JP2014156979A - Vapor compression type refrigeration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that, even in a refrigeration cycle into which a conventionally-known self-balance heat exchanger is assembled, defrosting actuation is limited and inadequate, therefore, furthermore complete and perfect defrosting effect cannot be obtained and satisfactory refrigerating effect and safety cannot be secured.SOLUTION: A vapor compression type refrigeration system as a vapor compression type refrigeration cycle which has steps of compression, condensation, expansion and vaporization of refrigerant has a primary side and a secondary side in one body, has a self-balance heat exchanger assembled therein in which the primary side and the secondary side have the same heat transfer area and capacity and has an expansion valve on a refrigerant inlet of the secondary side of the self-balance heat exchanger. Therein, a primary expansion valve is also provided on the refrigerant inlet of the primary side to which the refrigerant of the heat-self balance heat exchanger is introduced.

Description

  The present invention relates to a vapor compression refrigeration system, and incorporates a heat self-equilibrium heat exchanger in a refrigeration cycle having refrigerant gas compression, condensation, expansion, and evaporation steps to further increase the refrigeration capacity during heat pump heating and hot gas defrost operation. The present invention relates to a vapor compression refrigeration system that improves and prevents over-cooling and liquid back of the compressor and enables further safe operation.

  Conventionally, in a refrigeration cycle using a refrigerant gas, it is known that Patent Documents 1 to 7 incorporate a thermal self-equilibrium heat exchanger as an element for improving the cooling or heating effect. In these Patent Documents 1 to 7, the primary side and the secondary side are integrated, introduced to the primary side, and the refrigerant gas that has passed through the primary side is sent to the secondary side via the expansion valve, and the primary side The heat energy is condensed and evaporated as a heat source through the heat transfer plate on the secondary side and the heat energy is synergistically enhanced to enhance the functions of the primary and secondary sides. A heat exchanger that is stable is described.

  Patent Document 7 describes a technique for increasing the temperature of the refrigerant returning to the compressor by an eddy current heat generator that rotates with the rotational force of the turbine expander during the refrigeration cycle.

  However, conventionally, even in a refrigeration cycle incorporating the above-described heat exchanger, there is a limit to the defrost that can be said to be complete, and excessive work and cost are applied to the defrost. In particular, in cold regions, there is a limit to the efficient and safe operation as a heating device, and it has become practical to rely on heaters that use electricity for defrost.

JP 2003-214731 A Japanese Patent Laid-Open No. 2004-361033 JP 2005-98817 A JP 2005-114267 A JP 2006-64331 A JP 2009-156563 A JP 2011-58652 A

  The problem to be solved by the present invention is that there is a limit to the defrosting action even in a refrigeration cycle incorporating a conventionally known thermal self-equilibrium heat exchanger, and a more complete and perfect defrosting effect is obtained. That is, it was insufficient to ensure the freezing effect and safety.

  In order to solve this problem, a vapor compression refrigeration system according to the present invention is a vapor compression refrigeration cycle having refrigerant compression, condensation, expansion, and evaporation steps, in which a primary side and a secondary side are integrated. Steam that has a thermal self-equilibrium heat exchanger having the same heat transfer area and capacity on the primary side and the secondary side, and has an expansion valve at the refrigerant inlet on the secondary side of the heat self-equilibrium heat exchanger The compression refrigeration system is characterized in that a primary expansion valve is also provided at a primary refrigerant inlet into which a refrigerant of the thermal self-equilibrium heat exchanger is introduced.

  The vapor compression refrigeration system according to the present invention is characterized in that a bypass is provided in the primary expansion valve of the refrigerant inlet on the primary side, and the heat self-equilibrium heat exchanger described above is provided in the refrigeration cycle. A refrigerant flow is provided between the condenser and the evaporator.

  Furthermore, the vapor compression refrigeration system according to the present invention has a permanent magnet rotation between the evaporator into which the refrigerant is introduced from the refrigerant outlet on the secondary side of the thermal self-equilibrium heat exchanger and the compressor to which the refrigerant returns. It is characterized by interposing a type induction heater (magnet heater).

