The Current Status and Trends of Marine Pump Development

1. Application of Pumps on Ships

In various types of ships, a large number of mechanical and electrical equipment are needed to ensure their navigation and operational performance, meeting various different needs. Among the mechanical equipment on ships, pumps are a significant type, with a large quantity, diverse varieties, and important functions.

Generally, we refer to the pumps used on ships and the shore pumps serving ships as marine pumps. To ensure the normal navigation or mooring of the ship, and to guarantee the stability, buoyancy, habitability, vitality, and the completion of certain special missions of the ship, a certain number of marine pumps that can perform corresponding functions are required. These pumps are not only installed in the ship's power systems, cargo handling, life support, and other specialized systems, but are also equipped in certain auxiliary devices of the ship.

According to incomplete statistics, among various auxiliary mechanical equipment on ships, the total number of various types and different uses of marine pumps accounts for about 20% to 30% of the total amount of ship mechanical equipment. The total power consumed by marine pumps, depending on the ship's performance, functions, and equipment configuration, accounts for about 5% to 15% of the total energy consumption of the ship.

In addition, the price of marine pumps also occupies a relatively large proportion of the ship's equipment costs. In the total construction cost, marine pumps account for about 4% to 8% of the total equipment costs of the ship.

2. Technical Requirements for Marine Pumps

Due to the independence of ships and their requirements in terms of navigation capability, load capacity, operational performance, and size and weight, marine pumps inevitably have some special technical requirements that differ from pumps used for other purposes and land-based pumps. These special requirements are generally referred to as marine conditions.

It is precisely because of these marine conditions that marine pumps have certain special characteristics in terms of parameter selection, structural design, manufacturing, material selection, testing methods, acceptance standards, and operating conditions. If we specify the main points, they can be roughly summarized into the following main aspects:

(1) Reliable operating performance, with no cavitation damage issues.

(2) Low operational vibration and good vibration resistance.

(3) Low mechanical noise and liquid noise.

(4) Small size, light weight, and minimal space occupation.

(5) Ensure normal operation under tilting and swaying conditions.

(6) Sufficient impact resistance.

(7) Good corrosion resistance and wear resistance.

(8) Reliable sealing structure and sealing performance.

(9) Easy disassembly and assembly without special tools.

(10) High degree of generalization, etc.

3. Development of the Marine Pump Manufacturing Industry

Before liberation, China did not have its own marine pump manufacturing industry; the pumps used on various powered small ships were basically land-based pumps or land-derived pumps. After liberation, China established its own shipbuilding industry. During the shipbuilding imitation phase, most marine pumps were produced by shipbuilding manufacturers themselves.

In the 1960s, with the development of the shipbuilding industry, shipyards could no longer meet the production needs of marine pumps, thus shifting to pump manufacturing factories.

The factories producing marine pumps include Shanghai Pump Factory and Tianjin Industrial Pump Factory, which produced several varieties of the first batch of marine pump products according to marine pump technical standards.

With the rapid development of the shipbuilding industry and the needs for building ships and special vessels, many large and medium-sized pump factories, such as Shenyang Pump Factory, Changsha Pump Factory, and Chongqing Pump Factory, also successively trial-produced and manufactured certain large and medium-sized marine pumps.

4. Research Achievements in Marine Pump Technology

The development of the shipbuilding industry is a microcosm of the development of the national economy and the improvement of the country's scientific and technological level. With the development of China's shipbuilding industry, marine pumps in China have continuously developed, improved, and become increasingly refined in terms of scientific research, design, production, and process levels. This is not only due to the full absorption and utilization of design experience, production technology, and research achievements from other pump industries but also because of the uninterrupted scientific research work carried out over more than 40 years regarding marine pump conditions and the successful application and promotion of the results in design and production practice.

Research on hydraulic models is one of the early projects that achieved results. The series of marine pumps designed in the 1980s generally have efficiencies higher than the specified values of the original JB3559-1984 and are close to or reach the international advanced level of similar products at the same time. In addition, a series of gratifying research achievements have been made in the design of high cavitation performance pumps, self-priming pump design and self-priming time calculation, selection of anti-corrosion materials, research on water-lubricated bearings, development of high-pressure and variable pressure mechanical seals, as well as standardization, serialization, and generalization of products. Significant achievements have also been made in solving the calculation methods for special-purpose pumps, improving the product structure of pumps, and manufacturability, contributing beneficially to the development of our shipbuilding industry and equipment construction.

5. Trends in Marine Pump Technology Development

With the development of science and technology and the increasing technical requirements of ship pump systems design, usage, and shipowners for marine pump technology, the research and design departments of marine pumps have to continuously carry out research on the theoretical basis and engineering technical issues of marine pumps. Based on the achievements already made, the current and future planned research trends mainly include:

(1) Development of large pumps and special-purpose pumps, including special sealing pumps, seal-less pumps, and pumps specifically for special ships.

(2) Simplifying and improving the structure of pumps to facilitate installation and maintenance on ships, reducing the workload of maintenance and lowering the technical requirements for operational maintenance personnel.

(3) Conducting research on the economy of marine pumps themselves and pump systems, allowing pump designers and users to jointly explore ways to improve the efficiency of the pumps themselves and the operational efficiency of the pump systems.

(4) Using advanced technology and equipment to enhance the automation, speed regulation, and control level of marine pumps, enabling both on-site control and remote control, along with digital centralized data collection and processing.

(5) Adding new content to reliability and maintainability design calculations and evaluation standards in the product design calculation process, and developing fault prediction technology.

(6) Develop, apply, and promote new engineering materials, fully focusing on various corrosion resistance properties and compatibility in media while ensuring mechanical performance.

(7) Fully consider the installation and operating environmental conditions of marine pumps, improve the vibration resistance of the pump set, and reduce its operational vibration, mechanical noise, and fluid noise.

(8) Improve the standardization, serialization, and universality of internal pump components, reducing the number of specialized parts in the series products to minimize the spare parts on ships.

Six, Major Existing Problems

Based on the current situation, it can be considered that there is still a significant gap between the technical level and production status of marine pumps in our country and that of developed countries internationally, which is far from the grand goal of becoming a major shipbuilding nation in the near future. Therefore, it should be recognized that there are current shortcomings, and efforts should be made to improve the situation in the shortest possible time.

Overall, the main problems in the marine pump industry currently include the following aspects:

(1) Severe shortage of technical strength, which is reflected in a significant gap in the team of professional technical personnel in water pumps, as well as a lack of high-level technical talents.

(2) Serious lack of research and development investment; a considerable number of enterprise leaders do not regard technological development as the foundation and hope for the survival and development of the enterprise, neglecting technological innovation and research investment.

(3) Outdated production design, backward manufacturing processes, and weak quality awareness result in products that do not fully meet the design requirements, leading to poor product quality.

(4) The variety and specifications of products are too few, and many large and special-purpose marine pump products are still blank. The standardization, serialization, and universality of products are relatively low.

(5) The management mechanism is not sound enough; there is a certain degree of unfair competition, and the quality of pre-sale and after-sale services for products is poor; the completeness of products is lacking.

In summary, marine pumps are a type of product with certain characteristics, which still need further development and have bright prospects for development. Let us work together.