Submarine separated gravity heat pipe test device and test method

Abstract

The present invention proposes a submarine separated gravity heat pipe test device and a test method thereof. The submarine separated gravity heat pipe test device includes a heat source mechanism, a cooling mechanism, and a testing mechanism. The cooling mechanism includes a seawater tank and a chiller and a seawater circulation pump connected thereto via a pipeline. During the condenser test, the condenser is located inside the seawater tank, and the bottom end surface of the seawater tank is located above the top surface of the evaporator. The heat source mechanism includes a freshwater pump, a freshwater tank, and a first heating device connected to the evaporator's circulating water channel via a pipeline. The testing mechanism includes a temperature sensor and a flow meter installed on the heat source mechanism and the cooling mechanism pipeline. The submarine separated gravity heat pipe test device can simulate the actual installation state of the separated gravity heat pipe on a boat and the seawater headflow environment around the outboard condensing end. It can be used to carry out onshore bench tests such as variable operating condition performance tests and startup characteristic tests of the submarine separated gravity heat pipe, thereby facilitating the design and installation of submarine separated gravity heat pipes.

Description

Technical Field

[0001] The present invention relates to the technical field of submarine auxiliary equipment design, and in particular to a submarine separated gravity heat pipe test device and a test method thereof. Background Art

[0002] A separate gravity heat pipe is a heat exchange device driven by the pressure difference caused by the phase change of the working fluid and the force of the working fluid's gravity. Submarine separate gravity heat pipes place the evaporator end inside the cabin and the condenser end outside. Using the outboard seawater to flush the condenser end heat exchange pipes, passive cooling of the cabin's heat load is achieved. The outboard cold seawater temperature and the oncoming flow velocity are significantly affected by the boat's navigation conditions and often determine the separate gravity heat pipe's variable operating performance. Furthermore, installation factors such as the height difference between the hot and cold ends of the submarine separate gravity heat pipe, the working fluid charge, and the piping layout can also affect its heat exchange capacity. Without sufficient onshore testing and verification, direct installation on a boat would incur significant technical and engineering risks.

[0003] Based on the above background, it is necessary to construct a submarine separated gravity heat pipe test device and method. Summary of the Invention

[0004] The main purpose of the present invention is to provide a test device and a test method for a submarine-type separated gravity heat pipe, so as to realize the performance test of the separated gravity heat pipe.

[0005] In order to achieve the above-mentioned object, the present invention proposes a potential separation type gravity heat pipe test device, comprising a heat source mechanism for heating the evaporator of the gravity heat pipe, a cooling mechanism for cooling the condenser of the gravity heat pipe, and a testing mechanism, wherein:

[0006] The cooling mechanism includes a seawater tank for containing seawater, and a chiller and a seawater circulation pump connected to the seawater tank via a pipeline. During the test, the condenser is located inside the seawater tank, and the bottom end surface of the seawater tank is located above the top surface of the evaporator.

[0007] The heat source mechanism includes a fresh water pump, a fresh water tank and a first heating device connected to the evaporator circulating water channel through a pipeline;

[0008] The testing mechanism includes a temperature sensor and a flow meter installed on pipelines of the heat source mechanism and the cooling mechanism.

[0009] Preferably, the cooling mechanism further comprises a flow balancing pipe located inside the seawater tank for uniforming the flow rate of seawater.

[0010] Preferably, the internal water inlet and outlet sides of the seawater tank are both fixedly connected with flow balancing pipes.

[0011] Preferably, the flow balancing pipe includes a main pipe and multiple branch pipes connected to the main pipe, the side walls of the branch pipes are evenly distributed with multiple water outlets in the height direction, and the main pipe is sealed to the inlet or outlet at the bottom of the seawater tank.

[0012] Preferably, the cooling mechanism further comprises a second heating device located on the pipeline between the chiller and the seawater tank.

[0013] Preferably, the first heating device and the second heating device are both electric heating devices.

[0014] Preferably, the testing mechanism includes a first temperature sensor installed on the pipe at the inlet of the evaporator circulating water channel, a second temperature sensor installed on the pipe at the outlet of the evaporator circulating water channel, a first flow meter installed on the pipe between the fresh water tank and the evaporator, a third temperature sensor installed on the pipe on the inlet side of the seawater tank, a fourth temperature sensor installed on the outlet side of the seawater tank, a second flow meter installed on the outlet pipe of the seawater tank, and a flow meter installed inside the seawater tank.

