RU2513321C1 - Spacecraft thermal control system - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to thermal control systems of, mainly, telecommunication satellites. Thermal control system comprises closed heat carrier circulation circuit. The latter includes electrically driven pump unit, pressure accumulator, manifolds of control panels and those of radiators. Said elements are interconnected by lengths of connection pipelines with inlet and outlet flow sections complying with those of said elements. Portion of lengths of said connection pipelines feature identical equivalent ID smaller than diameters of the other parts and total length that satisfies the definite relationship.

EFFECT: decreased sizes, higher reliability.

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Description

The present invention relates to spacecraft (SC) and can be used, for example, to create telecommunication satellites, thermal control systems (CTP) which contain a closed circulation circuit with a coolant (liquid or two-phase).

Known for such a STR made on the basis of the patent of the Russian Federation (RF) No. 2446997 [1]. In such STRs, the coolant circulates through the collectors of the panels on which the devices are installed, and radiators are provided by an electric pump unit (ENA). As a rule, for satellites of various powers (which must have been operating in orbit for at least 15 years), an ENA is used, qualified in previous developments for operating conditions in orbit and having stable flow-pressure characteristics. At the same time, the main criterion for choosing the ENA is to ensure the flow of coolant through the collectors is not less than the required value, which guaranteed ensures the operating temperature not more than the maximum allowable. Due to the fact that the powers of various satellites being developed, for example, differ from each other by up to two times, the required flow rates of the coolant provided by the ENA with the same flow-pressure characteristics also differ up to two times through the instrument collectors, i.e. for less powerful satellites, the coolant flow rate provided by the above ENA through the panel collectors will be significantly more than the coolant flow rate required for them (up to two times more).

However, as the analysis shows, in this case, due to the increased flow rate of the coolant through the collectors, which are connected to each other by connecting pipelines, the uncompensated kinetic moment will also increase (twice) (its value, in particular, is directly proportional to the flow rate of the coolant), due to the work of the STR (the work of the circulation circuit). Therefore, in this case, onboard the spacecraft, an additional mass of the working fluid is required for the spacecraft orientation and stabilization system (SOS).

Thus, the significant disadvantages of the known STR are the increased uncompensated kinetic moments from the working STR, which includes a qualified ENA, for less powerful satellites, leading to increased mass costs in the spacecraft SOS.

The aim of the invention is to eliminate the above significant disadvantages of the known technical solutions.

This goal is achieved by the fact that in the STR KA, which includes a closed liquid circuit with a circulating coolant, incorporating elements: an electric pump unit, a hydraulic accumulator, manifolds of panels on which the devices are installed, and radiators, which are interconnected by sections of connecting pipelines with input and output cross sections identical with the output and input sections of the above elements, some sections of the connecting pipelines are made with the same nominal equivalent an inner diameter smaller than the diameters of the other parts, with a total length that satisfies the following condition (which was established by the authors based on an analysis of the physical processes that occur during the operation of the STR):

$$L_{X\Sigma }=L_{\Sigma }\cdot \left(\frac{d_X^5}{d^5}-\mathrm{one}\right)-\frac{{\mathrm{<figure-callout\; id="5"\; label="d\; X"\; filenames="00000004.png"\; state="\{\{state\}\}">d\; </figure-callout>}}_X^{}\cdot \Delta p_{E\mathrm{<figure-callout\; id="2"\; label="N\; BUT\; V"\; filenames="00000004.png"\; state="\{\{state\}\}">N\; </figure-callout>}\mathrm{BUT}}}{V^{}},\text{(one)}$$

where L _X∑ , d _X is the total length and inner diameter of parts of sections of connecting pipelines having a smaller equivalent nominal internal diameter of the bore than the diameters of the remaining parts of connecting pipelines and collectors, m;

L _∑ - the total length of all sections of the connecting pipelines and collectors, m;

d is the nominal internal equivalent diameter of most sections of connecting pipelines and collectors (where d> d _X ), m;

Δp _ENA - pressure electric pump unit in which it provides performance - flow in the liquid circuit is equal to the required minimum permissible nominal value, Pa;

V is the required minimum permissible nominal value of the coolant flow rate in the collectors, at which the operating temperature of the devices is guaranteed to be no higher than the permissible value, m ³ / s;

K is the average statistical experimental coefficient of hydraulic resistance of one linear meter used in the fluid circuits of various connecting pipelines and collectors, kg / m ³ · s, which is, according to the authors, the essential distinguishing features of the proposed technical solution.

As a result of the analysis conducted by the authors of the well-known patent and scientific and technical literature, the proposed combination of essential distinguishing features of the claimed invention was not found in the known information sources and, therefore, the known technical solutions do not exhibit the same properties as in the claimed spacecraft thermal control system.

The schematic diagram of the proposed STR KA is shown in figure 1 - includes a closed liquid circuit with a circulating coolant, comprising in its composition elements: an electric pump unit 5, a hydraulic accumulator 6, manifolds of panels 1, 2 on which the devices are installed, and radiators 3, 4, which interconnected by sections of connecting pipelines 7.1-7.7 with input and output flow sections identical to the output and input sections of the above elements, some of the sections of connecting pipelines 8.1 and 8.2 are made with the same nominal nominal inner diameter, smaller than the diameters of the remaining parts, with a total length that satisfies the following condition:

$$L_{X\Sigma }=L_{\Sigma }\cdot \left(\frac{d_X^5}{d^5}-\mathrm{one}\right)-\frac{{\mathrm{<figure-callout\; id="5"\; label="d\; X"\; filenames="00000004.png"\; state="\{\{state\}\}">d\; </figure-callout>}}_X^{}\cdot \Delta p_{E\mathrm{<figure-callout\; id="2"\; label="N\; BUT\; V"\; filenames="00000004.png"\; state="\{\{state\}\}">N\; </figure-callout>}\mathrm{BUT}}}{V^{}}$$

where L _X∑ , d _X is the total length and inner diameter of the parts of the sections of the connecting pipelines 8.1 and 8.2 having a smaller equivalent nominal inner diameter of the bore than the diameters of the remaining parts of the connecting pipelines 7.1-7.7 and collectors, m;

