Coolant control device and method of marine internal combustion engine

Abstract

To provide a coolant control device of a marine internal combustion engine which can properly control a jacket coolant in a cooling system of a marine internal combustion engine.SOLUTION: A coolant control device 1 of a marine internal combustion engine controls a jacket coolant of a cooling system 50 including a cooler 53 and a waste-heat utilization device 54 at a coolant circulation path 52 of a marine internal combustion engine 51. The coolant control device 1 includes: temperature detection means 2a, 2b which detect a temperature of the jacket coolant passing through the marine internal combustion engine 51; first bypass means 3 which adjusts a bypass flow rate of the jacket coolant which bypasses the coolant 53; second bypass means 4 which adjusts a bypass flow rate of the jacket coolant which bypasses the waste-heat utilization device 54; and control means 10 which controls operations of the first bypass means 3 and the second bypass means 4 based on detection of the temperature detection means 2a, 2b.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cooling water control device and method for a marine internal combustion engine.

Background Art

[0002] In a cooling water circulation path for cooling an internal combustion engine such as a marine diesel engine, in addition to a cooler for cooling jacket cooling water, waste heat utilization devices such as a water maker that utilizes the waste heat of the internal combustion engine are generally provided. A crew member of the ship adjusts the flow rate to the water maker or the like while observing the temperature of the jacket cooling water.

[0003] However, in recent years, due to manning reduction in the engine room and deterioration of crew skills, misoperations such as the flow rate adjustment to the water maker not being successful or the required amount of water production not being obtained have increased. Therefore, the need for automating the control of jacket cooling water has been increasing.

[0004] As a device for automating the control of jacket cooling water in a cooling system of an internal combustion engine, for example, a waste heat recovery and utilization system disclosed in Patent Document 1 is known. As shown in FIG. 4, the waste heat recovery and utilization system 100 includes, in addition to a jacket cooler 103, a power generation means 104 that recovers heat from jacket cooling water and generates electricity, and a water making means 105 that recovers heat from jacket cooling water and produces water, in a jacket cooling water circulation path 102 that circulates jacket cooling water of a diesel engine 101.

[0005] In this waste heat recovery and utilization system 100, the temperature of the jacket cooling water before being supplied to the diesel engine 101 is measured by a first temperature measuring means 106. When this measured temperature is lower than the set temperature, the jacket cooling water passes through a bypass passage 108 by driving control of a first three-way valve 107. Further, the temperature of the jacket cooling water after heat recovery by the power generation means 104 is measured by a second temperature measuring means 109, and the amount of recovered heat from the jacket cooling water by the power generation means 104 is adjusted by opening and closing control of an on-off valve 110 based on this measured temperature.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the above exhaust heat recovery and utilization system 100, the control for bypassing the jacket cooling water to the jacket cooler 103 and the power generation means 104 is both performed based on the measured temperature of the jacket cooling water. However, the first temperature measuring means 106 and the second temperature measuring means 109 for measuring each of them measure the temperature of the jacket cooling water flowing through different devices (that is, the diesel engine 101 and the power generation means 104). Therefore, when the load of the diesel engine 101 fluctuates, etc., it may be difficult to maintain the temperature of the jacket cooling water supplied to the diesel engine 101 within a desired range.

[0008] Therefore, an object of the present invention is to provide a cooling water control device and method for a marine internal combustion engine that can accurately control the jacket cooling water in the cooling system of the marine internal combustion engine.

Means for Solving the Problems

[0009] The object of the present invention is an apparatus for controlling the jacket cooling water of a cooling system provided with a cooler and waste heat utilization equipment in a cooling water circulation path of a marine internal combustion engine, the apparatus comprising: temperature detection means for detecting the temperature of the jacket cooling water passing through the marine internal combustion engine; first bypass means for adjusting a bypass flow rate for bypassing the cooler; second bypass means for adjusting a bypass flow rate for bypassing the waste heat utilization equipment; and control means for controlling the operation of the first bypass means and the second bypass means based on the detection by the temperature detection means. A plurality of the waste heat utilization equipment are provided, the second bypass means is provided for each of the waste heat utilization equipment, and the control means individually controls the operation of the second bypass means based on a preset priority order for the plurality of waste heat utilization equipment, which is achieved by a cooling water control apparatus for a marine internal combustion engine.

