Liquid level control system of economizer for ship

Abstract

The utility model belongs to the technical field of ships, and particularly discloses a liquid level control system of an economizer for ships, which comprises a PLC (programmable logic controller) control system, a liquid level sensor, a first valve, a second valve and a third valve, and the liquid level sensor, the first valve, the second valve and the third valve are connected with the PLC control system. The PLC control system controls the opening degree and opening and closing of the first valve, the second valve and the third valve according to the liquid level information. The first valve is installed on a liquid outlet pipeline of the economizer, the second valve is installed on a liquid inlet pipeline of the economizer, and the third valve is installed on an air supply pipeline of the economizer. And the liquid level sensor is arranged to monitor the liquid level of the economizer in real time. By arranging the second valve and the first valve, the safe liquid level can be controlled by controlling the second valve and the first valve. And by arranging the third valve, the third valve can be closed under the emergency situation that the liquid level is too high, and the problem that liquid is carried in air suction is effectively avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of ships, and in particular relates to a liquid level control system for an economizer used in ships. Background Art

[0002] For multi-stage compression centrifugal chillers, economizers are usually installed. The economizers are equipped with air supply pipes to supply air between compressor stages and improve the refrigeration efficiency of the refrigeration unit. Usually, the economizer is a space separation tank, and a manual air supply valve or no valve is installed on its air supply pipe.

[0003] However, when used in special fields such as ships, due to their special environment, they will face special environmental conditions such as the tilting and swaying of the hull. If the centrifugal chiller unit tilts and sways significantly with the hull, the liquid level of the economizer will inevitably fluctuate greatly. In this case, the abnormally high liquid level will cause the compressor to carry liquid in the air supply. The compressor will run with liquid, which may cause catastrophic damage to the compressor. Since the traditional economizer has a simple structure and does not have the ability to monitor and control the liquid level, it cannot adapt to special fields such as ships with characteristics such as tilting and swaying. Utility Model Content

[0004] The utility model aims to provide a liquid level control system for a marine economizer, which can monitor and control the liquid level of the economizer and effectively avoid the situation in which the compressor air replenishment is filled with liquid due to the economizer also floating due to the tilting and swaying of the ship.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the utility model is as follows: a liquid level control system for a marine economizer, comprising a PLC control system and a liquid level sensor, a first valve and a second valve connected to the PLC control system, the liquid level sensor being used to monitor the liquid level in the economizer and sending the liquid level information to the PLC control system in real time, the PLC control system controlling the opening and opening and closing of the first valve and the second valve according to the liquid level information; the first valve being installed on the liquid outlet pipe of the economizer, and the second valve being installed on the liquid inlet pipe of the economizer.

[0006] Furthermore, it also includes a third valve connected to the PLC control system, and the third valve is installed on the air supply pipeline of the economizer.

[0007] Furthermore, the third valve is an electric air supply valve, and the first valve and the second valve are both electric throttle valves.

[0008] Furthermore, the PLC control system is provided with a first set value, a second set value and a third set value which increase in sequence; when the liquid level information is higher than the first set value and less than or equal to the second set value, the PLC control system reduces the opening of the second valve; when the liquid level information is higher than the second set value and less than or equal to the third set value, the PLC control system increases the opening of the first valve; when the liquid level information is higher than the third set value, the PLC control system closes the third valve.

[0009] Furthermore, the liquid level sensor is a capacitive liquid level sensor, and the liquid level sensor is arranged outside the economizer.

[0010] The working principle of this technical solution is that the liquid level sensor monitors the liquid level in the economizer in real time and sends the liquid level information to the PLC control system, and the PLC control system controls the first valve, the second valve and the third valve according to the liquid level information and the size of the first set value, the second set value and the third set value. Specifically, when the liquid level information is higher than the first set value and less than or equal to the second set value, the PLC control system issues an instruction to close the second valve, so that the opening of the second valve is reduced; when the liquid level information is higher than the second set value and less than or equal to the third set value, the PLC control system issues an instruction to open the first valve, so that the opening of the first valve is increased; when the liquid level information is higher than the third set value, the PLC control system issues an instruction to close the third valve, so that the third valve is closed. When the system is restored, the valve is restored according to the reverse process mentioned above, that is, the third valve is opened first, then the first valve is reduced, and finally the second valve is increased.

[0011] The beneficial effects of this technical solution are: by setting a liquid level sensor on the economizer, real-time monitoring of the economizer liquid level can be achieved. By adding a second valve and a first valve to the inlet and outlet pipes of the economizer and connecting to a PLC control system, the control of the safety liquid level can be achieved by controlling the second valve and the first valve. By adding a third valve to the air supply pipe of the economizer and connecting to a PLC control system, the air supply valve can be automatically closed in an emergency situation where the liquid level is too high, effectively avoiding the problem of liquid inhalation. The automatic control of the PLC control system realizes the convenient and safe use of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The utility model is a schematic diagram of the liquid level control system of the marine economizer. DETAILED DESCRIPTION

[0013] The following is further described in detail through specific implementation methods:

[0014] The reference numerals in the drawings of the specification include: economizer 1, PLC control system 2, first valve 3, second valve 4, third valve 5, liquid level sensor 6, top pipe 7, bottom pipe 8, fourth valve 9, fifth valve 10.

