Control system for heating water from wastewater for microbial treatment

Abstract

The application discloses a control system for wastewater for water heating by microorganism treatment, wherein pressure sensors, liquid level sensors A, liquid level sensors B, liquid level sensors C, temperature sensors A and temperature sensors B transmit the signals collected by themselves to a processor, and the processor controls switch valves A, filtering water inlet pumps, switch valves B, switch valves C, switch valves D, switch valves E, switch valves F, water source heat pumps, cleaning liquid pumps, adjusting valves A and adjusting valves B through signals respectively. According to the above structure, the control system for wastewater for water heating by microorganism treatment can quickly reduce the temperature of wastewater to a temperature suitable for biological treatment, does not need to wait for the natural cooling of the wastewater, shortens the wastewater treatment time, and can also prepare hot water for use.

Description

Technical Field

[0001] This invention relates to the technical field of wastewater treatment and hot water production, specifically to a control system for producing hot water from wastewater treated by microorganisms. Background Technology

[0002] Industrial enterprises such as dyeing, papermaking, and slaughterhouses generate large amounts of hot wastewater discharge and have significant hot water demand. The temperature of this wastewater is significantly higher than that of bathhouse wastewater, typically around 50°C. However, due to the complex processes involved, the hot water temperature varies at different stages, resulting in a wide temperature range for the discharged wastewater, usually between 30°C and 60°C. All this wastewater requires purification treatment before final discharge. Purification typically employs biological methods, and the core of biological wastewater treatment lies in the activity of the microbial community.

[0003] Most microbial communities are most active at around 25℃, meaning that biological wastewater treatment is most efficient at this temperature. Outside this temperature range, the efficiency of biological wastewater treatment decreases significantly. For example, at temperatures above 40℃, most microbial communities are inhibited or even inactive; at temperatures below 8℃, most microbial communities are also inhibited or even enter a dormant state, thus affecting wastewater treatment efficiency.

[0004] Therefore, when utilizing the aforementioned wastewater, it is not only necessary to ensure that the hot water after heat exchange reaches a temperature suitable for reuse, but more importantly, it is also necessary to guarantee that the temperature of the wastewater after heat exchange meets the requirements for biological wastewater treatment. This is the technical problem that this application seeks to solve. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a control system for producing hot water from wastewater treated by microorganisms. This system can quickly reduce the temperature of wastewater to a temperature suitable for biological treatment without waiting for the wastewater to cool down naturally, thus shortening the wastewater treatment time. At the same time, it can also produce hot water for use.

[0006] The technical solution adopted in this invention is:

[0007] A control system for heating wastewater from microbial treatment includes a wastewater collection container, a wastewater filter, a hot water storage container, a preheater, a water source heat pump, and a cleaning fluid storage container. The inlet of the wastewater collection container is connected to the wastewater drain pipe of the production equipment. The outlets of the wastewater collection container and the cleaning fluid storage container are connected in parallel to the filter inlet pipe of the wastewater filter via wastewater outlet pipe and cleaning fluid outlet pipe, respectively. The filter outlet pipe of the wastewater filter is connected to the inlet of the wastewater channel of the preheater. The outlet of the wastewater channel is connected to the inlet of the evaporator of the water source heat pump via wastewater connecting pipe A. The outlet of the evaporator and the outlet of the wastewater filter are connected to the wastewater treatment container via wastewater discharge pipe A and wastewater discharge pipe B, respectively. The filter outlet pipe is also connected to the wastewater discharge pipe A via wastewater connecting pipe B.

[0008] The clean water supply pipe is connected to the inlet of the cleaning solution storage container and the inlet of the clean water channel of the heat exchanger of the preheater respectively through the parallel clean water inlet pipe A and clean water inlet pipe B. The outlet of the clean water channel of the heat exchanger is connected to the inlet of the condenser of the water source heat pump through the clean water connecting pipe A. The outlet of the condenser is connected to the liquid inlet pipe of the hot water storage container through the clean water connecting pipe B. The hot water storage container is connected to a hot water supply pipe.

[0009] The filter inlet pipe and filter outlet pipe are respectively connected to the automatic air inlet and outlet valves via vent pipe A and vent pipe B.

[0010] A switch valve A is connected to the wastewater outlet pipe. A cleaning liquid pump and a switch valve D are connected sequentially along the liquid flow direction to the cleaning liquid outlet pipe. A filter inlet pump is connected to the filter inlet pipe. A vent pipe A is connected to one end of the filter inlet pipe corresponding to the inlet of the filter inlet pump. A switch valve E is connected to the vent pipe A. A regulating valve A is connected to the filter outlet pipe. A temperature sensor B and a switch valve B are connected sequentially along the wastewater flow direction to the wastewater discharge pipe A. A switch valve C is connected to the wastewater connecting pipe B. One end of the wastewater connecting pipe B is connected to the filter outlet pipe at the position between the sewage filter and the regulating valve A, and the other end is connected to the wastewater discharge pipe A at the position between the evaporator and the switch valve B. A regulating valve B is connected to the clean water inlet pipe B. A switch valve F is connected to the wastewater discharge pipe B.

[0011] The sewage filter is equipped with a pressure sensor, the clean water connecting pipe B is connected to a temperature sensor A, the wastewater collection container is equipped with a level sensor A, the hot water storage container is equipped with a level sensor B, and the cleaning fluid storage container is equipped with a level sensor C.

