Waste water waste heat recovery system

Abstract

The utility model relates to the technical field of waste water waste heat recovery, in particular to a waste water waste heat recovery system. Comprising an electric heat pump system and a transverse pipe falling film evaporator, the electric heat pump system comprises an evaporator, a compressor, a condenser and a throttling valve which are connected in sequence, a water inlet of the evaporator is connected with a high-temperature waste water discharging pipeline, and a circulating medium inlet and a circulating medium outlet of the transverse pipe falling film evaporator are connected with the condenser through pipelines. And a water inlet of the horizontal pipe falling film evaporator is connected with a desalted water pipe. According to the system, high-temperature wastewater is introduced into an evaporator of an electric heat pump system, heat of the wastewater is taken away by a refrigerant of the electric heat pump system, the heat is released into a circulating medium of a horizontal tube falling film evaporator through a condenser, the heat is transferred to desalted water, and the desalted water absorbs the heat and is gasified into water vapor. Due to the fact that the refrigerant of the electric heat pump system can be cooled to a low temperature after throttling, the system can conduct heat recovery on waste water with low temperature, and water vapor with high utilization value is generated.

Description

TECHNICAL FIELD

[0001] The utility model relates to wastewater waste heat recovery technical field especially is a kind of wastewater waste heat recovery system. BACKGROUND

[0002] High-temperature wastewater refers to the wastewater containing high heat generated during the operation of boiler and auxiliary system in the process of thermal power generation, industrial production and heating, etc., which is mainly derived from the cooling circulating system of boiler, steam condensation and various heat exchange processes. If it is directly discharged without treatment, not only the waste of heat energy resources will be caused, but also the ecological system of receiving water body will be caused heat pollution. The characteristics of boiler high-temperature wastewater source: diverse sources, including boiler cooling water, steam condensate, heat exchanger discharge water, etc.; high temperature, usually higher than ambient temperature, some even close to or exceed 100℃, high energy density, containing a large amount of potential heat energy that can be recycled; water quality will change, according to the type of boiler and operating conditions, water quality may contain different concentrations of minerals, salts, dissolved gases and a small amount of pollutants; regular discharge, discharge volume and temperature may change with seasonality and load, with certain periodicity and regularity.

[0003] In the prior art, wastewater waste heat recovery is direct heat exchange between wastewater and steam generation equipment, so the pressure and temperature of water vapor produced by recycling wastewater heat cannot be controlled, which has limitations. Only when the temperature of wastewater is high, steam with high temperature can be generated. When the temperature of wastewater is low, steam cannot be generated or only steam with low temperature can be generated. The utilization value of low-temperature water vapor is low, and the income is also low. Therefore, the utility model is proposed. UTILITY MODEL CONTENT

[0004] The utility model aims to provide a wastewater waste heat recovery system, which can solve the problem of not being able to recycle heat to produce water vapor when the temperature of wastewater is not high.

[0005] The utility model provides a wastewater waste heat recovery system, which comprises an electric heat pump system and a horizontal tube falling film evaporator. The electric heat pump system comprises an evaporator, a compressor, a condenser and a throttling valve connected in sequence to form a loop. The water inlet of the evaporator is connected with a high-temperature wastewater discharge pipeline. The circulating medium inlet and the circulating medium outlet of the horizontal tube falling film evaporator are connected with the condenser through pipelines respectively. The water inlet of the horizontal tube falling film evaporator is connected with a desalted water pipe.

[0006] Further, the system further comprises a steam compressor, and the steam outlet of the horizontal tube falling film evaporator is connected with the steam compressor through a pipeline.

[0007] Further, the refrigerant outlet of the evaporator is connected with the refrigerant inlet of the compressor through a pipeline, the refrigerant outlet of the compressor is connected with the refrigerant inlet of the condenser through a pipeline, the refrigerant outlet of the condenser is connected with a throttling valve through a pipeline, the throttling valve is connected with the refrigerant inlet of the evaporator through a pipeline, and the water outlet of the evaporator is connected with a low-temperature waste water pipeline through a pipeline.

[0008] Further, a circulating pump is arranged on the pipeline connecting the circulating medium inlet of the horizontal-tube falling-film evaporator with the condenser.

[0009] Further, a water supplementing pump is arranged on the desalted water pipeline.

[0010] Further, the compressor in the electric heat pump system is a positive displacement compressor.

[0011] Further, the evaporator in the electric heat pump system is a shell-and-tube evaporator or a finned-tube evaporator.

[0012] Further, the steam compressor is a centrifugal compressor.

