CN108275743B

CN108275743B - Heat pump type wastewater treatment equipment and treatment method thereof

Info

Publication number: CN108275743B
Application number: CN201810316340.3A
Authority: CN
Inventors: 苑亚; 杨鲁伟; 张振涛; 蔺雪军; 肖波; 游韶玮
Original assignee: Technical Institute of Physics and Chemistry of CAS
Current assignee: Technical Institute of Physics and Chemistry of CAS
Priority date: 2018-04-10
Filing date: 2018-04-10
Publication date: 2020-07-10
Anticipated expiration: 2038-04-10
Also published as: CN108275743A

Abstract

The embodiment of the invention provides heat pump type wastewater treatment equipment which comprises a separator and a heat pump system, wherein the separator is provided with a feed inlet, an air outlet and an air inlet, the air inlet is used for introducing cold air into the separator, the feed inlet is used for discharging wastewater into the separator, the cold air and the wastewater are subjected to heat and humidity exchange, the heat pump system is communicated with the air outlet to cool the air discharged from the separator, and the heat pump system is communicated with the feed inlet to heat the wastewater. The invention also provides a method for treating wastewater by using the heat pump type wastewater treatment equipment. The invention recovers the waste heat in the air through the heat pump system, improves the energy efficiency of the heat pump system, can realize crystallization under normal temperature and normal pressure environment, reduces the equipment cost, and in the whole treatment process, the moist and hot air in the separator is not contacted with the compressor, thereby avoiding the corrosion of the compressor, improving the operation reliability of the system, and having compact integral structure and simple and convenient operation.

Description

Heat pump type wastewater treatment equipment and treatment method thereof

Technical Field

The invention relates to the technical field of water treatment, in particular to heat pump type wastewater treatment equipment and a treatment method thereof.

Background

The discharge amount of high-concentration salt-containing wastewater in industrial production is increasing day by day, and the ecological environment is seriously influenced. At present, the main method for treating industrial salt-containing wastewater is to provide heat energy for an evaporation system in a circulating manner by means of Mechanical Vapor Recompression (MVR) equipment and by utilizing secondary vapor and energy thereof generated by the evaporation system, so as to concentrate and crystallize the wastewater in a low-temperature and low-pressure environment.

However, the MVR equipment used in the method is complex, the initial investment is large, the production cost is high, the salt-containing wastewater needs to be crystallized under a negative pressure state, the inside of the compressor is easily corroded by hot and humid air generated in the treatment process, and the equipment maintenance cost is high. Therefore, in the process of concentrating and crystallizing the salt-containing wastewater, the heat energy utilization rate needs to be improved, the compressor is prevented from being corroded, the concentrated crystallization under the normal temperature and pressure state is realized, and the production cost is reduced.

Disclosure of Invention

Technical problem to be solved

One of the purposes of the invention is to provide heat pump type wastewater treatment equipment, which is used for solving the corrosion problem of a compressor, effectively recovering waste heat, reducing energy consumption and realizing a normal-temperature and normal-pressure crystallization environment.

Another object of the present invention is to provide a heat pump wastewater treatment method for wastewater treatment by the above-mentioned heat pump wastewater treatment facility.

(II) technical scheme

In order to solve the technical problems, the invention provides heat pump type wastewater treatment equipment which comprises a separator and a heat pump system, wherein the separator is provided with a feed inlet, an air outlet and an air inlet, the air inlet is used for introducing cold air into the separator, the feed inlet is used for discharging wastewater into the separator, the cold air and the wastewater are subjected to heat and humidity exchange in the separator, the heat pump system is communicated with the air outlet to cool the air discharged from the separator, and the heat pump system is communicated with the feed inlet to heat the wastewater.

In addition, the invention also provides a heat pump type wastewater treatment method, which comprises the following steps:

step S1, carrying out heat exchange between the waste water and the heat pump system, enabling the waste water to absorb heat and enter a separator from a feed inlet, wherein the feed inlet is formed in the separator, and cold air enters the separator from an air inlet;

step S2, performing heat and moisture exchange between the cold air and the wastewater in the separator, discharging the cold air from the air outlet after absorbing heat, and discharging the wastewater after releasing heat;

and step S3, cooling the air discharged from the separator through the heat pump system.

