scholarly journals Overview of electric pump units for spacecraft thermal control systems

2021 ◽  
Vol 5 (4) ◽  
pp. 198-207
Author(s):  
E. B. Korotkov ◽  
O. V. Shirobokov ◽  
S. A. Matveev ◽  
Z. A. Yudina

The paper reports a brief description of spacecraft operating conditions, the main reasons of heating and thermal gradient appearance and need to reassign the thermal energy. Active thermal control systems and their advantages are considered, spacecraft for which the use of this type of thermal control systems is a priority. The electric pumping unit is pointed as a key unit of active thermal control systems. The electric pump unit is considered from the as the electromechanical system, its key elements are pointed. A description of the preferred pump types is reported and the types of active thermal control systems are briefly discussed. The foreign and domestic operating experience of spacecraft electric pumping units, the features of their designs are considered, the most common types of key elements are determined. Based on the results of the review, it is concluded that the most relevant layout of the electric pump unit is a centrifugal electrical pump with a brushless DC motor and hydrodynamic bearings. It is also indicated that the electric pump unit is a product with a long lifetime, which complicates the task of monitoring the technical condition in order to prevent failure.

Author(s):  
N I Smirnov ◽  
N N Smirnov ◽  
M V Prozhega ◽  
S A Matveev ◽  
O V Shirobokov ◽  
...  

2021 ◽  
Vol 5 (4) ◽  
pp. 217-226
Author(s):  
Yu. A. Zhukov ◽  
E. B. Korotkov ◽  
S. A. Matveev ◽  
N. S. Slobodzyan ◽  
O. V. Shirobokov

The work is devoted to the protection of a spacecraft from the influence of unacceptable internal vibration sources. The urgency of reducing the vibration activity on board the spacecraft to improve the accuracy of the target equipment is indicated. A particular problem of vibration protection of the spacecraft platform from a vibration source – an electric pump unit of a liquid thermal control system – is being solved. The basic requirements for electric pump unit vibration protection have been determined. Possible ways to reduce the level of vibration excited by the electric pump unit on the surface of the spacecraft fixation are considered. Particular attention is paid to such vibration protection methods as damping and vibration isolation, implemented by installing special vibration protection devices between the source (electric pump unit) and the object (spacecraft) – vibration isolators and vibration dampers. The principles of operation of vibration dampers and vibration isolators, the most common materials for vibration dampers are described. Examples of constructive solutions for linear single-axial vibration isolators are considered, recommendations for the use of promising products are developed. Particularemphasis is placed on the use of metal rubber as a material for vibration isolators. With regard to a specific design of electric pump unit, a diagram of the spatial structure of vibration isolation is proposed. Formulas for calculation are given in detail, a mathematical model of the vibration isolation system is developed. The procedure for calculating the parameters of the system has been formed. Based on the model, the maximum possible level of vibration suppression in the mid-frequency region was determined. Minimum required number of operable pixels was identified for monitoring the water surface with sufficient accuracy and reliability.


Author(s):  
Stanislav A. Matveev ◽  
Evgeny B. Korotkov ◽  
Yuri A. Zhukov ◽  
Nikita S. Slobodzian ◽  
Mikhail I. Nadezhin ◽  
...  

Modern diagnostics methods ensuring the safety of production and operation, as well as the improvement of functional characteristics of electromechanical systems’ are discussed, method of diagnostics according to the spectrum and hodograph of the engine’s equivalent current is presented. Functional concept is presented for the system of control, diagnostic and monitoring of technical condition of thermal control systems’ electromechanical part in the spacecraft. The decision-making and forecasting algorithm for the operational resource is based on ground-based studies and diagnostic results. This approach to device diagnostics and monitoring is also used in other servo drives, mechatronic and robotic systems of space vehicles and other objects that are inaccessible and left unattended. Hardware-algorithmic implementation of the system is described, recommendations on the components base selection are given.


2020 ◽  
Vol 23 (2) ◽  
pp. 48-51
Author(s):  
V. KONDRATENKO ◽  
◽  
V. KALYNYCHENKO ◽  

Mine drainage systems, which are used at the main drainage of mining enterprises, have a drive capacity of up to 1600kW. To reduce non-productive energy losses, as well as for the continuous operation of the mining company, mine pumps must be energy efficient and reliable. Analysis of downtime of drainage systems shows that the weak point is the unloading device. This fact can lead not only to the failure of the pumping unit, but also to possible prolonged downtime of the mine. The main disadvantage of the existing disk unloading devices of mine pumps is their low reliability and low service life, due to the rapid wear of the components of the unloading unit. The most vulnerable elements of the unloading device are the unloading rings. The need for frequent replacement and adjustment of the elements of the discharge unit is associated with disassembly and assembly of the pump directly in the pump chamber. Such actions require significant costs of unproductive manual labor of service personnel, and rapid wear of parts of the unloading device necessitates their constant replenishment. Malfunctions in the unloading device can cause significant pump failures. To increase the reliability and energy efficiency of mine drainage systems, the method of control of the unloading device was used. During the experimental studies it was found that cavitation phenomena during the operation of pumping units are absent and, accordingly, can not be the cause of wear of the elements of the unloading unit. When the pumps are operating in steady state, the displacement of the rotors was monitored for 3-4 hours on each pump unit. After data processing, it was obtained that the wear of the surface of the unloading rings occurs at a rate of 0.05-0.15mm in one hour. To determine the wear of the rings of unloading during start-up - stop of the pump, at first the indicators of measuring devices at the established mode of operation of the pump unit were fixed. Then the pump was turned off and on again. After starting the pump unit, we made sure that the operating mode of the unloading device did not change and compared the readings of the shaft position indicator before stopping and after starting the pump. From the measurements made it followed that stopping and starting the pump does not lead to noticeable wear of the unloading device. Therefore, it can be assumed that mainly the wear of the discharge rings occurs during the steady operation of the pump unit.


2018 ◽  
Vol 170 ◽  
pp. 03017 ◽  
Author(s):  
Alexey Dmitriev ◽  
Vyacheslav Gerasimov

The expediency of using a variable frequency drive for pumping units was repeatedly proved both from the point of view of the economic component and the technological one. However, the construction of automatic control systems for the operating parameters of pumping stations is mainly based on maintaining the pressure setpoint and does not include monitoring the efficiency of the aggregates working in the group and, the more so, its regulation. In this paper, an algorithm is developed for the energy efficient management of centrifugal pump units, which allows not only maintaining the pressure setpoint, but also optimizing their efficiency.


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