[0010] In this cooling water control apparatus for a marine internal combustion engine, the temperature detection means can be arranged to detect the temperature of the jacket cooling water before being supplied to the marine internal combustion engine, and the control means can control the operation of the first bypass means and the second bypass means so that the detected temperature by the temperature detection means falls within a preset temperature range.

[0011] The apparatus may further comprise heating means for heating the jacket cooling water flowing through the cooling water circulation path, and the control means can control the operation of the heating means based on the detection by the temperature detection means.

[0012] At least one of the waste heat utilization equipment can be a water maker for producing fresh water by evaporating seawater using the jacket cooling water as a heat source.

[0013] Moreover, the object of the present invention is a method for controlling jacket cooling water of a cooling system provided with a cooler and waste heat utilization equipment in a cooling water circulation path of a marine internal combustion engine, the cooling system comprising temperature detection means for detecting the temperature of the jacket cooling water passing through the marine internal combustion engine, first bypass means for adjusting a bypass flow rate for bypassing the cooler, second bypass means for adjusting a bypass flow rate for bypassing the waste heat utilization equipment, and control means for controlling the operation of the first bypass means and the second bypass means based on the detection of the temperature detection means. A plurality of the waste heat utilization equipment are provided, the second bypass means is provided for each of the waste heat utilization equipment, and the control means controls the operation of the first bypass means and the second bypass means based on the detection of the temperature detection means, and individually controls the operation of the second bypass means based on a preset priority order for the plurality of waste heat utilization equipment. This is achieved by a method for controlling the cooling water of a marine internal combustion engine.

Advantages of the Invention

[0014] According to the present invention, it is possible to provide a cooling water control device and method for a marine internal combustion engine that can accurately control the jacket cooling water in the cooling system of the marine internal combustion engine.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a cooling water control device for a marine internal combustion engine according to an embodiment of the present invention. The cooling water control device (hereinafter simply referred to as "cooling water control device") 1 of the marine internal combustion engine shown in FIG. 1 controls the jacket cooling water flowing through the cooling water circulation path 52 in a cooling system 50 provided with a cooler 53 and a waste heat utilization device 54 in the cooling water circulation path 52 of a marine internal combustion engine 51 such as a diesel engine which is the main engine of a ship.

[0017] The waste heat utilization device 54 is, for example, a water maker, and produces fresh water by evaporating seawater using the jacket cooling water as a heat source. The waste heat utilization device 54 is not particularly limited as long as it is a device that recovers and utilizes the waste heat of the jacket cooling water, and examples other than the water maker can include a heating device, a power generation device, a hot water supply device, a power recovery device, and the like.

[0018] The cooling water control device 1 includes two temperature detection units 2a, 2b that detect the temperature of the jacket cooling water passing through the marine internal combustion engine 51, a first bypass unit 3 that adjusts the bypass flow rate for bypassing the cooler 53, a second bypass unit 4 that adjusts the bypass flow rate for bypassing the waste heat utilization device 54, and a control unit 10 that controls the operation of the first bypass unit 3 and the second bypass unit 4.

[0019] The two temperature detection units 2a, 2b are, for example, temperature sensors. One temperature detection unit 2a is arranged to detect the temperature of the jacket cooling water before being supplied to the marine internal combustion engine 51, and the other temperature detection unit 2b is arranged to detect the temperature of the jacket cooling water after being supplied to the marine internal combustion engine 51.

