CN116929772A - Cooling system of single-cylinder diesel engine test bed - Google Patents

Abstract

The invention discloses a cooling system of a single-cylinder diesel engine test bed, which comprises a fresh water circulation pipeline and a seawater circulation pipeline, wherein the fresh water circulation pipeline and the seawater circulation pipeline are connected into the diesel engine; the fresh water circulation pipeline comprises three fresh water circulation paths, namely a first fresh water circulation pipeline, a second fresh water circulation pipeline and a third fresh water circulation pipeline; the fresh water tank is communicated with the check valve, the check valve is communicated with the fresh water pump, and the outlet end of the fresh water pump is connected with the water inlet of the diesel engine; the water outlet of the diesel engine is connected with a three-way pipe; one end of the return pipe is communicated with the three-way pipe, and the return pipe is communicated with the fresh water tank to form a first fresh water circulation pipeline; one end of the constant temperature three-way valve is communicated with the three-way pipe; the constant temperature three-way valve is communicated with the cooler, and the cooler is communicated with the collecting pipe; the collecting pipe is connected to a pipeline between the fresh water pump and the one-way valve to form a second fresh water circulating pipeline; the constant temperature three-way valve is communicated with the collecting pipe to form a third fresh water circulation pipeline; the water return pipe is provided with a first control valve. The invention expands the application range of water temperature and avoids the situation of transitional cooling or insufficient cooling.

Description

A cooling system for single-cylinder diesel engine test bench

Technical field

The invention belongs to the field of engine technology, specifically a cooling system for a single-cylinder diesel engine test bench.

Background technique

The single-cylinder simulation test is the most economical and rapid test. Only through the single-cylinder test can it be possible to conduct extensive and step-by-step research on some basic theoretical issues and parameters in the cylinder, and greatly simplify the problem, thus speeding up the prototype. The role of development progress. During the simulation test of a marine single-cylinder diesel engine, the cooling system serves as a key link to ensure that the single-cylinder diesel engine runs at a suitable temperature. At present, most marine diesel engines use dual-circulation cooling systems, one for fresh water circulation and one for sea water circulation. For example, the Chinese patent "A Marine Diesel Engine Cooling System" with announcement number CN108071473A shows that this type of engine has its own heat exchanger, uses seawater to cool fresh water, and then uses fresh water to cool the engine.

The problem is that the diesel engine generates different amounts of heat under different working conditions, and the seawater temperature is unstable, ranging from -2°C to 35°C. Cooling transition is prone to occur, which is not conducive to combustion, fuel consumption is too high, and economic performance is poor, especially in severely cold areas; in hot areas, insufficient cooling may also occur, causing high temperatures in the diesel engine and affecting the life of the diesel engine. For this reason, a single-cylinder diesel engine test bench cooling system is needed to ensure that the single-cylinder diesel engine operates at a suitable temperature.

Contents of the invention

In order to overcome the deficiencies in the prior art, the present invention provides a single-cylinder diesel engine test bench cooling system. The purpose is to overcome the excessive cooling or insufficient cooling of marine single-cylinder diesel engines and provide different levels of cooling capacity with multiple sets of cooling circulation paths to meet the cooling needs of marine single-cylinder diesel engines operating under different working conditions.

In order to achieve the above object, the present invention provides the following technical solution: a single-cylinder diesel engine test bench cooling system; including an external fresh water circulation pipeline connected to the internal cooling pipeline of the diesel engine, and a heat exchange pipeline connected to the internal part of the diesel engine. The external seawater circulation pipeline of the device; the fresh water circulation pipeline includes three fresh water circulation paths, which are the first, second and third fresh water circulation pipelines;

