JPH04236077A - Liquid circulation type refrigerating or heat pump device - Google Patents

Abstract

PURPOSE:To increase the efficiency of a screw-type gas compressor by a method wherein non-azeotropic refrigerant (ammonia gas and water for example) is circulated by employing a gas compression type refrigerating device and a gas absorbing type refrigerating device in parallel while a liquid circulating pump, sending high-boiling point refrigerant solution into an aggregator (absorber), is miniaturized. CONSTITUTION:Low concentration ammonia water is injected from an evaporator (reproducer) 15 into the halfway of a screw type gas compressor 6 compressing ammonia gas from the evaporator (reproducer) 15 to seal and cool the gas. On the other hand, the ammonia water absorbs one part of the gas. A liquid circulating pump 16, sending low-concentration ammonia water from the evaporator (reproducer) 15 into a high-pressure condenser (absorber) 10, sends one part or all of the liquid to the low-pressure side of the compressor 6. According to this method, the load of the pump 16 is reduced.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid circulation refrigeration system or a heat pump system in which a gas compression refrigeration system and an absorption refrigeration system are used in combination to circulate a non-azeotropic mixed refrigerant.

0003

2. Description of the Related Art A liquid circulation type refrigeration system or a heat pump system that uses a conventional gas compression type refrigeration system and an absorption type refrigeration system in combination to circulate a non-azeotropic mixed refrigerant will be explained with reference to FIG. The low boiling point refrigerant gas compressed by the screw type gas compressor 1 heats the load side in the condenser (absorber) 2 where heat is exchanged with the load side fluid in a counter flow, and is also heated from the evaporator (regenerator) 3. The high boiling point refrigerant liquid is condensed while being heated and absorbed by the high boiling point refrigerant liquid, and the high boiling point refrigerant liquid is diluted. The mixed liquid exchanges heat with the low-temperature high-boiling refrigerant liquid from the evaporator (regenerator) 3 in the heat exchanger 4, and then passes through the expansion valve 5 and reaches the evaporator (regenerator) 3.
Here, the low boiling point refrigerant exchanges heat with the load-side fluid in a counterflow, evaporates, cools the load side, and is sucked into the screw type gas compressor 1. Further, the concentrated high-boiling refrigerant liquid is sent to a condenser (absorber) 2 by a liquid circulation pump 20.

[0004] Such liquid circulation type refrigeration or heat pump equipment is a Lorentz cycle that utilizes the fact that the mixed refrigerant condenses and evaporates while changing its composition, so its saturation temperature changes even under the same pressure. It requires less power than a gas compression type refrigeration system using a boiling point refrigerant, and has the advantage of increasing the reliability of the compressor since the pressure on the high pressure side of the compressor can be lowered.

[0005]

[Problems to be Solved by the Invention] However, conventional liquid circulation type refrigeration or heat pump equipment has a low pressure evaporator (
Since the refrigerant liquid is sent from the regenerator (regenerator) 3 to the high-pressure condenser (absorber) 2, the power loss of the liquid circulation pump 20 is high, and there is a problem that the effect of increasing the efficiency of the compressor 1 is lost. Furthermore, there is also the problem that the structure of the condenser (absorber) 2 becomes complicated and large.

In view of the above problems, the present invention provides a liquid circulation type refrigeration or heat pump device in which the power of the liquid circulation pump is reduced, the condenser (absorber) is made smaller, and the efficiency of the screw type gas compressor is increased. This is what we provide.

[Configuration of the invention]

[0008]

[Means for Solving the Problems] The liquid circulation type refrigeration or heat pump device of the present invention includes a gas compression type refrigeration device consisting of a screw type gas compressor, a condenser, an expansion valve, and an evaporator; In a liquid circulation type refrigeration or heat pump device that circulates a non-azeotropic mixed refrigerant, the low boiling point refrigerant from the evaporator (regenerator) is composed of an absorption type refrigerating device in which the evaporator is used as a regenerator and is connected with a liquid circulation pump. Liquid injection in which part or all of the high boiling point refrigerant liquid is injected from the evaporator (regenerator) via the liquid circulation pump during the gas compression process of the screw type gas compressor that sucks and compresses gas. It has a mouth.

[0009]

[Operation] In the liquid circulation type refrigeration or heat pump device of the present invention, the low boiling point refrigerant gas sucked into the screw type gas compressor is compressed, and the high boiling point refrigerant gas is further injected from the liquid injection port in the middle of the gas compression process. The liquid functions to seal the clearance between the rotors of the compressor and cool the compressed gas, and also acts as an absorber by absorbing a portion of the low-boiling point refrigerant gas into the high-boiling point refrigerant liquid. The mixed refrigerant discharged from the compressor exchanges heat with the cold source in the condenser (absorber), and the condensed low-boiling refrigerant is absorbed by the high-boiling refrigerant liquid, and the high-boiling refrigerant becomes a dilute solution.The mixed liquid passes through the expansion valve. The refrigerant is then sent to the evaporator (regenerator), where it generates cold heat and exchanges heat with the heat source.The low-boiling refrigerant is evaporated and sucked into the compressor, and the high-boiling refrigerant is regenerated as a concentrated solution. All of the gas is supplied by a liquid circulation pump during the gas compression process of the compressor, or a portion is branched off midway and sent as is to the evaporator (regenerator).

0010

[Embodiment] An embodiment of the present invention will be explained with reference to FIG.