[0020] The first bypass unit 3 includes a bypass flow path 3a for bypassing the cooler 53 and a three-way valve 3b for switching the flow path of the jacket cooling water flowing from the cooling water circulation path 52 toward the cooler 53 to the bypass flow path 3a. By adjusting the opening degree of the three-way valve 3b, the flow rate of the jacket cooling water flowing through the bypass flow path 3a can be adjusted.

[0021] The second bypass section 4 includes a bypass flow path 4a that bypasses the waste heat utilization device 54, and a three-way valve 4b that switches the flow path of the jacket cooling water flowing toward the waste heat utilization device 54 in the cooling water circulation path 52 to the bypass flow path 4a. By adjusting the opening degree of the three-way valve 4b, the flow rate of the jacket cooling water flowing through the bypass flow path 4a can be adjusted.

[0022] Further, the second bypass section 4 includes an auxiliary bypass flow path 4c, a flow rate adjustment valve 4d that adjusts the opening degree of the auxiliary bypass flow path 4c, and flow rate adjustment valves 4e and 4f respectively provided on the inlet side and the outlet side of the waste heat utilization device 54 between the waste heat utilization device 54 and the auxiliary bypass flow path 4c, for manually adjusting the bypass flow rate of the waste heat utilization device 54.

[0023] Based on the detections of the temperature detection sections 2a and 2b, the control section 10 adjusts the opening degrees of the three-way valve 3b of the first bypass section 3 and the three-way valve 4b of the second bypass section 4, and automatically controls the bypass flow rates of the cooler 53 and the waste heat utilization device 54.

[0024] Next, the operation of the cooling water control device 1 having the above configuration will be described. During the operation of the cooling system 50, the control section 10 controls the opening degree of the three-way valve 3b of the first bypass section 3 so that the outlet temperature of the marine internal combustion engine 51 detected by the temperature detection section 2b becomes the preset outlet set temperature Tout. Further, the control section 10 compares the inlet temperature Tin of the marine internal combustion engine 51 detected by the temperature detection section 2a with a lower limit value TinL (e.g., 72°C) and an upper limit value TinH (e.g., 78°C) of a preset inlet set temperature, and performs the following control. In the initial state, the flow rate adjustment valve 4d is fully closed, and the flow rate adjustment valves 4e and 4f are fully open.

[0025] When the inlet temperature Tin is lower than the lower limit value TinL of the inlet set temperature (Case 1: TinL > Tin), the control section 10 controls the three-way valve 4b of the second bypass section 4 so as to bypass all of the jacket cooling water to the waste heat utilization device 54 (that is, so that the jacket cooling water does not flow to the waste heat utilization device 54).

[0026] When the inlet temperature Tin is equal to or higher than the lower limit value TinL of the inlet set temperature and lower than the upper limit value TinH (Case 2: TinL ≤ Tin < TinH), the control unit 10 controls the three-way valve 4b of the second bypass unit 4 so that the entire amount of the jacket cooling water is supplied to the waste heat utilization device 54 (that is, the jacket cooling water does not flow through the bypass flow path 4a). Thereby, the flow rate of the jacket cooling water supplied to the waste heat utilization device 54 can be adjusted by manually adjusting the opening degrees of the flow rate adjustment valves 4d, 4e, and 4f.

[0027] In the above Case 2, the control unit 10 can also automatically adjust the flow rate of the jacket cooling water supplied to the waste heat utilization device 54 by adjusting the opening degree of the three-way valve 4. In this case, it is a condition that the inlet temperature Tin does not become lower than the lower limit value TinL of the inlet set temperature.