L _∑ - the total length of all sections of the connecting pipelines and collectors, m;

d is the nominal internal equivalent diameter of most sections of connecting pipelines and collectors (where d> d _X ), m;

Δр _ЭНА - the pressure of the electric pump unit at which it provides performance - flow rate in the liquid circuit equal to the required minimum permissible nominal value, Pa;

V is the required minimum permissible nominal value of the coolant flow rate in the collectors, at which the operating temperature of the devices is guaranteed to be no higher than the permissible value, m ³ / s;

K is the average experimental hydraulic coefficient of hydraulic resistance of one linear meter used in the fluid circuits of various connecting pipelines and collectors, kg / m ³ · s.

Create STR KA according to the proposed technical solution as follows.

In the process of manufacturing a qualified ENA, they experience the dependence of its productivity on the pressure (pressure difference between the output and the input) at a supply voltage equal to the supply voltage onboard the spacecraft in operating conditions in orbit.

In the process of developing drawings for the manufacture of a specific satellite of the appropriate power, based on the STR arrangement, the total length of the entire fluid path through which the coolant circulates in operating conditions is determined. Then, for the designated flow cross-section (for example, the equivalent nominal diameter of the collectors and connecting pipelines is d = 12 mm), the liquid circuit is determined using the flow-pressure characteristic of the ENA, the possible flow rate of the coolant: if it, for example, exceeds the required flow rate by more than 10% coolant deciding part portions connecting piping design with reduced internal diameter, e.g., d _X = 9 mm, and determining the total length of these sections with d _X = 9 mm according to the following pho mule:

$$L_{X\Sigma }=L_{\Sigma }\cdot \left(\frac{d_X^5}{d^5}-\mathrm{one}\right)-\frac{{\mathrm{<figure-callout\; id="5"\; label="d\; X"\; filenames="00000004.png"\; state="\{\{state\}\}">d\; </figure-callout>}}_X^{}\cdot \Delta p_{E\mathrm{<figure-callout\; id="2"\; label="N\; BUT\; V"\; filenames="00000004.png"\; state="\{\{state\}\}">N\; </figure-callout>}\mathrm{BUT}}}{V^{}}$$

where L _X∑ , d _X is the total length and inner diameter of parts of sections of connecting pipelines having a smaller equivalent nominal internal diameter of the bore than the diameters of the other parts of connecting pipelines and collectors, m (it should be noted that the minimum possible number of parts with d _X is determined capabilities fluid circuit design and thus need for L _XΣ; optimum number of parts to d _X from the viewpoint of simplicity of construction and economy as possible and the masses - one);

L _∑ - the total length of all sections of the connecting pipelines and collectors, m;

d is the nominal internal equivalent diameter of most sections of connecting pipelines and collectors (where d> d _X ), m;

Δр _ЭНА - the pressure of the electric pump unit at which it provides performance - flow rate in the liquid circuit equal to the required minimum permissible nominal value, Pa;

V is the required minimum permissible nominal value of the coolant flow rate in the collectors, at which the operating temperature of the devices is guaranteed to be no higher than the permissible value, m ³ / s;

To - the average experimental coefficient of hydraulic resistance of one linear meter used in the liquid circuits of various connecting pipelines and collectors, kg / m ³ · s.

After that, using the data obtained above, part of the sections in the drawings are specified and performed with d _X = 9 mm (the remaining sections with a length of, for example, up to 90% of the total contour length, are made with d = 12 mm).

After such execution of the drawings on the STR in the manufactured liquid circuit, the flow rate of the coolant will not significantly exceed the minimum acceptable value, which is confirmed by experimental data.

Thus, as a result of such manufacturing of the proposed design of the STR, under operating conditions, the coolant flow will be close to the nominal (minimum acceptable), and the uncompensated kinetic moment will be the minimum possible and, therefore, the mass flow of the working fluid in the SOS will also be the minimum possible, t. e. thereby achieving the objectives of the invention.

Claims (1)

The spacecraft’s thermal control system, which includes a closed liquid circuit with a circulating coolant, incorporating elements: an electric pump unit, a hydraulic accumulator, collectors of panels on which the devices are installed, and radiator panels, and these elements are interconnected by sections of connecting pipelines with input and output passageways sections identical with the output and input sections of the above-mentioned elements, characterized in that part of the sections of the connecting pipelines in polyene equivalent of the same nominal internal diameter smaller than the diameters of the other parts, and with a total satisfying the following condition long:

where L _X∑ , d _X is the total length and inner diameter of parts of sections of connecting pipelines having a smaller equivalent nominal internal diameter of the bore than the diameters of the remaining parts of connecting pipelines and collectors, m;
L _∑ - the total length of all sections of the connecting pipelines and collectors, m;
d is the nominal internal equivalent diameter of most sections of the connecting pipelines and collectors (where d> d _X ), m;
Δp _ENA - the pressure of the electric pump unit at which it provides the capacity (flow rate) in the liquid circuit equal to the required minimum permissible nominal value, Pa;
V is the required minimum permissible nominal value of the coolant flow rate in the collectors, at which the operating temperature of the devices is guaranteed to be no higher than the permissible value, m ³ / s;
To - the average experimental coefficient of hydraulic resistance of one linear meter used in the liquid circuits of various connecting pipelines and collectors, kg / m ³ · s.

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