Low-temperature unit

Abstract

The utility model relates to a low-temperature unit, which comprises an absorption type unit and a compressor unit, the compressor unit at least comprises a compressor, a siphon type evaporator and a throttling component, the siphon type evaporator comprises a gas-liquid separator and an evaporator which are communicated through a pipeline, and the gas-liquid separator is positioned above the evaporator. The compressor, a heat exchange pipeline of the absorption type unit, the throttling component and the siphon type evaporator are sequentially communicated through pipelines to form a main circulation loop of refrigerants so as to prepare low-temperature chilled water. After refrigerant liquid is throttled, one part of liquid refrigerant is flashed into gaseous refrigerant and gas-liquid refrigerant enters the gas-liquid separator, the gas-liquid separator is located above the evaporator and supplies liquid to the evaporator by means of gravity, and the liquid refrigerant absorbs heat of chilled water in the evaporator and is partially gasified, so that liquid at an inlet and an outlet of the evaporator generates density difference; the mass flow rate and the circulation ratio of the refrigerant in the tube pass of the evaporator are improved, the heat exchange efficiency of the refrigerant in the siphon evaporator is improved, and chilled water with the temperature below-30 DEG C is prepared.

Description

TECHNICAL FIELD

[0001] The utility model relates to heat recovery technical field, concretely relates to a low temperature unit. BACKGROUND

[0002] In the field of medium and large scale industrial refrigeration, the commonly used heat exchanger is generally a flooded evaporator, and a single compressor is used to produce refrigerated water at 0 DEG C to -20 DEG C. Among them, the refrigerated water is commonly known, and actually it is a salt solution or a freezing agent added in water. When the flooded evaporator is used to produce refrigerated water below -20 DEG C, the refrigerant is in the shell side of the flooded evaporator, and the refrigerated water is in the tube side. Because the concentration of the refrigerated water is very high, the viscosity resistance is large, and the Reynolds coefficient of the refrigerated water in the flooded evaporator is low, which is often lower than 2000, the refrigerated water in the tube side is in a laminar flow state, and the heat transfer effect is very poor, so it is impossible to produce refrigerated water below -20 DEG C. SUMMARY

[0003] The utility model provides a low temperature unit for the prior art problem.

[0004] The technical scheme for solving the above technical problem is as follows: a low temperature unit, comprising an absorption unit and a compressor unit, the compressor unit at least comprising a compressor, a siphon evaporator and a throttling component, the siphon evaporator comprising a gas-liquid separator and an evaporator connected by a pipeline, the gas-liquid separator being located above the evaporator, the liquid part of the gas-liquid separator being connected to the tube side inlet of the evaporator through a pipeline, the tube side outlet of the evaporator being connected to the gaseous part of the gas-liquid separator through a pipeline, and the shell side of the evaporator being the refrigerated water to be produced; the compressor, the heat exchange pipeline of the absorption unit, the throttling component and the siphon evaporator are sequentially connected by pipelines to form a refrigerant main circulation loop to produce low temperature refrigerated water.

[0005] On the basis of the above technical scheme, the utility model can also be improved as follows:

[0006] Preferably, the compressor is a single-stage compressor or a two-stage compressor.

[0007] Preferably, the compressor is an electrically driven compressor or a steam driven compressor.

[0008] Preferably, the driving heat source used by the absorption unit is waste heat above 70 DEG C.

[0009] Preferably, the driving heat source used by the absorption unit is flue gas, hot water or steam.

[0010] Preferably, the absorption unit comprises an absorber, a generator, a condenser and a coupled evaporator, and the heat exchange pipeline is a first heat exchange pipeline in the coupled evaporator.

[0011] Preferably, the absorption unit is a single-effect unit, and one absorption unit, one generator, one condenser and one coupled evaporator are provided; or the absorption unit is a double-effect unit, and two or more absorption units and coupled evaporators are provided, and the absorption units correspond to the coupled evaporators.

[0012] Preferably, the refrigerant is freon or R507a.

[0013] Preferably, an economizer is further provided, and the economizer is located between the throttling component and the gas-liquid separator, and the economizer is connected to the air supplement port of the compressor through a pipeline.