[0015] Preferably, the testing mechanism also includes a fifth temperature sensor and a sixth temperature sensor for measuring the top temperature and bottom temperature of the evaporator, and a seventh temperature sensor located on the internal pipe of the gravity heat pipe for measuring the evaporator outlet temperature, an eighth temperature sensor for measuring the evaporator inlet temperature, a ninth temperature sensor for measuring the condenser inlet temperature and a tenth temperature sensor for measuring the condenser outlet temperature.

[0016] The present invention further proposes a test method based on the above-mentioned latent separation gravity heat pipe test device, which includes the following steps when conducting a heat transfer performance test:

[0017] Start the cooling mechanism, adjust the power of the chiller and the flow of the seawater pump, so that the water temperature and flow rate of the cooling system can be changed to simulate different upstream flow environments;

[0018] The heat source mechanism is started, and the flow rate of the fresh water pump and the power of the first heating device are adjusted to adjust the fresh water flow rate and heat load to adjust the test conditions. The heat pipe automatically starts working under the drive of the temperature difference between the cooling mechanism and the heat source mechanism;

[0019] When the fresh water outlet temperature changes less than the first preset value within ten minutes, the heat pipe reaches a stable working state, and the parameters of each measuring point are recorded at this time;

[0020] The rated heat transfer, fresh water side heat transfer coefficient and sea water side heat transfer coefficient are calculated based on the parameters of each measuring point.

[0021] Preferably, the starting characteristic test includes the following steps:

[0022] Start the fresh water pump of the heat source mechanism and the sea water pump of the cooling mechanism at the same ambient temperature, and confirm that the temperature difference between the fresh water temperature T1 and the sea water temperature T3 is less than a second preset value;

[0023] Turn on the first heating device of the heat source mechanism and record the performance parameters of the separated gravity heat pipe from startup to stable operation;

[0024] The starting characteristic curve is obtained according to the performance parameters.

[0025] The proposed submarine-use separated gravity heat pipe test device can simulate the actual submarine installation conditions of the separated gravity heat pipe and the seawater headwater environment around the outboard condenser end. This device can be used to conduct onshore bench tests such as variable operating performance tests and startup characteristics tests on submarine-use separated gravity heat pipes. The test results are used to evaluate the effectiveness of the separated gravity heat pipes on submarines, thereby facilitating the design and installation of submarine-use separated gravity heat pipes. Furthermore, the present submarine-use separated gravity heat pipe test device has the advantages of a simple structure, ease of implementation, low manufacturing cost, and a simple and convenient testing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the principle of the submarine separated gravity heat pipe test device of the present invention;

[0027] Figure 2 This is a schematic structural diagram of the submarine separated gravity heat pipe test device of the present invention;

[0028] Figure 3 Schematic diagram of the structure of the flow-sharing tube in the submarine separated gravity heat pipe test device of the present invention;

[0029] Figure 4 This is a graph of heat transfer performance under varying operating conditions obtained using the test method of the potential-separated gravity heat pipe test device of the present invention;

[0030] Figure 5 This is a startup characteristic curve diagram obtained by the test method of the submarine separated gravity heat pipe test device of the present invention.

[0031] In the figure, 1-evaporator, 2-condenser, 3-working medium steam pipeline, 4-working medium condensate pipeline, 5-fresh water pump, 6-fresh water tank, 7-first heating device, 8-first flow meter, 9-chiller, 10-second heating device, 11-seawater circulation pump, 12-second flow meter, 13-seawater tank, 14-flow equalizing pipe, 15-main pipeline, 16-water outlet.

[0032] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0033] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] It should be noted that in the description of the present invention, the terms "transverse," "longitudinal," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] The invention provides a submarine separated gravity heat pipe test device.

[0036] Reference Figures 1 to 3 In this preferred embodiment, a latent separation type gravity heat pipe test device includes a heat source mechanism for heating the evaporator 1 of the gravity heat pipe, a cooling mechanism for cooling the condenser 2 of the gravity heat pipe, and a testing mechanism, wherein:

[0037] The cooling mechanism includes a seawater tank 13 for containing seawater, and a chiller 9 and a seawater circulation pump 11 connected to the seawater tank via a pipeline. During testing, the condenser 2 is located inside the seawater tank 13, and the bottom end surface of the seawater tank 13 is located above the top surface of the evaporator 1.

[0038] The heat source mechanism includes a fresh water pump 5, a fresh water tank 6 and a first heating device 7 connected to the circulating water channel of the evaporator 1 through a pipeline;

[0039] The testing mechanism includes a temperature sensor and a flow meter installed on pipelines of a heat source mechanism and a cooling mechanism.

