W artykule przeanalizowano przyczyny błędnego wykorzystania wskaźnika produktu krajowego brutto (PKB) przy ocenie wielkości i tempa wzrostu wytwarzanej w kraju produkcji. Z tych samych powodów wskaźnik PKB nie jest przydatny w ocenie efektywności prowadzonej w kraju polityki inwestycyjnej i inno-wacyjnej. Zaleca się zamianę wskaźnika PKB na wskaźnik dochodu krajowego brutto (DKB) i podaje się je-go definicję

Based on measurement results, an interpretation is presented of the tribological system boundary layer action in the form of a four-ball tester friction node. The evaluation was performed of the boundary layer action understood as transfer of energy Ep resulting from loading the tribological system in a determined time t with work lp, which may lead to breaking the boundary layer. That energy and time are the values unequivocally characterising the boundary layer action. This form of presenting the boundary layer action has also an advantage of offering a possibility of investigating it by carrying out precise measurements and expressing the results in a numerical form. Therefore, the proposed method of evaluating the boundary layer action deterioration process is the acoustic emission measurements

The paper presents proposal of scope of control surface for marine power plant of merchant ship, being an element of ship’s energy system and consists of devices and energy plants exchanging fuel energy into other kind of energy, auxiliary devices and others irrelevant to the energy conversion processes, but indispensable because of international safety at sea and environmental protection provisions. Accepted scope of control surface allows to derive useful energy, or total generated minus energy consumed for autonomous shipping, this is why the suggested term “autonomous ship’s power plant”. This way makes possible (among others) valuation of results of waste heat recovery system used on boar

In the paper has been described the Common Rail system, which operation is presented on the example of engine RT-flex 60C type. Three basic circuits have been dispersed in this system: low pressure circuit, high pressure circuit and electronically controlled system, but only low pressure circuit and high pressure circuit were discussed. Wave phenomena and fuel loss in the fuel pipe have been presented as an example of complex processes, which occur in the fuel apparatus of high pressure. For the description of shock waves disperse there has been considered the wave flow in thecentre, which fills the long pipe with variable section. The Euler’s equation, adiabatic equation and continuity equation were used to describe such flow. Advantages and disadvantages of the storage systems with fuel injection unit have been discussed in the resume

This paper deals with experimental selection of a cooling system of a brushless synchronous generator with permanent magnets and an additional excitation, designed and built in Department of Ship Electrical Power Engineering in Gdynia Maritime University. Three cooling system were tested: with an aluminium radiator and natural cooling with the aluminium radiator and an external fan and the aluminium radiator and two external fans. Results of thermal tests are presented for a machine with built-in thermocouples. The selection of cooling system for the investigated machine is based on the experimental results

The paper presents case of tool damage during valve seat machining process. The tool for valve seats machining was described, details of tool damage were characterized. Damage was illustrated by wrongly machined (destroyed) valve seat, cutting forces for correct valve seat machining and cutting forces for tool destruction case. For analysis was used LVDT contact sensor. General conclusions arising from tool damage process observation were presente

The paper presents cutting forces simulation method for valve seats machining. Cutting forces affecting on tool used for valve seats machining and mathematical relations used for simulating forces were described. Tool used for valve seats machining was presented and machining process was described. Analysis of tool setting against machined valve seat impact on area of the chip on tool blades was made by simulation. Simulated cutting forces for different tool settings against machined valve seat were presented. Test stand for verifying simulated cutting forces against measured cutting forces was characterized. General conclusions arising from simulations and further research plans were presente

The paper presents description of biogas utilization as a renewable energy source used for fueling cogeneration generating sets with IC engines. There are presented similarities of such systems to marine power plants and connected with this some propositions about utilization marine knowledge and experiences for developing polish decentralized engineering with biogas power plants

In the paper has been make an attempt to replace the conventional system of fuel dose control and injection passing angle with the elecrtronic control system, which has been realized this manner, that selected hydraulic accumulator, injector CR type and fuel dose controller has been attached to the marine engine. It has been as-sumed, that by controlling the current impulse of controller it is possible to model whichever size of fuel dose, injected to the combustion chamber and to control the injection lasting time. It has been presented the simplistic scheme of test stand and it has been described the basis of fuel dose controlling valve operation in the injector. The wave phenomenon and the flow loss in the fuel pipe of high pressure have been presente

The article presents results of operation investigations regarding one of the most important receivers of mechanical energy on dredgers: propellers. Operation investigations covered measurements of characteristic parameters of loading propellers on dredgers in two basic conditions of their work: dredging works and sailing at sea. Presented results are based on 10 dredgers (8 trailing suction hopper dredgers and 2 bucket dredgers). In the paper characteristics of spread of propellers loading, i.e. average value, standard deviation and coefficients of variations of loading spred are presented. Examples of load distribution propellers on chosen dredgers during some period of time are shown as well. Conclusions are formulated regarding average value of propellers loading and coefficients of variations of loading spred. Results presented in the paper will be used as a base for creation of random models describing real conditions of operation of dredgers’ power plants.

The quality of bilge waters collected in the machinery space during normal conditions and difficulties with the bilge water systems have been considered. Analyzed systems concern contemporary cargo vessels in which the reciprocating diesel engines constitute the ships propulsion. The proposal of the bilge water system, as part of the existing bilge water installations, has been presented. That system will increase the bilge water efficiency that is pumped out overboard of the ship, decreasing the number of the international law violations. More over the proposed bilge water system can lead to decreasing the operational ships costs and raise the operational effectiveness of the engineers department

Electric power estimation of contemporary container vessels for whole container capacity range is presented in the paper. The multiple regression model has been used to determine electric power, based on the container ships database created for that reason. During electric power calculations the division into ships with electric power created by shaft and diesel generators and vessels with diesel generators only was done

The article is presenting methodology and exemplifying effects of assigning the weighted average to the emission of toxic components of exhaust gases of the method of the preparation of petroleum based residues about various physical and chemical properties to burning. Waste is being burned after the preparation by: gravitational sedimentation, a homogenizing shredder-pump, a static homogeniser constructed at the Maritime University of Szczecin and serial connection of these two devices. Proposed methodology is tolerating on explicitly specification of the most profitable method of the preparation of petroleum waste to burning waste in auxiliary fired boilers

This study shows the importance of correct operation of controllable pitch propeller for the safety of navigation. Operation of pneumatic control of controllable pitch propeller in a ship’s power transmission system was identified. The results of the change of the actual setting value measurements of the pitch screw propeller in the function of the value of the control air pressure have been presented. Recorded differences were assigned to operational degradation of the technical state of the pitch propeller control system. They were further confronted with the relationships between the design and time of operation. Possible consequences of operating a controllable pitch propeller with such a defect, and its impact on the correct operation of a ship’s power transmission system have been outlined. Operational requirements were presente

W artykule podano metodykę projektowania statków rybackich, która pozwala zapewnić wibracje statku zadane według norm sanitarnych dla załogi w różnych kategoriach pomieszczeń

Renewable and CO2 – natural liquid fuels – biofuels such as vegetable oils, palm oils, coconut, sunflower and rape seed oils are today very appreciated in more and especially more European countries as the green energy sources for land and sea electrical power generation. The paper in the first part discusses the various controversial opinions on the rapidly growing production of vegetable oils for biodiesel production and the possibilities that this may cause higher food prices and spread famine in many countries. The second part of the paper highlights various technical issues of biofuels application on marine diesel engines. The pros and cons of biofuels application are given