[0013] In summary, the present application has the following advantages compared with the prior art.

[0014] The technical scheme provided by the present application introduces high-temperature waste water into the evaporator of the electric heat pump system, the heat of the waste water is taken away by the refrigerant of the electric heat pump system, the refrigerant of the electric heat pump system absorbs the heat of the waste water and releases the heat to the circulating medium of the horizontal-tube falling-film evaporator through the condenser, the heat is transferred to the desalted water in the horizontal-tube falling-film evaporator, and the desalted water absorbs the heat and is vaporized into water vapor. Since the refrigerant of the electric heat pump system can be reduced to a lower temperature after throttling, the system provided by the present application can recover the heat of waste water with a low temperature and produce water vapor with high utilization value. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme in the specific embodiments of the present application or the prior art, the drawings needed in the description of the specific embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0016] Figure 1 The process flow chart of the system in the embodiments of the present application.

[0017] Explanation of reference signs: 1 - electric heat pump system; 101 - evaporator; 102 - compressor; 103 - condenser; 104 - throttling valve; 2 - horizontal tube falling film evaporator; 3 - steam compressor; 4 - circulating pump; 5 - water replenishing pump. DETAILED DESCRIPTION

[0018] The technical solutions of the present application will be described below in conjunction with the embodiments, obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0019] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0020] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited. In addition, the terms "mounting", "connecting", "connecting" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0021] EMBODIMENT

[0022] A waste water waste heat recovery system, as shown in Figure 1 , comprising an electric heat pump system 1, a horizontal tube falling film evaporator 2, and a steam compressor 3.

[0023] The electric heat pump system 1 comprises an evaporator 101, a compressor 102, a condenser 103 and a throttling valve 104 connected in sequence to form a loop, and is located at the front end of the system, and mainly functions to transfer heat from high-temperature wastewater, and stably obtain heat energy from the high-temperature wastewater above 50℃, and then convert the heat energy into a heat source that can be used by the horizontal-tube falling-film evaporator 2.

[0024] The water inlet of the evaporator 101 is connected with a high-temperature wastewater discharge pipeline, the high-temperature wastewater discharge pipeline is connected with various wastewater discharge devices of a boiler system, the water outlet of the evaporator 101 is connected with a low-temperature wastewater pipeline, the refrigerant outlet of the evaporator 101 is connected with the refrigerant inlet of the compressor 102 through a pipeline, the refrigerant outlet of the compressor 102 is connected with the refrigerant inlet of the condenser 103 through a pipeline, the refrigerant outlet of the condenser 103 is connected with the throttling valve 104 through a pipeline, and the refrigerant inlet of the evaporator 101 is connected with the throttling valve 104 through a pipeline.

[0025] The horizontal-tube falling-film evaporator 2 is located at the middle section of the system, and mainly functions to absorb and utilize the heat transferred by the electric heat pump system 1, so as to generate water vapor. The water inlet of the horizontal-tube falling-film evaporator 2 is connected with a desalted water pipeline, the vapor outlet of the horizontal-tube falling-film evaporator 2 is connected with the vapor compressor 3 through a pipeline, the circulating medium inlet of the horizontal-tube falling-film evaporator 2 is connected with the circulating medium outlet of the condenser 103 through a pipeline, and the circulating medium outlet of the horizontal-tube falling-film evaporator 2 is connected with the circulating medium inlet of the condenser 103 through a pipeline. The vapor outlet of the vapor compressor 3 is connected with a vapor pipeline, and the generated high-temperature vapor is sent to the next process flow for utilization or reprocessing.

[0026] The desalted water pipeline is provided with a water supplement pump 5, and the pipeline connecting the circulating medium inlet of the horizontal-tube falling-film evaporator 2 and the circulating medium outlet of the condenser 103 is provided with a circulating pump 4.

[0027] The horizontal-tube falling-film evaporator 2 adopts a conventional horizontal-tube falling-film evaporator in the prior art, has high heat transfer efficiency, small occupied area, simple system, easy operation and maintenance. The operation principle of the horizontal-tube falling-film evaporator 2 is the heat exchange principle of a double-pipe heat exchanger. The high-temperature circulating medium flows in the tube side, the desalted water forms a uniform liquid film on the outer wall of the heat exchange tube through multiple nozzles, a large amount of water vapor is generated in the shell side after heat exchange, and the high-temperature vapor is obtained by compressing and heating the water vapor through the demister and the vapor compressor 3.