[0028] During normal operation, the inlet temperature Tin is lower than the upper limit value TinH of the inlet set temperature. However, for example, when the jacket cooling water is bypassed by controlling the second bypass unit 4 from a state where heat recovery is performed by supplying it to the waste heat utilization device 54, the cooling of the jacket cooling water by the cooler 53 may not catch up, and the inlet temperature Tin may become equal to or higher than the upper limit value TinH of the inlet set temperature (Case 3: Tin ≥ TinH). In this case, the control unit 10 supplies the jacket cooling water in the bypass state to the waste heat utilization device 54 again by controlling the second bypass unit 4. When the time change of the inlet temperature Tin rapidly rises beyond the set value when the supply of the jacket cooling water to the waste heat utilization device 54 is switched to bypass, the control unit 10 may control to supply the jacket cooling water to the waste heat utilization device 54 again even if the inlet temperature Tin has not reached the upper limit value TinH.

[0029] As described above, the cooling water control device 1 of the present embodiment is configured to automatically control the bypass flow rate that bypasses the cooler 53 and the waste heat utilization device 54 by controlling the operations of the first bypass section 3 and the second bypass section 4 based on the detection of the temperature of the jacket cooling water passing through the marine internal combustion engine 51. Thereby, while giving priority to properly maintaining the temperature of the marine internal combustion engine 51, the waste heat of the jacket cooling water can be efficiently utilized in the waste heat utilization device 54.

[0030] The cooling water control device 1 shown in FIG. 1 detects the temperature of the jacket cooling water passing through the marine internal combustion engine 51 by two temperature detection units 2a and 2b respectively arranged at the inlet and outlet of the marine internal combustion engine 51. Thereby, the output fluctuation of the marine internal combustion engine 51 can be measured in real time by the temperature detection unit 2b, and load following control can be easily performed. However, as shown in FIG. 2, it is also possible to control the operations of the first bypass section 3 and the second bypass section 4 only by the detection of the temperature detection unit 2a arranged at the inlet of the marine internal combustion engine 51. Thereby, the control is easy at low cost, and a simple configuration with a low failure rate can be achieved. In FIG. 2, the same reference numerals are assigned to the same components as in FIG. 1.

[0031] Similar to the cooling water control device 1 shown in FIG. 1, the cooling water control device 1'shown in FIG. 2 has the control unit 10 compare the inlet temperature Tin of the marine internal combustion engine 51 detected by the temperature detection unit 2a with a preset lower limit value TinL (e.g., 72 °C) and upper limit value TinH (e.g., 78 °C) for the inlet set temperature, and perform the same control as above.

[0032] On the other hand, unlike the control unit 10 of the cooling water control device 1' shown in FIG. 1, the control unit 10 of the cooling water control device 1' controls the opening degree of the three-way valve 3b of the first bypass section 3 so that the inlet temperature Tin becomes a preset temperature Tinset (e.g., 75°C) between the lower limit value TinL and the upper limit value TinH of the inlet set temperature. The temperature detection of the jacket cooling water passing through the marine internal combustion engine 51 can also be performed only by the temperature detection unit 2b disposed at the outlet of the marine internal combustion engine 51, and the control unit 10 can control the operations of the first bypass section 3 and the second bypass section 4 based on the detected temperature of the temperature detection unit 2b.

[0033] The cooling system 50 shown in FIGS. 1 and 2 has a configuration in which one waste heat utilization device 54 is provided in the cooling water circulation path 52. However, as shown in FIG. 3, the present invention can also be applied to a cooling system 50 including a plurality of waste heat utilization devices 54 and 55 in the cooling water circulation path 52 by providing second bypass sections 4 and 5 for each of the waste heat utilization devices 54 and 55, respectively.

[0034] Similar to the cooling water control device 1' shown in FIG. 2, the control unit 10 of the cooling water control device 1'' shown in FIG. 3 controls the opening degree of the three-way valve 3b of the first bypass section 3 so that the inlet temperature of the marine internal combustion engine 51 detected by the temperature detection unit 2a becomes a preset temperature. The control of the first bypass section 3 may be performed based on the outlet temperature of the marine internal combustion engine 51 detected by the temperature detection unit 2b, similar to the cooling water control device 1 shown in FIG. 1. Thus, even when a plurality of waste heat utilization devices 54 and 55 are provided, the marine internal combustion engine 51 by the cooler 53 has the highest priority, and the control of the first bypass section 3 is performed independently of the bypass control of the waste heat utilization devices 54 and 55.