[0040] Reference Figure 1 The separated gravity heat pipe mainly consists of an evaporator 1, a condenser 2, a working medium steam pipeline 3, and a working medium condensate pipeline 4. The cross-sectional area of ​​the seawater tank 13 should be considered to reduce the boundary layer effect and minimize the flow rate of the seawater pump group.

[0041] Reference Figure 2 , the seawater tank 13 can be installed above the evaporator 1 through the stand. The stand height can be adjusted, so as to facilitate the adjustment of the height difference between the condenser 2 and the condenser 2 of the separated gravity heat pipe. The test stand adopts a double-layer frame structure, such as Figure 2As shown, the upper layer is arranged with a separate gravity heat pipe condenser 2 and a high-mounted water tank 13, and the lower layer is arranged with an evaporator 1, a fresh water tank 6, a first heating device 7, a flow meter 8, a chiller 9 and other main equipment and pipelines; the condenser 2 is installed in the high-mounted water tank 13.

[0042] Furthermore, the cooling mechanism also includes a flow balancing pipe 14 located inside the seawater tank 13 for uniform seawater flow. By providing the flow balancing pipe 14, different uniform flow environments of seawater can be simulated. The internal water inlet and outlet sides of the seawater tank 13 are fixedly connected to the flow balancing pipe 14.

[0043] Combined with reference Figure 1 and Figure 3 This embodiment proposes a specific structure of a flow equalizing pipe 14: the flow equalizing pipe 14 includes a main pipe 15 and multiple branch pipes connected to the main pipe 15, and the side walls of the branch pipes are evenly distributed with multiple water outlet holes 16 in the height direction. The main pipe 15 is sealed with the inlet or outlet at the bottom of the seawater tank 13.

[0044] Furthermore, the cooling mechanism includes a second heating device 10 located on the pipeline between the chiller 9 and the seawater tank 13. In this embodiment, both the first heating device 7 and the second heating device 10 are electrically powered, making it easier to control the heating power. Sometimes, excessive cooling power can cause the seawater temperature to drop too low. In this case, the second heating device 10 adjusts the temperature of the seawater in the seawater tank 13.

[0045] Specifically, in this embodiment, the testing mechanism includes a first temperature sensor installed on the pipe at the inlet of the circulating water channel of the evaporator 1 (the measured temperature is T1), a second temperature sensor installed on the pipe at the outlet of the circulating water channel of the evaporator 1 (the measured temperature is T2), a first flow meter 8 installed on the pipe between the fresh water tank 6 and the evaporator 1 (the measured flow rate is Ge), a third temperature sensor installed on the pipe on the inlet side of the seawater tank 13 (the measured temperature is T3), a fourth temperature sensor installed on the outlet side of the seawater tank 13 (the measured temperature is T4), a second flow meter 12 installed on the outlet pipe of the seawater tank 13 (the measured flow rate is Gc), and a flow meter installed inside the seawater tank 13 (the measured flow rate is v).

[0046] The test mechanism also includes a fifth temperature sensor (the measured temperature is T5) and a sixth temperature sensor (the measured temperature is T6) for measuring the top temperature and bottom temperature of the evaporator 1, and a seventh temperature sensor (the measured temperature is T7) located on the internal pipe of the gravity heat pipe for measuring the outlet temperature of the evaporator 1, an eighth temperature sensor (the measured temperature is T8) for measuring the inlet temperature of the evaporator 1, a ninth temperature sensor (the measured temperature is T9) for measuring the inlet temperature of the condenser 2, and a tenth temperature sensor (the measured temperature is T10) for measuring the outlet temperature of the condenser 2.10 In addition, the test mechanism also includes a controller electrically connected to all temperature sensors, flow meters, and flow rate meters. The controller collects and stores real-time data of multiple parameters for calculation.

[0047] Before the test of this submarine separated gravity heat pipe test device, the installation height of the evaporation end of the heat pipe in the lower layer of the test bench and the direction of the working medium pipeline can be adjusted to simulate the installation state of the separated gravity heat pipe on a real boat; during the test, the cooling system is first started, and different upstream flow environments can be simulated by changing the water temperature and flow rate of the cooling system. Then, the heat source system is started, and the fresh water flow and heat load are adjusted to the test conditions. When the characteristic temperature of the heat pipe is T2~T 10 If the temperature changes by less than 1°C within 30 minutes, the heat pipe is considered to have reached a stable working state and measurement can be started.