Wherein, the outlet end of the fresh water tank is connected to a one-way valve, the outlet end of the one-way valve is connected to a fresh water pump, and the outlet end of the fresh water pump is connected to the water inlet of the internal cooling pipe of the diesel engine; the internal cooling pipe of the diesel engine The water outlet of the road is connected to a tee pipe, which is used to output two lanes of cooling water, namely a straight pipe and a bypass pipe; the straight pipe includes a return pipe with one end connected to the tee pipe, and the return pipe has The other end is directly connected to the fresh water tank to form a first fresh water circulation pipeline; the bypass pipeline includes a thermostatic three-way valve with one end connected to the three-way pipe; one outlet end of the thermostatic three-way valve is connected to the cooler , the outlet end of the cooler is connected to the collecting pipe; the outlet end of the collecting pipe is connected to the pipe between the fresh water pump and the one-way valve to form a second fresh water circulation pipeline; the other end of the thermostatic three-way valve The outlet end is connected to the collecting pipe to form a third fresh water circulation pipeline; the return water pipe is provided with a first control valve for controlling the connection or closing of the return water pipe.

As a further optimization, the seawater circulation pipeline includes a seawater tank with one end connected to the water outlet of the internal heat exchanger of the diesel engine, the outlet end of the seawater tank connected to the seawater filter, and the outlet end of the seawater filter connected to the seawater. Pump, the outlet end of the seawater pump is connected to the water inlet of the internal heat exchanger of the diesel engine; the seawater tank is provided with a seawater inlet pipe for injecting seawater into the seawater tank; the lower end of the seawater inlet pipe extends into A float valve is connected inside the seawater tank for closing the seawater inlet pipe when the seawater tank is filled.

As a further optimization, a filter is also provided on the pipeline between the fresh water tank and the one-way valve; a stop valve is also provided on the pipeline between the filter and the fresh water tank; and the fresh water pump is installed on the pipeline between the filter and the fresh water tank. The outlet end of the pipe connected to the water inlet of the internal cooling pipe of the diesel engine is provided with a first rubber pipe section for buffering the vibration of the diesel engine; a pipe between the first rubber pipe section and the fresh water pump is installed Temperature sensor and pressure sensor.

As a further optimization, the pipeline between the return pipe and the three-way pipe is provided with a second rubber pipe section; the pipeline between the thermostatic three-way valve and the three-way pipe is provided with a third rubber pipe section for buffering the diesel engine of vibration.

As a further optimization, a pipeline filter is provided on the pipeline between the third rubber pipe section and the thermostatic three-way valve.

As a further optimization, it also includes an electric valve and a water injection pipe; one end of the water injection pipe is connected to the part of the seawater inlet pipe located outside the seawater tank, and the other end bypasses the seawater tank and is connected to the seawater filter. on the pipeline between the seawater tank and the seawater tank; the electric valve is installed on the seawater inlet pipe, between the connection point between the water injection pipe and the seawater inlet pipe and the float valve; the water injection pipe A second control valve is installed on the water injection pipe for controlling the connection or closing of the water injection pipe.

Compared with the prior art, the beneficial effects of the present invention are:

(1) Through multiple cooling routes, the adaptive range of water temperature is expanded and the influence of unstable seawater temperature is reduced.

(2) Adapt to the calorific value of the diesel engine under different working conditions, so that the diesel engine has good performance under high/low working conditions, and the diesel engine has high effective efficiency.

(3) When the diesel engine is cold, the cooler does not work, which is beneficial to combustion, the fuel consumption rate is too low, and the economic performance is good; when the diesel engine overheats, rapid cooling measures are reserved to avoid damage to diesel engine parts and extend the life.

(4) When the diesel engine is operating normally, the thermostatic three-way valve is used to continuously adjust the water flow into the cooler to ensure that the water temperature fluctuates less when the diesel engine is operating normally, which is beneficial to the long-term operation of the diesel engine.

In short, by setting up multiple cooling routes, the adaptive range of water temperature is expanded, the influence of unstable seawater temperature is reduced, the adaptability of the diesel engine in different working conditions is improved, and excessive cooling or insufficient cooling is avoided.

Description of the drawings

Figure 1 is a schematic diagram of the cooling system according to Embodiment 1 of the present invention.

