Ballast tank antifreeze system and antifreeze method based on diesel engine cooling seawater pump

Abstract

The present invention provides a ballast tank antifreeze system and antifreeze method based on a diesel engine cooling seawater pump. The ballast tank antifreeze system includes a PLC control system, a central cooler, a main seawater pump, and a diesel engine cooling circuit system. When sailing under low-temperature conditions, in order to prevent the ballast tanks from freezing, the main seawater pump connects the ballast water of each ballast tank to the central cooler and the diesel engine cooling circuit system for heat exchange. On the one hand, it heats up the ballast water to prevent the ballast tanks from freezing, and on the other hand, it can take away the heat of the diesel engine to ensure the continuous and stable operation of the power system; when the seawater temperature does not cause the ballast tanks to freeze, the main seawater pump draws water from the ocean to cool the high-temperature cooling water of the diesel engine cooling circuit system, thereby ensuring the continuous and stable operation of the diesel engine; because the ballast water does not participate in the heat exchange, the ballast water temperature is prevented from being too high and affecting the ballast tank coating life.

Description

Technical Field

[0001] The present invention relates to antifreezing of ballast water tanks, and in particular to a ballast tank antifreezing system and an antifreezing method based on a diesel engine cooling seawater pump. Background Art

[0002] Existing ballast water tank antifreeze measures mostly use compressed air bubbling, ballast water circulation, steam injection, or heating by laying heating coils on the bilge. Directly using the waste heat from the diesel engine to heat the ballast water via a cooling seawater pump to achieve antifreeze is rare. This is mainly because, to ensure the stability requirements of the ship under various operating conditions, a large number of ballast tanks are usually required, ranging from a dozen to twenty or even more. In addition, the pipe resistance from the diesel engine cooling water system to each tank is different. With this method, if a centralized pumping system is used to simplify the system, unless the ballast tanks can be switched one by one at regular intervals, it is impossible to ensure that the water level in each ballast tank remains unchanged during the operation of the system, which will cause changes in the steady state of the ship.

[0003] Reference Figure 1 The figure shows a schematic diagram of the current method of using diesel engines to heat ballast water tanks. This method utilizes diesel engine waste heat, including heat energy generated by the jacket water, air cooler, and lubricating oil cooler, to raise the ballast water temperature. This method is currently considered a relatively energy-efficient and effective ballast tank anti-icing technology. However, most current methods utilize specialized heat exchangers and ballast water circulation pumps. Specifically, each ballast tank 11 is equipped with a heat exchanger 11-1 and a circulation pump 11-2. Low-temperature cooling fresh water from the diesel engine cooling system 20 exchanges heat with the ballast water in each tank through the heat exchanger 11-1. While this method effectively prevents ballast tank ice, the increased number of equipment, including pumps and heat exchangers, complicates layout, significantly increases initial investment and maintenance costs, and poses certain risks to the diesel engine cooling system.

[0004] A drawback of the existing technology is the complex equipment configuration, meaning that each ballast tank must be equipped with at least one ballast water circulation pump and one heater. If the circulation pump or heater in a ballast tank fails, the associated ballast tank antifreeze system must be immediately terminated to ensure that the normal operation of the entire ballast tank antifreeze system and the diesel engine cooling system is not affected. This configuration greatly reduces redundancy, and if dual sets of heaters and circulation pumps are configured for this purpose, the system becomes even more complex and bloated. In addition, the diesel engine's low-temperature fresh water pipeline is too long, which can cause the diesel engine's low-temperature fresh water system to malfunction. Especially when the low-temperature fresh water pump is an engine-driven pump, it is more likely to cause a low-pressure alarm in the cooling water system. Summary of the Invention

[0005] The purpose of this invention is to fully utilize the waste heat of the diesel engine without affecting the normal operation of the diesel engine cooling system, and to achieve energy conservation and emission reduction by using the diesel engine to cool the seawater pump to solve the problem of ballast tank circulation antifreeze. The specific solution is as follows:

[0006] A ballast tank antifreeze system based on a diesel engine cooling seawater pump uses a diesel engine as the ship's power system and the heat source for heating the ballast tank. The ballast tank antifreeze system includes a PLC control system, a central cooler, a main seawater pump, and a diesel engine cooling circuit system.

[0007] Each of the ballast tank water outlets is connected to a ballast main pipe, and each of the several ballast tank water inlets is connected to a ballast tank main water inlet pipe. Each ballast tank is equipped with a temperature sensor and a remote-controlled butterfly valve is provided at the water inlet and outlet.