(III) advantageous effects

The heat pump type wastewater treatment equipment provided by the invention has the advantages that the waste heat in the air is recovered through the heat pump system, the energy efficiency of the heat pump system is improved, meanwhile, the crystallization can be realized under the normal temperature and normal pressure environment, the equipment cost is reduced, and in the whole treatment process, the damp and hot air in the separator is not in contact with the compressor, so that the corrosion of the compressor is avoided, the operation reliability of the system is improved, the whole structure of the equipment is compact, and the operation is simple and convenient.

Drawings

FIG. 1 is a schematic diagram of a heat pump wastewater treatment plant according to the present invention;

FIG. 2 is a schematic closed cycle view of the heat pump wastewater treatment plant of FIG. 1;

FIG. 3 is a schematic open cycle view of the heat pump wastewater treatment plant of FIG. 1.

In the figure: 1. a stock solution tank; 2. adjusting a valve; 3. a liquid pump; 4. a separator; 41. a feed inlet; 42. a discharge port; 43. an air inlet; 44. an air outlet; 45. an observation window; 5. a spraying device; 51. a nozzle; 6. a centrifuge; 9. water filtering wire mesh; 10. filtering with a screen; 11. a first air valve; 12. a second air valve; 13. a third air valve; 14. a fan; 17. a compressor; 18. a condenser; 19. an expansion valve; 20. an evaporator.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1, a heat pump type wastewater treatment apparatus includes a separator 4 and a heat pump system including a compressor 17, a condenser 18, an expansion valve 19, and an evaporator 20. The compressor 17, the condenser 18, the expansion valve 19 and the evaporator 20 are sequentially connected end to form a circulation channel of a refrigeration working medium, the refrigeration working medium is Freon, ammonia, carbon dioxide, propane and the like, the refrigeration working medium releases heat in the condenser 18, absorbs heat in the evaporator 20, and the heat is transferred from a high position to a low position. The compressor 17, the condenser 18, the expansion valve 19 and the evaporator 20 jointly form a heat pump system, wherein the compressor 17 is a variable frequency compressor, the condenser 18 is a plate heat exchanger, and the evaporator 20 is a shell-and-tube heat exchanger.

Specifically, the separator 4 is provided with a feed inlet 41, an air inlet 43 and an air outlet 44. The condenser 18 is communicated with the feed inlet 41, and the waste water exchanges heat with the refrigeration working medium in the condenser 18 to absorb heat to form warm waste water which enters the separator 4 from the feed inlet 41. The cold air enters the separator 4 from the air inlet 43 and exchanges heat and moisture with the warm waste water in the separator 4. The heat of the warm waste water is absorbed by the cold air, a saturated solution and crystals are formed by the warm waste water, and the cold air absorbs the heat and becomes damp and hot air which is discharged from the air outlet 44. The evaporator 20 is communicated with the air outlet 44, the damp and hot air exchanges heat with the refrigeration working medium in the evaporator 20, the refrigeration working medium absorbs heat, and the damp and hot air releases heat.

In the above process, the waste heat in the hot and humid air is recovered through the evaporator 20, and the hot and humid air is only subjected to heat exchange with the refrigerant in the evaporator 20, and does not flow to the compressor 17 along with the refrigerant, so that the compressor 17 is prevented from being corroded. The waste heat is transferred along with the flow of the refrigeration working medium among the compressor 17, the condenser 18, the expansion valve 19 and the evaporator 20, and acts on the waste water, so that the waste heat is reused, and the energy efficiency of the heat pump system is improved. In addition, the crystallization of the waste water can be realized by means of the heat difference between the cold air and the warm waste water in the heat and humidity exchange process, the whole process can be carried out under the normal temperature and the normal pressure, and special environments such as negative pressure or high temperature are not needed. The equipment has compact integral structure, energy conservation, environmental protection and low energy consumption.

Further, the separator 4 is provided with a discharge port 42, and the saturated solution and the crystals are discharged from the separator 4 through the discharge port 42. The hot and humid air is cooled in the evaporator 20 and then discharged to the outside of the apparatus directly or is circulated to enter the separator 4 again.