In Figure 1: 1 is the fresh water tank, 2 is the stop valve, 3 is the filter, 4 is the one-way valve, 5 is the fresh water pump, 6 is the fresh water inlet pipe, 7 is the throttle valve, 8 is the pressure sensor, and 9 is the temperature. Sensor, 10 is a rubber pipe, 11 is a single-cylinder diesel engine, 12 is a seawater tank, 13 is a seawater sewage pipe, 14 is a liquid level gauge, 15 is a float valve, 16 is an electric valve, 17 is a seawater inlet pipe, and 18 is a water injection pipe. , 19 is a seawater filter, 20 is a seawater pump, 21 is a return pipe, 22 is a three-way pipe, 23 is a pipeline filter, 24 is a thermostatic three-way valve, 25 is a cooler, 26 is a bypass pipe, and 27 is a sewage pipe , 28 is the fresh water injection pipe, 29 is the collecting pipe, 30 is the first control valve, 31 is the second rubber pipe section, 32 is the third rubber pipe section, and 33 is the second control valve.

Detailed ways

The present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some of the preferred embodiments of the present invention, rather than all the embodiments. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of the present invention.

Embodiment 1: Please refer to Figure 1;

A single-cylinder diesel engine test bench cooling system is applied to a marine diesel engine with its own heat exchanger. It is divided into two parts, one part is a fresh water circulation system, and the other part is a seawater circulation system. The fresh water pumped out from the fresh water tank 1 by the fresh water pump 5 passes through the stop valve 2 and the filter 3 and enters the one-way valve 4. The function of the stop valve 2 is to facilitate the inspection of the fresh water circulation system failure when the fresh water circulation system fails. Filter 3 is installed to ensure the service life of the water pump and the cleanliness of fresh water. The function of the one-way valve 4 is to prevent fresh water from flowing back. Fresh water passes through the throttle valve 7 and enters the single-cylinder diesel engine 11 through the first rubber pipe section 10 . The function of the throttle valve 7 is to adjust the fresh water inlet pressure by controlling the fresh water flow into the single-cylinder diesel engine 11 to adjust the fresh water inlet pressure. A temperature sensor 9 and a pressure sensor 8 are installed between the throttle valve 7 and the first rubber pipe section 10 for monitoring the inlet pressure and temperature of fresh water. Since the vibration of the single-cylinder diesel engine 11 is relatively large, a first rubber pipe section 10 is installed at the fresh water and seawater inlets and outlets of the single-cylinder diesel engine 11 for vibration reduction and buffering of vibrations caused by the operation of the single-cylinder diesel engine 11 . Fresh water enters the single-cylinder diesel engine through the fresh water inlet pipe 6.

The fresh water return of the single-cylinder diesel engine 11 is divided into two channels through the tee pipe 22. One channel of fresh water passes through the first rubber pipe section 10 and the stop valve 2, and directly returns to the fresh water tank 1 through the fresh water return pipe 21. The other fresh water enters the fresh water pump 5 through the bypass pipe 26 and participates in the fresh water circulation again. This fresh water does not pass through the fresh water tank 1 and directly participates in the fresh water circulation. The function of the bypass pipeline is to adjust the fresh water temperature and pressure of the fresh water circulation system. When the fresh water temperature is too high or too low and needs to be adjusted, the bypass pipeline is opened. Fresh water passes through the first rubber pipe section 10 and the stop valve 2 and enters the pipeline filter 23. The stop valve 2 is opened. Because the fresh water directly passes through the fresh water pump 5 and enters the single-cylinder diesel engine 11 again without passing through the filter 3, a bypass pipe is installed. Pipe strainer 23. The function of the pipeline filter 23 is to clean the fresh water coming out of the single-cylinder diesel engine 11. A temperature sensor 9 and a pressure sensor 8 are installed between the first rubber pipe section 10 and the stop valve 2 for monitoring the fresh water return temperature and pressure, and adjusting the fresh water temperature and pressure according to the feedback fresh water temperature and pressure. The fresh water passes through the thermostatic valve three-way valve 24 and the cooler 25, and participates in the fresh water circulation again. The function of the thermostatic valve three-way valve 24 is to ensure that the fresh water temperature is within the set temperature range. The function of the cooler 25 is to cool the fresh water when the temperature of the fresh water is too high. The cooling water comes from external circulating water. External fresh water is injected into the fresh water tank 1 through the fresh water injection pipe 28, and the impurities and sewage in the fresh water tank 1 are regularly discharged through the sewage pipe 27.