[0008] A main seawater pump and a central cooler are provided in sequence between the ballast main pipe and the main water inlet pipe of the ballast tank. The main seawater pump is provided with two water inlets connected to the ballast main pipe and the seabed valve box respectively. Two heat exchange channels are provided in the central cooler. The first heat exchange channel is used to connect the main seawater pump and the main water inlet pipe of the ballast tank. The first heat exchange channel is provided with two drainage channels connected to the main water inlet pipe of the ballast tank and the overboard drain port respectively. The second heat exchange channel is connected to the diesel engine cooling circuit system.

[0009] The PLC control system is connected to the temperature sensors and remote-controlled butterfly valves of each ballast tank. The PLC control system opens the remote-controlled butterfly valves at the water inlet and outlet of the ballast tank in sequence. The ballast water enters the central cooler through the ballast main pipe and the main seawater pump. The low-temperature ballast water in the first heat exchange channel exchanges heat with the high-temperature cooling water of the diesel engine in the second heat exchange channel and is transported back to the current ballast tank to prevent the ballast water from freezing.

[0010] Furthermore, the ballast main pipe, the seabed valve box and the main seawater pump are connected through a second tee, and a first stop valve and a second stop valve are respectively provided between the second tee and the ballast main pipe and the seabed valve box.

[0011] Furthermore, the first heat exchange channel, the ballast tank main water inlet pipe, and the overboard drain port are connected through a first tee, and a stop valve and a stop check valve are respectively provided between the first tee and the ballast tank main water inlet pipe and the overboard drain port.

[0012] Furthermore, pressure gauge valves are provided at the inlet and outlet ends of the first heat exchange channel and the second heat exchange channel.

[0013] Further, the ballast main is connected to the ballast water pump;

[0014] The main seawater pump consists of multiple seawater cooling pumps connected in parallel.

[0015] Furthermore, the water outlet of the main seawater pump is provided with a pressure switch connected to the PLC control system; the diesel engine cooling circuit system is provided with a temperature control valve connected to the PLC control system.

[0016] Furthermore, the ballast tank antifreeze system also includes antifreeze facilities such as compressed air bubbling, steam injection or laying heating coils on the bottom of the tank.

[0017] A ballast tank antifreeze method based on the above ballast tank antifreeze system has two modes:

[0018] 1) If the overboard water temperature or the surrounding atmospheric temperature is too low, causing the ballast water in the ballast tank to freeze, the seabed valve box and the overboard drain outlet are closed, and the PLC control system opens the remote-controlled butterfly valves of the inlet and outlet of each ballast tank in sequence. The ballast water flows through the ballast main pipe and the main seawater pump to the first heat exchange channel of the central cooler. After the low-temperature ballast water in the first heat exchange channel exchanges heat with the high-temperature cooling water in the second heat exchange channel, it is transported back to the current ballast tank through the ballast tank main inlet pipe;

[0019] 2) If the overboard water temperature or the ambient atmospheric temperature does not cause the ballast water in the ballast tank to freeze, the main seawater pump is disconnected from the ballast main pipe and the main water inlet pipe of the ballast tank. The main seawater pump draws water from the seabed valve box and transports it to the central cooler. The seawater in the first heat exchange channel exchanges heat with the high-temperature cooling water in the second heat exchange channel and is discharged from the overboard drain outlet.

[0020] The advantages of the present invention are:

[0021] 1) When sailing in low-temperature conditions, to prevent ballast tanks from freezing, the main seawater pump connects the ballast water from each ballast tank to the central cooler and the diesel engine cooling circuit system for heat exchange. This not only heats up the ballast water to prevent ballast tanks from freezing, but also removes heat from the diesel engine to ensure continuous and stable operation of the power system.

[0022] 2) When the seawater temperature or the surrounding atmospheric temperature does not cause the ballast tank to freeze, the main seawater pump draws water from the ocean to cool the high-temperature cooling water in the diesel engine cooling circuit system, thereby ensuring the continuous and stable operation of the diesel engine; because the ballast water does not participate in heat exchange, the ballast water temperature is prevented from being too high and affecting the service life of the ballast tank coating.