[0012] It also includes a processor. The pressure sensor, liquid level sensor A, liquid level sensor B, liquid level sensor C, temperature sensor A, temperature sensor B, switch valve A, filter water inlet pump, switch valve B, switch valve C, switch valve D, switch valve E, switch valve F, water source heat pump, cleaning fluid pump, regulating valve A, and regulating valve B are all connected to the processor via signals. The pressure sensor, liquid level sensor A, liquid level sensor B, liquid level sensor C, temperature sensor A, and temperature sensor B transmit their respective collected signals to the processor. The processor controls switch valve A, filter water inlet pump, switch valve B, switch valve C, switch valve D, switch valve E, switch valve F, water source heat pump, cleaning fluid pump, regulating valve A, and regulating valve B through signals, respectively.

[0013] A further improvement of the present invention is that the liquid level value in the wastewater collection container collected and measured by the liquid level sensor A is set as h1, and the wastewater high water level control value h1high and the wastewater low water level control value h1low of the wastewater collection container are set; the liquid level value in the hot water storage container collected and measured by the liquid level sensor B is set as h2, and the hot water high water level control value h2high and the hot water low water level control value h2low of the hot water storage container are set; when h1>h1high and h2<h2low, the processor controls the water source heat pump to start and enters the hot water production mode; when h1<h1low or h2>h2high, the processor controls the water source heat pump to shut down and stops the hot water production mode;

[0014] When entering hot water production mode, the processor controls the opening of switch valve A, filter inlet pump, regulating valve A, switch valve B, regulating valve B and water source heat pump respectively, while the remaining switch valves and pumps are closed;

[0015] The wastewater in the wastewater collection container passes sequentially through the filter inlet pump, regulating valve A, preheater, water source heat pump and switch valve B, and finally enters the wastewater treatment device through the wastewater discharge system.

[0016] The clean water in the clean water supply pipe passes sequentially through regulating valve B, the preheater, and the water source heat pump before finally entering the hot water storage container.

[0017] A further improved solution of the present invention is that the differential pressure value between the inlet and outlet of the filter in the sewage filter collected by the pressure sensor is set as p1, and the upper limit value of the differential pressure control between the inlet and outlet of the filter in the sewage filter is set as pmax, and the lower limit value of the differential pressure control between the inlet and outlet of the filter is set as pmin; when p1 > pmax, the processor controls the cleaning motor in the sewage filter to start and drive the wire mesh cleaning brush to rotate to clean the filter screen; when p1 < pmin, the processor controls the switching valve F to open and maintain the opening time as T, and after the opening time T of the switching valve F is reached, the processor controls the switching valve F to close, and at the same time, the cleaning motor in the sewage filter is turned off.

[0018] A further improved solution of the present invention is that pmax and pmin are set according to the actual situation, and pmax > pmin, and T is set according to the actual usage situation.

[0019] A further improved solution of the present invention is that the control input value of the regulating valve B is set as a, the control input value of the regulating valve A is set as b, the hot water outlet temperature measured by the temperature sensor A is tq, the wastewater discharge temperature measured by the temperature sensor B is tf, and the upper limit value of the hot water outlet temperature is set as tqmax and the lower limit value of the hot water outlet temperature is set as tqmin, and the upper limit value of the wastewater discharge temperature is set as tfmax and the lower limit value of the wastewater discharge temperature is set as tfmin; when tq < tqmin and tfmin < tf < tfmax, the processor reduces a; when tq < tqmin and tf > tfmax, the processor reduces a and b; when tq < tqmax and tf < tfmin, the processor increases b; when tq > tqmax and tf > tfmin, the processor increases a; when tq > tqmax and tf < tfmin, the processor increases a and b; when tqmin < tq < tqmax and tf > tfmax, the processor reduces b.

[0020] A further improved solution of the present invention is that the target value tqt of the hot water outlet temperature tq is the average value of the upper limit value tqmax and the lower limit value tqmin of the hot water outlet temperature: tqt = (tqmin + tqmax) ÷ 2;

[0021] The target value tft of the wastewater discharge temperature tf is the average value of the upper limit value tfmax and the lower limit value tfmin of the wastewater discharge temperature: tft = (tfmin + tfmax) ÷ 2;

[0022] The range of the electrical signal values corresponding to the fully open to fully closed states of the regulating valve A and the regulating valve B is: n0~n1;

[0023] The clean water inlet temperature tq' of clean water inlet pipes A and B changes with the change of the outside temperature. The highest clean water inlet temperature is set as tq'max and the lowest clean water inlet temperature is set as tq'min.

[0024] The wastewater outlet temperature tf' varies with different equipment operating conditions and processes. The maximum wastewater outlet temperature is set as tf'max and the minimum wastewater outlet temperature is set as tf'min.

[0025] Decrease a: Target value of a: at = a - k × (a - n0) ÷ (tq'max - tq) × (tqt - tq);

[0026] Increase a: Target value of a: at = a + k × (n1 - a) ÷ (tq - tq'min) × (tq - tqt);

[0027] Decrease b: Target value of b: bt = b - k × (b - n0) ÷ (tf - tf'min) × (tf - tft);

[0028] Increase b: Target value of b: bt = b + k × (n1 - b) ÷ (tf'max - tf) × (tft - tf);

[0029] Where 0.3 < k < 0.85.

[0030] A further improvement of the present invention is that a and b are respectively set with control input lower limits amin and bmin. When the calculated at < amin, the value of at is slightly greater than amin; when the calculated bt < bmin, the value of bt is slightly greater than bmin.

[0031] A further improvement of the present invention is that when the regulating valve A is a valve with a current signal input, b is the input current value; when the regulating valve A is a valve with a voltage signal input, b is the input voltage value; when the regulating valve B is a valve with a current signal input, a is the input current value; and when the regulating valve B is a valve with a voltage signal input, a is the input voltage value.

