A high-temperature water recovery system for ship main engines

Abstract

The present invention provides a high-temperature water recovery system for a ship's main engine. In this system, the cylinder and air cooler in the main engine are arranged in parallel, which helps to increase the temperature or flow of the high-temperature water flowing to the water maker, that is, the heat available for the water maker is increased, thereby increasing the fresh water production; secondly, the present invention effectively utilizes the heat in the main engine exhaust gas and the heat in the generator exhaust gas by arranging an exhaust gas economizer, a first heat exchanger, and a second heat exchanger in the recovery system, thereby improving the waste heat utilization rate and helping to increase the fresh water production; in addition, adding a main engine preheater between the water maker and the main engine can increase the temperature of the high-temperature water entering the water maker, which can also increase the fresh water production; finally, the present invention realizes multiple working modes to meet production needs through unique pipeline design and the use of a controller to adjust the pipeline connection.

Description

Technical Field

[0001] The present invention belongs to the technical field of shipbuilding, and in particular relates to a high-temperature water recovery system for a ship main engine. Background Art

[0002] Fresh water is an extremely important consumable resource for ships sailing or working at sea. Therefore, it is necessary to equip ships with water generators to reduce the amount of fresh water reserves on board while meeting the ship's demand for fresh water.

[0003] At present, the waste heat of high temperature water generated by the main engine of the ship is the heat source for the operation of the water maker, but the quality of the waste heat (i.e. temperature and flow) will directly affect the fresh water output of the water maker. In the existing main engine high temperature water recovery system, the air cooler and the cylinder are usually connected in series. Figure 1 As shown, this design is limited by the high-temperature outlet temperature requirement of the main engine, which restricts the quality of waste heat that can be utilized by the water generator, thereby affecting freshwater production. Furthermore, in addition to the waste heat generated by the wastewater in the main engine, a large amount of waste heat is also stored in the main engine exhaust gas. However, this waste heat from the main engine exhaust gas is currently mainly recovered through the exhaust gas economizer, while the waste heat from the generator exhaust gas is often not recovered. Even after passing through the exhaust gas economizer, the main engine exhaust gas still contains high-quality waste heat. Therefore, this waste heat urgently needs to be utilized to increase the freshwater production of the water generator. Summary of the Invention

[0004] In view of the shortcomings of the prior art mentioned above, the present invention provides a high-temperature water recovery system for a ship main engine, in which the cylinder and air cooler in the main engine are arranged in parallel, which helps to increase the temperature or flow of high-temperature water flowing to the water maker, that is, the heat available to the water maker is increased, thereby increasing the fresh water production; secondly, the present invention effectively utilizes the heat in the main engine exhaust gas and the heat in the generator exhaust gas by arranging an exhaust gas economizer, a first heat exchanger and a second heat exchanger in the recovery system, thereby improving the waste heat utilization rate and helping to increase the fresh water production; in addition, adding a main engine preheater between the water maker and the main engine can increase the temperature of the high-temperature water entering the water maker, which can also increase the fresh water production; finally, the present invention realizes a variety of working modes to meet production needs through a unique pipeline design and the use of a controller to adjust the pipeline connection.

[0005] To achieve the above-mentioned and other related purposes, the present invention provides a high-temperature water recovery system for a ship main engine, comprising:

[0006] A main engine, wherein the main engine is provided with a cylinder and an air cooler, and the cylinder and the air cooler are arranged in parallel;

[0007] A main engine preheater, connected to the waste liquid outlet of the main engine, for preheating the high-temperature water output by the main engine;

[0008] a cooler, wherein the inlet of the cooler is communicated with the preheater, the outlet of the cooler is communicated with the main engine, and a first shut-off valve is provided between the preheater and the cooler;

[0009] A water maker is provided between the preheater and the cooler and is connected in parallel with the first stop valve for producing fresh water.

[0010] Optionally, the host preheater includes:

[0011] a first preheater connected to the waste liquid outlet of the main unit, and a temperature sensor is provided between the first preheater and the main unit for detecting the temperature of the high-temperature water output by the main unit;

[0012] The second preheater is arranged in series with the first preheater, and a first three-way valve is provided between the second preheater and the first preheater, for allowing the high-temperature water output by the first preheater to flow to the cooler and / or the second preheater.

[0013] Optionally, a second three-way valve is provided at the outlet of the second preheater, for allowing the high-temperature water output by the second preheater to flow to the host and / or the water maker.

