JPH05264108A - Refrigeration device - Google Patents

Abstract

PURPOSE:To heat and evaporate refrigerant when refrigeration load is reduced to prevent a return of liquid by providing a water.refrigerant heat exchanger between an evaporator and a compressor and providing in said heat exchanger a cooling line for causing cooling water to flow from the delivery side of a water-cooled condenser corresponding to the suction temperature of the refrigerant. CONSTITUTION:In a refrigeration device, the high temperature, high pressure refrigerant leaving a compressor 1 is liquefied at a water-cooled condenser 2, throttled by a throttle valve 3, so as to be adiabatically expanded, and then absorbs heat at an evaporator 4 to cool the ambient air, where the refrigerant is evaporated and gassified, which is returned to the compressor 1. In such a device, a water.refrigerant heat exchanger 10 is provided on the suction side of the compressor l to introduce the cooling water from the outlet of the condenser 2 into the exchanger 10 through a cooling water line including a control valve 1!!J And when refrigeration load for the evaporator 4 has become reduced, suction temperature becomes lower than a set temperature of a regulator 12 and hence the valve 11 is opened. As a result, the refrigerant is heated and evaporated so as to increase the degree of suction overheating of the refrigerant, thereby preventing the return of liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus for saving the cooling heat source of the refrigerating apparatus and preventing liquid from returning.

[0002]

2. Description of the Related Art FIG. 4 shows a refrigerant system diagram of a conventional refrigeration system.

Reference numeral 1 is a compressor, 2 is a water-cooled condenser, 3 is a throttle valve, 4 is an evaporator, and 6 is a water pump to the water-cooled condenser 2. The high-temperature and high-pressure refrigerant that has exited the compressor 1 is cooled and liquefied by the water-cooled condenser 2, narrowed down by the throttle valve 3 and adiabatically expanded, and absorbs heat by the evaporator 4 and returns to the compressor 1. The water pump 6 sends water to the water-cooled condenser 2, and the high-temperature high-pressure refrigerant and water are heat-exchanged. When the refrigerating load of the evaporator 4 decreases, the non-evaporated refrigerant that cannot be completely evaporated in the evaporator 4 returns to the compressor 1.

FIG. 5 is a refrigerant system diagram of a conventional refrigeration system with a liquid / gas heat exchanger, 1 is a compressor, 2 is a water-cooled condenser,
3 is a throttle valve, 4 is an evaporator, 5 is a receiver, 6 is a water pump, and 7 is a liquid / gas heat exchanger.

The high-temperature and high-pressure refrigerant discharged from the compressor 1 is pumped by the pump 6.
Is cooled and liquefied by the water-cooled condenser 2 which is supplied with water, enters the liquid / gas heat exchanger 7 via the receiver 5, where heat is radiated, and is adiabatically expanded by being throttled by the throttle valve 3 and the evaporator. 4, the low-temperature refrigerant vapor that has left the evaporator 4 and the high-pressure liquid refrigerant that exits the receiver 5 and enters the throttle valve 3 are heat-exchanged, and again through the liquid / gas heat exchanger 7, the compressor 1 The vaporized refrigerant is superheated, the non-evaporated refrigerant is evaporated by the heat, and the vaporized refrigerant is returned to the compressor 1. FIG. 6 is a Mollier diagram.

[0006]

The above conventional refrigeration system has the following problems to be solved.

That is, in the apparatus shown in FIG. 4, the refrigeration load is reduced, so that the non-evaporated refrigerant that cannot be evaporated in the evaporator 4 returns to the compressor 1 in the liquid refrigerant state. However, there is a problem in that the liquid is compressed when it returns to the compressor 1 and damages the compressor 1.

Further, as shown in FIG. 5, when the liquid / gas heat exchanger 7 for increasing the cooling capacity is provided and the degree of supercooling is increased, the degree of superheat of the suction gas rises and the temperature of the discharge gas rises. ..

An object of the present invention is to provide a refrigerating device which solves the above problems.

