Thermal film coupled seawater desalination system with multiple modes of operation

Abstract

The application discloses a thermal film coupling seawater desalination system with multiple operation modes, wherein heat of low-temperature hot water is lifted in quality by a heat pump, and then is used to heat circulating water or high-temperature steam through a heat exchanger to heat the circulating water as a heat source of a water generator; medium-temperature hot water can be directly used as the heat source of the water generator; and a reverse osmosis system is further arranged; the operation mode can be adjusted according to power and heat conditions; in the case that seawater temperature is too low in winter, warm drainage of the water generator is mixed with taken seawater to serve as raw water of reverse osmosis, so that the economy and safety of reverse osmosis operation are improved; and in the case that the content of seawater suspensions is high, concentrated water of reverse osmosis can be used as raw water of the water generator to prevent the water generator from being blocked by dirt.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of seawater desalination and waste heat utilization, and more particularly to a heat film coupled seawater desalination system with multiple operation modes. BACKGROUND

[0002] Seawater desalination is an important means to increase water resources from the source and ensure water safety, and is increasingly valued and developed. In addition to building large seawater desalination plants on the coast, there are many small seawater desalination needs for special occasions such as remote areas, small islands, offshore platforms, and ocean-going fishing vessels. In these special occasions, small distributed energy stations are generally equipped, usually combining diesel generators, wind power, photovoltaic and other energy forms, which are difficult to provide a certain stable energy supply for seawater desalination devices.

[0003] Currently, reverse osmosis is a mature and low-cost desalination technology, but it requires a stable power supply for operation. In the northern sea area, the seawater temperature is too low in winter to be directly used for reverse osmosis seawater desalination. Therefore, the reliability of using reverse osmosis alone for freshwater supply is low. Plate water makers can use hot water as a heat source for seawater desalination, but the grade of the heat source is often fluctuating, and the temperature is too low or too high to be directly used. Therefore, it is urgent to develop a heat film coupled seawater desalination system with multiple operation modes to enhance the reliability of freshwater supply. SUMMARY

[0004] The purpose of the present application is to overcome the deficiencies in the prior art and provide a heat film coupled seawater desalination system with multiple operation modes.

[0005] The technical solution of the present application is summarized as follows:

[0006] The application discloses a thermal film coupling seawater desalination system with multiple operation modes, which comprises a heat pump evaporator 1, a refrigerant outlet of the heat pump evaporator 1 is connected with a compressor 2, a heat pump condenser 3, a throttling valve 4 and a refrigerant inlet of the heat pump evaporator 1 in sequence through pipelines, the heat pump evaporator 1 is connected with a low-temperature hot water source inlet pipe 32 and a low-temperature hot water source return pipe 33, a water generator comprises a water generator evaporator 45 and a water generator condenser 44 which are installed in a water generator shell 6, the water generator evaporator 45 is arranged below, the water generator condenser 44 is arranged above, and the water generator evaporator 45 and the water generator condenser 44 are separated by a foam catching net 46 and a partition plate 47, a hot water outlet of the heat pump condenser 3 is connected with a fourth valve 22 through a pipeline and is divided into two branches, one branch is connected with a water generator evaporator hot water inlet 52 through a pipeline, and the other branch is connected with a first valve 19 and a hot water outlet of a high-temperature steam heat exchanger 56 in sequence through pipelines, a medium-temperature hot water source inlet pipe 37 is connected with a sixth valve 24 through a pipeline and then is connected with the water generator evaporator hot water inlet 52, a steam interface of the high-temperature steam heat exchanger 56 is connected with a high-temperature steam source inlet pipe 34, a condensate water interface of the high-temperature steam heat exchanger 56 is connected with a condensate water pump 13 and a high-temperature steam source condensate water return pipe 35 in sequence through pipelines, an outlet of a buffer water tank 5 is connected with a hot water pump 14 through a pipeline and is divided into two branches, one branch is connected with a second valve 20 and a hot water inlet of the high-temperature steam heat exchanger 56 in sequence through pipelines, and the other branch is connected with a third valve 21 and a hot water inlet of the heat pump condenser 3 in sequence through pipelines, a water generator evaporator hot water outlet 54 is connected with a seventh valve 25 and an eighth valve 26 through pipelines respectively, the seventh valve 25 is connected with an inlet of the buffer water tank 5 through a pipeline, the eighth valve 26 is connected with a medium-temperature hot water source return pipe 36, a water generator condenser seawater outlet 48 is connected with a water generator evaporator seawater inlet 53 and a seawater inlet of a water jet vacuum pump 7 through pipelines respectively, a water generator condenser non-condensable gas outlet 49 is connected with a non-condensable gas inlet of the water jet vacuum pump 7 through a pipeline, a water generator condenser fresh water outlet 50 is connected with a fresh water pump 15 through a pipeline and then is connected with a water generator water outlet pipe 39, a water generator condenser seawater inlet 51 is connected with a ninth valve 27 through a pipeline and is divided into two branches, one branch is connected with a tenth valve 28 and an inlet of an original water tank 8 in sequence through pipelines, and the other branch is connected with an eleventh valve 29 and then is connected with a seawater supply pipe 40, a water generator concentrated water discharge outlet 55 is connected with a concentrated water inlet of the water jet vacuum pump 7 through a pipeline, a discharge outlet of the water jet vacuum pump 7 is divided into two branches through a pipeline, one branch is connected with a fifth valve 23 and an inlet of the original water tank 8 in sequence through pipelines, and the other branch is connected with a water generator concentrated water discharge pipe 41, an outlet of the original water tank 8 is connected with an original water pump 16, a multi-medium filter 9, a precision filter 10, a security filter 11, a pump end of a high-pressure pump 17 with energy recovery and a seawater inlet of a reverse osmosis unit 12 in sequence through pipelines, the multi-medium filter 9 is connected with a backwashing water discharge pipe 43, and a water outlet of the reverse osmosis unit 12 is connected with a reverse osmosis water outlet pipe 38.The concentrated water outlet of the reverse osmosis unit 12 is connected with the energy recovery end of the high-pressure pump 17 with energy recovery through a pipeline, and is divided into two paths, one of which is connected with the twelfth valve 30 and the reverse osmosis concentrated water pump 18 through a pipeline in sequence, and then connected to the pipeline between the ninth valve 27 and the eleventh valve 29, and the other is connected with the thirteenth valve 31 through a pipeline, and the thirteenth valve 31 is connected with the reverse osmosis concentrated water discharge pipe 42.

[0007] The water maker is a plate type water maker.

[0008] Advantages of the present application:

[0009] (1) The present application recovers the waste heat of 40-60 DEG C hot water by a heat pump, improves the grade and uses it as

[0010] The heat source of the water maker, or directly uses 60-100 DEG C hot water into the water maker as the heat source of the water maker, or uses the heat of >100 DEG C steam through a high-temperature steam heat exchanger as the heat source of the water maker, has the ability to adapt to multiple grade heat sources.

[0011] (2) The present application can only run the reverse osmosis under the condition of sufficient power and insufficient heat, can only run the water maker under the condition of sufficient heat and insufficient power, and can simultaneously run the reverse osmosis and the water maker under the condition of sufficient power and heat, and can adjust the operation mode according to the power and heat conditions.

[0012] (3) The present application can use the concentrated water of the water maker mixed with the seawater taken as the raw material water of the reverse osmosis to improve the temperature of the raw material water of the reverse osmosis, thereby improving the economy and safety of the operation of the reverse osmosis.

[0013] (4) The present application can use the concentrated water of the reverse osmosis as the raw material water of the water maker when the content of seawater suspended matter is high, to prevent the pollution and blockage of the water maker. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a schematic diagram of the heat film coupled seawater desalination system with multiple operation modes of the present application.

