change prediction rate of the anaerobic tank; the compressor rotating speed control module is used for controlling the rotating speed change of the compressor according to the temperature change prediction rate of the anaerobic tank so as to adjust the temperature of water output to the anaerobic tank; the sewage purification module is used for purifying the sewage through an anaerobic tank and then discharging the sewage again. Heat in sewage is absorbed by adopting the magnetic suspension heat pump, the heat in the sewage is effectively utilized through the magnetic suspension heat pump, the temperature of the adjusting water is increased, the adjusting water is discharged into the anaerobic tank, and the temperature of the anaerobic tank is maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage afterheat treatment, in particular to a magnetic levitation heat pump system for sewage afterheat recovery and purification. Background Art

[0002] With the acceleration of the urbanization process and the expansion of industrial scale, the energy efficiency and purification capacity of sewage treatment systems are facing severe challenges. In traditional sewage treatment processes, as a key unit for water quality and quantity regulation, the effluent from the equalization tank is usually directly transported to the anaerobic tank for biodegradation treatment. However, this process has defects: First, the effluent temperature of the equalization tank is generally lower than the operating requirements of the anaerobic tank, and direct discharge will cause a sudden drop in the temperature of the tank, severely inhibiting the metabolic activities of anaerobic microorganisms such as methanogens. Experimental data shows that when the water temperature drops from 35°C to 25°C, the organic matter degradation rate decreases by more than 40%, and the risk of volatile fatty acid accumulation increases by 3 times, which is extremely likely to cause system acidification and collapse; Second, the low-grade heat energy generated during the sewage treatment process is not effectively recovered. For example, the drainage temperatures of the primary sedimentation tank and the biochemical tank often reach 25 - 30°C without being utilized and are directly dissipated through the drainage pipe network, resulting in energy waste.

[0003] In the prior art, external heat sources are used to compensate for the heat deficit in the anaerobic tank, but there are limitations: (1) The electric heating method has extremely high energy consumption. Taking a sewage treatment plant with a treatment scale of 100,000 tons per day as an example, maintaining the constant temperature of the anaerobic tank requires an additional power consumption of about 2,000 kWh per day, and the annual operating cost increases by more than one million yuan; (2) Although the gas boiler heating has slightly better energy efficiency, it has nitrogen oxide emission pollution and is limited by the coverage of the natural gas pipeline network. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a magnetic levitation heat pump system for sewage afterheat recovery and purification, which absorbs the heat in sewage by using a magnetic levitation heat pump, effectively utilizes the heat in sewage through the magnetic levitation heat pump, raises the temperature of the regulating water and then discharges it into the anaerobic tank to maintain the temperature of the anaerobic tank.

[0005] The technical solution adopted by the present invention to solve its technical problems is: A magnetic levitation heat pump system for sewage afterheat recovery and purification, including a magnetic levitation heat pump, a temperature acquisition module, a sewage purification module, and a temperature prediction algorithm module. The magnetic levitation heat pump includes a condenser, an evaporator, and a compressor speed control module.

[0006] The temperature acquisition module includes a pool temperature sensing module and an ambient temperature sensing module. The temperature sensing module acquires the temperature of the anaerobic tank in the sewage purification module, and the ambient temperature sensing module acquires the ambient temperature. The temperature prediction algorithm module performs an exponentially weighted average on the temperature of the anaerobic tank acquired by the temperature sensing module and the ambient temperature acquired by the ambient temperature sensing module at the same moment along the time axis to obtain the predicted rate of change of the temperature of the anaerobic tank.

[0007] The compressor speed control module predicts the rate according to the temperature change of the anaerobic pond, controls the change of the compressor speed, and adjusts the water temperature output to the anaerobic pond;

[0008] The sewage purification module discharges the sewage after purification through the anaerobic pond.

[0009] As a further improvement of the present invention: the sewage purification module includes a sewage pretreatment module. The sewage treatment module removes suspended solids in the sewage through a self-cleaning filter, and uses a flushing method to remove dirt on the filter screen to strip attached particulate matter. The flushing wastewater is discharged through a pipeline.

[0010] As a further improvement of the present invention: the evaporator enables the pretreated sewage to enter the evaporation section in the evaporator of the magnetic levitation heat pump through a heat pump. The evaporation section has a heat absorption structure. The refrigerant in the compressor evaporates into refrigerant gas after absorbing the heat of the sewage through the heat absorption structure of the evaporation section.