[0032] A further improvement of the present invention is that the processor sets the cumulative working time of the water source heat pump to C. When C reaches an integer multiple of C1, the processor shuts down the water source heat pump and enters a backflushing cleaning mode without cleaning fluid. When C reaches C2, the processor shuts down the water source heat pump and enters a backflushing mode with cleaning fluid. In addition, the processor resets C to zero and restarts the accumulation. C1 is less than C2. After the backflushing cleaning is completed, the processor restores the working state corresponding to the state before the backflushing cleaning. C1 and C2 are set according to the actual usage.

[0033] A further improvement of the present invention is that when entering the backwashing mode without cleaning fluid, the processor controls the opening of switch valves C and E respectively, while the remaining switch valves and pumps are closed. Then the processor starts the filter inlet water pump to perform backwashing cycle. After the backwashing time reaches T1, the backwashing mode without cleaning fluid ends.

[0034] A further improvement of the present invention is that, when entering the backwashing mode with cleaning fluid, the processor first controls the switch valve A, the filter water inlet pump, the regulating valve B, the switch valve D, and the switch valve F to close respectively, while the remaining switch valves are all opened, allowing the wastewater in the pipeline to be discharged into the wastewater discharge system through the switch valve B and finally into the wastewater treatment device. External air enters the pipeline through the automatic air inlet and outlet valves to fully drain the wastewater in the pipeline. The drainage time is TQ.

[0035] After the system wastewater is drained, the processor controls the regulating valve A and the switching valve B to close, and the switching valve D and the cleaning fluid pump to open. The cleaning fluid in the cleaning fluid storage container is injected into the pipeline through the switching valve D into all the wastewater channels in the pipeline, including the filter inlet pump, the sewage filter, the heat exchanger wastewater channel and the evaporator, until it is full. After it is full, the processor controls the cleaning fluid pump and the switching valve D to close.

[0036] Then the processor starts the filter inlet pump to perform backwashing and cleaning cycle. After the backwashing and cleaning time reaches T3, the processor controls the filter inlet pump to shut down.

[0037] The backwashing cycle should be repeated at least twice, and the wastewater in the pipeline should be allowed to stand for a period of T4 between two adjacent backwashing cycles.

[0038] The processor then controls valves A, the filter inlet pump, regulating valve B, valve D, and valve F to close, while opening all other valves. This allows the wastewater in the pipeline to be discharged through valve B into the wastewater system and ultimately into the wastewater treatment device. External air enters the pipeline through the automatic air intake and exhaust valves, thoroughly draining the wastewater. The drainage time is T5, at which point the backwashing mode with cleaning fluid ends.

[0039] A further improvement of the present invention is that the processor is also connected to a data memory via communication, and the processor transmits all the collected data and the control data issued to the data memory.

[0040] A further improvement of the present invention is that the cleaning fluid storage container is connected to a cleaning fluid concentrate injection port.

[0041] A further improvement of the present invention is that the cleaning fluid stock solution is injected into the cleaning fluid storage container through the cleaning fluid stock solution injection port by an injection pump, and the processor injects a matching amount of cleaning fluid stock solution according to the power of the water source heat pump; when injecting the cleaning fluid stock solution, the switch valve D and the cleaning fluid pump remain closed.

[0042] A further improvement of the present invention is that a manual maintenance valve is also provided on the cleaning fluid outlet pipe between the cleaning fluid pump and the cleaning fluid storage container. The manual maintenance valve is kept open and is only closed during maintenance.

[0043] A further improvement of the present invention is that, when the wastewater collection container is an open wastewater pool, one end of the wastewater outlet pipe inside the wastewater pool extends into the bottom of the wastewater pool and is connected to a bottom valve; when the wastewater collection container is a wastewater tank, one end of the wastewater outlet pipe inside the wastewater tank extends into the bottom of the wastewater pool.

[0044] A further improvement of the present invention is that the processor is a PLC.

[0045] The beneficial effects of this invention are as follows:

[0046] First, the control system for producing hot water from wastewater for microbial treatment of the present invention can quickly reduce the temperature of wastewater to a temperature suitable for biological treatment without waiting for the wastewater to cool down naturally, thus shortening the wastewater treatment time; at the same time, it can also produce hot water for use.

[0047] Secondly, the control system for wastewater heating from microbial treatment of the present invention can also realize automatic backflushing of heat exchange pipelines through the processor, thereby extending the continuous operation time of heat exchange pipelines.

[0048] Third, the control system for wastewater to hot water production from microbial treatment of the present invention has two types of automatic backflushing: backflushing without cleaning liquid and backflushing with cleaning liquid. This further extends the continuous operation time of the heat exchange pipeline while reducing flushing costs and the average backflushing time.

[0049] Fourth, the control system for wastewater to hot water production from microbial treatment of the present invention can effectively control the action of the regulating valve through the function of the control system, so that the wastewater discharge temperature and the hot water outlet temperature can be quickly stabilized to the target temperature.

[0050] Fifth, in the control system for producing hot water from wastewater treated by microorganisms of the present invention, the wastewater outlet pipe is first connected to a sewage filter before exchanging heat with the clean water inlet pipe B, thereby filtering impurities in the wastewater in the first instance and maintaining long-term stable operation. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the piping system in this application.