Specifically, the air outlet 44 is located above the air inlet 43, and the air flows upward after entering from the air inlet 43 after passing through the separator 4 and is discharged from the air outlet 44. The discharge port 42 is located below the feed port 41, and wastewater enters from the feed port 41 and moves downward in the separator 4 to be discharged from the discharge port 42. The air inlet 43 is located below the inlet 41, and the cold air entering from the air inlet 43 moves towards the warm waste water entering from the inlet 41 to generate heat and moisture exchange. In the separator 4, the cold air absorbs heat from the high temperature waste water to form hot and humid air, and the temperature of the warm waste water is reduced to form saturated solution and crystals.

Further, the heat pump type wastewater treatment equipment also comprises a water filtering screen 9, a filter screen 10 and a fan 14. The filter screen 10 is installed at the air outlet 44 for filtering moisture in the hot and humid air discharged from the separator 4, and less corrosion of the hot and humid air to subsequent devices. The water filtering screen 9 and the fan 14 are installed at the air inlet 43, and the air and/or the external air processed by the evaporator 20 is filtered by the water filtering screen 9 to remove moisture therein and then enters the separator 4 from the air inlet 43 under the blowing action of the fan 14, so that the cold air entering the separator 4 is dry air, and the effect of generating crystallization by performing a damp-heat reaction with the wastewater is better.

Further, the heat pump type wastewater treatment equipment further comprises a pipeline, a first air valve 11, a second air valve 12 and a third air valve 13. The condenser 18 is communicated with the water filtering screen 9 through a pipeline, and the damp and hot air enters the pipeline after being cooled in the condenser 18. The first air valve 11 is arranged in the pipeline and located between the evaporator 20 and the water filtering screen 9, the second air valve 12 is installed on the pipe wall of the pipeline between the first air valve 11 and the condenser 18, and the third air valve 13 is installed on the pipe wall of the pipeline between the first air valve 11 and the water filtering screen 9.

Specifically, the first air valve 11, the second air valve 12 and the third air valve 13 are air valves with adjustable opening degrees, so as to control the temperature and humidity of air at the air inlet 43, and conveniently adjust the heat-humidity balance of the whole equipment. When the first air valve 11 is opened and the second air valve 12 and the third air valve 13 are both closed, the heat pump type wastewater treatment equipment is in a closed circulation state and is not influenced by the external environment, as shown in fig. 2. In a closed circulation state, the wet and hot air is cooled by the evaporator 20, filtered by the water filtering screen 9 along the air duct, and then enters the separator 4 from the air inlet 43 under the action of the fan 14, so that the air is recycled in the equipment. When the first air valve 11 is closed and the second air valve 12 and the third air valve 13 are opened, the heat pump type wastewater treatment equipment is in an open cycle state, as shown in fig. 3 in particular. In the open cycle state, the humid and hot air is cooled by the evaporator 20 and then directly discharged to the outside of the equipment from the second air valve 12, and the outside air enters the air duct from the third air valve 13, and enters the separator 4 from the air inlet 43 under the blowing action of the fan 14 after being absorbed by the water filtering screen 9. When the first air valve 11, the second air valve 12 and the third air valve 13 are all in the open state, the heat pump type wastewater treatment equipment is in the mixed circulation state. Under the mixed circulation state, the exchange amount between the air in the equipment and the outside air can be effectively controlled by adjusting the opening degree of each air valve, the temperature and humidity of the air entering the separator 4 are ensured to meet the requirements, and at the moment, the air entering the separator 4 is a mixed gas formed by the outside air and the air cooled by the evaporator 20.

In the heat pump type wastewater treatment equipment, an air inlet 43, an air outlet 44, a filter screen 10, an evaporator 20, a first air valve 11, a second air valve 12, a third air valve 13, a water filtering screen 9 and a fan 14 are matched with each other to form a circulating air system. Which is a blowing device of the separator 4, dehumidifies warm air in the separator 4 at a low temperature, and sends dry cold air to the separator 4. The circulating air system can realize closed or open or mixed circulation, and has variable modes and multiple adaptive industrial environments.

Further, the heat pump type wastewater treatment apparatus further includes a spraying device 5 located in the separator 4. The spraying device 5 is communicated with the feeding hole 41, a plurality of nozzles 51 are arranged on the spraying device 5, the nozzles 51 are distributed according to a reasonable geometric position, warm waste water is uniformly sprayed in the separator 4, and therefore sufficient heat and moisture exchange with cold air can be carried out. An observation window 45 is further arranged on the separator 4, and the observation window 45 is made of transparent glass, so that an operator can observe the condition in the separator 4 conveniently.