[0015] REFERENCE NUMERALS:

[0016] 1 heat pump evaporator, 2 compressor, 3 heat pump condenser, 4 throttle valve, 5 buffer water tank, 6 water generator shell, 7 water jet vacuum pump, 8 raw water tank, 9 multi-medium filter, 10 precision filter, 11 security filter, 12 reverse osmosis unit, 13 condensate pump, 14 hot water pump, 15 fresh water pump, 16 raw water pump, 17 high pressure pump with energy recovery, 18 reverse osmosis concentrated water pump, 19 first valve, 20 second valve, 21 third valve, 22 fourth valve, 23 fifth valve, 24 sixth valve, 25 seventh valve, 26 eighth valve, 27 ninth valve, 28 tenth valve, 29 eleventh valve, 30 twelfth valve, 31 thirteenth valve, 32 low temperature hot water heat source inlet pipe, 33 low temperature hot water heat source return pipe, 34 high temperature steam heat source inlet pipe, 35 high temperature steam heat source condensate return pipe, 36 medium temperature hot water heat source return pipe, 37 medium temperature hot water heat source inlet pipe, 38 reverse osmosis water pipe, 39 water generator water pipe, 40 seawater supply pipe, 41 water generator concentrated water discharge pipe, 42 reverse osmosis concentrated water discharge pipe, 43 backwash water discharge pipe, 44 water generator condenser, 45 water generator evaporator, 46 mist net, 47 partition, 48 water generator condenser seawater outlet, 49 water generator condenser non-condensable gas port, 50 water generator condenser fresh water outlet, 51 water generator condenser seawater inlet, 52 water generator evaporator hot water inlet, 53 water generator evaporator seawater inlet, 54 water generator evaporator hot water outlet, 55 water generator concentrated water discharge port, 56 high temperature steam heat exchanger. DETAILED DESCRIPTION

[0017] The various components of the present application are all commercially available, and the components of the water generator and heat pump are either commercially available or are custom made as required.

[0018] The present application will be further described below with reference to the accompanying drawings.

[0019] The heat film coupled seawater desalination system with multiple operating modes is shown in Figure 1, including heat pump evaporator 1, heat pump evaporator 1 refrigerant outlet through the pipeline in turn with compressor 2, heat pump condenser 3, throttle valve 4, heat pump evaporator 1 refrigerant inlet connection; Heat pump evaporator 1 is connected with low temperature hot water heat source to pipe 32 and low temperature hot water heat source back pipe 33; Water generator includes water generator evaporator 45 and water generator condenser 44 installed inside water generator shell 6, water generator evaporator 45 is lower, water generator condenser 44 is upper, which is separated by the middle of the catch net 46 and partition 47; The hot water outlet of heat pump condenser 3 is connected with the fourth valve 22 through the pipeline and is divided into two ways, one way is connected with water generator evaporator hot water inlet 52 through the pipeline, and the other way is connected with the hot water outlet of high temperature steam heat exchanger 56 through the pipeline in turn and the first valve 19; The medium temperature hot water heat source to pipe 37 is connected with the sixth valve 24 through the pipeline and then connected with water generator evaporator hot water inlet 52; The steam interface of high temperature steam heat exchanger 56 is connected with high temperature steam heat source to pipe 34; The condensate water interface of high temperature steam heat exchanger 56 is connected with condensate pump 13 and high temperature steam heat source condensate water back pipe 35 through the pipeline in turn; The outlet of buffer tank 5 is connected with hot water pump 14 through the pipeline and is divided into two ways, one way is connected with the second valve 20 and the hot water inlet of high temperature steam heat exchanger 56 through the pipeline in turn; One way is connected with the third valve 21 and the hot water inlet of heat pump condenser 3 through the pipeline in turn; Water generator evaporator hot water outlet 54 is connected with the seventh valve 25 and the eighth valve 26 through the pipeline respectively, the seventh valve 25 is connected with the inlet of buffer tank 5 through the pipeline; The eighth valve 26 is connected with medium temperature hot water heat source back pipe 36; Water generator condenser seawater outlet 48 is connected with water generator evaporator seawater inlet 53 and seawater inlet of water jet vacuum pump 7 through the pipeline respectively; Water generator condenser non-condensing gas port 49 is connected with non-condensing gas port of water jet vacuum pump 7 through the pipeline; Water generator condenser fresh water outlet 50 is connected with fresh water pump 15 through the pipeline and then connected with water generator water pipe 39; Water generator condenser seawater inlet 51 is connected with the ninth valve 27 through the pipeline and is divided into two ways, one way is connected with the tenth valve 28 and the inlet of raw water tank 8 through the pipeline in turn, and the other way is connected with the eleventh valve 29 and then connected with seawater supply pipe 40; Water generator concentrated water discharge port 55 is connected with concentrated water inlet of water jet vacuum pump 7 through the pipeline; The discharge port of water jet vacuum pump 7 is divided into two ways through the pipeline, one way is connected with the fifth valve 23 and the inlet of raw water tank 8 through the pipeline in turn, and the other way is connected with water generator concentrated water discharge pipe 41; The outlet of raw water tank 8 is connected with raw water pump 16, multi-medium filter 9, precision filter 10, security filter 11, pump end of high pressure pump 17 with energy recovery, seawater inlet of reverse osmosis unit 12 through the pipeline in turn, multi-medium filter 9 is connected with backwash water discharge pipe 43, and water outlet of reverse osmosis unit 12 is connected with reverse osmosis water pipe 38;The concentrated water outlet of the reverse osmosis unit 12 is connected with the energy recovery end of the high-pressure pump 17 with energy recovery through a pipeline, and is divided into two paths, one of which is connected with the twelfth valve 30 and the reverse osmosis concentrated water pump 18 through a pipeline in sequence, and then connected to the pipeline between the ninth valve 27 and the eleventh valve 29, and the other of which is connected with the thirteenth valve 31 through a pipeline, and the thirteenth valve 31 is connected with the reverse osmosis concentrated water discharge pipe 42.