[0052] Figure 2 This is a control diagram of the system in this application. Detailed Implementation

[0053] Combination Figure 1 and Figure 2 It is understood that the control system for producing hot water from wastewater treated by microorganisms includes a wastewater collection container 1, a sewage filter 5, a hot water storage container 15, a preheater 21, a water source heat pump 22, and a cleaning liquid storage container 24. The inlet of the wastewater collection container 1 is connected to the wastewater drain pipe of the production equipment. The outlets of the wastewater collection container 1 and the cleaning liquid storage container 24 are connected in parallel to the filter inlet pipe of the sewage filter 5 through the wastewater outlet pipe and the cleaning liquid outlet pipe, respectively. The filter outlet pipe of the sewage filter 5 is connected to the inlet of the heat exchanger wastewater channel 8 of the preheater 21. The outlet of the heat exchanger wastewater channel 8 is connected to the inlet of the evaporator 9 of the water source heat pump 22 through the wastewater connecting pipe A. The outlet of the evaporator 9 and the sewage outlet of the sewage filter 5 are connected to the wastewater treatment container through the wastewater discharge pipe A and the wastewater discharge pipe B, respectively. The filter outlet pipe is also connected to the wastewater discharge pipe A through the wastewater connecting pipe B.

[0054] The clean water supply pipe is connected to the inlet of the cleaning fluid storage container 24 and the inlet of the heat exchanger clean water channel 13 of the preheater 21 respectively through the parallel connected clean water inlet pipe A and clean water inlet pipe B. The outlet of the heat exchanger clean water channel 13 is connected to the inlet of the condenser 14 of the water source heat pump 22 through the clean water connecting pipe A. The outlet of the condenser 14 is connected to the liquid inlet pipe of the hot water storage container 15 through the clean water connecting pipe B. The hot water storage container 15 is connected to a hot water supply pipe.

[0055] The filter inlet pipe and filter outlet pipe are respectively connected to the automatic air inlet and outlet valve 19 via vent pipe A and vent pipe B.

[0056] A switch valve A3 is connected to the wastewater outlet pipe. A cleaning liquid pump 26 and a switch valve D17 are connected sequentially along the liquid flow direction to the cleaning liquid outlet pipe. A filter inlet pump 4 is connected to the filter inlet pipe. A vent pipe A is connected to the end of the filter inlet pipe corresponding to the inlet of the filter inlet pump 4. A switch valve E18 is connected to the vent pipe A. A regulating valve A6 is connected to the filter outlet pipe. A temperature sensor B30 and a switch valve B10 are connected sequentially along the wastewater flow direction to the wastewater discharge pipe A. A switch valve C16 is connected to the wastewater connecting pipe B. One end of the wastewater connecting pipe B is connected to the filter outlet pipe at the position between the sewage filter 5 and the regulating valve A6, and the other end is connected to the wastewater discharge pipe A at the position between the evaporator 9 and the switch valve B10. A regulating valve B11 is connected to the clean water inlet pipe B. A switch valve F20 is connected to the wastewater discharge pipe B.

[0057] The sewage filter 5 is equipped with a pressure sensor 7, the clean water connecting pipe B is connected to a temperature sensor A29, the wastewater collection container 1 is equipped with a liquid level sensor A12, the hot water storage container 15 is equipped with a liquid level sensor B27, and the cleaning fluid storage container 24 is equipped with a liquid level sensor C28.

[0058] It also includes a processor 31. The pressure sensor 7, level sensor A12, level sensor B27, level sensor C28, temperature sensor A29, temperature sensor B30, switching valve A3, filter water inlet pump 4, switching valve B10, switching valve C16, switching valve D17, switching valve E18, switching valve F20, water source heat pump 22, cleaning fluid pump 26, regulating valve A6, and regulating valve B11 are all connected to the processor 31. The pressure sensor 7, level sensor A12, level sensor B27, level sensor C28, temperature sensor A29, and temperature sensor B30 transmit their respective collected signals to the processor 31. The processor 31 controls the switching valve A3, filter water inlet pump 4, switching valve B10, switching valve C16, switching valve D17, switching valve E18, switching valve F20, water source heat pump 22, cleaning fluid pump 26, regulating valve A6, and regulating valve B11 through signals.

[0059] The liquid level value in the wastewater collection container 1 collected and measured by the liquid level sensor A12 is set as h1, and the high water level control value h1high and the low water level control value h1low of the wastewater collection container 1 are set; the liquid level value in the hot water storage container 15 collected and measured by the liquid level sensor B27 is set as h2, and the high water level control value h2high and the low water level control value h2low of the hot water storage container 15 are set; when h1>h1high and h2<h2low, the processor 31 controls the water source heat pump 22 to start and enter the hot water production mode; when h1<h1low or h2>h2high, the processor 31 controls the water source heat pump 22 to shut down and stop the hot water production mode;

[0060] When entering the hot water production mode, the processor 31 controls the opening of the switch valve A3, the filter water inlet pump 4, the regulating valve A6, the switch valve B10, the regulating valve B11 and the water source heat pump 22 respectively, while the remaining switch valves and pumps are closed.

[0061] The wastewater in the wastewater collection container 1 passes sequentially through the filter inlet pump 4, regulating valve A6, preheater 21, water source heat pump 22 and switch valve B10, and finally enters the wastewater treatment device (in this embodiment, the wastewater treatment device is a wastewater treatment container passage) through the wastewater discharge system (in this embodiment, the wastewater discharge system is a drainage ditch).

[0062] The clean water in the clean water supply pipe passes through the regulating valve B11, the preheater 21 and the water source heat pump 22 in sequence, and finally enters the hot water storage container 15.