[0011] As a further improvement of the present invention: the magnetic levitation heat pump uses a three-stage magnetic levitation compressor to perform three-stage compression on the refrigerant gas. The three-stage magnetic levitation compressor has three compression chambers. Each compression chamber has an impeller, and the diameter of each stage of impeller decreases. The low-temperature and low-pressure refrigerant gas is compressed into high-temperature and high-pressure refrigerant gas through three-stage compression.

[0012] As a further improvement of the present invention: the condenser releases heat in a condensing manner by passing the high-temperature and high-pressure refrigerant gas through the condensing section of the condenser and the regulating water. The high-temperature and high-pressure refrigerant transfers the heat to the regulating water. After the regulating water is heated, it is discharged from the compressor to supply heat to the anaerobic pond.

[0013] As a further improvement of the present invention: the pond temperature sensing module obtains the temperatures at multiple positions in the anaerobic pond, and takes the average value of the temperatures at multiple positions as the temperature of the anaerobic pond. The ambient temperature sensing module obtains the ambient temperature outside the anaerobic pond. The pond temperature sensing module and the ambient temperature sensing module respectively obtain the temperature of the anaerobic pond and the ambient temperature at regular intervals along the time axis.

[0014] As a further improvement of the present invention: the process for the temperature prediction algorithm module to obtain the predicted rate of temperature change in the anaerobic pond is as follows: the pond temperature sensing module and the ambient temperature sensing module respectively obtain the temperature of the anaerobic pond and the ambient temperature at regular intervals along the time axis, calculate the current rate of temperature change in the anaerobic pond and the rate of temperature change in the ambient temperature respectively, and calculate the predicted rate of temperature change in the anaerobic pond at the previous moment. The predicted rate of temperature change in the anaerobic pond at the current moment is obtained through the formula

[0015]

[0016]

[0017] Among them, is the temperature change rate of the anaerobic tank at time t, is the environmental temperature change rate at time t, is the temperature of the anaerobic tank at time t, is the environmental temperature at time t, α is the smoothing coefficient, α = 3, and β is the environmental temperature influence factor.

[0018] As a further improvement of the present invention: the environmental temperature influence factor is calculated by regression analysis

[0019]

[0020] Among them, when the change rate is greater than 0.5, β is 0.8.

[0021] As a further improvement of the present invention: the compressor speed control module controls the change of the compressor speed according to the predicted rate of temperature change in the anaerobic tank, including:

[0022] When the compressor speed is increased by 20%;

[0023] When the compressor speed is increased by 10%; When

[0024] the compressor speed is decreased by 10%. As a further improvement of the present invention: the sewage purification module further includes an equalization tank, and the equalization tank is used to provide regulating water for the condensation process of the condenser of the compressor.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] By using a magnetic levitation heat pump to absorb the heat in the sewage, and effectively utilizing the heat in the sewage through the magnetic levitation heat pump, heating the regulating water and discharging it into the anaerobic tank to maintain the temperature of the anaerobic tank. The present invention also uses the in-tank temperature sensing module and the environmental temperature sensing module in the system to obtain the temperature of the anaerobic tank and the environmental temperature, and uses the temperature prediction algorithm module to obtain the predicted rate of temperature change in the anaerobic tank, and cooperates with the compressor speed control module to control the speed of the magnetic levitation heat pump to adjust the water temperature output to the anaerobic tank, so as to automatically maintain the temperature of the anaerobic tank and maintain the activity of anaerobic microorganisms in the anaerobic tank, thereby improving the sewage purification efficiency.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] In order to clearly and completely understand the technical solution, the present invention will be further described below in conjunction with embodiments and drawings. Obviously, the described embodiments are only part of 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.

[0030] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0031] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0032] It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0033] An embodiment of the present invention provides a magnetic levitation heat pump system for sewage waste heat recovery and purification, including a magnetic levitation heat pump, a temperature acquisition module, a sewage purification module and a temperature prediction algorithm module. The magnetic levitation heat pump includes a condenser, an evaporator and a compressor speed control module. The temperature acquisition module includes a pool temperature sensing module and an ambient temperature sensing module. The pool temperature sensing module acquires the temperature of the anaerobic tank in the sewage purification module, and the ambient temperature sensing module acquires the ambient temperature. The temperature prediction algorithm module performs an exponentially weighted average on the temperature of the anaerobic tank acquired by the temperature sensing module and the ambient temperature acquired by the ambient temperature sensing module at the same moment along the time axis to obtain the predicted rate of change of the temperature of the anaerobic tank.