The external seawater of the seawater circulation system is injected into the seawater tank 12 through the seawater inlet pipe 17. The seawater pump 20 pumps out the seawater in the seawater tank 12, passes through the seawater filter 19, and enters the single-cylinder diesel engine 11. The impurities and sewage at the bottom of the seawater tank 12 pass through The sea water is discharged through the sewage pipe 13. The water level in the seawater tank 12 is controlled by the float valve 15 in the seawater tank 12, and it always maintains a water state, meeting the water requirements of the single-cylinder diesel engine 11. The function of the liquid level gauge 14 is to monitor the seawater level in the seawater tank 12 to prevent the seawater tank 12 from having a low liquid level, so that water can be replenished in time. The electric valve 16 is a switch during maintenance and is normally open. Before starting, the water inlet pipe of the seawater pump 20 is filled with water through the water injection pipe 18. After the seawater pump 20 works normally, water injection is stopped.

It can be seen that the fresh water circulation pipeline includes three fresh water circulation paths, which are the first, second and third fresh water circulation pipelines; among them, the outlet end of the fresh water tank 1 is connected to the one-way valve 4, and the one-way valve 4 The outlet end is connected to the fresh water pump 5, and the outlet end of the fresh water pump 5 is connected to the water inlet of the internal cooling pipeline of the diesel engine; the water outlet of the internal cooling pipeline of the diesel engine is connected to the tee pipe 22 for outputting two-way cooling. Water is a straight-through pipeline and a bypass pipeline respectively; the straight-through pipeline includes a return pipe 21 with one end connected to the three-way pipe 22, and the other end of the return pipe 21 is directly connected to the fresh water tank 1 to form a third A fresh water circulation pipeline; the bypass pipeline includes a thermostatic three-way valve 24 with one end connected to the three-way pipe 22; an outlet end of the thermostatic three-way valve 24 is connected to a cooler 25, and the outlet end of the cooler 25 Connected to the collecting pipe 29; the outlet end of the collecting pipe 29 is connected to the pipeline between the fresh water pump 5 and the one-way valve 4 to form a second fresh water circulation pipeline; the other outlet of the thermostatic three-way valve 24 The end is connected to the collecting pipe 29 to form a third fresh water circulation pipeline; the return pipe 21 is provided with a first control valve 30 for controlling the connection or closing of the return pipe 21 .

When using, take the temperature of the engine from low to high as an example. Among them, the thermostatic three-way valve 24 can automatically control the output direction and opening amount according to the temperature of the inflowing water flow, thereby controlling the water flow output in different directions.

When the diesel engine is at low temperature, the first control valve 30 is closed and the third fresh water circulation pipeline is activated. The cooling water output from the diesel engine flows through the three-way pipe 22, the thermostatic three-way valve 24, the collecting pipe 29, and the fresh water pump 5 before returning to the diesel engine. And the cycle repeats. At this time, the thermostatic three-way valve 24 closes the cooler 25, and all water flows to the fresh water pump 5. The third fresh water circulation pipeline has the shortest flow route, and the pipeline naturally dissipates less heat, and does not flow through the cooler 25 to protect the engine from heating up to a suitable temperature as quickly as possible.

