RU2241915C2 - Phase transition heat storage - Google Patents

Abstract

FIELD: thermal engineering; heating of houses.

SUBSTANCE: proposed heat storage designed for storage and recovery of low-potential heat of liquids or gases that cannot be stored and/or accumulated in large quantities without special equipment, such as corrosive chemically active materials, stack gases of chemical plants, and the like has cylindrical housing with spherical bottom, block of vertical tubular capsules filled with heat-storage material that undergoes phase transition in operating temperature range, as well as inlet and outlet pipes. Novelty is that it is provided in addition with partition dividing housing into isolated chambers, heat pump evaporator disposed in top chamber close to capsule block, two tubular members with air admission holes on surface, one of them being made in the form of coil that encloses capsule lines and is mounted on partition in top chamber; other tubular member is made in the form of helix and mounted on housing bottom in bottom chamber; capsule block is mounted on transverse partition so that capsule evaporative section is disposed in bottom chamber and condensing section, in top one; outlet pipe is located in bottom over longitudinal axis of housing; inlet pipe is placed in bottom chamber tangentially to housing; top chamber is filled with heat storage medium, such as concentrated salt solution, undergoing phase transition in operating temperature range.

EFFECT: enhanced efficiency and reliability of heat storage and its ability of continuous operation.

1 cl, 3 dwg

Description

The invention relates to heat engineering, is intended for the accumulation and utilization of low-grade heat of liquids or gases that cannot be stored and / or accumulated in large volumes without special equipment, for example corrosive substances, flue gases from chemical plants, etc., and can be used for heating buildings.

Known heat accumulator of the phase transition according to the patent of Russia No. 2187049, F 24 H 7/00, containing a cylindrical body, consisting of one chamber, a block of horizontally arranged capsules filled with heat-accumulating substance, undergoing a phase transformation in the operating temperature range, inlet and outlet pipes. Capsules are made of coaxially arranged cylinders.

The inlet pipe is located on the longitudinal axis of the housing, and the outlet pipe is offset relative to this axis.

This arrangement of the nozzles does not ensure the twisting of the incoming and outgoing media, as a result of which stagnant zones are formed in the lower part of the housing. When passing a contaminated heat transfer medium, the space between the capsule block is clogged with dirt, which reduces the reliability of the device.

The lack of means of forced mixing of the incoming medium reduces heat transfer and the efficiency of the device.

It is impossible to transfer heat from a contaminated medium to a clean one without contamination of the latter in a single-chamber housing due to direct contact of the heat-releasing and heat-accumulating media with the same section of storage capsules. This reduces the efficiency of the device.

The disadvantage is the frequency in the operation of the device, because The flow of heat-releasing and heat-accumulating media occurs at different times (in turn) due to the lack of an additional chamber.

In addition, it is impossible to use low potential heat due to the absence of a heat pump in the design of the evaporator.

The heat accumulator according to the Russian patent No. 2145404, F24H 7/00, adopted as a prototype and containing a cylindrical body with a spherical bottom, consisting of one chamber, a block of vertical tubular capsules filled with a heat-accumulating substance, undergoing a phase transformation in the operating temperature range, supplying and outlet branch pipes. The inlet pipe is located on the longitudinal axis of the housing, and the outlet pipe is offset relative to this axis.

This arrangement of the nozzles does not ensure the twisting of the incoming and outgoing media, as a result of which stagnant zones are formed in the lower part of the housing. When passing a contaminated heat transfer medium, the space between the capsule block is clogged with dirt, which reduces the reliability of the device.

The lack of means of forced mixing of the incoming medium reduces heat transfer and the efficiency of the device.

It is impossible to transfer heat from a contaminated medium to a clean one without contamination of the latter in a single-chamber housing due to direct contact of the heat-releasing and heat-accumulating media with the same section of storage capsules. This reduces the efficiency of the device.

The disadvantage is the frequency in the operation of the device, because The flow of heat-releasing and heat-accumulating media occurs at different times (in turn) due to the lack of an additional chamber. In addition, it is impossible to use low-grade heat due to the absence of a heat pump in the design of the evaporator.

The objective of the invention is to increase the efficiency, reliability and continuity of the device.

The phase transition thermal accumulator comprises a cylindrical body with a spherical bottom, a block of vertical tubular capsules filled with a heat-accumulating substance, undergoing a phase transformation in the range of operating temperatures, and supply and outlet pipes.

Unlike the prototype, it is additionally equipped with a partition separating the housing into insulated chambers, a heat pump evaporator located in the upper chamber near the capsule block, two tubular elements with openings on the surface for air supply, one is made in the form of a coil covering the rows of capsules and installed on the partition in the upper chamber, the other is made in the form of a spiral and mounted on the bottom of the housing in the lower chamber, the capsule block is mounted on the transverse partition so that the lower chamber is located their evaporation section is located, and in the upper one there is a condensation section, the discharge pipe is located in the bottom on the longitudinal axis of the housing, and the supply pipe is in the lower chamber tangentially to the housing, the upper chamber is filled with a heat-accumulating medium that undergoes phase transformation in the range of operating temperatures, for example, concentrated salt solution .

The supply of the device with a partition allows the housing to be divided into two insulated chambers, ensuring the separation of heat-transferring and heat-accumulating media. As a result, a constant process of heat exchange occurs simultaneously in both chambers.