[0020] The water generator is a plate type water generator.

[0021] The hot film coupled seawater desalination system has multiple operation modes, which can be water generation by the water generator alone, water generation by the reverse osmosis unit alone, hot film coupled operation water generation with reverse osmosis concentrated water as the supplementary raw material water of the water generator, hot film coupled operation water generation with water generator concentrated water as the reverse osmosis supplementary raw material water, and the like.

[0022] The working principle of the present application is that the refrigerant circulates and flows between the compressor, the heat pump condenser, the throttling valve and the heat pump evaporator under the driving of the compressor, the pressure and temperature of the refrigerant are reduced after throttling of the throttling valve, the refrigerant changes from liquid phase to gas phase in the heat pump evaporator while absorbing the heat of the low-temperature hot water, the gas-phase refrigerant is heated and pressurized after the compressor, and then changes from gas phase to liquid phase in the heat pump condenser while transferring heat to the circulating hot water as the heat source of the water generator; the high-temperature steam heats the circulating water through the high-temperature steam heat exchanger as the heat source of the water generator; the medium-temperature hot water can be directly used as the heat source of the water generator.

[0023] When low-temperature hot water is used, the first valve is closed, the second valve is closed, the third valve is opened, the fourth valve is opened, the sixth valve is closed, the seventh valve is opened, and the eighth valve is closed; when high-temperature steam is used, the first valve is opened, the second valve is opened, the third valve is closed, the fourth valve is closed, the sixth valve is closed, the seventh valve is opened, and the eighth valve is closed.

[0024] When medium-temperature hot water is used, the first valve is closed, the second valve is closed, the third valve is closed, the fourth valve is closed, the sixth valve is opened, the seventh valve is closed, and the eighth valve is opened.

[0025] The heat source heats seawater in the water generator evaporator, and the heated seawater is evaporated to generate steam under negative pressure. The steam enters the water generator condenser after removing small droplets carried by the foam trap. In the water generator condenser, the steam is condensed into fresh water, and heat is released to preheat the original seawater. Part of the preheated original seawater enters the water generator evaporator, and part of it enters the water jet vacuum pump as power. The water jet vacuum pump simultaneously sucks non-condensable gas and concentrated seawater in the water generator to maintain the internal vacuum degree of the water generator. The seawater in the raw water tank is pressurized by the raw water pump and then filtered by the multi-medium filter, precision filter and security filter before entering the high-pressure pump with energy recovery. After the pressure is further increased, the water enters the reverse osmosis unit and produces fresh water through the reverse osmosis membrane. The concentrated water in the reverse osmosis unit is discharged after recovering pressure energy through the energy recovery end of the high-pressure pump with energy recovery.

