System and method for realizing automatic temperature control of marine urea cabin

Abstract

The invention discloses a system and method for achieving automatic temperature control of a marine urea cabin, and the system comprises a heat exchange pipe, a heating medium source, a refrigerant source, a temperature sensor and a controller. Two ends of the heat exchange pipe are respectively connected with a first header pipe and a second header pipe; the first refrigerant branch pipe and the first heating medium branch pipe are connected to the first header pipe, and the second refrigerant branch pipe and the second heating medium branch pipe are connected to the second header pipe. The first refrigerant branch pipe, the first heating medium branch pipe, the second refrigerant branch pipe and the second heating medium branch pipe are each provided with an electric valve. The temperature sensor and the electric valve are both connected to the controller. Automatic switching between heating water and cooling water is achieved, manual operation is not needed, temperature adjustment is flexible, it is ensured that the temperature of the urea cabin is controlled within the normal storage temperature range, and the operation and maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of ships, and in particular to a system and method for realizing automatic temperature control of a marine urea tank. Background Art

[0002] In order to meet the restrictions on ship nitrogen oxide (NOx) emissions stipulated by the International Maritime Organization, new ships and modified ships currently use selective catalytic reduction (SCR) technology to reduce NOx emissions. SCR technology can achieve up to 95% NOx emission reduction. Urea aqueous solution is widely used in marine SCR systems due to its advantages such as high efficiency denitrification, high safety, convenient storage and transportation, and cost-effectiveness. The specific process is that urea solution is sprayed into the exhaust pipe as a reducing agent for the SCR reaction, decomposed into ammonia in the high-temperature exhaust gas, and selectively reduces NOx in the exhaust gas into pollution-free nitrogen and water under the action of the catalyst. Urea solution is stored in the urea tank on the ship, and the storage temperature requirements are relatively strict. When the solution temperature is lower than 5°C, crystals will precipitate and the solution concentration will decrease; when the solution temperature is greater than 35°C, urea is easy to decompose and deteriorate. Urea solution storage temperature that is too high or too low will interfere with the normal progress of the SCR reaction and reduce the denitrification efficiency. The decomposition and deterioration of urea at high temperature will also cause considerable losses to shipowners. Therefore, the temperature in the urea tank needs to be controlled within the normal range, usually 5 to 35°C. Both China Classification Society and American Bureau of Shipping have made requirements for the configuration of necessary temperature control systems for urea storage.

[0003] Traditional methods of heating the urea tank include boiler heating or electric heating. The former method requires increasing the boiler capacity for the urea tank, which is disadvantageous in terms of onboard space, pipeline layout and cost control; electric heating requires installing a heating rod in the tank. Since the heating rod is smaller than the urea tank, the heating effect is not good and there is a problem of uneven heating.

[0004] The traditional cooling method uses seawater cooling, but seawater is prone to cause pipeline corrosion, and the design operating temperature of seawater is usually 32°C, the heat exchange temperature difference is small, and the cooling effect is not ideal. In extreme environments, the seawater temperature even reaches and exceeds 35°C, which cannot be used to cool the urea tank. In addition, the existing urea tank temperature control method is only a single heating or cooling process, and the temperature adjustment is not flexible enough. It is difficult to ensure that the urea tank temperature is within the normal range when the ambient temperature is unstable or the ship changes its route.

[0005] The existing marine urea tank temperature control method is only a single heating or cooling process, which cannot achieve flexible and effective temperature control of the urea tank, and the simple control logic is easy to cause the system temperature to be overcooled or overheated, affecting the quality of urea. In addition, the heating and cooling methods have certain limitations. For example, the use of electric heating will increase power consumption, and the use of seawater cooling will easily cause pipeline corrosion and the cooling effect is not ideal. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art and provide a system and method for realizing automatic temperature control of a marine urea tank.