When the diesel engine is at a medium temperature, the first control valve 30 is closed, enabling the parallel state of the second and third fresh water circulation lines. The cooling water output from the diesel engine flows through the three-way pipe 22 and the thermostatic three-way valve 24 and is divided into two channels. One channel flows through the cooler 25 and the other channel directly leads to the collecting pipe 29. After passing through the fresh water pump 5, it returns to the diesel engine. The cycle goes back and forth. At this time, the thermostatic three-way valve 24 is in a half-open state, dividing the water flow into two paths. The cooler 25 cools part of the water flow, and the other part of the water flows through the pipeline to naturally dissipate heat, and then the two water flows merge in the collecting pipe 29 and return to the diesel engine. It can be seen that the cooling water of the diesel engine has been partially cooled, and the temperature does not drop much, so as to avoid excessive cooling.

When the diesel engine is at high temperature, the first control valve 30 is closed and the second fresh water circulation pipeline is activated. The cooling water output from the diesel engine flows through the three-way pipe 22 and the thermostatic three-way valve 24, then all flows to the cooler 25, and then through the collecting pipe 29 and the fresh water pump 5, it returns to the diesel engine and the cycle repeats. At this time, the thermostatic three-way valve 24 is in a fully open state, forcing all high-temperature water to flow through the cooler 25 to improve the heat dissipation effect and avoid insufficient cooling.

When the diesel engine is at ultra-high temperature, that is, under extreme high temperature conditions, the first control valve 30 is opened to activate the parallel state of the first and second fresh water circulation pipelines. The cooling water output from the diesel engine flows through the three-way pipe 22 and is divided into two channels. After one channel flows through the thermostatic three-way valve 24, it all flows to the cooler 25 and then enters the collecting pipe 29; the other channel enters the fresh water tank through the return pipe 21. 1; The cold water pre-stored in the fresh water tank 1 flows through the one-way valve 4 and merges with the cooled water in the collecting pipe 29, and then is re-inputted into the diesel engine 11 through the fresh water pump 5 for a reciprocating cycle. At this time, there are two cooling paths, one is cooled by the cooler 25, and the other path has the longest flow path and flows through the fresh water tank 1. The natural heat dissipation of the pipeline is the largest, thereby achieving the maximum heat dissipation effect to cope with instantaneous extremes. high temperature conditions.

Among them, an exemplary control method uses the pressure sensor 8 and the temperature sensor 9 on the pipeline to collect water temperature and pressure signals, and then controls the opening or closing of the first control valve 30 through electrical signals.

Through the above implementation, the advantages compared with the existing technology are:

(1) Through multiple cooling routes, the adaptive range of water temperature is expanded and the influence of unstable seawater temperature is reduced.

(2) Adapt to the calorific value of the diesel engine under different working conditions, so that the diesel engine has good performance under high/low working conditions, and the diesel engine has high effective efficiency.

(3) When the diesel engine is cold, the cooler 25 does not work, which is beneficial to combustion, the fuel consumption rate is too low, and the economic performance is good; when the diesel engine is overheated, rapid cooling measures are reserved to avoid damage to diesel engine parts and extend the service life.

(4) When the diesel engine is operating normally, the thermostatic three-way valve 24 is used to continuously adjust the water flow into the cooler 25 to ensure that the water temperature fluctuates less when the diesel engine is operating normally, which is beneficial to the long-term operation of the diesel engine.

In short, by setting up multiple cooling routes, the adaptive range of water temperature is expanded, the influence of unstable seawater temperature is reduced, the adaptability of the diesel engine in different working conditions is improved, and excessive cooling or insufficient cooling is avoided.

The parts not described in detail in the present invention are prior art; for those of ordinary skill in the art, the technical features of the above embodiments can be combined in any way. In order to simplify the description, each technical feature in the above embodiments is not described. All possible combinations of features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims (6)