[0063] The pressure difference value between the inlet and outlet of the sewage filter 5, collected and measured by the pressure sensor 7, is set as p1. The upper limit of the pressure difference control between the inlet and outlet of the sewage filter 5 is set as pmax, and the lower limit of the pressure difference control between the inlet and outlet of the sewage filter 5 is set as pmin. When p1 > pmax, the processor 31 controls the cleaning motor in the sewage filter 5 to start and drive the wire mesh cleaning brush to rotate to clean the filter screen. When p1 < pmin, the processor 31 controls the switch valve F20 to open and keep it open for a time T. After the time T of keeping the switch valve F20 open is reached, the processor 31 controls the switch valve F20 to close and simultaneously turns off the cleaning motor in the sewage filter 5.

[0064] The pmax and pmin are set according to the actual situation, and pmax > pmin. The T is set according to the actual usage (in this embodiment, T is 60 seconds).

[0065] The control input value of regulating valve B11 is set to a, the control input value of regulating valve A6 is set to b, the hot water outlet temperature measured by temperature sensor A29 is tq, and the wastewater discharge temperature measured by temperature sensor B30 is tf. An upper limit value for the hot water outlet temperature tqmax (55℃ in this embodiment) and a lower limit value for the hot water outlet temperature tqmin (50℃ in this embodiment) are set, as are an upper limit value for the wastewater discharge temperature tfmax (25℃ in this embodiment) and a lower limit value for the wastewater discharge temperature tfmin (20℃ in this embodiment). When tq < 50℃ and 20℃ < tf < 25℃, processor 31 decreases a; when tq < 50℃ and tf > 25℃, processor 31 decreases both a and b; when tq < 55℃ and tf < 20℃, processor 31 increases b; when tq > 55℃ and tf > 20℃, processor 31 increases a; when tq > 55℃ and tf > 20℃, processor 31 increases a. When the temperature is 55℃ and tf < 20℃, processor 31 increases a and b; when the temperature is between 50℃ and tq and 55℃ and tf > 25℃, processor 31 decreases b.

[0066] The target value of the hot water outlet temperature tq is tqt, which is the average of the upper limit of the hot water outlet temperature (55℃) and the lower limit of the hot water outlet temperature (50℃): tqt = (50℃ + 55℃) ÷ 2 = 52.5℃;

[0067] The target value of the wastewater discharge temperature tf is the average of the upper limit of the wastewater discharge temperature (25℃) and the lower limit of the wastewater discharge temperature (20℃): tft = (20℃ + 25℃) ÷ 2 = 22.5℃;

[0068] When regulating valve A6 is a valve with a current signal input, b is the input current value; when regulating valve A6 is a valve with a voltage signal input, b is the input voltage value; when regulating valve B11 is a valve with a current signal input, a is the input current value; when regulating valve B11 is a valve with a voltage signal input, a is the input voltage value (in this embodiment, both regulating valve A6 and regulating valve B11 are valves with current signal input).

[0069] The current signal value range corresponding to the full opening to full closing of regulating valve A6 and regulating valve B11 is: n0~n1 (in this embodiment, the current signal value range of regulating valve A6 and regulating valve B is 4-20mA, that is, n0=4mA, n1=20mA).

[0070] The clean water inlet temperature tq' of clean water inlet pipe A and clean water inlet pipe B varies with the change of the outside temperature. The highest clean water inlet temperature is set as tq'max (65℃ in this embodiment) and the lowest clean water inlet temperature is set as tq'min (30℃ in this embodiment).

[0071] The wastewater outlet temperature tf' varies with different equipment operating conditions and processes. The maximum wastewater outlet temperature is set as tf'max (35℃ in this embodiment) and the minimum wastewater outlet temperature is set as tf'min (3℃ in this embodiment).

[0072] Reduce a: Target value of a: at = a - k × (a - 4ma) ÷ (65℃ - tq) × (52.5℃ - tq);

[0073] Increase a: Target value of a: at = a + k × (20ma - a) ÷ (tq - 30℃) × (tq - 52.5℃);

[0074] Reduce b: Target value of b: bt = b - k × (b - 4ma) ÷ (tf - 3℃) × (tf - 22.5℃);

[0075] Increase b: Target value of b: bt = b + k × (20ma - b) ÷ (35℃ - tf) × (22.5℃ - tf);

[0076] Where 0.3 < k < 0.85.

[0077] The values ​​a and b are respectively set to control input lower limits amin=4ma and bmin=4ma. When the calculated at < 4ma, at is set to 5ma; when the calculated bt < 4ma, bt is set to 5ma.

[0078] The processor 31 continuously reads and detects the hot water outlet temperature tq and wastewater discharge temperature tf of the heat pump, and calculates the target value a at and the target value bt according to the aforementioned calculation method. The results are then output to the corresponding regulating valves B11 and A6. After the valves are in place, tq and tf are detected again. This process is repeated until the target values ​​tqt for the hot water outlet temperature tq and tft for the wastewater discharge temperature tf are reached.

[0079] The processor 31 sets the cumulative working time of the water source heat pump 22 to C. When C reaches an integer multiple of C1, the processor 31 shuts down the water source heat pump 22 and enters a backflushing cleaning mode without cleaning fluid. When C reaches C2, the processor 31 shuts down the water source heat pump 22 and enters a backflushing mode with cleaning fluid. In addition, the processor 31 resets C to zero and restarts the accumulation. C1 is less than C2. After the backflushing cleaning is completed, the processor returns to the working state before the backflushing cleaning. C1 and C2 are set according to the actual usage (in this embodiment, C1 is 24h and C2 is 168h).