[0014] Optionally, the ship main engine high-temperature water recovery system further includes a circulation pipeline, the circulation pipeline is connected to the first preheater, and the circulation pipeline has a flowing medium, and the flowing medium is used to provide heat for the first preheater.

[0015] Optionally, the circulation pipeline is provided with a circulation pump, a water making machine preheater, a first heat exchanger and a second heat exchanger, wherein the first heat exchanger and the second heat exchanger are arranged in parallel.

[0016] Optionally, the water maker preheater is connected to the water maker, and a water inlet is provided on the water maker preheater, and seawater flows into the water maker preheater and the water maker from the water inlet in sequence, and is converted into fresh water in the water maker.

[0017] Optionally, the ship main engine high-temperature water recovery system also includes an exhaust gas economizer, the inlet of the exhaust gas economizer is connected to the exhaust gas outlet of the main engine, and the outlet of the exhaust gas economizer is connected to the first heat exchanger, and the exhaust gas economizer is used to recover heat in the exhaust gas generated by the main engine.

[0018] Optionally, a second stop valve is provided at the inlet of the water maker to control the high-temperature water to flow into the water maker; a third stop valve is provided at the outlet of the water maker to control the high-temperature water to flow out of the water maker.

[0019] Optionally, a third three-way valve is provided at the inlet of the cooler to allow the high-temperature water flowing therethrough to flow to the host and / or the cooler.

[0020] Optionally, the ship main engine high-temperature water recovery system also includes a controller for controlling pipeline connections.

[0021] The high-temperature water recovery system for ship main engines provided by the present invention has at least the following beneficial effects:

[0022] In the high-temperature water recovery system for the main engine of a ship provided by the present invention, the cylinder and the air cooler in the main engine are arranged in parallel, which helps to increase the temperature or flow of the high-temperature water flowing to the water maker, that is, the heat available to the water maker is increased, thereby increasing the fresh water production; secondly, the present invention effectively utilizes the heat in the main engine exhaust gas and the heat in the generator exhaust gas by arranging an exhaust gas economizer, a first heat exchanger and a second heat exchanger in the recovery system, thereby improving the waste heat utilization rate and helping to increase the fresh water production; in addition, adding a main engine preheater between the water maker and the main engine can increase the temperature of the high-temperature water entering the water maker, which can also increase the fresh water production; finally, the present invention realizes a variety of working modes to meet production needs through a unique pipeline design and the use of a controller to adjust the pipeline connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It shows a structural schematic diagram of a high-temperature water recovery system for a ship main engine in the prior art.

[0024] Figure 2 Shown is a structural schematic diagram of a high-temperature water recovery system for a ship main engine provided in an embodiment.

[0025] Figures 3a to 3f Shown is a diagram of the working principles of the ship main engine high-temperature water recovery system under different working modes provided by the embodiment.

[0026] Component number description

[0027] 10 Host 71 Preheating pump

[0028] 11 Cylinder 72 Cooling pump

[0029] 12 Air cooler 81 first stop valve

[0030] 101 Waste liquid outlet 82 Second stop valve

[0031] 102 Waste liquid inlet 83 Third stop valve

[0032] 103 Exhaust gas outlet 90 Circulation pipeline

[0033] 21 First preheater 91 Circulation pump

[0034] 22 Second preheater 92 Water making machine preheater

[0035] 30 Cooler 920 Water maker preheater water inlet

[0036] 40 Water Making Machine 93 First Heat Exchanger

[0037] 50 Temperature sensor 930 First heat exchanger exhaust port

[0038] 61 First three-way valve 94 Second heat exchanger

[0039] 62 Second three-way valve 100 Exhaust gas economizer

[0040] 63 Third three-way valve DETAILED DESCRIPTION

[0041] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0042] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Although the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation, the form, quantity, positional relationship and proportion of each component in actual implementation can be changed at will under the premise of realizing the technical solution of this party, and the component layout form may also be more complicated.

[0043] Example

[0044] This embodiment provides a high-temperature water recovery system for a ship main engine, such as Figure 2 As shown, it includes a main unit 10, a main unit preheater, a cooler 30 and a water maker 40.