Further, the heat pump type wastewater treatment equipment further comprises a stock solution tank 1, a liquid pump 3 and a centrifuge 6. The stock solution tank 1 pretreats the wastewater, such as adjusting the pH value, the water quality, the organic matter content and the like, thereby forming a stock solution. One end of the centrifuge 6 is communicated with the discharge hole 42, and the other end is simultaneously communicated with the stock solution tank 1 and the liquid pump 3 through a Y-pipe. The liquid pump 3 is a variable frequency pump, and the outlet end of the variable frequency pump is communicated with a condenser 18. And discharging the saturated solution and the crystals from the discharge port 42, and then feeding the saturated solution and the crystals into the centrifuge 6 to realize solid-liquid separation, wherein the saturated solution is discharged from a liquid outlet of the centrifuge 6, mixed with the stock solution in the stock solution tank 1 and then pumped into the condenser 18 under the action of the liquid pump 3.

In addition, the heat pump type wastewater treatment equipment further comprises four electronically controlled regulating valves 2 which are respectively arranged at the discharge port of the stock solution tank 1, the liquid outlet of the centrifuge 6, the discharge port 42 of the separator 4 and the outlet end of the liquid pump 3 and are used for controlling the flow of wastewater.

In the device, a feed inlet 41, a discharge outlet 42, a centrifuge 6, a stock solution tank 1, a liquid pump 3 and a condenser 18 are matched with each other to form a wastewater water replenishing system, and wastewater to be treated is continuously supplied to a separator 4.

In order to further improve the heat recovery rate, the outer surfaces of the separator 4 and the evaporator 20 are respectively provided with an insulating layer. The heat-insulating layer is made of polyurethane heat-insulating material.

Furthermore, the heat pump type wastewater treatment equipment also comprises a control system which automatically controls the wastewater water replenishing system, the circulating air system, the separator and the heat pump system to realize the autonomous operation of the whole equipment, wherein the control system comprises a control switch, a temperature controller, a humidity controller and a P L C panel.

The working principle of the heat pump type wastewater treatment equipment is explained in detail by taking salt water desalination crystallization as an example as follows:

the air and the brine droplets move in opposite directions in the separator 4 and perform heat and moisture exchange, the brine droplets are cooled and dehumidified to form crystallized salt and saturated brine, and the crystallized salt and the saturated brine are discharged into the centrifuge 6 from the discharge port 42 and are separated. The saturated saline water and the stock solution are mixed and then discharged into a liquid pump 3, the mixture is discharged into a condenser 18 through the liquid pump 3 to be heated and heated, and then the mixture is discharged into a spraying device 5, the salt solution is prepared into a mist structure, and the mist structure is in heat and moisture exchange with the air which reversely runs in the separator 4. The damp and hot air formed after heat and humidity exchange is discharged from the separator 4, the small liquid drops in the air are filtered by the filter screen 10, and then the air enters the evaporator 20 for cooling and dehumidifying. The air after temperature reduction and dehumidification is discharged into the separator 4 through the fan 14 after being dehumidified by the water filtering screen 9, and performs heat and humidity exchange with the mist-shaped liquid drops moving in the reverse direction, so that the air is heated and humidified, and the liquid drops are cooled and dehumidified. The above processes are repeated circularly and the wastewater treatment is continuously carried out.

The method for treating wastewater by using the heat pump type wastewater treatment equipment comprises the following steps:

in step S1, the waste water exchanges heat with the heat pump system, the waste water absorbs heat and enters the separator 4 through the inlet 41, and the cold air enters the separator 4 through the inlet 43. Specifically, the refrigeration working medium in the condenser 18 exchanges heat with the wastewater, the wastewater absorbs heat to form warm wastewater, the warm wastewater enters the separator 4 from the feeding port 41, and the heat released by the refrigeration working medium enters the evaporator 20 through the expansion valve 19; the cold air enters the separator 4 from the air inlet 43, wherein the inlet 41 and the air inlet 43 are both arranged on the separator 4.