[0023] 3) The ballast tank temperature sensor, remote-controlled butterfly valve, pressure switch at the main seawater pump outlet, and temperature control valve of the diesel engine cooling circuit system are all connected to the PLC control system. They can automatically heat up the low-temperature ballast water and transfer seawater to cool the diesel engine cooling circuit system without manual intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a schematic diagram of the prior art using a diesel engine to heat a ballast water tank;

[0026] Figure 2 This is a schematic diagram of a ballast tank antifreeze system based on a diesel engine cooling seawater pump provided by the present invention;

[0027] Figure 3 for Figure 2 A local map of

[0028] Figure 4 It is the workflow diagram of the present invention. DETAILED DESCRIPTION

[0029] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0030] In order to fully understand the present invention, detailed steps and detailed structures will be presented in the following description to illustrate the technical solution of the present invention. Preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0031] Reference Figure 2-3 As shown, the present invention provides a ballast tank antifreeze system based on a diesel engine cooling seawater pump, which uses a diesel engine as a ship power system and a heat source for heating the ballast tank 11. The ballast tank antifreeze system includes a PLC control system 100, a central cooler 200, a main seawater pump 400, and a diesel engine cooling circuit system 300.

[0032] Each ballast tank outlet is connected to a ballast main pipe 1, and each of the several ballast tanks 11 has its inlet connected to a ballast tank main water inlet pipe 2. Each ballast tank 11 is equipped with a temperature sensor 4 and a remote-controlled butterfly valve 5 at both the inlet and outlet. A main seawater pump 400 and a central cooler 200 are located between the ballast main pipe 1 and the ballast tank main water inlet pipe 2, in the direction of water flow. The main seawater pump 400 has two water inlets, connected to the ballast main pipe 1 and the subsea valve chest 401, respectively. The central cooler 200 has two heat exchange channels. The first heat exchange channel 210 connects the main seawater pump 400 and the ballast tank main water inlet pipe 2. The first heat exchange channel 210 has two drains, connected to the ballast tank main water inlet pipe 2 and the overboard drain port 7, respectively. The second heat exchange channel 220 is connected to the diesel engine cooling circuit system 300. The PLC control system 100 is connected to the temperature sensor 4 and the remote-controlled butterfly valve 5 of each ballast tank. The PLC control system 100 opens the remote-controlled butterfly valve 5 at the water inlet and outlet of the ballast tank 11 in sequence. The ballast water enters the central cooler 200 through the ballast main pipe 1 and the main seawater pump 400. The low-temperature ballast water in the first heat exchange channel 210 exchanges heat with the high-temperature diesel engine cooling water in the second heat exchange channel 220 and is transported back to the current ballast tank 11 to prevent the ballast water from freezing.

[0033] The ballast tank antifreeze system based on the diesel engine cooling seawater pump provided by the present invention has two water inlets each of the main seawater pump 400 and the first heat exchange channel 210 of the central cooler 200. The corresponding water inlets of the main seawater pump 400 and the central cooler 200 are selectively opened according to the operating conditions of the ship, and the diesel engine cooling circuit system 300 is used to heat the ballast water in each ballast tank (under low temperature conditions), or seawater is taken to cool the high-temperature cooling water of the diesel engine cooling circuit system 300, thereby ensuring the continuous and stable operation of the diesel engine.

[0034] In an optional embodiment, the ballast main pipe 1, the seabed valve box 401 and the main seawater pump 400 are connected through the second tee 10, and a first stop valve 12 and a second stop valve 13 are respectively provided between the second tee 10 and the ballast main pipe 1 and the seabed valve box 401. Figure 2 See further Figure 3 The first heat exchange channel 210, the ballast tank main water inlet pipe 2, and the overboard drain port 7 are connected through the first tee 6, and a stop valve 8 and a stop check valve 9 are respectively provided between the first tee 6 and the ballast tank main water inlet pipe 2 and the overboard drain port 7.

[0035] By opening the first stop valve 12 and closing the second stop valve 13, and by opening the stop valve 8 and closing the stop check valve 9, the main seawater pump 400 draws water from each ballast tank, using the diesel engine cooling circuit system 300 to heat the ballast water in each ballast tank. By closing the first stop valve 12 and opening the second stop valve 13, and by closing the stop valve 8 and opening the stop check valve 9, the main seawater pump 400 draws water from the ocean and sends it to the central cooler 200, where it exchanges heat with the high-temperature cooling water in the diesel engine cooling circuit system 300 to cool the diesel engine. The heat-exchanged seawater is then directly discharged overboard.

[0036] In an optional embodiment, the ballast main pipe 1 is connected to the ballast water pump 3 , and the main seawater pump 400 is composed of a plurality of seawater cooling pumps 420 connected in parallel.

[0037] In an optional embodiment, pressure gauge valves 211 are provided at the inlet and outlet ends of the first heat exchange channel 210 and the second heat exchange channel 220 .