[0045] like Figure 2As shown, the main unit 10 has a waste liquid outlet 101, a waste liquid inlet 102 and a waste gas outlet 103. The main unit 10 is provided with a cylinder 11 and an air cooler 12, and the cylinder 11 and the air cooler 12 are arranged in parallel. Such an arrangement can increase the inlet temperature of the main unit's high-temperature water while ensuring that the outlet temperature of the main unit's high-temperature water remains unchanged, thereby increasing the waste heat that can be utilized by the water maker 40. For example, assuming that the heat exchange capacity of the high-temperature water in the host 10 remains unchanged and is fixed at Q, when the cylinder 11 and the air cooler 12 are arranged in series, the inlet temperature of the high-temperature water of the host is about 55°C, and the outlet temperature is about 90°C, then the required water volume F1 in the host 10 = Q / (90°C-55°C) / c, where c is the specific heat of the high-temperature water; however, when the cylinder 11 and the air cooler 12 are arranged in parallel, the inlet temperature of the high-temperature water of the host is about 70°C, and the outlet temperature is still 90°C, then the required water volume F2 in the host 10 = Q / (90°C-70°C) / c = 1.75*F1. It can be seen that the required water volume increases, that is, the amount of water entering the water maker 40 increases, so that the waste heat that can be used by the water maker 40 is amplified by 1.75 times. In another optional embodiment, assuming that the amount of water required in the host 10 remains unchanged, F = Q / (90°C-55°C) / c, where Q is composed of the heat exchange Q1 of the cylinder 11 and the heat exchange Q2 of the air cooler 12. Generally, Q2 = 3Q1. In order to keep the outlet temperature of the high-temperature water of the host 10 unchanged, the amount of water entering the cylinder 11 should be F1 = Q1 / (90°C-70°C) / c, and the amount of water entering the air cooler 12 should be F2 = F-F1 = Q / (90°C-55°C) / c-Q1 / (90°C-70°C) / c = Q2 / 46.7 / c. That is, the temperature of the high-temperature water output by the air cooler 12 is 116.7°C, and after mixing with the high-temperature water output by the cylinder 11, its temperature can reach 105°C. It can be seen that the temperature of the high-temperature water output by the host 10 increases, that is, the temperature of the high-temperature water entering the water maker 40 increases, which greatly improves the quality of the waste heat that can be used by the water maker 40.

[0046] As an example, the host preheater is connected to the waste liquid outlet 101 of the host 10, and the host preheater is used to preheat the high-temperature water output by the host 10, which helps to increase the temperature of the high-temperature water entering the water maker 40, thereby increasing the fresh water production. Figure 2 As shown, the main engine preheater includes a first preheater 21 and a second preheater 22, wherein the first preheater 21 uses the heat in the circulation pipeline 90 to preheat the high-temperature water, thereby reducing the energy consumption of the ship; the second preheater 22 uses electric heating or steam heating to preheat the high-temperature water.

[0047] As an example, the first preheater 21 is connected to the waste liquid outlet 101 of the main unit, and a temperature sensor 50 is further provided between the first preheater 21 and the main unit 10. The temperature sensor 50 is used to detect the temperature of the high-temperature water output by the main unit 10. In this embodiment, the temperature of the high-temperature water output by the main unit 10 is less than or equal to 90°C.

[0048] As an example, the second preheater 22 is arranged in series with the first preheater 21, and a first three-way valve 61 and a preheating pump 71 are provided between the second preheater 22 and the first preheater 21. The first three-way valve 61 is used to allow the high-temperature water output by the first preheater 21 to flow to the cooler 30 and / or the second preheater 22, and the flow rate of the high-temperature water flowing to the cooler 30 and / or the second preheater 22 can be adjusted by adjusting the opening of the first three-way valve 61; the preheating pump 71 is used to allow the high-temperature water output by the first preheater 21 to flow to the second preheater 22. Figure 2 As shown, a second three-way valve 62 is provided at the outlet of the second preheater 22, which is used to allow the high-temperature water output by the second preheater 22 to flow to the main unit 10 and / or the water maker 40, and the flow rate of high-temperature water flowing to the main unit 10 and / or the water maker 40 can be adjusted by adjusting the opening of the second three-way valve 62.

[0049] like Figure 2 As shown, the inlet of the cooler 30 is connected to the first preheater 21, and the outlet of the cooler 30 is connected to the main unit 10. After being cooled in the cooler 30, the high-temperature water flows back to the main unit 10 through the waste liquid inlet 102 of the main unit. As an example, a first stop valve 81 is provided between the first preheater 21 and the cooler 30 to control the opening and closing of the pipeline; a third three-way valve 63 is provided at the inlet of the cooler 30 to allow the high-temperature water flowing through to flow to the main unit 10 and / or the cooler 30, and the flow rate of the high-temperature water flowing to the main unit 10 and / or the cooler 30 can be adjusted by adjusting the opening of the third three-way valve 63; a cooling pump 72 is also provided between the outlet of the cooler 30 and the waste liquid inlet 102 of the main unit to allow the high-temperature water output by the cooler 30 to flow to the main unit 10.