1. A cooling system of a single-cylinder diesel engine test bed comprises an external fresh water circulation pipeline connected with an internal cooling pipeline of a diesel engine and an external sea water circulation pipeline connected with an internal heat exchanger of the diesel engine; the method is characterized in that: the fresh water circulation pipeline comprises three fresh water circulation paths, namely a first fresh water circulation pipeline, a second fresh water circulation pipeline and a third fresh water circulation pipeline;

the outlet end of the fresh water tank (1) is communicated with a one-way valve (4), the outlet end of the one-way valve (4) is communicated with a fresh water pump (5), and the outlet end of the fresh water pump (5) is connected with a water inlet of an internal cooling pipeline of the diesel engine; the water outlet of the cooling pipeline inside the diesel engine is connected with a three-way pipe (22) and is used for outputting two paths of cooling water, namely a straight-through pipeline and a bypass pipeline; the straight-through pipeline comprises a return pipe (21) with one end communicated with the three-way pipe (22), and the other end of the return pipe (21) is directly communicated with the fresh water tank (1) to form the first fresh water circulation pipeline;

the bypass pipeline comprises a constant temperature three-way valve (24) with one end communicated with the three-way pipe (22); one outlet end of the constant temperature three-way valve (24) is communicated with a cooler (25), and the outlet end of the cooler (25) is communicated with a collecting pipe (29); the outlet end of the collecting pipe (29) is connected to a pipeline between the fresh water pump (5) and the one-way valve (4) to form the second fresh water circulation pipeline;

the other outlet end of the constant temperature three-way valve (24) is communicated with the collecting pipe (29) to form the third fresh water circulation pipeline;

the water return pipe (21) is provided with a first control valve (30) for controlling the communication or closing of the water return pipe (21).

2. A single cylinder diesel engine test stand cooling system as defined in claim 1, wherein: the seawater circulation pipeline comprises a seawater tank (12) with one end communicated with a water outlet of the internal heat exchanger of the diesel engine, wherein the outlet end of the seawater tank (12) is communicated with a seawater filter (19), the outlet end of the seawater filter (19) is communicated with a seawater pump (20), and the outlet end of the seawater pump (2) is communicated with a water inlet of the internal heat exchanger of the diesel engine;

a seawater inlet pipe (17) is arranged on the seawater tank (12) and is used for injecting seawater into the seawater tank (12); the lower end of the seawater inlet pipe (17) stretches into the seawater tank (12) and is connected with a ball float valve (15) which is used for closing the seawater inlet pipe (17) after the seawater tank (12) is filled.

3. A single cylinder diesel engine test stand cooling system as defined in claim 2, wherein: a filter (3) is arranged on the pipeline between the fresh water tank (1) and the one-way valve (4); a stop valve (2) is also arranged on the pipeline between the filter (3) and the fresh water tank (1);

a first rubber pipe section (10) is arranged at the tail end of a pipeline connected with the outlet end of the fresh water pump (5) and connected with the water inlet of the internal cooling pipeline of the diesel engine, and is used for buffering the vibration of the diesel engine; a temperature sensor (9) and a pressure sensor (8) are arranged on the pipeline between the first rubber pipe section (10) and the fresh water pump (5).

4. A single cylinder diesel engine test stand cooling system according to claim 3, wherein: a second rubber pipe section (31) is arranged on the pipeline between the water return pipe (21) and the three-way pipe (22); and a third rubber pipe section (32) is arranged on the pipeline between the constant-temperature three-way valve (24) and the three-way pipe (22) and is used for buffering the vibration of the diesel engine.

5. The single cylinder diesel test stand cooling system as set forth in claim 4, wherein: a pipeline filter (23) is arranged on the pipeline between the third rubber pipe section (32) and the constant temperature three-way valve (24).

6. A single cylinder diesel engine test stand cooling system as defined in claim 2, wherein: the device also comprises an electric valve (16) and a water injection pipe (18); one end of the water injection pipe (18) is connected to the part of the seawater inlet pipe (17) positioned outside the seawater tank (12), and the other end of the water injection pipe bypasses the seawater tank (12) and is communicated with a pipeline between the seawater filter (19) and the seawater tank (12);

the electric valve (16) is arranged on the seawater inlet pipe (17) and is positioned between the floating ball valve (15) and the connecting point of the water injection pipe (18) and the seawater inlet pipe (17);

the water injection pipe (18) is provided with a second control valve for controlling the communication or closing of the water injection pipe (18).