[0026] The heat film coupled seawater desalination system with multiple operating modes of the present application can have different operating modes such as water production by the water generator alone, water production by the reverse osmosis unit alone, heat film coupled operation water production with reverse osmosis concentrated water as water generator supplemental raw material water, and heat film coupled operation water production with water generator concentrated water as reverse osmosis supplemental raw material water.

[0027] When the water generator produces water alone, the fifth valve is closed, the ninth valve is opened, the tenth valve is closed, the eleventh valve is opened, the twelfth valve is closed, and the thirteenth valve is closed. When the reverse osmosis unit produces water alone, the fifth valve is closed, the ninth valve is closed, the tenth valve is opened, the eleventh valve is opened, the twelfth valve is closed, and the thirteenth valve is opened.

[0028] When the reverse osmosis concentrated water is used as the water generator supplemental raw material water for heat film coupled operation water production, the fifth valve is closed, the ninth valve is partially opened, the tenth valve is partially opened, the eleventh valve is partially opened, the twelfth valve is opened, and the thirteenth valve is closed.

[0029] When the water generator concentrated water is used as the reverse osmosis supplemental raw material water for heat film coupled operation water production, the fifth valve is partially opened, the ninth valve is partially opened, the tenth valve is partially opened, the eleventh valve is opened, the twelfth valve is closed, and the thirteenth valve is opened.

[0030] Taking the case of heat film coupled operation water production with water generator concentrated water as reverse osmosis supplemental raw material water when the seawater temperature is low in winter and the water generator uses low-temperature hot water, the specific working steps of the present application are as follows:

[0031] The first valve is closed, the second valve is closed, the third valve is opened, the fourth valve is opened, the sixth valve is closed, the seventh valve is opened, the eighth valve is closed, the fifth valve is partially opened, the ninth valve is partially opened, the tenth valve is partially opened, the eleventh valve is opened, the twelfth valve is closed, and the thirteenth valve is opened. The refrigerant circulates between the compressor, the heat pump condenser, the throttling valve, and the heat pump evaporator under the driving of the compressor. After being throttled by the throttling valve, the refrigerant is reduced in pressure and temperature. The refrigerant changes from liquid phase to gas phase in the heat pump evaporator while absorbing the heat of the low-temperature hot water. The gaseous refrigerant is heated and pressurized by the compressor, and then changes from gas phase to liquid phase in the heat pump condenser while transferring heat to the circulating hot water, serving as the heat source of the water generator. The circulating hot water circulates between the buffer tank, the heat pump condenser, and the water generator evaporator under the power of the hot water pump. The heat source heats the seawater in the water generator evaporator, and the heated seawater evaporates under negative pressure to generate steam. The steam enters the water generator condenser after removing small droplets by the foam trap. The steam condenses into fresh water in the water generator condenser while releasing heat to preheat the original seawater. Part of the preheated original seawater enters the water generator evaporator, and part of it enters the water jet vacuum pump as power. The water jet vacuum pump simultaneously sucks non-condensable gas and concentrated seawater in the water generator, maintaining the internal vacuum degree of the water generator. Part of the concentrated water of the water generator mixes with part of the original seawater in the original water tank, and the temperature is controlled between 2°C and 35°C. The seawater in the original water tank is pressurized by the original water pump, filtered by the multi-media filter, precision filter, and safety filter, and then enters the pump end of the high-pressure pump with energy recovery. After the pressure is further increased, the seawater enters the reverse osmosis unit to produce fresh water through the reverse osmosis membrane. The concentrated water of the reverse osmosis unit is discharged after recovering pressure energy by the energy recovery end of the high-pressure pump with energy recovery.