[0050] like Figure 2 As shown, the water generator 40 is disposed between the first preheater 21 and the cooler 30 and is arranged in parallel with the first shut-off valve 81. The water generator 40 is used to produce fresh water. As an example, a second shut-off valve 82 is provided at the inlet of the water generator 40 to control the flow of high-temperature water into the water generator 40; a third shut-off valve 83 is provided at the outlet of the water generator 40 to control the flow of high-temperature water out of the water generator 40.

[0051] like Figure 2As shown, the high-temperature water recovery system for a ship main engine further includes an exhaust gas economizer 100. The inlet of the exhaust gas economizer 100 is connected to the exhaust gas outlet 103 of the main engine, and the outlet of the exhaust gas economizer 100 is connected to the first heat exchanger 93. The exhaust gas economizer 100 is used to recover heat from the exhaust gas generated by the main engine 10. As an example, the exhaust gas economizer 100 also has a fresh water inlet and a steam outlet (not shown in the figure). The exhaust gas generated by the main engine 10 flows into the exhaust gas economizer 100. Fresh water is introduced into the exhaust gas economizer 100 from the fresh water inlet (not shown in the figure) to cool the exhaust gas. The cooled high-temperature water flows to the first heat exchanger 93, and the generated steam is discharged from the steam outlet (not shown in the figure), thereby completing the heat recovery from the exhaust gas generated by the main engine 10.

[0052] like Figure 2 As shown, the high-temperature water recovery system for the main engine of the ship also includes a circulation pipeline 90, which is connected to the first preheater 21 and contains a flowing medium for providing heat to the first preheater 21. The circulation pipeline 90 is provided with a circulation pump 91, a water generator preheater 92, a first heat exchanger 93, and a second heat exchanger 94, wherein the first heat exchanger 93 and the second heat exchanger 94 are arranged in parallel.

[0053] In this embodiment, the first heat exchanger 93 is used to further cool the high-temperature water produced by the exhaust gas economizer 100. The gas in the first heat exchanger 93 is discharged through the exhaust port 930. The second heat exchanger 94 is a generator exhaust heat exchanger, used to cool the exhaust gas produced by the generator (not shown). As an example, after absorbing heat from the first heat exchanger 93 and the second heat exchanger 94, the fluid in the circulation pipeline 90 flows into the first preheater 21, where the first preheater 21 uses this heat to preheat the high-temperature water. The fluid then flows into the water generator preheater 92 under the action of the circulation pump 91.

[0054] In this embodiment, the water generator preheater 92 is connected to the water generator 40 and is provided with a water inlet 920. Seawater flows into the water generator preheater 92 through the water inlet 920, is preheated in the water generator preheater 92, and then flows into the water generator 40. After being converted into fresh water in the water generator 40, it flows out. As an example, the flowing medium flows into the water generator preheater 92 to provide heat for the preheating process, and then flows to the first heat exchanger 93 and the second heat exchanger 94, respectively.

[0055] In this embodiment, the high-temperature water recovery system for the main engine of the ship further includes a controller (not shown in the figure) for controlling the connection of the pipeline. As an example, the controller is connected in communication with the main engine 10 to control the opening or closing of the main engine 10; the controller is connected in communication with the first preheater 21 and the second preheater 22 to control the opening or closing of the first preheater 21 and the second preheater 22; the controller is connected in communication with the water generator 40 to control the opening or closing of the water generator 40; the controller is connected in communication with the temperature sensor 50 and the third three-way valve 63, and the controller adjusts the opening of the third three-way valve 63 according to the temperature of the high-temperature water detected by the temperature sensor 50, thereby controlling the flow rate of the high-temperature water entering the cooler 30; the controller is also connected in communication with the first three-way valve 61 and the second three-way valve 62 to adjust the flow direction and flow rate of the high-temperature water; the controller is connected in communication with the first stop valve 81, the second stop valve 82, and the third stop valve 83 to adjust the opening or closing of the pipeline.

