RU2282652C1 - Phase-transfer heat-storage material - Google Patents

Abstract

FIELD: heating engineering .

SUBSTANCE: invention provides material that can be used for thermostatically controlling object under cooling conditions or outside heating, in particular, in medicine for storage and transportation of living tissues and organs and in instrumentation engineering when manufacturing phase-transfer executing sensors operated ay low temperatures. Phase-transfer contains 52.5-54.1% octane, 43.9-45.5% nonane, and tetradecane in balancing amount.

EFFECT: lowered allowed working temperature of material.

2 tbl, 3 ex

Description

The invention relates to heat-accumulating materials and can be used for temperature control of an object under cooling or heating from the outside, in particular in medicine for storage and transportation of living tissues and organs, in instrumentation when creating phase-transition executive sensors operating at low temperatures.

Known heat storage material containing, wt.%:

Geneikosan 3-4 Palmitic acid 1-2 Octadecan rest

having a melting point of 23.5 ± 0.5 ° C and a heat of fusion of 250 kJ / kg (Patent of the Russian Federation No. 2084485, 6 C 09 K 5/06, 07/20/97 Bull. No. 22).

The disadvantage of the analogue is too high a melting point, which makes it impossible to use in phase-transition Executive sensors and other heat accumulators operating at low temperatures.

The closest in technical essence is a heat storage material based on saturated hydrocarbons, containing, wt.%:

Geneikosan 1,5-7,5 Palmitic acid 1.0-7.5 Tetradecane rest

having a melting point of 3.8 ± 0.2 ° C and a heat of fusion of 218 ± 0.5 kJ / kg (Patent of the Russian Federation No. 2084486, 6 C 09 K 5/06, 07/20/97 Bull. No. 22).

The disadvantage of the prototype is too high a melting point. The use of this material is not possible for use in phase-transition executive sensors and other heat accumulators operating at low temperatures.

The task of the invention is to develop a composition for use as a phase transition heat storage material at a low temperature of 65 ° C.

The technical result is to lower the operating temperature of the phase transition heat storage material.

The technical result is achieved by the fact that the proposed phase transition heat storage material containing a saturated hydrocarbon-tetradecane additionally contains octane and nonane in the following ratio of components, wt.%:

Octane 52.5-54.1 Nonan 43.9-45.5 Tetradecane rest

Table No. 1 shows the physico-chemical characteristics of the components of the proposed phase-transition heat-accumulating material, which show that the properties of the components differ from each other and only with the proposed ratio of the components can the eutectic point be reached.

Table number 1 Physico-chemical characteristics of the components used Feature \ Component Octane Nonan Tetradecane Density (kg / m ³ ) 702.2 717.6 762 Viscosity (n * s / m ² ) 0.542 0.714 0.914 Molecular weight (g / mol) 114.22 128.25 198.4 Melting point ° C -56.8 -53.5 5.9 Phase transition heat (kJ / kg) 181.15 120.26 227.3 Appearance at nos clear liquid clear liquid clear liquid

The proposed ratio of the components of octane and nonane in a phase-transition heat-accumulating material containing tetradecane allows us to obtain a composition suitable for use in phase-transition executive sensors operating at low temperatures. In addition, the relatively high heat of the liquid - solid phase transition allows the use of this composition as a heat accumulator operating at a low temperature of 65 ° C.

Thus, the set of essential features set forth in the claims, allows to achieve the desired technical result.

Phase-transition heat storage material is prepared as follows.

The calculated amount of octane, nonane and tetradecane is poured into one laboratory glassware and mixed thoroughly. In this case, a clear solution with a characteristic odor of saturated hydrocarbons is obtained.

Example No. 1. Optimum ratio of components

53.3 g of octane, 44.7 g of nonane and 2 g of tetradecane are placed in laboratory glassware and mixed thoroughly. The resulting composition has the properties shown in table No. 2.

Example No. 2. Minimum ratio of components

52.5 g of octane, 43.9 g of nonane and 3.6 g of tetradecane are placed in laboratory glassware and mixed thoroughly. The resulting composition has the properties shown in table No. 2.

Example No. 3 Maximum ratio of components.

54.1 g of octane, 45.5 g of nonane and 0.4 g of tetradecane are placed in laboratory glassware and mixed thoroughly. The resulting composition has the properties shown in table No. 2.

The main indicators for phase transition heat storage materials are the temperature and heat of the liquid - solid phase transition. Both indicators were determined on a DSC-2M instrument.

As studies have shown, upon receipt of a phase-transition heat-accumulating material, a heat-accumulating composition is formed having a liquid state. The low crystallization temperature and the relatively high heat of the phase transition make it possible to use this composition in phase transition executive sensors and other heat accumulators operating at low temperatures.

The following are the compositions and properties of the invention "phase transition heat storage material"

Table number 2 Compositions and properties of phase transition heat storage material Material Composition, wt.% Temperature melted ° C The heat of fusion. kJ / kg Heptane octane tetradecane Minimum 52,5 43.9 rest -63.2 201 Optimal 53.3 44.7 rest -65.6 203 Maximum 54.1 45.5 rest -63.7 202

Claims (1)

Phase-transition heat storage material containing a saturated hydrocarbon tetradecane, characterized in that it additionally contains octane and nonane in the following ratio of components, wt.%: Octane 52.5-54.1 Nonan 43.9-45.5 Tetradecane Rest