[0028] The vapor compressor 3 is located at the end section of the system, and mainly functions to compress the water vapor generated by the horizontal-tube falling-film evaporator 2 to achieve the purpose of temperature and pressure increase.

[0029] The evaporator 101 in the electric heat pump system 1 adopts a tube-in-shell evaporator or a finned evaporator, the compressor 102 adopts a positive displacement compressor, and the vapor compressor 3 adopts a centrifugal compressor.

[0030] The waste water waste heat recovery system provided by the utility model utilizes the electric heat pump system 1 as a stable heat energy transfer system, and realizes that stable quality steam can be produced when the waste water temperature is above 50 DEG C by combining with the horizontal tube falling film evaporator 2 and the steam compressor 3, and the detailed process flow is as follows: the high temperature waste water above 50 DEG C enters the evaporator 101 of the electric heat pump system 1, the heat of the high temperature waste water is taken away by the refrigerant in the evaporator 101, the temperature of the high temperature waste water is reduced and enters the next process flow through the low temperature waste water pipeline for reprocessing or reuse, the refrigerant in the evaporator 101 is gasified after absorbing the waste water heat, then enters the compressor 102, forms the high temperature and high pressure gaseous refrigerant after compression, and then enters the condenser 103, releases the heat to the circulating medium of the horizontal tube falling film evaporator 2, the refrigerant with reduced temperature in the condenser 103 then enters the throttle valve 104 for temperature and pressure reduction and then flows to the evaporator 101, so that the closed loop electric heat pump system 1 is formed; the circulating medium of the horizontal tube falling film evaporator 2 after absorbing the heat of the high temperature and high pressure gaseous refrigerant is sent to the tube side of the horizontal tube falling film evaporator 2 through the circulating pump 4, and the heat is transferred to the desalted water in the shell side of the horizontal tube falling film evaporator 2, the desalted water is gasified into water vapor after absorbing the heat, and the water vapor enters the steam compressor 3 for compression, temperature rise and pressure rise, and the water vapor with higher utilization value is obtained.

[0031] The waste water waste heat recovery system can be integrated and optimized, advanced automatic control systems and detection equipment are combined, the whole treatment process is optimized, precise control and efficient management of the waste water treatment process are realized, stable operation of the system is ensured, and energy saving effect maximization is achieved, the utility model and the automatic control are combined, energy utilization efficiency is improved, greenhouse gas emission is reduced, enterprise operation cost and environmental influence are significantly reduced, and the concept of circular economy and sustainable development is embodied.

[0032] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A waste water heat recovery system, characterized by, The application relates to an electric heat pump system (1) comprising a horizontal tube falling film evaporator (2), wherein the electric heat pump system (1) comprises an evaporator (101), a compressor (102), a condenser (103) and a throttle valve (104) connected in sequence to form a circuit, the water inlet of the evaporator (101) is connected with a high-temperature wastewater discharge pipeline, the circulating medium inlet and the circulating medium outlet of the horizontal tube falling film evaporator (2) are connected with the condenser (103) through pipelines respectively, and the water inlet of the horizontal tube falling film evaporator (2) is connected with a desalted water pipeline.

2. The waste water heat recovery system according to claim 1, characterized by, A steam compressor (3) is further arranged, and the steam outlet of the horizontal tube falling film evaporator (2) is connected with the steam compressor (3) through a pipeline.

3. The waste water heat recovery system according to claim 1, characterized by, The refrigerant outlet of the evaporator (101) is connected with the refrigerant inlet of the compressor (102) through a pipeline, the refrigerant outlet of the compressor (102) is connected with the refrigerant inlet of the condenser (103) through a pipeline, the refrigerant outlet of the condenser (103) is connected with the throttle valve (104) through a pipeline, the throttle valve (104) is connected with the refrigerant inlet of the evaporator (101) through a pipeline, and the water outlet of the evaporator (101) is connected with a low-temperature wastewater pipeline through a pipeline.

4. The waste water heat recovery system according to claim 1, characterized by, A circulating pump (4) is arranged on the pipeline connecting the circulating medium inlet of the horizontal tube falling film evaporator (2) with the condenser (103).

5. The waste water heat recovery system according to claim 1, wherein A water supplement pump (5) is arranged on the desalted water pipeline.

6. The waste water heat recovery system of claim 1, wherein The compressor (102) in the electric heat pump system (1) is a volumetric compressor.

7. The waste water heat recovery system of claim 1, wherein The evaporator (101) in the electric heat pump system (1) is a tube-shell or finned evaporator.

8. The waste water heat recovery system of claim 2, wherein, The steam compressor (3) is a centrifugal compressor.

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