[0007] The present invention solves the above technical problems through the following technical solutions:

[0008] A system for realizing automatic temperature control of a marine urea tank comprises a heat exchange pipe arranged in the urea tank, and also comprises a heat medium source, a cold medium source and a temperature sensor capable of detecting the temperature in the urea tank; two ends of the heat exchange pipe are respectively connected to a first main pipe and a second main pipe; a cold medium outlet of the cold medium source is connected to a cold medium first branch pipe, and a hot medium outlet of the hot medium source is connected to a hot medium first branch pipe; a cold medium inlet of the cold medium source is connected to a cold medium second branch pipe, and a hot medium inlet of the hot medium source is connected to a hot medium second branch pipe; the cold medium first branch pipe and the hot medium first branch pipe are both connected to the first main pipe, and the cold medium second branch pipe and the hot medium second branch pipe are both connected to the second main pipe; electric valves are arranged on the cold medium first branch pipe, the hot medium first branch pipe, the cold medium second branch pipe and the hot medium second branch pipe; the system for realizing automatic temperature control of a marine urea tank also comprises a controller; and the temperature sensor and the electric valve are both connected to the controller.

[0009] Furthermore, the refrigerant source is refrigerant water of an air-conditioning refrigeration system.

[0010] Furthermore, the heat medium source is main engine cylinder jacket water.

[0011] Furthermore, the heat medium source is low-temperature fresh water before the inlet of the low-temperature fresh water cooler.

[0012] Furthermore, the electric valve and the controller are connected via wireless communication.

[0013] Furthermore, the electric valve and the controller are connected via a cable.

[0014] Furthermore, the temperature sensor and the controller are connected via wireless communication.

[0015] Furthermore, the temperature sensor and the controller are connected via a cable.

[0016] Furthermore, the electric valve is an electric remote-controlled ball valve.

[0017] Furthermore, a water inlet valve is provided on the first main pipe.

[0018] A method for realizing automatic temperature control of a marine urea tank, which adopts the aforementioned system for realizing automatic temperature control of a marine urea tank, and comprises:

[0019] Step 1: When the temperature measured by the temperature sensor is lower than the first set value, go to step 2; when the temperature measured by the temperature sensor is higher than the second set value, go to step 3; when the temperature measured by the temperature sensor is between the first set value and the second set value, the electric valves on the first branch pipe of the refrigerant, the first branch pipe of the heat medium, the second branch pipe of the refrigerant, and the second branch pipe of the heat medium are all closed;

[0020] Step 2, the controller opens the electric valves on the first branch pipe of the heat medium and the second branch pipe of the heat medium, and closes the electric valves on the first branch pipe of the refrigerant and the second branch pipe of the refrigerant; the heat medium of the heat medium source flows through the first branch pipe of the heat medium, the first main pipe, the heat exchange pipe, the second main pipe and the second branch pipe of the heat medium in sequence; the heat exchange pipe heats the urea tank; until the temperature measured by the temperature sensor reaches the third set value, the controller closes the electric valves on the first branch pipe of the heat medium and the second branch pipe of the heat medium, and stops heating the urea tank; return to step 1;

[0021] In step 3, the controller opens the electric valves on the first refrigerant branch and the second refrigerant branch, and closes the electric valves on the first heat medium branch and the second heat medium branch; the refrigerant from the refrigerant source flows through the first refrigerant branch, the first main pipe, the heat exchange pipe, the second main pipe and the second refrigerant branch in sequence, and the heat exchange pipe cools the urea compartment; until the temperature measured by the temperature sensor reaches a fourth set value, the controller closes the electric valves on the first refrigerant branch and the second refrigerant branch to stop cooling the urea compartment; and returns to step 1.

[0022] Further, in step 1, the first set value is 5°C.

[0023] Further, in step 1, the second set value is 35°C.

[0024] Further, in step 2, the third set value is 8°C.

[0025] Further, in step 3, the fourth set value is 32°C.

[0026] Furthermore, in step 1, when the temperature measured by the temperature sensor is lower than the fifth set value, the controller outputs an alarm signal while entering step 2.

[0027] Furthermore, the fifth set value is 4°C.

[0028] Furthermore, in step 1, when the temperature measured by the temperature sensor is higher than the sixth set value, the controller outputs an alarm signal while entering step 3.

[0029] Furthermore, the sixth set value is 36°C.

[0030] The beneficial effects of the present invention are as follows: the system and method for realizing automatic temperature control of a marine urea tank of the present invention have both automatic heating and cooling functions, realize heating or cooling of the urea tank through a set of devices, improve the heating and cooling methods, and realize automatic switching of heating water and cooling water by setting a temperature monitoring and control device to adjust the opening and closing of the valve of the heating / cooling medium, without manual operation, and flexible temperature adjustment to ensure that the temperature of the urea tank is controlled within the normal storage temperature range, reducing operation and maintenance costs. The present invention uses jacket water as the heating medium, fully utilizes the waste heat of the main engine, is conducive to energy conservation and emission reduction, and reduces operating costs; uses refrigerant water of the air conditioning refrigeration system as the cooling medium to achieve a sufficient cooling effect and avoid pipeline corrosion problems caused by seawater cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0032] A preferred embodiment is given below, and the present invention is described more clearly and completely in conjunction with the accompanying drawings.