[0035] The bypass control of the second bypass parts 4 and 5 for the respective waste heat utilization devices 54 and 55 is basically performed by the same control as the cooling water control device 1 shown in FIG. 1. However, when the temperature of the jacket cooling water supplied to the marine internal combustion engine 51 is higher than the set lower limit value and the jacket cooling water can be supplied to the waste heat utilization devices 54 and 55, based on the preset priority order for each of the waste heat utilization devices 54 and 55, the second bypass parts 4 and 5 are individually bypass-controlled. For example, when the priority of the waste heat utilization device 54 composed of a water maker is higher than the priority of the waste heat utilization device 55 composed of a heating device, the supply of the jacket cooling water to the waste heat utilization device 54 is preferentially performed. When there is a surplus in the amount of heat of the jacket cooling water, the jacket cooling water is also supplied to the waste heat utilization device 55 together with the waste heat utilization device 54. In this way, the waste heat of the jacket cooling water can be efficiently distributed according to the priority order of each of the waste heat utilization devices 54 and 55.

[0036] When there is a possibility that the amount of heat of the jacket cooling water may temporarily be insufficient by providing a plurality of waste heat utilization devices 54 and 55, as shown in FIG. 3, a heating part 20 for heating the jacket cooling water flowing through the cooling water circulation path 52 may be provided. The heating part 20 is configured such that the jacket cooling water is heated by heat exchange between steam and the jacket cooling water, and the opening and closing of the steam valve 21 are controlled by the control part 10. When the amount of heat of the jacket cooling water becomes insufficient during the supply of the jacket cooling water to both of the waste heat utilization devices 54 and 55, the control part 10 can continue to supply the jacket cooling water to the waste heat utilization devices 54 and 55 by operating the heating part 20 instead of performing bypass control on one of the waste heat utilization devices 55.

[0037] As described above, by providing the heating part 20 for heating the jacket cooling water, the control part 10 can more flexibly perform the operation control of the second bypass parts 4 and 5 while considering the balance between the heat input and output of the jacket cooling water and also considering the priority order of each of the waste heat utilization devices 54 and 55.

[0038] Temperature detectors 4g and 4h are respectively arranged at the inlet and outlet of the waste heat utilization device 54, and temperature detectors 5c and 5d are respectively arranged at the inlet and outlet of the waste heat utilization device 55. For the cooler 53 and the heater 20, temperature detectors 3c and 3d are respectively arranged at the inlet and outlet of the cooler 53, and temperature detectors 6a and 6b are respectively arranged at the inlet and outlet of the heater 20. Detection signals of the respective temperature detectors 3c, 3d, 4g, 4h, 5c, 5d, 6a, and 6b are input to the control unit 10 in the same manner as the detection signals of the temperature detectors 2a and 2b corresponding to the marine internal combustion engine 51.

[0039] Regarding the heat balance of the jacket cooling water, assuming that the heat input amounts in the marine internal combustion engine 51 and the heating unit 20 are Qme and Qd, the heat output amounts in the cooler 53 and the waste heat utilization devices 54 and 55 are Qa, Qb, and Qc, and the heat loss is Qloss, it is expressed as Qme + Qd = Qa + Qb + Qc + Qloss. Since the heat input amounts Qme and Qd and the heat output amounts Qa, Qb, and Qc are proportional to the temperature differences between the inlet temperature and the outlet temperature of the jacket cooling water passing through them respectively, the control unit 10 can control the heat balance of the jacket cooling water based on the detected temperatures of the temperature detectors 2a, 2b, 3c, 3d, 4g, 4h, 5c, 5d, 6a, and 6b.