[0080] When entering the backwashing mode without cleaning fluid, the processor 31 controls the opening of switch valves C16 and E18 respectively, while the remaining switch valves and pumps are closed. Then, the processor 31 starts the filter water inlet pump 4 to perform backwashing cycle. After the backwashing time reaches T1 (in this embodiment, T1 is 10 minutes), the backwashing mode without cleaning fluid ends.

[0081] When entering the backwashing mode with cleaning fluid, the processor 31 first controls the switch valve A3, filter water pump 4, regulating valve B11, switch valve D17, and switch valve F20 to close respectively, while the remaining switch valves are all opened, allowing the wastewater in the pipeline to be discharged into the drainage ditch through switch valve B10 and finally into the wastewater treatment container. External air enters the pipeline through the automatic air intake and exhaust valve 19 to fully drain the wastewater in the pipeline. The drainage time is TQ (in this embodiment, TQ is in the range of 1min to 20min).

[0082] After the system wastewater is drained, the processor 31 controls the regulating valve A6 and the switching valve B10 to close, and the switching valve D17 and the cleaning fluid pump 26 to open. The cleaning fluid in the cleaning fluid storage container 24 is injected into all the wastewater channels in the pipeline, including the filter inlet pump 4, the sewage filter 5, the heat exchanger wastewater channel 8 and the evaporator 9, through the switching valve D17 until it is full. After it is full, the processor 31 controls the cleaning fluid pump 26 and the switching valve D17 to close.

[0083] Then the processor 31 starts the filter inlet pump 4 to perform backwashing and cleaning cycle. After the backwashing and cleaning time reaches T3 (in this embodiment, T3 is in the range of 5min to 30min), the processor 31 controls the filter inlet pump 4 to shut down.

[0084] The backwashing cycle is repeated at least twice (in this embodiment, the backwashing cycle is repeated twice), and the wastewater in the pipeline is left to stand for a period of time of T4 between two adjacent backwashing cycles (in this embodiment, T4 is 1 hour).

[0085] The processor 31 controls the switching valve A3, the filter inlet pump 4, the regulating valve B11, the switching valve D17, and the switching valve F20 to close respectively, while the remaining switching valves are opened. This allows the wastewater in the pipeline to be discharged into the drainage ditch through the switching valve B10 and finally into the wastewater treatment container. External air enters the pipeline through the automatic air intake and exhaust valve 19, which fully drains the wastewater from the pipeline. The drainage time is T5 (in this embodiment, T4 is equal to TQ). The backwashing mode with cleaning fluid ends.

[0086] The processor 31 is also connected to a data storage 32 via communication, and the processor 31 transmits all the collected data and the control data issued to the data storage 32.

[0087] The cleaning fluid storage container 24 is connected to a cleaning fluid concentrate injection port 23.

[0088] The cleaning fluid concentrate is injected into the cleaning fluid storage container 24 through the cleaning fluid concentrate injection port 23 via the injection pump. The processor injects a matching amount of cleaning fluid concentrate according to the power of the water source heat pump 22. When injecting the cleaning fluid concentrate, the switch valve D17 and the cleaning fluid pump 26 remain closed.

[0089] In this embodiment, 1 liter of cleaning solution stock solution is injected for every 1P of power of the water source heat pump 22. Taking a 42P water source heat pump 22 as an example, 42 liters of cleaning solution stock solution needs to be injected. During injection, the amount of cleaning solution stock solution injected can be determined by the change in water level in the cleaning solution storage container 24, or a flow meter can be installed in the injection pipeline of the cleaning solution stock solution to determine the amount of cleaning solution stock solution injected.

[0090] A manual maintenance valve 25 is also provided on the cleaning fluid outlet pipe between the cleaning fluid pump 26 and the cleaning fluid storage container 24. The manual maintenance valve 25 is kept open and is only closed during maintenance.

[0091] When the wastewater collection container 1 is an open wastewater pool, the end of the wastewater outlet pipe located inside the wastewater pool extends into the bottom of the wastewater pool and is connected to a bottom valve 2; when the wastewater collection container 1 is a wastewater tank, the end of the wastewater outlet pipe located inside the wastewater tank extends into the bottom of the wastewater pool.

[0092] The processor 31 is a PLC.