[0033] like Figure 1 As shown, a system for realizing automatic temperature control of a marine urea tank comprises a heat exchange pipe 13 arranged in a urea tank 10, a heat medium source 30, a cold medium source 20 and a temperature sensor 14 capable of detecting the temperature in the urea tank. The temperature sensor 14 is arranged in the urea tank.

[0034] The two ends of the heat exchange tube are respectively connected to a first header pipe 11 and a second header pipe 12. The first header pipe 11 is provided with a water inlet valve 16.

[0035] The refrigerant outlet of the refrigerant source 20 is connected to a refrigerant first branch pipe 21 , and the heat medium outlet of the heat medium source 30 is connected to a heat medium first branch pipe 31 .

[0036] The refrigerant inlet of the refrigerant source 20 is connected to a refrigerant second branch pipe 22 , and the heat medium inlet of the heat medium source 30 is connected to a heat medium second branch pipe 32 .

[0037] The first refrigerant branch pipe 21 and the first heat medium branch pipe 31 are both connected to the first header pipe 11 , and the second refrigerant branch pipe 22 and the second heat medium branch pipe 32 are both connected to the second header pipe 12 .

[0038] Electric valves 17 are provided on the first refrigerant branch pipe 21 , the first heat medium branch pipe 31 , the second refrigerant branch pipe 22 , and the second heat medium branch pipe 32 .

[0039] The system for realizing automatic temperature control of marine urea tank also includes a controller 15. The temperature sensor 14 and the electric valve 17 are both connected to the controller 15. The controller can be a temperature controller, a temperature controller, or a programmable logic controller. The controller performs simple logical judgment. After receiving the temperature value measured by the temperature sensor, the controller compares the temperature value with the preset temperature value, and sends a signal according to the comparison result. The controller is an existing common component and will not be described in detail here.

[0040] In this embodiment, the refrigerant source 20 is the refrigerant water of the air conditioning refrigeration system; the heat medium source 30 is the main engine cylinder jacket water.

[0041] In other embodiments, the heat medium source may also be low-temperature fresh water before the inlet of the low-temperature fresh water cooler. That is, when the diesel engine cannot provide cylinder jacket water out of the engine alone, the low-temperature fresh water before the inlet of the low-temperature fresh water cooler is used as a heat medium source to achieve heating as an alternative.

[0042] The electric valve 17 and the controller 15 are connected via wireless communication; or, the electric valve and the controller are connected via a cable.

[0043] The temperature sensor 14 and the controller 15 are connected via wireless communication; or, the temperature sensor 14 and the controller 15 are connected via a cable.

[0044] In this embodiment, the electric valve is an electric remote-controlled ball valve.

[0045] Figure 1 In the figure, arrows indicate the flow direction of the heat medium or the refrigerant, and the connection between the temperature sensor and the controller, and the connection between the electric valve and the controller are indicated by dotted lines.

[0046] Several temperature values ​​can be preset in the controller. The temperature values ​​preset in the controller can be the first set value, the second set value, the third set value, the fourth set value, the fifth set value and the sixth set value. After the temperature sensor measures the temperature, it transmits the temperature signal to the controller. The controller makes a simple comparison between the temperature measured by the temperature sensor and the preset temperature value, and sends a signal to the electric valve according to the comparison result, so that the electric valve is opened or closed.

[0047] The invention discloses a working principle of a system for realizing automatic temperature control of a marine urea tank, that is, a method for realizing automatic temperature control of a marine urea tank.

[0048] A method for realizing automatic temperature control of a marine urea tank, which adopts the aforementioned system for realizing automatic temperature control of a marine urea tank, and comprises:

[0049] Step 1, when the temperature measured by the temperature sensor is lower than the first set value, go to step 2; when the temperature measured by the temperature sensor is higher than the second set value, go to step 3; when the temperature measured by the temperature sensor is between the first set value and the second set value, the electric valves on the first branch of the refrigerant, the first branch of the heat medium, the second branch of the refrigerant, and the second branch of the heat medium are all closed.