[0014] The low-temperature unit has the following advantages: after throttling, the refrigerant liquid is subjected to a sudden pressure drop, and the temperature is greatly reduced, and a part of the liquid refrigerant is flashed into gas, so that the gas-liquid two-phase refrigerant enters the gas-liquid separator, the gas-liquid separator is located above the evaporator, and a certain hydrostatic pressure is maintained, and the liquid is supplied to the evaporator by gravity, the liquid refrigerant absorbs the heat of the chilled water in the evaporator, and is partially vaporized, so that the density difference of the liquid at the inlet and outlet of the evaporator is generated, the power is generated by the density difference, the mass flow rate and the circulation ratio of the refrigerant in the evaporator tube are improved, the heat exchange efficiency of the refrigerant in the siphon evaporator is improved, the tube is filled with refrigerant, and the shell is filled with chilled water, and the chilled water has sufficient flow space, so that the problem of poor heat exchange caused by the laminar flow effect of the chilled water in the tube in the prior art is solved, therefore, the low-temperature unit can be applied to the heat exchange of medium and large high-viscosity fluids, the purpose of obtaining chilled water below-30℃ by a single compressor is achieved, and the absorption unit and the siphon evaporator are matched as a complete machine, the waste heat is used as a driving heat source, and the use requirement of the process occasion with waste heat source and the need of obtaining chilled water below-30℃ is met. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 FIG. 1 is a structural schematic view of the low-temperature unit.

[0016] The reference signs are recorded as follows: 1, absorption unit; 2, compressor; 3, siphon evaporator; 4, throttling component; 5, economizer; 301, gas-liquid separator; 302, evaporator. DETAILED DESCRIPTION

[0017] The principles and characteristics of the low-temperature unit are described below in combination with the drawings, and the examples are only used to explain the low-temperature unit, and are not used to limit the range of the low-temperature unit.

[0018] As shown in FIG. 1, the low-temperature unit comprises an absorption unit 1, a compressor 2, a siphon evaporator 3, a throttling component 4 and a gas-liquid separator 301. Figure 1The utility model discloses a low temperature unit, including absorption unit 1 and compressor unit, and compressor unit at least includes compressor 2, siphon evaporimeter 3 and throttling component 4, and compressor 2 is single stage compressor or two stage compressor, and throttling component 4 is throttle valve, and siphon evaporimeter 3 includes gas -liquid separator 301 and evaporimeter 302 that are communicated by pipeline, and gas -liquid separator 301 is located above evaporimeter 302, and the liquid state of gas -liquid separator 301 is communicated to the pipe pass inlet of evaporimeter 302 through pipeline, and the pipe pass outlet of evaporimeter 302 is communicated to the gaseous part of gas -liquid separator 301 through pipeline, and the shell pass of evaporimeter 302 is the refrigerated water to be prepared, and thus, the shell pass of evaporimeter 302 is equipped with refrigerated water inlet and refrigerated water outlet, and the pipe pass of evaporimeter 302 is refrigerant, and the refrigerant is freon or R507a, the heat exchange pipeline of compressor 2, absorption unit 1, throttling component 4 and the pipe pass of siphon evaporimeter 3 are sequentially communicated through pipeline and form the main circulation loop of refrigerant to prepare low temperature refrigerated water.

[0019] The refrigerant liquid after throttling through throttling component 4, due to pressure drop, temperature reduces greatly, and enters gas -liquid separator 301 in the form of gas -liquid two -phase, and when working, the liquid refrigerant maintains certain static liquid pressure, and supplies liquid to evaporimeter 302 by virtue of gravity, and the liquid refrigerant absorbs the heat of refrigerated water in the pipe pass of evaporimeter 302, and itself is partially gasified, and makes the liquid of the inlet and outlet of evaporimeter 302 produce density difference, and the density difference produces power, and makes the mass flow rate and circulation ratio of refrigerant in the pipe pass of evaporimeter 302 improve, and this is thermal siphon effect, and improves the heat exchange effect and efficiency of refrigerant and refrigerated water, and this scheme is applicable to the heat exchange of medium -large -scale high viscosity fluid, and realizes the purpose of preparing refrigerated water below-30 DEG C by single compressor.

[0020] Specifically, compressor 2 is electric drive type compressor or steam drive type compressor, wherein, electric drive type compressor uses motor as power source, has high energy efficiency ratio, can start and stop quickly, and can adjust output according to demand, has good speed regulation performance etc., steam drive type compressor provides power through steam turbine or engine, especially when the occasion itself produces a large amount of waste heat or steam, steam drive compressor can effectively utilize these resources, improve overall energy utilization rate, according to the use place, selects the corresponding driving mode, improves the flexibility of use.