[0010]

As a means for solving the above problems, the present invention is to provide a refrigerating apparatus described in the following (1) and (2). (1). In a refrigeration system including a compressor, a water-cooled condenser, a throttle mechanism, and an evaporator, a water / refrigerant heat exchanger is provided between the evaporator and the compressor, and the water-cooled condenser is attached to the water / refrigerant heat exchanger. A refrigeration system provided with a cooling water circuit for flowing cooling water from an outlet side in accordance with a suction temperature of a refrigerant. (2). In a refrigeration system including a compressor, a water-cooled condenser, a throttle mechanism and an evaporator, a first water / refrigerant heat exchanger is provided between the evaporator and the compressor, and a first water-refrigerant heat exchanger is provided between the water-cooled condenser and the throttle mechanism. Two water / refrigerant heat exchangers are provided, and the first
And a second water / refrigerant heat exchanger, in which a cooling water circuit is provided in which the cooling water from the outlet side of the water cooling condenser is caused to flow in accordance with the discharge temperature of the refrigerant.

[0011]

Since the present invention is constructed as described above, it has the following actions. (1). In the configuration of (1) above, when the refrigeration load of the evaporator decreases, the amount of water flowing through the water-refrigerant heat exchanger increases,
Since the refrigerant is heated, the degree of superheat of suction is increased to prevent the liquid refrigerant from returning. (2). In the configuration of (2) above, when the refrigerating load of the evaporator increases, the discharge temperature exceeds the set temperature set in the controller, so the control valve works in the opening direction, The amount of water flowing through the second water-refrigerant heat exchanger increases, the superheat degree of the refrigerant vapor sucked into the compressor decreases, and the discharge gas temperature decreases. Further, when the refrigeration load of the evaporator is reduced, the discharge temperature becomes lower than the set temperature set in the controller, so that the control valve works toward the valve closing direction, and the first and second water-refrigerant heat exchanges are performed. The amount of water flowing through the vessel is reduced, and the degree of superheat of the refrigerant vapor drawn into the compressor is reduced.

On the other hand, the degree of supercooling is kept substantially constant.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first and second embodiments of the present invention will be described with reference to FIGS. The same components as those in the conventional example or the previous example are designated by the same reference numerals, and the description thereof will be omitted unless necessary.

(First Embodiment) A first embodiment will be described with reference to FIG.

FIG. 1 is a diagram of a refrigerating apparatus with a liquid return prevention mechanism according to the first embodiment. The high temperature and high pressure refrigerant discharged from the compressor 1 is cooled and liquefied by a water cooling condenser 2 and is throttled by a throttle valve 3. Adiabatically expands, absorbs heat in the evaporator 4, and returns to the compressor 1. A refrigerant / water heat exchanger 10 is provided on the suction side of the compressor 1 to heat and evaporate the non-evaporated refrigerant that is about to return in a liquid refrigerant state when the refrigerating load of the evaporator 4 is reduced, and the suction superheat degree. Control valve 11 for controlling the amount of water to the refrigerant / water heat exchanger 10, a temperature sensor 13 for detecting the suction temperature on the suction side of the compressor 1, and a control valve 11 according to the suction temperature. The adjusting device 12 for adjusting is provided. When the refrigeration load on the evaporator 4 decreases, the suction temperature becomes lower than the set temperature of the controller 12, so the control valve 11 works in the opening direction, and the amount of water flowing through the refrigerant / water heat exchanger 10 increases. , Heating and evaporating the refrigerant so that the suction superheat of the refrigerant increases,
Prevents liquid from returning. Further, the water discharged from the refrigerant / water heat exchanger 10 is cooled, and the cooling heat source of the refrigerating apparatus can be reduced as compared with the conventional case.

(Second Embodiment) Second Embodiment FIGS. 2 and 3
Will be explained.

FIG. 2 is a view of a refrigerating apparatus with a liquid / gas heat exchanger according to a second embodiment, in which 14b is a refrigerant / water interposed between a water-cooled condenser 2 and a throttle valve 3. Heat exchanger, 1
4 a is a refrigerant / water heat exchanger interposed between the evaporator 4 and the compressor 1, 15 is a control valve, 16 is a discharge temperature sensor, 17
Is a regulator.

