# Investigation of Self-Driven Profiler with Buoyancy Adjusting System towards Ocean Thermal Energy

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## Abstract

**:**

## 1. Introduction

## 2. Design of the Self-Driven Buoyancy Regulation System

## 3. Dynamic Performance of the Buoyancy Regulation System

- (1)
- The initial energy of the profiler comes from the ocean thermal energy. The conversion of the ocean thermal energy to the potential energy of the high-pressure fluid in the accumulator is a slow process. It is assumed that the initial source of energy is the accumulator.
- (2)
- The solidification of the phase change material is a very slow process. It is assumed that the solidification shrinkage rate of the phase change material is the same as the oil discharge rate of the inner cylinder.
- (3)
- The melting of the phase change material is a slow change process. It can be assumed that the melting and expansion rate of the phase change material is the same as the oil charging rate of the accumulator.
- (4)
- The accumulator releases oil for a short time, which is regarded as an isothermal process.

#### 3.1. Float Control

#### 3.2. Sink Control

#### 3.3. PCM Solidification Process

#### 3.4. PCM Melting Process

## 4. Mathematical Model of the Flow Control System

#### 4.1. Key Parameters Calculation

#### 4.1.1. Accumulator Fluid Capacity

#### 4.1.2. Fluid Capacity of Inside Cylinder and Outside Cylinder

#### 4.1.3. Fluid Resistance of Valves

#### 4.2. State Equation Construction

#### 4.3. Simulation Results and Analysis

## 5. Experimental Research of Profiler Driven by Ocean Thermal Energy

## 6. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Conflicts of Interest

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**MDPI and ACS Style**

Xia, Q.; Muhammad, G.; Chen, B.; Zhang, F.; Zhang, Z.; Zhang, S.; Yang, C.
Investigation of Self-Driven Profiler with Buoyancy Adjusting System towards Ocean Thermal Energy. *Appl. Sci.* **2021**, *11*, 7086.
https://doi.org/10.3390/app11157086

**AMA Style**

Xia Q, Muhammad G, Chen B, Zhang F, Zhang Z, Zhang S, Yang C.
Investigation of Self-Driven Profiler with Buoyancy Adjusting System towards Ocean Thermal Energy. *Applied Sciences*. 2021; 11(15):7086.
https://doi.org/10.3390/app11157086

**Chicago/Turabian Style**

Xia, Qingchao, Gul Muhammad, Bingzhe Chen, Feng Zhang, Zhifeng Zhang, Sheng Zhang, and Canjun Yang.
2021. "Investigation of Self-Driven Profiler with Buoyancy Adjusting System towards Ocean Thermal Energy" *Applied Sciences* 11, no. 15: 7086.
https://doi.org/10.3390/app11157086