[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] The embodiment is basically as shown in the attached Figure 1 As shown: the liquid level control system of the marine economizer includes a PLC control system 2 and a liquid level sensor 6, a first valve 3, a second valve 4 and a third valve 5 connected to the PLC control system 2. The third valve 5 adopts an electric air supply valve, and the first valve 3 and the second valve 4 both adopt electric throttle valves. The liquid level sensor 6 is used to monitor the liquid level in the economizer 1 and send the liquid level information to the PLC control system 2 in real time. The PLC control system 2 controls the opening and opening and closing of the first valve 3, the second valve 4 and the third valve 5 according to the liquid level information; the first valve 3 is installed on the liquid outlet pipe of the economizer 1, the second valve 4 is installed on the liquid inlet pipe of the economizer 1, and the third valve 5 is installed on the air supply pipe of the economizer 1.

[0017] The PLC control system 2 is provided with a first set value, a second set value and a third set value which increase in sequence; when the liquid level information is higher than the first set value and is less than or equal to the second set value, the PLC control system 2 reduces the opening of the second valve 4 (in the present embodiment, it is adjusted to the minimum opening); when the liquid level information is higher than the second set value and is less than or equal to the third set value, the PLC control system 2 increases the opening of the first valve 3 (in the present embodiment, it is adjusted to the maximum opening); when the liquid level information is higher than the third set value, the PLC control system 2 closes the third valve 5 to avoid suction with liquid.

[0018] The liquid level sensor 6 is a capacitive liquid level sensor, and the liquid level sensor 6 is arranged outside the economizer 1. Specifically, the top and bottom of the economizer 1 are connected to a top pipe 7 and a bottom pipe 8, respectively, and the top pipe 7 and the bottom pipe 8 are connected to both sides of the liquid level sensor 6. A fourth valve 9 and a fifth valve 10 are respectively arranged on the top pipe 7 and the bottom pipe 8, and the fourth valve 9 and the fifth valve 10 can be electric valves and connected to the PLC control system 2, or manual valves can be used to open manually.

[0019] The specific implementation process is as follows:

[0020] The liquid level sensor 6 monitors the liquid level in the economizer 1 in real time and sends the liquid level information to the PLC control system 2. The PLC control system 2 controls the first valve 3, the second valve 4 and the third valve 5 according to the liquid level information and the size of the first set value, the second set value and the third set value. Specifically, when the liquid level information is higher than the first set value and less than or equal to the second set value, the PLC control system 2 issues an instruction to close the second valve 4, so that the opening of the second valve 4 is adjusted to the minimum; when the liquid level information is higher than the second set value and less than or equal to the third set value, the PLC control system 2 issues an instruction to open the first valve 3, so that the opening of the first valve 3 is adjusted to the maximum; when the liquid level information is higher than the third set value, the PLC control system 2 issues an instruction to close the third valve 5, so that the third valve 5 is closed to avoid suction and liquid. When the system is restored, the valve is restored according to the above reverse process, that is, the third valve 5 is opened first, the first valve 3 is adjusted down, and the second valve 4 is adjusted up at last.

[0021] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0022] The above is only an embodiment of the utility model. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the utility model before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, which will not affect the effect of the implementation of the utility model and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to explain the content of the claims.

Claims

1. A liquid level control system for a marine economizer, characterized in that: The invention comprises a PLC control system (2) and a liquid level sensor (6), a first valve (3) and a second valve (4) connected to the PLC control system (2); the liquid level sensor (6) is used to monitor the liquid level in the economizer (1) and send the liquid level information to the PLC control system (2) in real time; the PLC control system (2) controls the opening and closing of the first valve (3) and the second valve (4) according to the liquid level information; the first valve (3) is installed on the liquid outlet pipe of the economizer (1), and the second valve (4) is installed on the liquid inlet pipe of the economizer (1).

2. The liquid level control system of a marine economizer according to claim 1, characterized in that: It also comprises a third valve (5) connected to the PLC control system (2), wherein the third valve (5) is installed on the air supply pipeline of the economizer (1).

3. The liquid level control system of a marine economizer according to claim 2, characterized in that: The third valve (5) is an electric air supply valve, and the first valve (3) and the second valve (4) are both electric throttle valves.

4. The liquid level control system of a marine economizer according to claim 3, characterized in that: The PLC control system (2) is provided with a first set value, a second set value and a third set value which increase in sequence; when the liquid level information is higher than the first set value and less than or equal to the second set value, the PLC control system (2) reduces the opening of the second valve (4); when the liquid level information is higher than the second set value and less than or equal to the third set value, the PLC control system (2) increases the opening of the first valve (3); when the liquid level information is higher than the third set value, the PLC control system (2) closes the third valve (5).

5. The liquid level control system of a marine economizer according to claim 1, characterized in that: The liquid level sensor (6) is a capacitive liquid level sensor, and the liquid level sensor (6) is arranged outside the economizer (1).

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