[0056] The high-temperature water recovery system for ship main engines provided in this embodiment has six working modes, which are described in detail as follows:

[0057] 1. Host preheating mode

[0058] In this operating mode, the generator is not running and there is no waste heat available in the second heat exchanger 94. Figure 3a As shown, the controller is used to switch the first three-way valve 61 and the second three-way valve 62 to the AB connection position. At this time, the first preheater 21 is in the shutdown state, and the second preheater 22 is in the working state. The high-temperature water enters the host 10 after being heated by the second preheater 22, and heats the key components such as the cylinder 10 to ensure that the host 10 can be started at any time. In this working mode, the flow direction of the high-temperature water is referenced. Figure 3a Indicated by the arrow in .

[0059] 2. Host energy-saving preheating mode

[0060] In this operating mode, the generator is running and waste heat is available in the second heat exchanger 94. Figure 3b As shown, the controller is used to switch the first three-way valve 61 and the second three-way valve 62 to the AB connection position. At this time, the first preheater 21 is in operation and the second preheater 22 is in shutdown. In addition, the circulation pump 91 is turned on, so that the flowing medium in the circulation pipeline 90 absorbs heat in the second heat exchanger 94 and releases heat in the first preheater 21, which provides heat for the preheating of the high-temperature water in the first preheater 21. After being heated by the first preheater 21, the high-temperature water enters the main unit 10, heating the key components such as the cylinder 10 to ensure that the main unit 10 can be started at any time. In this working mode, the flow direction of the high-temperature water and the flowing medium is referenced. Figure 3b Indicated by the arrow in .

[0061] In addition, when the waste heat in the second heat exchanger 94 is insufficient to ensure preheating of the host 10, the controller starts the second preheater 22 to supplementally heat the high-temperature water to ensure that the host can be started at any time.

[0062] 3. Host cooling mode

[0063] Reference Figure 3c As shown, the controller switches the first three-way valve 61 and the third three-way valve 63 to the AC connection position, and the first stop valve 81 is connected, the second stop valve 82 and the third stop valve 83 are closed, and the first preheater 21 and the second preheater 22 are both in the shutdown state. In this operating mode, the high-temperature water output by the host 10 flows through the first three-way valve 61, the first stop valve 81 and the third three-way valve 63 in sequence before entering the cooler 30. After cooling in the cooler 30, it is transported back to the host 10 via the cooling pump 72, thereby cooling the components in the host 10. The flow direction of the high-temperature water is shown in FIG. Figure 3c In this process, the controller can adjust the opening of the third three-way valve 63 according to the temperature of the high-temperature water detected by the temperature sensor 50, thereby adjusting the amount of water entering the cooler 30.

[0064] 4. Water production mode

[0065] Reference Figure 3d As shown, the controller is used to switch the first three-way valve 61 and the third three-way valve 63 to the AC connection position, and the first stop valve 81 is closed, the second stop valve 82 and the third stop valve 83 are connected, and the first preheater 21 and the second preheater 22 are both in the shutdown state. In this working mode, the high-temperature water output by the main unit 10 flows through the first three-way valve 61 and the second stop valve 82 in sequence into the water maker 40, where it provides heat for the production of fresh water; then, the high-temperature water flows out of the water maker 40, passes through the third three-way valve 63 and enters the cooler 30. After cooling in the cooler 30, it is transported back to the main unit 10 via the cooling pump 72. The flow direction of the high-temperature water is referenced. Figure 3d In this process, the controller can adjust the opening of the third three-way valve 63 according to the temperature of the high-temperature water detected by the temperature sensor 50, thereby adjusting the amount of water entering the cooler 30.

[0066] 5. Efficient water production mode

[0067] Reference Figure 3eAs shown, the controller switches the first three-way valve 61 and the third three-way valve 63 to the AC connection position, and the first stop valve 81 is closed, the second stop valve 82 and the third stop valve 83 are connected, the first preheater 21 is in operation, the second preheater 22 is in shutdown, and the circulation pump 91 is turned on. In this working mode, the high-temperature water output by the host 10 flows through the first three-way valve 61 and the second stop valve 82 in sequence into the water maker 40, where it provides heat for the production of fresh water; then, the high-temperature water flows out of the water maker 40, passes through the third three-way valve 63 and enters the cooler 30. After cooling in the cooler 30, it is transported back to the host 10 via the cooling pump 72. The flow direction of the high-temperature water is as shown in FIG. Figure 3e In addition, the flowing medium in the circulation pipeline 90 absorbs heat in the first heat exchanger 93 and / or the second heat exchanger 94, and releases heat in the first preheater 21, providing heat for the preheating of the high-temperature water in the first preheater 21; then, the flowing medium enters the water making machine preheater 92, providing heat for the preheating of the seawater in the water making machine preheater 92, thereby improving the working efficiency of the water making machine 40. The flow direction of the flowing medium is shown in FIG. Figure 3e Indicated by the arrow in .