The high-temperature, high-pressure refrigerant leaving the compressor 1 is cooled by the water pumped by the water pump 6, which is a water-cooled condenser 2.
Is liquefied by the coolant and enters the refrigerant / water heat exchanger 14b via the receiver 5, where the water pumped up by the water pump 6 absorbs the heat obtained in the refrigerant / water heat exchanger 14a, and squeezes it. A part of the low-temperature refrigerant vapor discharged from the evaporator 4 and the high-temperature water discharged from the water-cooled condenser 2 are discharged to the discharge pipe of the compressor 1 after being throttled by the valve 3 and adiabatically expanded. The discharge temperature sensor 16 provided detects the discharge temperature, and when the valve open state of the control valve 15 becomes lower than the temperature set in the regulator 17, the control valve 15 works in the valve opening direction to exchange heat between the refrigerant and water. The heat is exchanged in the vessel 14a, the heat is absorbed in the next refrigerant / water heat exchanger 14b, and the heat is returned to the compressor 1.

When the cooling load of the evaporator 4 increases, the discharge temperature exceeds the set temperature of the controller 17, so the control valve 15
Operates in the opening direction, the amount of water flowing through the refrigerant / water heat exchanger 14a increases, the degree of superheat of the refrigerant vapor sucked into the compressor 1 decreases, and the discharge gas temperature becomes lower than in the conventional case. Also, the evaporator 4
When the refrigerating load is reduced, the discharge temperature becomes lower than the set temperature of the controller 17, so that the control valve 15 works toward the closing direction, the amount of water flowing through the refrigerant / water heat exchangers 14a and 14b decreases, and Prevention of backlash and increase of refrigeration capacity are achieved.

FIG. 3 is a diagram qualitatively showing the open / closed state of the control valve 15 with respect to the set temperature of the discharge gas temperature of the compressor 1 shown in FIG.

[0021]

Since the present invention is constructed as described above, it has the following effects.

That is, in the invention of claim 1, when the refrigerating load is reduced, the water refrigerant heat exchanger heats and evaporates the refrigerant so that the suction superheat degree of the refrigerant increases, and the liquid returns. Can be prevented. Further, the cooling heat source of the refrigerating apparatus is smaller than that of the conventional one, and energy saving can be achieved.

Further, in the invention of claim 2, when the refrigerating load of the evaporator increases, the control valve opens, the amount of water flowing through the first and second water-refrigerant heat exchangers increases, and the refrigerant vapor Since the superheat degree decreases, the discharge gas temperature can be lowered. Also, when the refrigeration load of the evaporator decreases, the control valve closes, the amount of water flowing through the first and second refrigerant heat exchangers decreases, and the degree of superheat and supercooling of the refrigerant vapor becomes better than before. Therefore, it is possible to prevent the liquid from returning and increase the refrigerating capacity.

[Brief description of drawings]

FIG. 1 is a refrigerant system diagram of a first embodiment of the present invention,

FIG. 2 is a refrigerant system diagram of a second embodiment of the present invention,

FIG. 3 is a relational diagram of the control valve opening with respect to the discharge gas temperature in the second embodiment,

FIG. 4 is a refrigerant system diagram of a conventional example,

FIG. 5 is a refrigerant system diagram of another conventional example,

FIG. 6 is a Mollier diagram of the conventional example shown in FIG.

[Explanation of symbols]

 1 Compressor 2 Water Cooling Condenser 3 Throttle Valve 4 Evaporator 5 Receiver 6 Water Pump 10 Refrigerant / Water Heat Exchanger 11 Control Valve 12 Regulator 13 Intake Temperature Sensor 14a Refrigerant / Water Heat Exchanger (First Water / Refrigerant Heat) Exchanger) 14b Refrigerant / water heat exchanger (second water / refrigerant heat exchanger) 15 Control valve 16 Discharge temperature sensor 17 Regulator

Claims (2)

[Claims] 1. A refrigeration apparatus comprising a compressor, a water-cooled condenser, a throttle mechanism, and an evaporator, wherein a water / refrigerant heat exchanger is provided between the evaporator and the compressor, and the water / refrigerant heat exchanger is provided. A refrigerating apparatus comprising: a cooling water circuit for flowing cooling water from the outlet side of the water-cooled condenser in accordance with a suction temperature of a refrigerant. 2. A refrigeration system comprising a compressor, a water-cooled condenser, a throttle mechanism and an evaporator, wherein a first water / refrigerant heat exchanger, the water-cooled condenser and the throttle mechanism are provided between the evaporator and the compressor. And a second water / refrigerant heat exchanger, respectively, between the first and second water / refrigerant heat exchangers, in that order, the cooling water from the outlet side of the water-cooled condenser is discharged into the refrigerant. A refrigeration system provided with a cooling water circuit that flows in accordance with the above.