[0048] The heat transfer capacity is calculated according to formula (1):

[0049] Q = Ge × cp (T2-T1) (1)

[0050] Where: Q is the total heat transfer capacity of the system, kW; Ge is the mass flow rate of fresh water, kg / s; cp is the specific heat capacity at constant pressure, J / (kg·℃); T2 is the fresh water inlet temperature, unit: ℃; T1 is the fresh water outlet temperature, unit: ℃.

[0051] The heat transfer coefficient on the fresh water side is calculated according to formulas (2) and (3):

[0052] (2)

[0053] Q e =Q-Q1. (3)

[0054] Where: he-heat transfer coefficient on the fresh water side; - Inner surface area of ​​heat exchange tube of evaporator 1, m 2 ; - Average temperature outside the heat exchange tube of evaporator 1, °C; -Heat pipe operating temperature, °C; -Heat transfer of fresh water side heat pipe working medium, kW; Q1-heat leakage at evaporation end, kW.

[0055] The heat transfer coefficient on the seawater side is calculated according to formulas (4) and (5):

[0056] , (4)

[0057] Q c =Q-Q2. (5)

[0058] Where: h c -Heat transfer coefficient on the seawater side; Ac-inner surface area of ​​the heat exchange tube of condenser 2, m 2 ;Twc - Average temperature outside the heat exchange tube of condenser 2, °C;

[0059] Q c -Heat transfer from the working fluid of the heat pipe to the seawater side, kW; Q2-Heat leakage between the working fluid pipeline and the condensing end, kW.

[0060] The heat leakage is calculated using the following formula:

[0061] (6)

[0062] Where: -Heat leakage at the evaporation end or condensation end, kW; -Heat leakage coefficient, W / m 2 ℃;

[0063] -Surface area of ​​each heat leakage part, m 2 ; -Temperature difference between the outer surface of each heat leakage part and the environment, ℃.

[0064] Among them, T v 、T we and T wc Calculated using the following formula:

[0065] T v =(T5+T6+T7+T8+T9+T 10 ) / 6, (7)

[0066] T we = (T1 + T2) / 2, (8)

[0067] T wc = (T3 + T4) / 2. (9)

[0068] The submarine-use separated gravity heat pipe test apparatus proposed in this embodiment can simulate the actual installation state of a separated gravity heat pipe on a ship and the seawater headwater environment surrounding the outboard condenser end. This allows for onshore bench testing of the submarine-use separated gravity heat pipe, including variable operating performance testing and startup characteristics testing. The test results are used to evaluate the effectiveness of the separated gravity heat pipe on-ship applications, thereby facilitating guidance for the design and installation of submarine-use separated gravity heat pipes. Furthermore, this submarine-use separated gravity heat pipe test apparatus offers the advantages of a simple structure, ease of implementation, low manufacturing cost, and a simple and convenient testing process.

[0069] The invention provides a test method for a submarine separated gravity heat pipe test device.

[0070] In this preferred embodiment, a test method based on the above-mentioned submersible separated gravity heat pipe test device, when conducting a heat transfer performance test, includes the following steps:

[0071] Step S1, starting the cooling mechanism, adjusting the power of the chiller 9 and the flow rate of the seawater pump, so as to change the water temperature and flow rate of the cooling system to simulate different headwind environments;

[0072] Step S2, starting the heat source mechanism, adjusting the flow rate of the fresh water pump 5 and the power of the first heating device 7, so that the fresh water flow rate and heat load are adjusted to adjust the test conditions, and the heat pipe automatically starts to work under the temperature difference between the cooling mechanism and the heat source mechanism;

[0073] Step S3: When the fresh water outlet temperature (T2) changes less than a first preset value (which can be set to 1 degree Celsius) within ten minutes, the heat pipe reaches a stable working state, and the parameters of each measuring point are recorded;

[0074] Step S4, calculating the rated heat transfer capacity, the heat transfer coefficient on the fresh water side, and the heat transfer coefficient on the sea water side according to the parameters of each measuring point.

[0075] By changing the power of different chillers 9 and the flow rate of seawater pumps, the water temperature and flow rate of the cooling system are changed to simulate different upstream flow environments, thereby obtaining the variable working condition heat transfer performance of the separated gravity heat pipe, such as Figure 4 shown.

[0076] Rated operating conditions refer to cooling water inlet temperature of 24℃±1℃ and cooling water flow rate of approximately 0.1m / s.