[0034] The compressor speed control module controls the change of the compressor speed according to the predicted rate of change of the temperature of the anaerobic tank to adjust the water temperature output to the anaerobic tank. The sewage purification module purifies the sewage through the anaerobic tank and then discharges it again.

[0035] In the present invention, a magnetic levitation heat pump is adopted to absorb the heat in the sewage, and the heat in the sewage is effectively utilized through the magnetic levitation heat pump. The regulated water is heated up and then discharged into the anaerobic pond to maintain the temperature of the anaerobic pond. The temperature sensing module in the system is also used in cooperation with the ambient temperature sensing module to obtain the temperature of the anaerobic pond and the ambient temperature, and the temperature prediction algorithm module is used to obtain the predicted rate of temperature change of the anaerobic pond. The rotation speed of the magnetic levitation heat pump is controlled in cooperation with the compressor rotation speed control module to adjust the water temperature output to the anaerobic pond, so as to automatically maintain the temperature of the anaerobic pond and maintain the activity of anaerobic microorganisms in the anaerobic pond, thereby improving the sewage purification efficiency.

[0036] In one embodiment of the present invention, the sewage purification module includes a sewage pretreatment module. The sewage treatment module removes the suspended solids in the sewage through a self-cleaning filter, and adopts a flushing method to remove the dirt on the filter screen to peel off the attached particulate matter. The flushing wastewater is discharged through a pipeline. In this embodiment, before the evaporator of the magnetic levitation heat pump exchanges heat with the sewage, the suspended solids in the sewage are filtered first, and the self-cleaning filter is used to remove the suspended solids in the sewage, so as to avoid damaging the evaporator during the heat exchange process between the sewage and the evaporator. At the same time, the self-cleaning filter also has the function of cleaning its own filter screen, and can peel off the attached particulate matter by flushing to avoid clogging of the filter screen.

[0037] In one embodiment of the present invention, the evaporator enables the pretreated sewage to enter the evaporation section in the evaporator of the magnetic levitation heat pump through the heat pump. The evaporation section has a heat absorption structure. The refrigerant in the compressor evaporates into a refrigerant gas after absorbing the heat of the sewage through the heat absorption structure in the evaporation section. In this embodiment, the sewage temperature is relatively low, and effective heat extraction can be achieved by optimizing the matching between the evaporator and the heat pump. The heat absorption mechanism in the evaporation section is made of high thermal conductivity materials, which can greatly improve the heat exchange efficiency between the sewage and the refrigerant, and quickly absorb the waste heat in the sewage. After the refrigerant absorbs heat and evaporates into a gas, it is efficiently compressed by the magnetic levitation compressor to convert low-grade heat energy into high-grade heat energy, realizing the recycling of sewage heat energy.

[0038] In an embodiment of the present invention, the magnetic levitation heat pump adopts a three-stage magnetic levitation compressor to perform three-stage compression on the refrigerant gas. The three-stage magnetic levitation compressor has three compression chambers, each compression chamber has an impeller, and the diameter of each stage of impeller decreases. The low-temperature and low-pressure refrigerant gas is compressed into a high-temperature and high-pressure refrigerant gas through three-stage compression. In this embodiment, the pressure of the refrigerant gas is gradually increased through the three-stage compression chambers to avoid energy loss caused by too high a single-stage compression ratio, so as to improve the compression efficiency. The initial refrigerant gas is in a low-temperature and low-pressure state, and three-stage compression can gradually heat the low-temperature and low-pressure refrigerant gas to a high-temperature and high-pressure state, enhancing the utilization ability of low-grade heat energy. The three-stage magnetic levitation compressor realizes the conversion of low-temperature waste heat into high-temperature heat energy through step-by-step compression and the efficient drive of magnetic levitation technology. The high-temperature and high-pressure refrigerant gas can efficiently release more heat.

[0039] In an embodiment of the present invention, the condenser releases heat in a condensing manner by passing the high-temperature and high-pressure refrigerant gas through the condensing section of the condenser and the regulating water. The high-temperature and high-pressure refrigerant transfers heat to the regulating water, and the regulating water is discharged after heating up to supply heat to the anaerobic pond. In this embodiment, the high-temperature and high-pressure refrigerant gas quickly releases heat to the regulating water, realizing the conversion and utilization of sewage heat. The heated regulating water is directly supplied to the anaerobic pond to supplement heat and maintain the temperature of the anaerobic pond.