[0038] A pressure switch 410 is provided at the water outlet of the main seawater pump 400 , and a temperature control valve 310 is provided in the diesel engine cooling circuit system 300 . Both the pressure switch 410 and the temperature control valve 310 are connected to the PLC control system 100 .

[0039] In an optional embodiment, the ballast tank antifreeze system further includes antifreeze facilities including compressed air bubbling, steam injection or heating coils laid on the tank bottom.

[0040] A ballast tank antifreeze method based on the above ballast tank antifreeze system has two working modes:

[0041] Mode 1: If the overboard water temperature or the surrounding atmospheric temperature is too low, causing the ballast water in the ballast tank 11 to be about to freeze, the seabed valve box 401 and the overboard drain port 7 are closed, and the PLC control system 100 opens the remote-controlled butterfly valve 5 at the water inlet and outlet of each ballast tank 11 in turn. The ballast water flows through the ballast main pipe 1 and the main seawater pump 400 to the first heat exchange channel 210 of the central cooler 200. After the low-temperature ballast water in the first heat exchange channel 210 exchanges heat with the high-temperature cooling water in the second heat exchange channel 220, it is transported back to the current ballast tank 11 through the ballast tank main water inlet pipe 2.

[0042] Mode 2: If the overboard water temperature or the ambient atmospheric temperature does not cause the ballast water in the ballast tank 11 to freeze, close the first stop valve 12 connected to the ballast main pipe 1 and the stop valve 8 connected to the ballast tank main water inlet pipe 2, and then disconnect the main seawater pump 400 from the ballast main pipe 1 and the ballast tank main water inlet pipe 2. At this time, the main seawater pump 400 draws water from the seabed valve box 401 and transports it to the central cooler 200. The seawater in the first heat exchange channel 210 exchanges heat with the high-temperature cooling water in the second heat exchange channel 220 and is discharged from the overboard drain 7.

[0043] In summary, the present invention is based on a ballast tank antifreeze system of a diesel engine cooling seawater pump, and connects the diesel engine cooling circuit system 300 to the ballast tank, which can partially utilize the ship's ballast pipelines and even remote control valves. Since the ballast system pipe diameter and displacement are usually larger than the diesel engine cooling circuit system 300 (i.e., the main seawater cooling system), and when the ballast tank circulation heating system is working, the general ballast system will not work. However, the general ballast system and the main seawater cooling system are not compatible, so the ballast tank circulation heating cannot completely borrow the ballast pump and ballast system. By opening the first stop valve 12 and the stop valve 8, the cooling seawater originally taken from the seabed valve box 401 can be taken from the ballast tank 11, and the cooling seawater originally prepared to be discharged overboard after being heated by the central cooler 200 can be diverted and discharged back to the original ballast tank 11.

[0044] By controlling the opening / closing of the inlet and outlet remote control valves 5 of each ballast tank 11 requiring heating through the remote control valves 5 and ballast tank temperature sensors 4 in each ballast tank 11, and through the PLC control system 100, the ballast tanks requiring antifreeze protection are sequentially connected to the diesel engine cooling circuit system 300. The final heating temperature of the ballast tanks can be preset, for example, to +3°C. This temperature can be determined based on the total number and quantity of ballast tanks requiring heating, but cannot exceed the design upper limit of the main seawater cooling system (typically +32°C). Automatic switching between ballast tanks requiring antifreeze is achieved by heating the water temperature of each ballast tank to a specified temperature, or by controlling the heat exchange between the ballast water in each ballast tank and the diesel engine cooling circuit system 300 for a specified period of time.

[0045] A pressure switch 410 is installed at the outlet of the main seawater pump 400 to control the automatic start and stop of the cooling seawater backup circulation pump. This ensures that seawater cooling and ballast tank heating are effectively integrated into a single system. Simultaneously, by switching the water source valves (i.e., the first stop valve 12 and the second stop valve 13), the main seawater pump can also perform a partial ballasting function, effectively reducing the total displacement of the dedicated ballast pump and truly achieving energy conservation and emission reduction.