[0040] As a specific example, the heat output of the waste heat utilization device 54 can be controlled in three stages of QbH, QbM, and QbL, and the heat output of the waste heat utilization device 55 can be controlled in three stages of QcH, QcM, and QcL. It is assumed that the waste heat utilization device 55 has a lower priority than the waste heat utilization device 54, but at least the heat output of QcM needs to be ensured. The control unit 10 calculates the ratio of the heat outputs Qb and Qc of the waste heat utilization devices 54 and 55 based on the temperature difference detected by the two temperature detection units 4g and 4h of the waste heat utilization device 54 and the temperature difference detected by the two temperature detection units 5c and 5d of the waste heat utilization device 55, and controls the bypass control of the second bypass units 4 and 5 to control the heat outputs Qb and Qc of the waste heat utilization devices 54 and 55. The heat outputs [Qb, Qc] of each waste heat utilization device 54 and 55 are controlled to [QbH, QcH] when there is a margin in the heat quantity of the jacket cooling water, and are sequentially changed as [QbH, QcM] → [QbM, QcM] → [QbL, QcM] → [QbL, QcL] as the heat quantity of the cooling water decreases.

Explanation of symbols

[0041] 1 Cooling water control device for marine internal combustion engine 2a, 2b Temperature detection unit 3 First bypass unit 4, 5 Second bypass unit 10 Control unit 20 Heating unit 50 Cooling system 51 Marine internal combustion engine 52 Cooling water circulation path 53 Cooler 54, 55 Waste heat utilization device

Claims

1. An apparatus for controlling jacket cooling water of a cooling system provided with a cooler and waste heat utilization equipment in a cooling water circulation path of a marine internal combustion engine, comprising: temperature detection means for detecting the temperature of jacket cooling water passing through the marine internal combustion engine; first bypass means for adjusting a bypass flow rate for bypassing the cooler; second bypass means for adjusting a bypass flow rate for bypassing the waste heat utilization equipment; control means for controlling the operation of the first bypass means and the second bypass means based on the detection by the temperature detection means; a plurality of the waste heat utilization equipment are provided, and the second bypass means is provided for each of the waste heat utilization equipment; The control means is a cooling water control device for a marine internal combustion engine that individually controls the operation of the second bypass means based on a preset priority order for the plurality of waste heat utilization equipment.

2. The temperature detection means is arranged to detect the temperature of the jacket cooling water before being supplied to the marine internal combustion engine, The control means controls the operation of the first bypass means and the second bypass means so that the detected temperature by the temperature detection means is within a preset temperature range. The cooling water control device for a marine internal combustion engine according to Claim 1.

3. The cooling water control device for a marine internal combustion engine according to Claim 1, further comprising heating means for heating the jacket cooling water flowing through the cooling water circulation path, The control means controls the operation of the heating means based on the detection by the temperature detection means.

4. The cooling water control device for a marine internal combustion engine according to any one of Claims 1 to 3, wherein at least one of the waste heat utilization equipment is a water maker that produces fresh water by evaporating seawater using the jacket cooling water as a heat source.

5. A method for controlling jacket cooling water of a cooling system provided with a cooler and waste heat utilization equipment in a cooling water circulation path of a marine internal combustion engine, comprising: providing in the cooling system temperature detection means for detecting the temperature of the jacket cooling water passing through the marine internal combustion engine, first bypass means for adjusting a bypass flow rate for bypassing the cooler, second bypass means for adjusting a bypass flow rate for bypassing the waste heat utilization equipment, and control means for controlling the operation of the first bypass means and the second bypass means based on the detection by the temperature detection means; a plurality of the waste heat utilization equipment are provided, and the second bypass means is provided for each of the waste heat utilization equipment; A cooling water control method for a marine internal combustion engine, in which the control means controls the operation of the first bypass means and the second bypass means based on the detection by the temperature detection means, and individually controls the operation of the second bypass means based on a preset priority order for a plurality of the waste heat utilization devices.

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