Claims

1. A control system for producing hot water from wastewater treated by microorganisms, characterized in that: The system includes a wastewater collection container (1), a sewage filter (5), a hot water storage container (15), a preheater (21), a water source heat pump (22), and a cleaning fluid storage container (24). The inlet of the wastewater collection container (1) is connected to the wastewater drain pipe of the production equipment. The outlets of the wastewater collection container (1) and the cleaning fluid storage container (24) are connected in parallel to the filter inlet pipe of the sewage filter (5) through the wastewater outlet pipe and the cleaning fluid outlet pipe, respectively. The filter outlet pipe of the filter (5) is connected to the inlet of the heat exchanger wastewater channel (8) of the preheater heat exchanger (21). The outlet of the heat exchanger wastewater channel (8) is connected to the inlet of the evaporator (9) of the water source heat pump (22) through the wastewater connecting pipe A. The outlet of the evaporator (9) and the outlet of the drain filter (5) are connected to the wastewater treatment container through the wastewater drain pipe A and the wastewater drain pipe B respectively. The filter outlet pipe is also connected to the wastewater drain pipe A through the wastewater connecting pipe B. The clean water supply pipe is connected to the inlet of the cleaning liquid storage container (24) and the inlet of the heat exchanger clean water channel (13) of the front heat exchanger (21) respectively through the parallel connected clean water inlet pipe A and clean water inlet pipe B. The outlet of the heat exchanger clean water channel (13) is connected to the inlet of the condenser (14) of the water source heat pump (22) through the clean water connecting pipe A. The outlet of the condenser (14) is connected to the liquid inlet pipe of the hot water storage container (15) through the clean water connecting pipe B. The hot water storage container (15) is connected to a hot water supply pipe. The filter inlet pipe and filter outlet pipe are respectively connected to the automatic air inlet and outlet valve (19) through vent pipe A and vent pipe B; A switch valve A (3) is connected to the wastewater outlet pipe. A cleaning fluid pump (26) and a switch valve D (17) are connected sequentially along the liquid flow direction on the cleaning fluid outlet pipe. A filter inlet pump (4) is connected to the filter inlet pipe. A vent pipe A is connected to the end of the filter inlet pipe corresponding to the inlet of the filter inlet pump (4). A switch valve E (18) is connected to the vent pipe A. A regulating valve A (6) is connected to the filter outlet pipe. A wastewater discharge pipe A is connected along the wastewater flow direction. A temperature sensor B (30) and a switching valve B (10) are sequentially provided. A switching valve C (16) is connected to the wastewater connecting pipe B. One end of the wastewater connecting pipe B is connected to the filter outlet pipe at the position between the sewage filter (5) and the regulating valve A (6), and the other end is connected to the wastewater discharge pipe A at the position between the evaporator (9) and the switching valve B (10). A regulating valve B (11) is connected to the clean water inlet pipe B, and a switching valve F (20) is connected to the wastewater discharge pipe B. The sewage filter (5) is equipped with a pressure sensor (7), the clean water connecting pipe B is connected to a temperature sensor A (29), the wastewater collection container (1) is equipped with a liquid level sensor A (12), the hot water storage container (15) is equipped with a liquid level sensor B (27), and the cleaning fluid storage container (24) is equipped with a liquid level sensor C (28). It also includes a processor (31), and the pressure sensor (7), level sensor A (12), level sensor B (27), level sensor C (28), temperature sensor A (29), temperature sensor B (30), switching valve A (3), filter water pump (4), switching valve B (10), switching valve C (16), switching valve D (17), switching valve E (18), switching valve F (20), water source heat pump (22), cleaning fluid pump (26), regulating valve A (6), and regulating valve B (11) are all signal connected to the processor (31). Sensors (7), liquid level sensor A (12), liquid level sensor B (27), liquid level sensor C (28), temperature sensor A (29) and temperature sensor B (30) transmit their respective collected signals to processor (31). The processor (31) controls switch valve A (3), filter water pump (4), switch valve B (10), switch valve C (16), switch valve D (17), switch valve E (18), switch valve F (20), water source heat pump (22), cleaning fluid pump (26), regulating valve A (6) and regulating valve B (11) respectively through signals. The control input value of the regulating valve B (11) is set to a, the control input value of the regulating valve A (6) is set to b, the hot water outlet temperature measured by the temperature sensor A (29) is tq, the wastewater discharge temperature measured by the temperature sensor B (30) is tf, and the upper limit value of the hot water outlet temperature tqmax and the lower limit value of the hot water outlet temperature tqmin are set, and the upper limit value of the wastewater discharge temperature tfmax and the lower limit value of the wastewater discharge temperature tfmin are set; when tq < tqmin and tfmin < tf < tfmax, the processor (31) decreases a; when tq < tqmin and tf > tfmax, the processor (31) decreases a and b; when tq < tqmax and tf < tfmin, the processor (31) increases b; when tq > tqmax and tf > tfmin, the processor (31) increases a; when tq > tqmax and tf < tfmin, the processor (31) increases a; when tq > tqmax and tf < tfmin, the processor (31) increases a; when tq > tqmax and tf < tfmin, the processor (31) increases a; when tq < ... When tfmin, processor (31) increases a and b; when tqmin < tq < tqmax and tf > tfmax, processor (31) decreases b.

2. The control system for wastewater heating from microbial treatment as described in claim 1, characterized in that: The liquid level value in the wastewater collection container (1) collected and measured by the liquid level sensor A (12) is set as h1, and the wastewater high water level control value h1high and the wastewater low water level control value h1low of the wastewater collection container (1) are set; the liquid level value in the hot water storage container (15) collected and measured by the liquid level sensor B (27) is set as h2, and the hot water high water level control value h2high and the hot water low water level control value h2low of the hot water storage container (15) are set; when h1>h1high and h2<h2low, the processor (31) controls the water source heat pump (22) to start and enter the hot water production mode; when h1<h1low or h2>h2high, the processor (31) controls the water source heat pump (22) to shut down and stop the hot water production mode; When entering the hot water production mode, the processor (31) controls the opening of the switch valve A (3), the filter water inlet pump (4), the regulating valve A (6), the switch valve B (10), the regulating valve B (11) and the water source heat pump (22), while the other switch valves and pumps are closed. The wastewater in the wastewater collection container (1) passes through the filter inlet pump (4), regulating valve A (6), preheater (21), water source heat pump (22) and switch valve B (10) in sequence, and finally enters the wastewater treatment device through the wastewater discharge system; The clean water in the clean water supply pipe passes through regulating valve B (11), preheater (21) and water source heat pump (22) in sequence, and finally enters hot water storage container (15).