The installation of the capsule block in such a way that their evaporation section is located in the lower chamber and the condensation section in the upper one ensures the continuity of the heat exchange process between the heat transfer medium and the consumer (through the heat pump).

Placing the heat pump in the upper chamber - the condensation chamber near the capsule block provides uniform heat removal to the consumer, which increases the efficiency of the heat pump and the entire device.

The execution of the tubular element on the bottom of the casing is spiral, the location of the inlet pipe tangentially to the casing, and the outlet pipe on the longitudinal axis of the casing in the bottom and the spherical shape of the bottom itself contributes to the twisting of the coolant in a spiral. This, in turn, contributes to an increase in the velocity of the heat carrier in the lower chamber and intensive uniform washing of the capsule block even at a low speed of the heat carrier, which increases the efficiency of heat transfer, as well as the efficiency of the heat pump and the device as a whole.

In addition, the effect of forced swirling of the coolant in the lower chamber eliminates the formation of stagnant zones and provides reliable separation of the solid suspension in the coolant (to the center of the bottom and its removal through the outlet pipe), which increases the reliability of the device.

The implementation of the tubular element in the form of a coil is easy to manufacture and allows you to conveniently place it between the rows of capsules for the possibility of uniform air supply throughout the entire volume of the upper chamber.

Holes on the surface of both tubular elements allow air to be supplied into them, which provides for forced mixing of the medium (sparging) throughout the entire volume of each chamber. This speeds up the heat transfer process between the capsule block and the medium, and in the lower chamber contributes to an additional twisting of the medium due to the spiral shape of the tubular element. All this increases the speed of the medium, which increases the heat transfer coefficient and the efficiency of the device.

The use of a concentrated salt solution as a heat storage medium allows, without increasing the dimensions of the device, to accumulate a large amount of thermal energy in a relatively small volume of salt solution due to the latent heat of the phase transition of salt from crystals to solution, which is necessary to ensure efficient operation of the pump, i.e. . to transfer heat to the consumer even at low temperatures of the salt solution.

Thus, all of the claimed features are significant and solve the problem.

The inventive device is presented in the drawings:

figure 1 - thermal battery phase transition, General view;

figure 2 - section aa in figure 1;

figure 3 - heat accumulator phase transition, isometry.

The thermal battery phase transition (Fig.1,3) contains a housing consisting of two parts: the upper is made in the form of a parallelepiped 1, the lower in the form of a cylinder 2, separated by a transverse partition 3 into two chambers - respectively, the upper 4 and lower 5; a block of vertical tubular capsules 6 filled with a heat-accumulating substance that undergoes a phase transformation in the range of operating temperatures; inlet 7 and outlet 8 nozzles located in the lower chamber 5; heat pump evaporator 9; a tubular element 10 made in the form of a coil and mounted on a partition 3 in the upper chamber 4; a tubular element 11 (figure 2), made in the form of a spiral and mounted on the spherical bottom of the housing 12 in the lower chamber 5. The tubular elements 10 and 11 are made with holes on the surface for air supply. The upper chamber 4 is filled with concentrated salt solution. The inlet pipe 7 is located tangentially to the housing 2. The outlet pipe 8 is located in the bottom 12 on the longitudinal axis of the housing.

The device operates as follows.

Through the inlet pipe 7 into the lower chamber 5, a heat-transfer medium (coolant) enters, which, twisting in a spiral, accelerates its movement and evenly washes the evaporation section of the capsule block 6 (Fig.1,2). At the same time, air is supplied through the holes in the tubular element 11. Intensive and uniform mixing of the medium occurs (bubbling). The liquid in the block of capsules 6 begins to boil and evaporate intensively, rising to their upper condensation part, located in the upper chamber 4, where it condenses, giving off heat to the salt solution and accumulating there. For uniform mixing of the medium, air is supplied to the upper chamber 4 through openings in the tubular element 10. As a result, the salt solution uniformly washes the condensation section of the capsule block 6 and the heat pump evaporator 9, transferring heat to the latter. Then, through a heat pump (not shown), heat enters the consumer.

Having lost its heat, the cooled coolant exits through the outlet pipe 8, twisting in a spiral and forming a funnel in the center of the bottom 12, into which a solid suspension is drawn in with acceleration.

Thus, the heat transfer process occurs continuously in both chambers: in the lower chamber 5, heat transfer, in the upper chamber 4, heat reception and accumulation.

Claims (2)

1. A thermal phase-transfer accumulator comprising a cylindrical body with a spherical bottom, a block of vertical tubular capsules filled with a heat-accumulating substance, undergoing a phase transformation in the range of operating temperatures, supply and discharge pipes, characterized in that it is additionally equipped with a partition separating the case into insulated chambers , a heat pump evaporator located in the upper chamber near the capsule block, two tubular elements with holes on the surface for supplying air ear, one is made in the form of a coil covering the rows of capsules and mounted on a partition in the upper chamber, the other is made in the form of a spiral and mounted on the bottom of the body in the lower chamber, the capsule block is fixed on the transverse partition so that their evaporative section is located in the lower chamber and in the upper one there is a condensation section, the discharge pipe is located in the bottom on the longitudinal axis of the housing, and the supply pipe is in the lower chamber tangentially to the housing, the upper chamber is filled with a heat storage medium, undergoing boiling range of working temperatures phase transformation. 2. The phase-transfer thermal battery according to claim 1, characterized in that a concentrated salt solution is used as the heat storage medium filling the upper chamber.

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