In step S2, the cold air and the waste water perform heat and moisture exchange in the separator 4, the cold air absorbs heat and is discharged from the air outlet 44, and the waste water releases heat and is discharged. Specifically, the cold air and the warm waste water perform heat and moisture exchange in the separator 4, wherein the cold air absorbs heat to become damp and hot air and is discharged from the air outlet 44, and the waste water releases heat to form saturated solution and crystals.

In step S3, the air discharged from the separator 4 is cooled by the heat pump system. Specifically, the hot humid air exchanges heat with the refrigerant in the evaporator 20, and the refrigerant absorbs heat and transfers the heat to the condenser 18 via the compressor 17.

And step S4, discharging the wastewater from the discharge port 42, allowing the wastewater to enter the centrifuge 6 for solid-liquid separation, mixing the solution discharged from the centrifuge 6 with the stock solution, and pumping the mixture into a heat pump system through the liquid pump 3. Specifically, the saturated solution and the crystals are discharged from the discharge port 42 and enter the centrifuge 6 for solid-liquid separation, and the saturated solution is discharged from the centrifuge 6, mixed with the stock solution, and pumped into the condenser 18 through the liquid pump 3.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A heat pump type wastewater treatment device is characterized by comprising a separator and a heat pump system, wherein the separator is provided with a feed inlet, an air outlet and an air inlet, the air inlet is used for introducing cold air into the separator, the feed inlet is used for discharging wastewater into the separator, the cold air and the wastewater carry out heat and moisture exchange in the separator, the heat pump system and the air outlet are communicated for cooling the air discharged from the separator, the heat pump system and the feed inlet are communicated for heating the wastewater, the heat pump system comprises a condenser, a compressor, an evaporator and an expansion valve which are sequentially connected, the condenser is communicated with the feed inlet, the evaporator is communicated with the air outlet, the heat pump type wastewater treatment device further comprises a filter screen, a water filtering screen and a fan, the filter screen install in air outlet department, the drainage silk screen with the fan from the extroversion inwards install in proper order in air inlet department, heat pump type waste water treatment equipment still includes pipeline, first blast gate, second blast gate and third blast gate, the condenser with the pipeline intercommunication, the drainage silk screen is located in the pipeline, first blast gate install in the evaporimeter with between the drainage silk screen in the pipeline, the second blast gate install in first blast gate with between the condenser one side pipe wall of pipeline, the third blast gate install in first blast gate with between the drainage silk screen one side pipe wall of pipeline.

2. A heat pump wastewater treatment apparatus according to claim 1, wherein said separator comprises a viewing window positioned in a sidewall of said separator, said apparatus further comprising a spray device in communication with said feed inlet, said spray device comprising a plurality of nozzles through which said wastewater enters said feed inlet and is ejected therefrom.

3. A heat pump wastewater treatment plant according to claim 1, wherein said condenser is a plate cooler and said evaporator is a finned heat exchanger.

4. A heat pump wastewater treatment apparatus according to claim 1, further comprising a raw liquid tank, a centrifuge, and a liquid pump, wherein the separator further comprises a discharge port located below the feed port, one end of the centrifuge is connected to the discharge port, the other end of the centrifuge is connected to the raw liquid tank and the liquid pump, an outlet of the liquid pump is connected to the heat pump system, and the raw liquid in the raw liquid tank is mixed with the saturated liquid discharged from the centrifuge and then pumped into the heat pump system by the liquid pump.

5. A heat pump wastewater treatment apparatus according to claim 4, further comprising four regulating valves, said four regulating valves being respectively mounted at a discharge of said raw liquid tank, at a liquid outlet of said centrifuge, at a discharge of said liquid pump, and at an outlet of said liquid pump.

6. A method of wastewater treatment using the heat pump wastewater treatment facility of any of claims 1-5, comprising the steps of:

step S1, carrying out heat exchange between the waste water and the heat pump system, enabling the waste water to absorb heat and enter a separator from a feed inlet, and enabling cold air to enter the separator from an air inlet;

7. The wastewater treatment method according to claim 6, further comprising a step S4 after the step S3, wherein the wastewater is discharged from a discharge port, enters a centrifuge for solid-liquid separation, and the solution discharged from the centrifuge is mixed with a stock solution and pumped into the heat pump system through a liquid pump.