[0021] The absorption unit 1 comprises an absorber, a generator, a condenser and a coupled evaporator. The generator is provided with a driving heat source inlet and a driving heat source outlet, wherein the driving heat source adopts waste heat above 70 DEG C, such as flue gas, hot water or steam, etc. The absorber is connected with a cooling water inlet. The condenser is connected with a cooling water outlet. The working principle of the absorption unit is as follows: the heat exchange pipeline in the generator can be communicated with the external high-temperature driving heat source. In the embodiment, the external heat source is waste heat above 70 DEG C. Under the action of the high-temperature driving heat source, part of the cold agent in the dilute solution flowing back to the generator is evaporated to form cold agent steam, which becomes a concentrated solution and enters the absorber again. The heat released by the dilute solution in the absorber is absorbed by the cooling water in the heat exchange pipeline in the absorber, so as to ensure the absorption capacity of the concentrated solution. The dilute solution after being diluted in the absorber returns to the generator again through a pipeline. The cold agent steam evaporated from the generator is condensed in the condenser to form cold agent water, which is supplied to the coupled evaporator for evaporation to generate the cold agent steam required by the absorber. In the embodiment, the heat exchange pipeline is a first heat exchange pipeline in the coupled evaporator. The high-temperature and high-pressure refrigerant medium discharged from the compressor 2 can heat the cold agent in the coupled evaporator to produce the steam required by the absorber when flowing through the first heat exchange pipeline, so as to improve the heat utilization rate. The steam generated by the coupled evaporator is introduced into the absorber and is absorbed by the concentrated solution.

[0022] In the embodiment, the absorption unit 1 is a single-effect machine, and one absorber, one generator, one condenser and one coupled evaporator are arranged, so that the connection structure of the unit is simplified.

[0023] Alternatively, the absorption unit 1 can be a double-effect machine, and two or more absorbers and coupled evaporators are arranged, and the absorbers correspond to the coupled evaporators.

[0024] The compressor unit further comprises an economizer 5 located between the throttling component 4 and the gas-liquid separator 301. The economizer 5 can optimize the circulation process of the refrigerant, so that the evaporation of the refrigerant in the evaporator 302 is more sufficient, thereby realizing the production of low-temperature chilled water. The economizer 5 is connected with the air supplementing port of the compressor 2 through a pipeline. The air supplementing port can improve the performance of the compressor 2, improve the refrigerating capacity, and reduce the exhaust temperature of the compressor 2, so as to improve the reliability and stability of the whole unit.

[0025] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A low temperature unit, characterized in that: The invention comprises an absorption unit (1) and a compressor unit, wherein the compressor unit comprises at least a compressor (2), a siphon evaporator (3) and a throttling component (4), the siphon evaporator (3) comprises a gas-liquid separator (301) and an evaporator (302), the gas-liquid separator (301) is located above the evaporator (302), the liquid part of the gas-liquid separator (301) is connected to the tube side inlet of the evaporator (302) through a pipeline, and the tube side outlet of the evaporator (302) is connected to the gas part of the gas-liquid separator (301) through a pipeline, and the shell side of the evaporator (302) contains chilled water to be produced; the compressor (2), the heat exchange pipe of the absorption unit (1), the throttling component (4) and the tube side of the siphon evaporator (3) are connected in sequence through pipelines to form a main circulation loop of the refrigerant to produce low-temperature chilled water.

2. The cryogenic unit according to claim 1, characterized in that: The compressor (2) is a single-stage compressor or a two-stage compressor.

3. The low-temperature unit according to claim 2, characterized in that: The compressor (2) is an electrically driven compressor or a steam driven compressor.

4. The cryogenic unit according to claim 1, characterized in that: The driving heat source used by the absorption unit (1) is waste heat above 70°C.

5. The low-temperature unit according to claim 4, characterized in that: The driving heat source used by the absorption unit (1) is flue gas, hot water or steam.

6. The cryogenic unit according to claim 1, characterized in that: The absorption unit (1) comprises an absorber, a generator, a condenser and a coupled evaporator, and the heat exchange pipe is a first heat exchange pipe in the coupled evaporator.

7. The low-temperature unit according to claim 6, characterized in that: The absorption unit (1) is a single-effect machine, and each of the absorber, the generator, the condenser, and the coupled evaporator is provided with one; or, the absorption unit (1) is a double-effect machine, and each of the absorber and the coupled evaporator is provided with two or more, and the absorber corresponds to the coupled evaporator.

8. The cryogenic unit according to claim 1, characterized in that: The refrigerant is Freon or R507a.

9. The cryogenic unit according to claim 1, characterized in that: It also includes an economizer (5), which is located between the throttling component (4) and the gas-liquid separator (301), and the economizer (5) is connected to the air supply port of the compressor (2) through a pipeline.

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