  The vapor compression refrigeration system according to the present invention is configured as described above. Therefore, according to the thermal self-equilibrium heat exchanger in the present invention, the high-pressure refrigerant liquid passes through the novel primary expansion valve and becomes an intermediate-pressure refrigerant, and the intermediate-pressure refrigerant evaporates through the secondary expansion valve, and the low-pressure low-temperature Low pressure refrigerant. Due to the two-stage evaporation, the refrigerant becomes a refrigerant whose pressure is reduced, and a temperature difference from the outside air heat is generated to increase the heat absorption amount. That is, it leads to an increase in condensation latent heat and improves the refrigeration capacity.

  The heat exchanger is in contact with the outside air and frost formation increases, but if the primary expansion valve is bypassed and only the secondary expansion valve is operated, the operating pressure is high, the evaporation temperature is high, and high-temperature refrigerant gas is sent out. Thus, frost formation can be melted while operating the refrigeration cycle, and heating can be continued without stopping the heating process during the defrosting.

1 is a circuit diagram showing a vapor compression refrigeration system embodying the present invention. It is a circuit diagram which shows the example incorporating a permanent magnet rotary induction heater. It is a Ph diagram of a refrigerant.

  This was realized by configuring as illustrated in the drawings and described in the examples.

  Next, preferred embodiments of the present invention will be described with reference to the drawings. The circuit shown in the figure assumes a heating operation. In FIG. 1, reference numeral 1 denotes a compressor, and high-temperature and high-pressure refrigerant is discharged from the compressor 1 (T2). The refrigerant discharged from the compressor 1 is sent to the condenser 2. This condenser 2 becomes an indoor heat exchanger, and performs the heating action by radiating the condensed heat into the room.

  The high-pressure refrigerant liquid discharged from the condenser 2 is sent to the thermal self-equilibrium heat exchanger 3 (T3). The thermal self-equilibrium heat exchanger 3 is configured such that the primary side and the secondary side are integrated, and the primary side 4 and the secondary side 5 have the same heat transfer area and capacity. A primary expansion valve 6 is provided, passes through the primary expansion valve 6, and is introduced into the primary side 4 in a reduced pressure and low temperature state (T 4). The primary expansion valve 6 is provided with a bypass 10 provided with a switching valve 9.

  The refrigerant whose pressure is reduced and reduced by the primary expansion valve 6 and introduced to the primary side 4 becomes an intermediate pressure refrigerant and is discharged from the primary side 4 (T5). The intermediate-pressure refrigerant discharged from the primary side 4 passes through the secondary expansion valve 7 provided at the inlet of the secondary side 5 and evaporates, so that the low-pressure and low-pressure is lower than the intermediate-pressure refrigerant (T5). It becomes a refrigerant (T6) and is introduced into the secondary side 5. And the refrigerant | coolant which passed the secondary side turns into the evaporative refrigerant | coolant (T7) further pressure-lowered, produces a big temperature difference with external heat, and increases heat absorption.

  That is, the thermal self-equilibrium heat exchanger 3 according to the embodiment of the present invention is configured to evaporate and depressurize in two stages by providing the primary expansion valve 6, and has a far greater effect than the conventional thermal self-equilibrium heat exchanger. Can be obtained. Further, the evaporative refrigerant that has passed through the secondary side 5 passes through the evaporator (outdoor heat absorber) 8 to absorb heat (T1) and circulates back to the compressor 1.

  When the refrigerant gas passes through the primary expansion valve 6 of the thermal self-equilibrium heat exchanger 3 and is on the primary side 4, it is an incompletely evaporated intermediate pressure refrigerant. The intermediate pressure refrigerant on the primary side 4 evaporates through the secondary expansion valve 7, and becomes a lower temperature evaporative refrigerant in the secondary side 5. The low-temperature evaporative refrigerant on the secondary side 5 cools the intermediate-pressure refrigerant on the primary side 4 through the heat transfer surface partitioning the primary side 4 and the secondary side 5 to form a supercooled refrigerant liquid. If the refrigerant becomes supercooled in the primary side 4, it becomes a low-temperature refrigerant gas when passing through the secondary expansion valve 7, thereby improving the refrigeration effect.

  The refrigerant in the thermal self-equilibrium heat exchanger 3 sequentially interacts with the primary side 4 and the secondary side 5 to exchange heat, and after change with time, the intermediate pressure refrigerant on the primary side 4 is used as a supercooled refrigerant liquid. , It will be a more complete refrigerant liquid and will exhibit heat exchange capability by changing the gas-liquid phase of the refrigerant.