[0068] 6. High-efficiency production and water production model

[0069] This working mode is based on the high-efficiency water production mode. The difference from the high-efficiency water production mode is that when the fresh water output of the water generator 40 is lower than the set value in the controller, the controller connects the AB position and the AC position of the first three-way valve 61, and the first preheater 21 and the second preheater 22 are both in working state. Figure 3f As shown, the high-temperature water output by the host 10 is diverted when flowing through the first three-way valve 61. A part of the high-temperature water flows through the AC connection position of the first three-way valve 61 and the second stop valve 82 to enter the water generator 40; the other part of the high-temperature water flows through the AB connection position of the first three-way valve 61, is heated in the second preheater 22, and then enters the water generator 40 through the second three-way valve 62. Therefore, the heat available in the water generator 40 is increased, thereby increasing the fresh water production. The flow direction of the high-temperature water is shown in FIG. Figure 3f In addition, the flow medium in the circulation pipeline 90 absorbs heat in the first heat exchanger 93 and / or the second heat exchanger 94, providing heat for the preheating of the high-temperature water in the first preheater 21 and the preheating of the seawater in the water making machine preheater 92, thereby improving the working efficiency of the water making machine 40. The flow direction of the flow medium is shown in FIG. Figure 3f Indicated by the arrow in .

[0070] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A high-temperature water recovery system for a ship main engine, characterized in that: include: A main engine, wherein the main engine is provided with a cylinder and an air cooler, and the cylinder and the air cooler are arranged in parallel; A main engine preheater is connected to the waste liquid outlet of the main engine and is used to preheat the high-temperature water output by the main engine; wherein the main engine preheater includes: a first preheater connected to the waste liquid outlet of the main unit, and a temperature sensor is provided between the first preheater and the main unit for detecting the temperature of the high-temperature water output by the main unit; a second preheater, arranged in series with the first preheater, and a first three-way valve is provided between the second preheater and the first preheater, for allowing the high-temperature water output by the first preheater to flow to the cooler and / or the second preheater; a cooler, wherein the inlet of the cooler is communicated with the preheater, the outlet of the cooler is communicated with the main engine, and a first shut-off valve is provided between the preheater and the cooler; a water maker, disposed between the preheater and the cooler and connected in parallel with the first stop valve, for producing fresh water; The ship main engine high-temperature water recovery system further includes: a circulation pipeline, the circulation pipeline is connected to the first preheater, and a flow medium is provided in the circulation pipeline, the flow medium is used to provide heat for the first preheater; the circulation pipeline is also provided with a circulation pump, a water generator preheater, a first heat exchanger and a second heat exchanger, wherein the first heat exchanger and the second heat exchanger are arranged in parallel; An exhaust gas economizer, wherein the inlet of the exhaust gas economizer is connected to the exhaust gas outlet of the main engine, and the outlet of the exhaust gas economizer is connected to the first heat exchanger, for recovering heat from the exhaust gas generated by the main engine.

2. The high-temperature water recovery system for a ship main engine according to claim 1, characterized in that: The outlet of the second preheater is provided with a second three-way valve for allowing the high-temperature water outputted by the second preheater to flow to the host machine and / or the water maker.

3. The high-temperature water recovery system for a ship main engine according to claim 1, characterized in that: The water maker preheater is connected to the water maker, and a water inlet is provided on the water maker preheater. Seawater flows into the water maker preheater and the water maker from the water inlet in sequence and is converted into fresh water in the water maker.

4. The high-temperature water recovery system for a ship main engine according to claim 1, characterized in that: The inlet of the water maker is provided with a second stop valve for controlling the high-temperature water to flow into the water maker; the outlet of the water maker is provided with a third stop valve for controlling the high-temperature water to flow out of the water maker.

5. The high-temperature water recovery system for a ship main engine according to claim 1, characterized in that: The inlet of the cooler is provided with a third three-way valve for allowing the high-temperature water flowing therethrough to flow to the host and / or the cooler.

6. The high-temperature water recovery system for a ship main engine according to claim 1, characterized in that: The ship main engine high-temperature water recovery system also includes a controller for controlling pipeline connections.

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