[0046] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-mentioned disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention that do not depart from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. A ballast tank antifreeze system based on a diesel engine cooling seawater pump, using a diesel engine as a ship power system and a heat source for heating the ballast tank (11), characterized in that: The ballast tank antifreeze system includes a PLC control system (100), a central cooler (200), a main seawater pump (400), and a diesel engine cooling circuit system (300); Each ballast tank outlet is connected to a ballast main pipe (1), and each ballast tank (11) inlet is connected to a ballast tank main inlet pipe (2). Each ballast tank (11) is equipped with a temperature sensor (4) and a remote-controlled butterfly valve (5) is provided at the inlet and outlet. A main seawater pump (400) and a central cooler (200) are sequentially arranged between the ballast main pipe (1) and the ballast tank main water inlet pipe (2). The main seawater pump (400) is provided with two water inlet routes respectively connected to the ballast main pipe (1) and the seabed valve box (401). Two heat exchange channels are provided in the central cooler (200). The first heat exchange channel (210) is provided with two drainage routes respectively connected to the ballast tank main water inlet pipe (2) and the overboard drain port (7). The second heat exchange channel (220) is connected to the diesel engine cooling circuit system (300). The PLC control system (100) is connected to the temperature sensor (4) and the remote-controlled butterfly valve (5) of each ballast tank. The PLC control system (100) sequentially opens the remote-controlled butterfly valves (5) at the water inlet and outlet of the ballast tank (11). The ballast water enters the central cooler (200) through the ballast main pipe (1) and the main seawater pump (400). The low-temperature ballast water in the first heat exchange channel (210) exchanges heat with the high-temperature cooling water of the diesel engine in the second heat exchange channel (220) and is transported back to the current ballast tank (11), thereby preventing the ballast water from freezing.

2. The ballast tank antifreeze system based on a diesel engine cooling seawater pump as claimed in claim 1, characterized in that: The ballast main pipe (1), the seabed valve box (401) and the main seawater pump (400) are connected via a second tee (10), and a first stop valve (12) and a second stop valve (13) are respectively provided between the second tee (10), the ballast main pipe (1) and the seabed valve box (401).

3. The ballast tank antifreeze system based on a diesel engine cooling seawater pump as claimed in claim 1, characterized in that: The first heat exchange channel (210), the ballast tank main water inlet pipe (2), and the overboard drain port (7) are connected via a first tee (6), and a stop valve (8) and a stop check valve (9) are respectively provided between the first tee (6), the ballast tank main water inlet pipe (2), and the overboard drain port (7).

4. The ballast tank antifreeze system based on a diesel engine cooling seawater pump as claimed in claim 2, characterized in that: Pressure gauge valves (211) are provided at the inlet and outlet ends of the first heat exchange channel (210) and the second heat exchange channel (220).

5. The ballast tank antifreeze system based on a diesel engine cooling seawater pump as claimed in claim 1, characterized in that: The ballast main pipe (1) is connected to the ballast water pump (3); The main seawater pump (400) is composed of a plurality of seawater cooling pumps (420) connected in parallel.

6. The ballast tank antifreeze system based on a diesel engine cooling seawater pump as claimed in claim 1, characterized in that: The water outlet of the main seawater pump (400) is provided with a pressure switch (410) connected to the PLC control system (100); The diesel engine cooling circuit system (300) is provided with a temperature control valve (310) connected to a PLC control system (100).

7. The ballast tank antifreeze system based on a diesel engine cooling seawater pump as claimed in claim 1, characterized in that: The ballast tank antifreeze system also includes antifreeze facilities such as compressed air bubbling, steam injection or laying heating coils on the bottom of the tank.

8. A ballast tank antifreezing method based on the ballast tank antifreezing system according to any one of claims 1 to 7, characterized in that: If the overboard water temperature or the ambient atmospheric temperature is too low and the ballast water in the ballast tank (11) is about to freeze, the seabed valve box (401) and the overboard drain outlet (7) are closed, and the PLC control system (100) opens the remote-controlled butterfly valves (5) of the inlet and outlet of each ballast tank (11) in sequence, and the ballast water flows through the ballast main pipe (1) and the main seawater pump (400) to the first heat exchange channel (210) of the central cooler (200). After the low-temperature ballast water in the first heat exchange channel (210) exchanges heat with the high-temperature cooling water in the second heat exchange channel (220), the ballast water is transported back to the current ballast tank (11) through the ballast tank main water inlet pipe (2); If the overboard water temperature or the ambient atmospheric temperature does not cause the ballast water in the ballast tank (11) to freeze, the main seawater pump (400) is disconnected from the ballast main pipe (1) and the ballast tank main water inlet pipe (2), and the main seawater pump (400) draws water from the seabed valve box (401) and transports it to the central cooler (200). The seawater in the first heat exchange channel (210) exchanges heat with the high-temperature cooling water in the second heat exchange channel (220) and is discharged from the overboard drain port (7).

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