[0032] The above merely illustrates the specific embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A thermal film coupled seawater desalination system with multiple modes of operation, comprising a heat pump evaporator (1), characterized in that, The refrigerant outlet of the heat pump evaporator (1) is connected with the compressor (2), the heat pump condenser (3), the throttling valve (4) and the refrigerant inlet of the heat pump evaporator (1) in sequence through pipes; the heat pump evaporator (1) is connected with low-temperature hot water source inlet pipe (32) and low-temperature hot water source return pipe (33); the water generator comprises a water generator evaporator (45) and a water generator condenser (44) installed inside the water generator shell (6), the water generator evaporator (45) is below, the water generator condenser (44) is above, and the middle is separated by a mesh (46) and a partition (47); the hot water outlet of the heat pump condenser (3) is connected with the fourth valve (22) through pipes and then is divided into two paths, one path is connected with the water generator evaporator hot water inlet (52) through pipes, and the other path is connected with the first valve (19) and the hot water outlet of the high-temperature steam heat exchanger (56) in sequence through pipes; the medium-temperature hot water source inlet pipe (37) is connected with the sixth valve (24) through pipes and then is connected with the water generator evaporator hot water inlet (52); the steam interface of the high-temperature steam heat exchanger (56) is connected with the high-temperature steam source inlet pipe (34); the condensate water interface of the high-temperature steam heat exchanger (56) is connected with the condensate pump (13) and the high-temperature steam source condensate water return pipe (35) in sequence through pipes; the outlet of the buffer tank (5) is connected with the hot water pump (14) through pipes and then is divided into two paths, one path is connected with the second valve (20) and the hot water inlet of the high-temperature steam heat exchanger (56) in sequence through pipes; the other path is connected with the third valve (21) and the hot water inlet of the heat pump condenser (3) in sequence through pipes; the water generator evaporator hot water outlet (54) is connected with the seventh valve (25) and the eighth valve (26) through pipes respectively, the seventh valve (25) is connected with the inlet of the buffer tank (5) through pipes; the eighth valve (26) is connected with the medium-temperature hot water source return pipe (36); the seawater outlet (48) of the water generator condenser is connected with the water generator evaporator seawater inlet (53) and the seawater inlet of the water jet vacuum pump (7) through pipes respectively; the non-condensable gas outlet (49) of the water generator condenser is connected with the non-condensable gas outlet of the water jet vacuum pump (7) through pipes; the fresh water outlet (50) of the water generator condenser is connected with the fresh water pump (15) through pipes and then is connected with the water generator water production pipe (39); the seawater inlet (51) of the water generator condenser is connected with the ninth valve (27) through pipes and then is divided into two paths, one path is connected with the tenth valve (28) and the inlet of the raw water tank (8) in sequence through pipes, and the other path is connected with the eleventh valve (29) and then is connected with the seawater supply pipe (40); the concentrated water discharge port (55) of the water generator is connected with the concentrated water inlet of the water jet vacuum pump (7) through pipes; the discharge port of the water jet vacuum pump (7) is divided into two paths through pipes, one path is connected with the fifth valve (23) and the inlet of the raw water tank (8) in sequence, and the other path is connected with the concentrated water discharge pipe (41) of the water generator;The outlet of the raw water tank (8) is connected with the raw water pump (16), the multi-medium filter (9), the precision filter (10), the security filter (11), the pump end of the high-pressure pump (17) with energy recovery, the seawater inlet of the reverse osmosis unit (12) in sequence through pipelines, the multi-medium filter (9) is connected with the backwash water discharge pipe (43), the water outlet of the reverse osmosis unit (12) is connected with the reverse osmosis water pipe (38); the concentrated water outlet of the reverse osmosis unit (12) is connected with the energy recovery end of the high-pressure pump (17) with energy recovery through pipelines and is divided into two ways, one way is connected with the twelfth valve (30) and the reverse osmosis concentrated water pump (18) in sequence through pipelines and then is connected to the pipeline between the ninth valve (27) and the eleventh valve (29), and the other way is connected with the thirteenth valve (31) through pipelines, and the thirteenth valve (31) is connected with the reverse osmosis concentrated water discharge pipe (42).

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