[0050] In step 1, the first set value is 5°C.

[0051] In step 1, the second set value is 35°C.

[0052] Step 2, the controller opens the electric valves on the first branch pipe of the heat medium and the second branch pipe of the heat medium, and closes the electric valves on the first branch pipe of the refrigerant and the second branch pipe of the refrigerant; the heat medium of the heat medium source flows through the first branch pipe of the heat medium, the first main pipe, the heat exchange pipe, the second main pipe and the second branch pipe of the heat medium in sequence; the heat exchange pipe heats the urea tank; until the temperature measured by the temperature sensor reaches the third set value, the controller closes the electric valves on the first branch pipe of the heat medium and the second branch pipe of the heat medium, and stops heating the urea tank; return to step 1.

[0053] In step 2, the third set value is 8°C.

[0054] In step 3, the controller opens the electric valves on the first refrigerant branch and the second refrigerant branch, and closes the electric valves on the first heat medium branch and the second heat medium branch; the refrigerant from the refrigerant source flows through the first refrigerant branch, the first main pipe, the heat exchange pipe, the second main pipe and the second refrigerant branch in sequence, and the heat exchange pipe cools the urea compartment; until the temperature measured by the temperature sensor reaches a fourth set value, the controller closes the electric valves on the first refrigerant branch and the second refrigerant branch to stop cooling the urea compartment; and returns to step 1.

[0055] In step 3, the fourth set value is 32°C.

[0056] Through the above method, the temperature of the urea compartment can be automatically controlled within the normal storage temperature range, that is, the temperature of the urea compartment can be automatically controlled within 5 to 35° C. to prevent urea from deteriorating or crystallizing.

[0057] In one embodiment, in step 1, when the temperature measured by the temperature sensor is lower than the fifth set value, the controller outputs an alarm signal while entering step 2.

[0058] Preferably, the fifth set value is 4°C.

[0059] In another embodiment, in step 1, when the temperature measured by the temperature sensor is higher than the sixth set value, the controller outputs an alarm signal while entering step 3.

[0060] Preferably, the sixth setting value is 36°C.

[0061] In this way, the staff can receive the alarm signal and intervene in time to prevent urea from deteriorating or crystallizing.

[0062] The present invention uses the cylinder jacket water as the heating medium, fully utilizes the waste heat of the main engine, is beneficial to energy conservation and emission reduction, and reduces operating costs; uses the refrigerant water of the air conditioning refrigeration system as the cooling medium to achieve a sufficient cooling effect and avoid the pipeline corrosion problem caused by seawater cooling.

[0063] The system and method for realizing automatic temperature control of a marine urea tank of the present invention have both automatic heating and cooling functions, realize heating or cooling of the urea tank through a set of devices, improve heating and cooling methods, and realize automatic switching of heating water and cooling water by setting a temperature monitoring and control device to adjust the opening and closing of the valve of the heating / cooling working medium. No manual operation is required, and the temperature adjustment is flexible, so as to ensure that the temperature of the urea tank is controlled within the normal storage temperature range, thereby reducing operation and maintenance costs.

[0064] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A system for realizing automatic temperature control of a marine urea tank, comprising a heat exchange pipe arranged in the urea tank, It is characterized in that It also includes a heat medium source, a cold medium source and a temperature sensor capable of detecting the temperature in the urea tank; the two ends of the heat exchange tube are respectively connected to the first main pipe and the second main pipe; the cold medium outlet of the cold medium source is connected to the first cold medium branch pipe, and the hot medium outlet of the hot medium source is connected to the first hot medium branch pipe; the cold medium inlet of the cold medium source is connected to the second cold medium branch pipe, and the hot medium inlet of the hot medium source is connected to the second hot medium branch pipe; the first cold medium branch pipe and the first hot medium branch pipe are both connected to the first main pipe, and the second cold medium branch pipe and the second hot medium branch pipe are both connected to the second main pipe; the first cold medium branch pipe, the first hot medium branch pipe, the second cold medium branch pipe and the second hot medium branch pipe are all provided with electric valves; the system for realizing automatic temperature control of the marine urea tank also includes a controller; the temperature sensor and the electric valve are both connected to the controller.