6 is a screw type gas compressor, in which a low boiling point refrigerant suction gas pipe 7 is introduced into one end on the low pressure side, a mixed refrigerant discharge gas pipe 8 is led out from the other end on the high pressure side, and a liquid is injected in the middle of the gas compression path. A mouth 9 is provided. The discharge gas pipe 8 is introduced into a condenser (absorber) 10, and the condenser (absorber) 1
0 is configured such that the cooling fluid from the cold heat source serving as the load side during the heat pump and the discharged mixed refrigerant exchange heat in counterflow. A high-temperature mixed liquid pipe 11 led out from a condenser (absorber) 10 passes through a heat exchanger 12 that exchanges heat with a low-temperature high-boiling refrigerant liquid on the way, and then reaches an expansion valve 13. The mixed liquid pipe 14 is connected to the evaporator (
regenerator) 15. Evaporator (regenerator) 15
The refrigerating system is configured such that during refrigeration, heat is exchanged between the heated fluid from the heat source on the load side and the low-pressure mixed refrigerant in counterflow. The suction gas pipe 7 is led out from the gas phase portion of the evaporator (regenerator) 15 and introduced into the compressor 6, and is led out from the liquid phase portion of the evaporator (regenerator) 15 and is connected to the liquid circulation pump 16 along the way.
A high boiling point refrigerant liquid pipe 17 having a high boiling point refrigerant liquid pipe 17 is connected to the liquid injection port 9 of the compressor 6 via the heat exchanger 12. moreover,
A branch liquid pipe 18 branched from the middle of the high boiling point refrigerant liquid pipe 17 after passing through the heat exchanger 12 is connected to the condenser (absorber) 10.
has been introduced.

Next, the operation of the above embodiment will be explained.

As the non-azeotropic mixed refrigerant, ammonia is used as a low boiling point refrigerant, and water is used as a high boiling point refrigerant.

In the evaporator (regenerator) 15, the high concentration ammonia water as a non-azeotropic mixed refrigerant exchanges heat with the heating fluid from the heat source in a counter flow, becoming ammonia gas and low concentration ammonia water, The ammonia gas is sucked into the compressor 6 through the suction gas pipe 7, and the low-concentration ammonia water is sent to the high boiling point refrigerant liquid pipe 17 by the liquid circulation pump 16, where it exchanges heat with the high-temperature mixed refrigerant in the heat exchanger 12 in the middle. After that, part of the liquid is introduced into the liquid injection port 9 of the compressor 6, and the other part is introduced into the condenser (absorber) 10 through a branch pipe 18. In the compressor 6, ammonia gas is compressed, and during the compression process, low-temperature, low-concentration ammonia water is injected to seal the rotor clearance, cool the ammonia gas by the latent heat of vaporization of the ammonia water, and cool the ammonia gas. Some of it is absorbed by aqueous ammonia. The high-pressure ammonia gas, whose concentration has decreased somewhat by being absorbed by the ammonia water, is discharged from the compressor 6 and introduced into the condenser (absorber) 10, where it exchanges heat with the cooling fluid from the cold heat source in a counterflow and liquefies it. However, it is absorbed by the low concentration ammonia water introduced from the branch liquid pipe 18. The highly concentrated ammonia water that has absorbed the ammonia gas is led out through a mixed liquid pipe 11 and is transferred to a heat exchanger 1 on the way.
After exchanging heat with the low-temperature high-boiling refrigerant liquid at step 2, the pressure is reduced at the expansion valve 13, and the refrigerant is introduced into the evaporator (regenerator) 15 and circulated again.

[0015] In the above embodiment, the evaporator (regenerator)
A part of the high boiling point refrigerant liquid from 15 is injected into the compressor 6, and the rest is branched from a branch liquid pipe 18 and introduced into the condenser (absorber) 10, as shown by the chain line in FIG. heat exchanger 12
It is also possible to directly connect the second high-boiling refrigerant liquid pipe 19 led out from the compressor 6 to the liquid injection port 9 of the compressor 6 to inject the entire amount of the high-boiling refrigerant liquid to the compressor 6.

[0016]

[Effects of the Invention] According to the present invention, a Lorentz cycle is formed by circulating a non-azeotropic refrigerant in a refrigeration system that combines a gas compression refrigeration system and an absorption refrigeration system. The reliability of the machine can be improved. In addition, by injecting a high-boiling refrigerant liquid during the gas compression process of the compressor, the pressure increase in the liquid circulation pump can be lowered compared to sending liquid to a high-pressure condenser (absorber), thereby reducing power. Savings can be made and pump reliability can be increased. Furthermore, a portion of the low boiling point refrigerant gas is absorbed by the high boiling point refrigerant liquid injected into the compressor, and the compressor also acts as an absorber, reducing the effect of the next condenser (absorber) and making it more compact. can be converted into Furthermore, the high boiling point refrigerant liquid injected into the screw type gas compressor seals and cools the clearance between the screw rotors, thereby improving the gas compression effect.

[Brief explanation of the drawing]

FIG. 1 is a flow sheet diagram of a liquid circulation type refrigeration or heat pump device showing one embodiment of the present invention.

FIG. 2 is a flow sheet diagram of a conventional device.

[Explanation of symbols]

6 Screw type gas compressor 9 Liquid injection port 10 Condenser (absorber) 13. Expansion valve 15 Evaporator (regenerator) 16 Liquid circulation pump

Claims (1)

[Claims] Claim 1: A gas compression type refrigeration system consisting of a screw type gas compressor, a condenser, an expansion valve, and an evaporator, and an absorption system in which the condenser is used as an absorber and the evaporator is used as a regenerator, connected by a liquid circulation pump. In a liquid circulation type refrigeration system or a heat pump system that circulates a non-azeotropic mixed refrigerant, the gas of the screw type gas compressor sucks and compresses the low boiling point refrigerant gas from the evaporator (regenerator). A liquid circulation type refrigeration or heat pump characterized in that a liquid injection port for injecting part or all of the high boiling point refrigerant liquid from the evaporator (regenerator) through the liquid circulation pump is provided in the middle of the compression process. Device.