  Here, the defrost of the evaporator 8 in the circuit described above will be described. The refrigerant that has passed through the secondary expansion valve 7 and introduced into the secondary side 5 becomes a lower-temperature evaporative refrigerant gas, becomes cooler due to the outside air temperature that absorbs heat, expands the temperature difference, and absorbs air from outside air. The amount of heat increases and the latent heat of condensation increases.

  Since the decompressed refrigerant temperature from the secondary expansion valve 7 is low, the amount of frost on the evaporator 8 increases in contact with the outside air. As this defrosting method, the primary expansion valve 6 is closed and the switching valve 9 is closed. Opening the refrigerant through the bypass 10 and omitting the depressurization step, and operating only the secondary expansion valve 7, rather than operating the primary expansion valve 6 and the secondary expansion valve 7 simultaneously, The operating pressure is high, the evaporation temperature is high, and a high-temperature refrigerant gas is sent out, so that frost formation can be thawed while operating the refrigeration cycle. Heating can be continued without stopping the heating process due to defrosting. In other words, the use of the bypass 10 can provide the same effect as the system of Japanese Patent No. 4398687 already obtained by the applicant.

  Next, the thermal self-equilibrium heat exchanger 3 and the condensation, evaporation, and latent heat transfer mechanism will be described for a system in which the supercooled liquid refrigerant is not returned to the compressor 1 (no liquid back). In the Ph diagram shown in FIG. 3, R2 and R3 indicate high-pressure refrigerant liquid, R4 and R5 indicate intermediate-pressure refrigerant, and R6 and R7 indicate low-pressure refrigerant gas. h1 is a work input of the compressor 1 and is dissipated as latent heat of condensation.

  Since h2 and h3 are in contact with the same heat transfer surface on the primary side 4 and the secondary side 5 of the thermal self-equilibrium heat exchanger 3, the condensation latent heat on the primary side 4 becomes an evaporation heat source on the secondary side 5, and this secondary The latent heat of vaporization on the side 5 becomes a condensation heat source on the primary side 4, the mutual latent heat is heat-exchanged, the refrigerant sucked into the compressor 1 of R 1 becomes the latent heat of vaporization “0”, and the liquid refrigerant to the compressor 1 (latent heat of vaporization) Is exhausted.

  Further, the operation of the thermal self-equilibrium heat exchanger 3 will be described. Since the heat pump system is a refrigeration cycle that draws heat into a refrigerant having a temperature lower than that of the external air heat and dissipates heat as a high-temperature refrigerant to the external air heat. When the heat is absorbed from a low-temperature external heat source at h2, the opposite condensation latent heat is obtained, and the heat dissipation capability is obtained. Heat radiation and cooling are performed with priority given to evaporating heat source acquisition from the outside of the refrigeration cycle system and condensation heat source heat radiation to the outside.

  Originally, the latent heat of evaporation and the latent heat of condensation are in a state of latent heat “0” through mutual heat exchange, so that the latent heat from the outside is sufficiently received. The refrigeration cycle can be stably maintained by keeping the heat exchange capacities of the primary side 4 and the secondary side 5 in equilibrium by adjusting the amount of increase / decrease in the external heat source.

  Referring to FIG. 3, the high-pressure refrigerant liquid introduced from the condenser 2 passes through the primary expansion valve 6, evaporates on the primary side 4, becomes intermediate-pressure refrigerant R <b> 4, R <b> 5, and is discharged from the primary side 4. The refrigerant passes through the secondary expansion valve 7 and is introduced to the secondary side 5 to become low-pressure refrigerants R6, R7, and R1. The intermediate pressure refrigerant on the primary side 4 is cooled by the cooler refrigerant on the secondary side 5 and becomes a supercooled refrigerant. The R4 and R1 of the primary side 4 absorbs the same amount of latent heat of vaporization absorbed by R7 and R1, and the heat of condensation and the latent heat of condensation becomes the latent heat of condensation. This means that barter heat exchange is performed on the secondary side 5 to maintain thermal equilibrium.