2. The system for realizing automatic temperature control of marine urea tank according to claim 1, It is characterized in that The refrigerant source is the refrigerant water of the air conditioning refrigeration system.

3. The system for realizing automatic temperature control of marine urea tank according to claim 1, It is characterized in that The heat medium source is the main engine cylinder jacket water.

4. The system for realizing automatic temperature control of marine urea tank according to claim 1, It is characterized in that The heat medium source is the low-temperature fresh water before the inlet of the low-temperature fresh water cooler.

5. The system for realizing automatic temperature control of marine urea tank according to claim 1, It is characterized in that The electric valve and the controller are connected via wireless communication.

6. The system for realizing automatic temperature control of marine urea tank according to claim 1, It is characterized in that The electric valve and the controller are connected via cables.

7. The system for realizing automatic temperature control of marine urea tank according to claim 1, It is characterized in that The temperature sensor and the controller are connected via wireless communication.

8. The system for realizing automatic temperature control of marine urea tank according to claim 1, It is characterized in that The temperature sensor and the controller are connected via a cable.

9. The system for realizing automatic temperature control of marine urea tank according to claim 1, It is characterized in that The electric valve is an electric remote-controlled ball valve.

10. The system for realizing automatic temperature control of marine urea tank according to claim 1, It is characterized in that A water inlet valve is arranged on the first main pipe.

11. A method for realizing automatic temperature control of a marine urea tank, which adopts the system for realizing automatic temperature control of a marine urea tank according to any one of claims 1 to 10, wherein include: Step 1: When the temperature measured by the temperature sensor is lower than the first set value, proceed to step 2; When the temperature measured by the temperature sensor is higher than the second set value, the process goes to step 3; when the temperature measured by the temperature sensor is between the first set value and the second set value, the electric valves on the first branch pipe of the refrigerant, the first branch pipe of the heat medium, the second branch pipe of the refrigerant, and the second branch pipe of the heat medium are all closed; Step 2, the controller opens the electric valves on the first branch pipe of the heat medium and the second branch pipe of the heat medium, and closes the electric valves on the first branch pipe of the refrigerant and the second branch pipe of the refrigerant; the heat medium of the heat medium source flows through the first branch pipe of the heat medium, the first main pipe, the heat exchange pipe, the second main pipe and the second branch pipe of the heat medium in sequence; the heat exchange pipe heats the urea tank; until the temperature measured by the temperature sensor reaches the third set value, the controller closes the electric valves on the first branch pipe of the heat medium and the second branch pipe of the heat medium, and stops heating the urea tank; return to step 1; In step 3, the controller opens the electric valves on the first refrigerant branch and the second refrigerant branch, and closes the electric valves on the first heat medium branch and the second heat medium branch; the refrigerant from the refrigerant source flows through the first refrigerant branch, the first main pipe, the heat exchange pipe, the second main pipe and the second refrigerant branch in sequence, and the heat exchange pipe cools the urea compartment; until the temperature measured by the temperature sensor reaches a fourth set value, the controller closes the electric valves on the first refrigerant branch and the second refrigerant branch to stop cooling the urea compartment; and returns to step 1.

12. The method for realizing automatic temperature control of a marine urea tank according to claim 11, It is characterized in that In step 1, the first set value is 5°C.

13. The method for realizing automatic temperature control of a marine urea tank according to claim 11, It is characterized in that In step 1, the second set value is 35°C.

14. The method for realizing automatic temperature control of a marine urea tank according to claim 11, It is characterized in that In step 2, the third set value is 8°C.

15. The method for realizing automatic temperature control of a marine urea tank according to claim 11, It is characterized in that In step 3, the fourth set value is 32°C.

16. The method for realizing automatic temperature control of a marine urea tank according to claim 11, It is characterized in that In step 1, when the temperature measured by the temperature sensor is lower than the fifth set value, the controller outputs an alarm signal while entering step 2.

17. The method for realizing automatic temperature control of a marine urea tank according to claim 16, It is characterized in that The fifth set value is 4°C.

18. The method for realizing automatic temperature control of a marine urea tank according to claim 11, It is characterized in that In step 1, when the temperature measured by the temperature sensor is higher than the sixth set value, the controller outputs an alarm signal while entering step 3.

19. The method for realizing automatic temperature control of a marine urea tank according to claim 18, It is characterized in that The sixth set value is 36°C.

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