3. The control system for wastewater heating from microbial treatment as described in claim 1, characterized in that: The pressure difference value between the inlet and outlet of the sewage filter (5) collected and measured by the pressure sensor (7) is set as p1, and the upper limit of the pressure difference control between the inlet and outlet of the sewage filter (5) is set as pmax, and the lower limit of the pressure difference control between the inlet and outlet of the sewage filter (5) is set as pmin. When p1 > pmax, the processor (31) controls the cleaning motor in the sewage filter (5) to start and drive the wire mesh cleaning brush to rotate to clean the filter screen. When p1 < pmin, the processor (31) controls the switch valve F (20) to open and keep it open for a time T. After the time T of keeping the switch valve F (20) open is reached, the processor (31) controls the switch valve F (20) to close and simultaneously shuts off the cleaning motor in the sewage filter (5).

4. The control system for wastewater heating from microbial treatment as described in claim 3, characterized in that: The pmax and pmin are set according to the actual situation, and pmax > pmin. The T is set according to the actual usage.

5. The control system for wastewater heating from microbial treatment as described in claim 1, characterized in that: The target value tqt of the hot water outlet temperature tq is the average of the upper limit value tqmax and the lower limit value tqmin of the hot water outlet temperature: tqt=(tqmin+tqmax)÷2; The target value tft of the wastewater discharge temperature tf is the average of the upper limit value tfmax and the lower limit value tfmin of the wastewater discharge temperature: tft=(tfmin+tfmax)÷2; The range of electrical signal values ​​corresponding to the full opening to full closing of regulating valve A (6) and regulating valve B (11) is: n0~n1; The clean water inlet temperature tq' of clean water inlet pipes A and B changes with the change of the outside temperature. The highest clean water inlet temperature is set as tq'max and the lowest clean water inlet temperature is set as tq'min. The wastewater outlet temperature tf' varies with different equipment operating conditions and processes. The maximum wastewater outlet temperature is set as tf'max and the minimum wastewater outlet temperature is set as tf'min. Decrease a: Target value of a: at = a - k × (a - n0) ÷ (tq'max - tq) × (tqt - tq); Increase a: Target value of a: at = a + k × (n1 - a) ÷ (tq - tq'min) × (tq - tqt); Decrease b: Target value of b: bt = b - k × (b - n0) ÷ (tf - tf'min) × (tf - tft); Increase b: Target value of b: bt = b + k × (n1 - b) ÷ (tf'max - tf) × (tft - tf); Where 0.3 < k < 0.

85.

6. The control system for wastewater heating from microbial treatment as described in claim 5, characterized in that: The values ​​a and b are respectively set to control input lower limits amin and bmin. When the calculated at < amin, the value of at is greater than amin; when the calculated bt < bmin, the value of bt is greater than bmin.

7. The control system for wastewater heating from microbial treatment as described in claim 1, characterized in that: The processor (31) sets the cumulative working time of the water source heat pump (22) to C. When C reaches an integer multiple of C1, the processor (31) shuts down the water source heat pump (22) and enters the backwash cleaning mode without cleaning fluid. When C reaches C2, the processor (31) shuts down the water source heat pump (22) and enters the backwash mode with cleaning fluid. In addition, the processor (31) resets C to zero and starts accumulating again. C1 is less than C2. After the backwash cleaning is completed, the processor restores the working state corresponding to the backwash cleaning. C1 and C2 are set according to the actual usage.

8. The control system for wastewater heating from microbial treatment as described in claim 7, characterized in that: When entering the backwashing mode without cleaning fluid, the processor (31) controls the opening of the switch valve C (16) and the switch valve E (18), while the other switch valves and pumps are closed. Then the processor (31) starts the filter water pump (4) to perform backwashing cycle. After the backwashing time reaches T1, the backwashing mode without cleaning fluid ends.

9. The control system for wastewater heating from microbial treatment as described in claim 7, characterized in that: When entering the backwashing mode with cleaning fluid, the processor (31) first controls the switch valve A (3), filter water pump (4), regulating valve B (11), switch valve D (17), and switch valve F (20) to close respectively, and the remaining switch valves are opened, so that the wastewater in the pipeline is discharged into the wastewater system through switch valve B (10) and finally enters the wastewater treatment device. External air enters the pipeline through the automatic air intake and exhaust valve (19) to fully drain the wastewater in the pipeline. The drainage time is TQ. After the system wastewater is drained, the processor (31) controls the regulating valve A (6) and the switch valve B (10) to close, and the switch valve D (17) and the cleaning fluid pump (26) to open, so that the cleaning fluid in the cleaning fluid storage container (24) is injected into all the wastewater channels in the pipeline, including the filter inlet pump (4), the sewage filter (5), the heat exchanger wastewater channel (8) and the evaporator (9), until it is full. After it is full, the processor (31) controls the cleaning fluid pump (26) and the switch valve D (17) to close. Then the processor (31) starts the filter inlet pump (4) to perform backwashing cycle. After the backwashing time reaches T3, the processor (31) controls the filter inlet pump (4) to shut down. The backwashing cycle should be repeated at least twice, and the wastewater in the pipeline should be allowed to stand for a period of T4 between two adjacent backwashing cycles. The processor (31) controls the switch valve A (3), filter water pump (4), regulating valve B (11), switch valve D (17), and switch valve F (20) to close respectively, while the remaining switch valves are opened, allowing the wastewater in the pipeline to be discharged into the wastewater system through switch valve B (10) and finally enter the wastewater treatment device. External air enters the pipeline through the automatic air intake and exhaust valve (19) to fully drain the wastewater in the pipeline. The drainage time is T5, and the backwash cleaning mode with cleaning liquid ends.

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