  A second embodiment of the present invention will be described with reference to FIG. In the second embodiment, parts common to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In this second embodiment, a permanent magnet rotary induction heater 11 is incorporated between the evaporator 8 and the compressor 1 where the refrigerant returns, and the permanent magnet rotary induction heater in this second embodiment. 11 uses a motor 12 as a drive source.

  This permanent magnet rotary induction heater 11 is used for the purpose of generating more complete heating, complementing the inefficiency of using outside air heat particularly in cold regions. Therefore, before passing through the evaporator 8 and being sucked into the compressor 1, the low-pressure refrigerant gas is directly heated by incorporating the permanent magnet rotary induction heater 11 by the general-purpose motor 12 in the refrigerant pipe.

  When the magnetic field is changed in the vicinity of the current flow or the conductor, the permanent rotating induction heater 11 generates Joule heat in the conductor and raises the temperature. Permanent magnets are mounted alternately on the rotating disk rotated by the motor 12, and when the poles are arranged in parallel with the conductors and rotated in parallel with the conductors, the conductors become heating elements and the passing refrigerant can be heated. In this state, the refrigerant is not returned to the compressor 1.

  The vapor compression refrigeration system according to the present embodiment is configured as described above. Prior to the introduction of the refrigerant to the primary side 4 of the thermal self-equilibrium heat exchanger 3, the refrigerant evaporates into an intermediate pressure refrigerant by passing through the primary expansion valve 6, and this intermediate pressure refrigerant is subjected to secondary expansion. Since it introduce | transduces to the secondary side 5 through the valve 7, it becomes a low-temperature evaporative refrigerant, becomes a supercooled refrigerant liquid, improves a freezing effect, and exhibits the heat exchange capability by the gas-liquid phase change of a refrigerant | coolant.

  The primary expansion valve 6 is provided with a bypass 10. When the primary expansion valve 6 is not used, the primary expansion valve 6 is configured in the same manner as the defrost system for which the applicant has acquired the right and operates without stopping the refrigeration cycle. However, defrosting can be performed, and heating can be continued without stopping operation due to heating for defrosting.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Thermal self-equilibrium heat exchanger 4 Primary side 5 Secondary side 6 Primary expansion valve 7 Secondary expansion valve 8 Evaporator 9 Switching valve 10 Bypass 11 Permanent magnet rotary induction heater 12 Motor

In order to solve this problem, the vapor compression refrigeration system according to the present invention is a vapor compression refrigeration cycle having refrigerant compression, condensation, expansion, and evaporation steps, and has passed through the primary side and the primary side. A thermal self-equilibrium heat exchanger, which has a secondary side into which refrigerant flows in and has the same heat transfer area and capacity on the primary side and secondary side, is installed between the condenser and the evaporator. e Bei an expansion valve to the refrigerant inlet of the secondary side of the heat exchanger, in the thermal self-balancing heat exchanger vapor compression refrigeration system refrigerant and a primary expansion valve to the refrigerant inlet of the primary side to be introduced in The primary expansion valve of the primary side refrigerant inlet is provided with a bypass .

Claims (4)

  A vapor compression refrigeration cycle having steps of refrigerant compression, condensation, expansion, and evaporation, having a primary side and a secondary side integrally, and the primary side and the secondary side have the same heat transfer area and capacity In a vapor compression refrigeration system incorporating a thermal self-equilibrium heat exchanger and having an expansion valve at the refrigerant inlet on the secondary side of the thermal self-equilibrium heat exchanger, the refrigerant of the thermal self-equilibrium heat exchanger is introduced A vapor compression refrigeration system comprising a primary expansion valve at a refrigerant inlet on a primary side.   The vapor compression refrigeration system according to claim 1, wherein a bypass is provided in the primary expansion valve of the primary refrigerant inlet.   The vapor compression refrigeration system according to claim 1 or 2, wherein the thermal self-equilibrium heat exchanger is provided between a condenser and an evaporator in a refrigerant flow in a refrigeration cycle. .   A permanent magnet rotary induction heater (magnet heater) is interposed between the evaporator into which the refrigerant is introduced from the refrigerant outlet on the secondary side of the thermal self-equilibrium heat exchanger and the compressor to which the refrigerant returns. The vapor compression refrigeration system according to claim 1, wherein the vapor compression refrigeration system is provided.

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