Chemical heat pumps using a dispersion of a metal salt ammoniate in an inert solvent

Wentworth, W. E.; Johnston, D. W.; Raldow, Wiktor

doi:10.1016/0038-092x(81)90077-3

Cited by 19 publications

(6 citation statements)

References 6 publications

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“…In this reversible chemical reaction, ΔH (enthalpy change) is 43.8 kJ/mol at 0.1 MPa, 304 K [1], and the value is considerably higher than the latent heat of vaporization of liquid NH 3 , 23.4 kJ/mol at 0.1 MPa, 240 K [2]. Furthermore, this chemical reaction is well known as higher energy density system as compared with those reactions for other energy storage systems.…”

Section: Introductionmentioning

confidence: 99%

Performance of Thermal Energy Storage Unit Using Solid Ammoniated Salt (CaCl2-NH3 System)

Sakamoto¹,

Yamamoto²

2014

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The exothermic chemical reaction of CaCl2 (calcium chloride) with NH3 (ammonia) can be utilized as an energy storage system. Since this reaction is a typical gas-solid reaction, the reaction rate is controlled by the heat transfer rate. In order to improve the low heat transfer rate of the ammoniation and the deammoniation of CaCl2, the influence of a heat transfer media (Ti: titanium) on the heat transfer rate of the solid ammoniated salt (CaCl2•mNH3) was studied and tested experimentally. The performance tests were carried out under the conditions of various weight ratios of Ti. No decrease of the activation of chemical reaction and no corrosion of experimental apparatus were observed on the repeated runs (≥30 times each). The heat transfer rate of ammoniated salt was greatly improved by adding Ti under the constant pressure (0.5 MPa). The reaction time required for the ammoniation of CaCl2 mixed with Ti was approximately 16%-54% shorter than that of CaCl2 alone, and the reaction time required for the deammoniation was also approximately 19%-59% shorter than that of CaCl2 alone.

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Section: Introductionmentioning

confidence: 99%

Performance of Thermal Energy Storage Unit Using Solid Ammoniated Salt (CaCl2-NH3 System)

Sakamoto¹,

Yamamoto²

2014

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“…On this issue, most of the data used for this study are known with a good accuracy (especially for metallic chlorides, and to a lower extent for bromides and iodides). Based on the experimental uncertainties provided by Wentworth et al [29], Böhringer [30] and Touzain [27], uncertainty propagation calculations have been conducted with EES software for the three reactants considered in this section. The results are displayed in Table 2.…”

Section: Parametermentioning

confidence: 99%

Novel hybrid thermochemical cycles for low-grade heat storage and autothermal power generation: A thermodynamic study

2020

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The principle of hybridizing a solid/gas thermochemical refrigeration cycle with a power cycle is extended to two novel hybrid cycles (called operating modes). They can be driven by low-grade heat, and they allow storing this energy and converting it predominantly into mechanical power. For this purpose, they integrate an original autothermal power production during their discharging step, which is deeply analyzed. In addition, depending on the operating mode, power can be produced in both charging and discharging steps and an additional cold production can be provided. A deep thermodynamic study was carried out to assess the performance of these cycles, for 103 solid/gas pairs. These cycles allow converting low-grade heat sources from 87 °C to 250 °C. The maximal energy and exergy efficiencies for power and cold cogeneration are 0.24 and 0.40, respectively, and the maximal exergy density is 722 kJ/kgNH3. The part of power production reaches 62% (when it occurs only in discharging step) to 78% (when it occurs in both steps).

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“…Andrews (1955) and Buffington (1933) used insoluble refrigerant/absorbent pairs, such as NH,/CaCl, and NH,/SrCl,, but found that they had poor heat and mass transfer characteristics. Taube and Furrer (1980), Wentworth and Johnston (1981) and Riffat et al (1986) have carried out work with the aim of improving heat and mass transfer in solid absorbent beds. NH,/CaCl, and NH,/SrCl, were found to form mobile slurries in inert liquids such as n-heptanol and kerosene, but energy storage densities were poor owing to the small solid content of these slurries.…”

Section: (I) Regeneration Phasementioning

confidence: 99%

A storage heat pump using an ‘ozone-friendly’ refrigerant

Riffat

Shankland

Nicholson³

1992

Int. J. Energy Res.

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The paper describes the integration of a chemical and a vapour‐compression heat pump for energy storage applications. The vapour‐compression system is designed to operate using the UK cheap rate ‘Economy 7’ electricity tariff. The system is characterized thermodynamically using various refrigerant/absorbent pairs in the chemical storage circuit and an ozone‐friendly refrigerant, R134a, in the vapour‐compression circuit. Results indicate that the H2O/Na2S pair provides a high energy storage density and is the most suitable for use in this system. The paper also describes the design features of a domestic‐sized version of this heat pump system. Air in the sunspace (conservatory) of a house was used as a heat source for the heat pump.

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Chemical heat pumps using a dispersion of a metal salt ammoniate in an inert solvent

Cited by 19 publications

References 6 publications

Performance of Thermal Energy Storage Unit Using Solid Ammoniated Salt (CaCl<sub>2</sub>-NH<sub>3</sub> System)

Performance of Thermal Energy Storage Unit Using Solid Ammoniated Salt (CaCl<sub>2</sub>-NH<sub>3</sub> System)

Novel hybrid thermochemical cycles for low-grade heat storage and autothermal power generation: A thermodynamic study

A storage heat pump using an ‘ozone-friendly’ refrigerant

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Chemical heat pumps using a dispersion of a metal salt ammoniate in an inert solvent

Cited by 19 publications

References 6 publications

Performance of Thermal Energy Storage Unit Using Solid Ammoniated Salt (CaCl&lt;sub&gt;2&lt;/sub&gt;-NH&lt;sub&gt;3&lt;/sub&gt; System)

Performance of Thermal Energy Storage Unit Using Solid Ammoniated Salt (CaCl&lt;sub&gt;2&lt;/sub&gt;-NH&lt;sub&gt;3&lt;/sub&gt; System)

Novel hybrid thermochemical cycles for low-grade heat storage and autothermal power generation: A thermodynamic study

A storage heat pump using an ‘ozone-friendly’ refrigerant

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Product

Resources

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Performance of Thermal Energy Storage Unit Using Solid Ammoniated Salt (CaCl<sub>2</sub>-NH<sub>3</sub> System)

Performance of Thermal Energy Storage Unit Using Solid Ammoniated Salt (CaCl<sub>2</sub>-NH<sub>3</sub> System)