[0077] Specifically, the test method of the submersible separated gravity heat pipe test device includes the following steps when conducting a startup characteristic test:

[0078] Step S10, starting the fresh water pump 5 of the heat source mechanism and the sea water pump of the cooling mechanism at the same ambient temperature, and confirming that the temperature difference between the fresh water temperature T1 and the sea water temperature T3 is less than a second preset value (which can be set to 1 degree Celsius);

[0079] Step S20, turning on the first heating device 7 of the heat source mechanism, and recording the performance parameters of the split-type gravity heat pipe from startup to stable operation;

[0080] Step S30: obtaining a startup characteristic curve according to the performance parameters.

[0081] The starting characteristic curve obtained by the above method is as follows: Figure 5 shown.

[0082] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A submarine separated gravity heat pipe test device, characterized in that: It includes a heat source mechanism for heating the evaporator of the gravity heat pipe, a cooling mechanism for cooling the condenser of the gravity heat pipe, and a testing mechanism, wherein: The cooling mechanism includes a seawater tank for containing seawater, and a chiller and a seawater circulation pump connected to the seawater tank via a pipeline. During the test, the condenser is located inside the seawater tank, and the bottom end surface of the seawater tank is located above the top surface of the evaporator. The heat source mechanism includes a fresh water pump, a fresh water tank and a first heating device connected to the evaporator circulating water channel through a pipeline; The testing mechanism includes temperature sensors and flowmeters installed on the pipes of the heat source mechanism and the cooling mechanism; the testing mechanism includes a first temperature sensor installed on the pipe at the inlet of the evaporator circulating water channel, a second temperature sensor installed on the pipe at the outlet of the evaporator circulating water channel, a first flowmeter installed on the pipe between the fresh water tank and the evaporator, a third temperature sensor installed on the pipe on the inlet side of the seawater tank, a fourth temperature sensor installed on the outlet side of the seawater tank, a second flowmeter installed on the outlet pipe of the seawater tank, and a flowmeter installed inside the seawater tank; the testing mechanism also includes a fifth temperature sensor and a sixth temperature sensor for measuring the top temperature and the bottom temperature of the evaporator tank, as well as a seventh temperature sensor located on the internal pipe of the gravity heat pipe for measuring the evaporator outlet temperature, an eighth temperature sensor for measuring the evaporator inlet temperature, a ninth temperature sensor for measuring the condenser inlet temperature, and a tenth temperature sensor for measuring the condenser outlet temperature.

2. The submarine separated gravity heat pipe test device according to claim 1, characterized in that: The cooling mechanism further comprises a flow balancing pipe located inside the seawater tank for uniforming the flow rate of seawater.

3. The submarine separated gravity heat pipe test device according to claim 2, characterized in that: The internal water inlet and outlet sides of the seawater tank are both fixedly connected with flow equalizing pipes.

4. The submarine separated gravity heat pipe test device according to claim 2, characterized in that: The flow balancing pipe includes a main pipe and multiple branch pipes connected to the main pipe. The side walls of the branch pipes are evenly distributed with multiple water outlets in the height direction. The main pipe is sealed with the inlet or outlet at the bottom of the seawater tank.

5. The submarine separated gravity heat pipe test device according to claim 1, characterized in that: The cooling mechanism further comprises a second heating device located on the pipeline between the chiller and the seawater tank.

6. The submarine separated gravity heat pipe test device according to claim 5, characterized in that: The first heating device and the second heating device are both electric heating devices.

7. A test method based on the submarine separated gravity heat pipe test device according to any one of claims 1 to 6, characterized in that: The heat transfer performance test includes the following steps: Start the cooling mechanism, adjust the power of the chiller and the flow of the seawater pump, so that the water temperature and flow rate of the cooling system can be changed to simulate different upstream flow environments; The heat source mechanism is started, and the flow rate of the fresh water pump and the power of the first heating device are adjusted to adjust the fresh water flow rate and heat load to adjust the test conditions. The heat pipe automatically starts working under the drive of the temperature difference between the cooling mechanism and the heat source mechanism; When the fresh water outlet temperature changes less than the first preset value within ten minutes, the heat pipe reaches a stable working state, and the parameters of each measuring point are recorded at this time; The rated heat transfer, fresh water side heat transfer coefficient and sea water side heat transfer coefficient are calculated based on the parameters of each measuring point.

8. The test method of the submarine separated gravity heat pipe test device according to claim 7, characterized in that: The starting characteristics test includes the following steps: Start the fresh water pump of the heat source mechanism and the sea water pump of the cooling mechanism under the same ambient temperature, and confirm that the temperature difference between the fresh water temperature and the sea water temperature is less than a second preset value; Turn on the first heating device of the heat source mechanism and record the performance parameters of the separated gravity heat pipe from startup to stable operation; The starting characteristic curve is obtained according to the performance parameters.

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