[0040] As a further improvement of the present invention: The pool temperature sensing module obtains the temperatures at multiple positions in the anaerobic pond, and takes the average value of the temperatures at multiple positions as the temperature of the anaerobic pond. The environmental temperature sensing module obtains the environmental temperature outside the anaerobic pond. The pool temperature sensing module and the environmental temperature sensing module respectively obtain the temperature of the anaerobic pond and the environmental temperature at regular intervals along the time axis. In this embodiment, by collecting the temperatures at multiple positions in the anaerobic pond by the pool temperature sensing module and taking the average value, the local temperature measurement deviation is eliminated, and the overall temperature state in the pond is truly reflected, avoiding misjudgment caused by the error of a single measurement point. At the same time, combined with the external temperature data of the environmental temperature sensing module, the heat supply strategy of the heat pump is dynamically adjusted to improve the temperature control accuracy.

[0041] In an embodiment of the present invention, the process for the temperature prediction algorithm module to obtain the predicted rate of temperature change in the anaerobic pond is as follows: The pool temperature sensing module and the environmental temperature sensing module respectively obtain the temperature of the anaerobic pond and the environmental temperature at regular intervals along the time axis, calculate the rate of temperature change in the anaerobic pond and the rate of temperature change in the environment at the current moment respectively, and calculate the predicted rate of temperature change in the anaerobic pond at the previous moment. The predicted rate of temperature change in the anaerobic pond at the current moment is calculated through the formula

[0042]

[0043] where is the rate of temperature change in the anaerobic pond at time t, is the rate of temperature change in the environment at time t, is the temperature of the anaerobic tank at time t, is the ambient temperature at time t, α is the smoothing coefficient, α = 0.3, and β is the ambient temperature influence factor.

[0044] Furthermore, the ambient temperature influence factor is calculated through regression analysis

[0045]

[0046] Among them, when the change rate is greater than 0.5, β is 0.8.

[0047] In this embodiment, by simultaneously analyzing the real-time change rates of the temperature of the anaerobic tank and the ambient temperature, and integrating the internal and external influencing factors of the anaerobic tank, the environmental adaptability of the prediction model is improved. Based on the predicted rate, heating or cooling is adjusted in advance to prevent the temperature of the anaerobic tank from exceeding the activity range of anaerobic bacteria and maintain the microbial metabolism efficiency.

[0048] In an embodiment of the present invention, the compressor speed control module controls the change of the compressor speed according to the predicted rate of the temperature change of the anaerobic tank, including:

[0049] When the compressor speed is increased by 20%;

[0050] When the compressor speed is increased by 10%; When

[0051] the compressor speed is decreased by 10%. When

[0052] In this embodiment, the temperature prediction algorithm module is used to obtain the predicted rate of the temperature change of the anaerobic tank, and cooperate with the compressor speed control module to control the speed of the magnetic levitation heat pump to adjust the water temperature output to the anaerobic tank, so as to automatically maintain the temperature of the anaerobic tank and maintain the activity of anaerobic microorganisms in the anaerobic tank, thereby improving the sewage purification efficiency.

[0053] In an embodiment of the present invention, the sewage purification module further includes an equalization tank, and the equalization tank is used to provide regulating water for the condensation process of the condenser of the compressor.

[0054] In this embodiment, the equalization tank serves as a buffer unit to balance the effluent fluctuation of the sewage purification module and the dynamic demand of the condenser, prevent the decline of heat transfer efficiency caused by insufficient instantaneous flow or overload, and ensure that the regulating water supplied to the condenser is clean and has stable physical properties, maintaining the high-efficiency heat transfer performance of the condensation section.

[0055] In summary, after reading the present invention document, those of ordinary skill in the art can make various corresponding transformation schemes without creative mental labor according to the technical solutions and concepts of the present invention, and all of them fall within the scope protected by the present invention.

Claims

1. A magnetic levitation heat pump system for sewage waste heat recovery and purification, comprising a magnetic levitation heat pump, a temperature acquisition module, a sewage purification module and a temperature prediction algorithm module, characterized in that, The magnetic levitation heat pump includes a condenser, an evaporator, and a compressor speed control module. The temperature acquisition module includes a pool temperature sensing module and an ambient temperature sensing module. The temperature sensing module acquires the temperature of the anaerobic pool in the sewage purification module, and the ambient temperature sensing module acquires the ambient temperature. The temperature prediction algorithm module performs an exponentially weighted average of the temperature of the anaerobic pool acquired by the temperature sensing module and the ambient temperature acquired by the ambient temperature sensing module at the same moment along the time axis to obtain the predicted rate of temperature change of the anaerobic pool. The compressor speed control module controls the change of the compressor speed according to the predicted rate of temperature change of the anaerobic pool to adjust the water temperature output to the anaerobic pool. The sewage purification module purifies the sewage through the anaerobic pool and then discharges it again.

2. The magnetic levitation heat pump system for sewage waste heat recovery and purification according to claim 1, characterized in that, The sewage purification module includes a sewage pretreatment module. The sewage treatment module removes the suspended solids in the sewage through a self-cleaning filter and uses a flushing method to remove the dirt on the filter screen to peel off the attached particulate matter. The flushing wastewater is discharged through a pipeline.

3. A magnetic levitation heat pump system for sewage waste heat recovery and purification according to claim 2, characterized in that, The evaporator enables the pretreated sewage to enter the evaporation section in the evaporator of the magnetic levitation heat pump through the heat pump. The evaporation section has a heat absorption structure. The refrigerant in the compressor absorbs the heat of the sewage through the heat absorption structure in the evaporation section and then evaporates into a refrigerant gas.

4. A magnetic levitation heat pump system for sewage waste heat recovery and purification according to claim 3, characterized in that, The magnetic levitation heat pump uses a three-stage magnetic levitation compressor to perform three-stage compression on the refrigerant gas. The three-stage magnetic levitation compressor has three compression chambers, each compression chamber has an impeller, and the diameter of each stage of impeller decreases. The low-temperature and low-pressure refrigerant gas is compressed into a high-temperature and high-pressure refrigerant gas through three-stage compression.

5. A magnetic levitation heat pump system for sewage waste heat recovery and purification according to claim 4, characterized in that, The condenser releases heat in a condensing manner by passing the high-temperature and high-pressure refrigerant gas through the condensing section of the condenser and the regulating water. The high-temperature and high-pressure refrigerant transfers the heat to the regulating water, and the regulating water is discharged after heating up to supply heat to the anaerobic pool.

6. A magnetic levitation heat pump system for sewage waste heat recovery and purification according to claim 1, characterized in that, The pool temperature sensing module acquires the temperatures at multiple positions in the anaerobic pool, and takes the average value of the temperatures at multiple positions as the temperature of the anaerobic pool. The ambient temperature sensing module acquires the ambient temperature outside the anaerobic pool. The pool temperature sensing module and the ambient temperature sensing module respectively acquire the temperature of the anaerobic pool and the ambient temperature at regular intervals along the time axis.

7. A magnetic levitation heat pump system for sewage waste heat recovery and purification according to claim 6, characterized in that, The process for the temperature prediction algorithm module to obtain the predicted rate of temperature change of the anaerobic pool is as follows: The pool temperature sensing module and the ambient temperature sensing module respectively acquire the temperature of the anaerobic pool and the ambient temperature at regular intervals along the time axis, calculate the temperature change rate of the anaerobic pool and the temperature change rate of the ambient temperature at the current moment respectively, and calculate the predicted rate of temperature change of the anaerobic pool at the previous moment. The predicted rate of temperature change of the anaerobic pool at the current moment is calculated through the formula Among them, is the temperature change rate of the anaerobic tank at time t, is the environmental temperature change rate at time t, is the temperature of the anaerobic tank at time t, is the environmental temperature at time t, α is the smoothing coefficient, α = 3, and β is the environmental temperature influence factor.

8. A magnetic levitation heat pump system for sewage waste heat recovery and purification according to claim 7, characterized in that, The ambient temperature influence factor is calculated through regression analysis. Among them, when the change rate is greater than 0.5, β is 0.

8.

9. A magnetic levitation heat pump system for sewage waste heat recovery and purification according to claim 8, characterized in that, The compressor speed control module controls the change of the compressor speed according to the predicted rate of temperature change of the anaerobic pool, including: When the compressor speed increases by 20%; When the compressor speed increases by 10%; When the compressor speed is reduced by 10%.

10. A magnetic levitation heat pump system for sewage waste heat recovery and purification according to claim 1, characterized in that, The sewage purification module further includes an equalization tank, and the equalization tank is used to provide regulating water for the condensation process of the condenser of the compressor.

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